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Agronomy, Volume 12, Issue 12 (December 2022) – 322 articles

Cover Story (view full-size image): Winter wheat is one of the most important food crops in China, and it is of great significance for ensuring national food security. The accurate extraction of wheat-growing areas is a prerequisite for growth assessments, stress monitoring, and yield assessments. In this study, GF-6 (8 m resolution) and Sentinel-2 (10 m resolution) remote sensing images were used to create datasets for the accurate extraction of winter-wheat-growing areas by improving the U-Net model. First, U-Net was used as the base network to extract features, and then, the convolutional block attention module (CBAM) was embedded in the basic convolutional units in the coding and decoding layers of the network to enhance or suppress the features to improve the feature expression capability of the model. Finally, end-to-end winter-wheat planting-area extraction was completed. View this paper
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Article
Leaf Gas Exchange and Growth Responses of Tomato Plants to External Flavonoids Application as Biostimulators under Normal and Salt-Stressed Conditions
Agronomy 2022, 12(12), 3230; https://doi.org/10.3390/agronomy12123230 - 19 Dec 2022
Viewed by 639
Abstract
The exogenous application of natural metabolites, such as phenolic compounds, is a useful strategy to stimulate growth and reduce the adverse effects of abiotic stress on crops, such as salinity. Salinity stress is one of the most damaging abiotic stresses to plants, causing [...] Read more.
The exogenous application of natural metabolites, such as phenolic compounds, is a useful strategy to stimulate growth and reduce the adverse effects of abiotic stress on crops, such as salinity. Salinity stress is one of the most damaging abiotic stresses to plants, causing reductions in growth by changes in the physiology, biochemistry, and gene expression. In this work, we investigated the effect of the foliar application of flavonoids (CropBioLife, CBL) on control and salt-stressed (NaCl 60 mM) tomato plants grown in controlled conditions. The results showed that CBL mainly influenced the stimulation of photosynthesis, increasing CO2 fixation and promoting growth. Furthermore, a higher stomata number in an open state was found in CBL-treated plants in relation to the higher CO2 fixation, which also resulted in a higher H2O uptake due to increasing stomatal conductance and nutrient uptake that plants need for growth. The results were due to the increase of phenolic metabolism and the expression of most of the aquaporins, which could be the triggering signal for the rest to the changes observed. The effect of the biostimulation of CBL under salinity was related to higher levels of photosynthesis, the increase of some mineral nutrients, and the increase of some PIP aquaporins expression, although no effect on growth was observed. The results of this work showing the mechanism of action of flavonoids in tomato plants open a new line of investigation with great importance for the future of agronomy. Full article
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Article
Dose–Response Curves of Pelargonic Acid against Summer and Winter Weeds in Central Italy
Agronomy 2022, 12(12), 3229; https://doi.org/10.3390/agronomy12123229 - 19 Dec 2022
Viewed by 515
Abstract
Pelargonic acid is a non-selective post-emergence contact bio-herbicide which is registered both for cropping and non-cropping uses in several countries. Dose–response curves on the efficacy of pelargonic acid against common weeds in Mediterranean areas are not available. Dose–response curves of pelargonic acid efficacy [...] Read more.
Pelargonic acid is a non-selective post-emergence contact bio-herbicide which is registered both for cropping and non-cropping uses in several countries. Dose–response curves on the efficacy of pelargonic acid against common weeds in Mediterranean areas are not available. Dose–response curves of pelargonic acid efficacy against summer and winter annual weeds were evaluated in two field experiments (winter exp. in 2019 and summer exp. in 2020) in central Italy. Pelargonic acid was applied at five doses (1.4, 2.7, 5.4, 10.9 and 21.8 kg a.i. ha−1). Data on weed density, weed dry weight, and weed ground cover were used to calculate the efficacy of pelargonic acid against winter and summer weeds. Data were subjected to a non-linear regression analysis using the logistic dose–response model. Dose of pelargonic acid required to obtain 50%, 70%, 90% and 95% weed control against each weed species (ED50, ED70, ED90 and ED95) were estimated. ED values allowed us to classify winter and summer weeds with respect to their susceptibility to pelargonic acid (ED50 values in kg ha−1 are reported in parenthesis): Kickxia spuria (2.6) (more susceptible) > Heliotropium europaeum (3.0) > Echinochloa crus-galli (3.4) > Solanum nigrum (3.6) > Stachys annua (5.3) > Papaver rhoeas (6.5) > Veronica hederifolia (10.3) > Amaranthus retroflexus (11.4) > Matricaria chamomilla (11.6) > Portulaca oleracea (18.7) > Lolium multiflorum (>21.8) (less susceptible). These findings will allow for the optimization of weed control by pelargonic acid and its use in weed management strategies, both in organic and sustainable cropping systems, under different environmental conditions. Full article
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Article
Leaching of Sulfadiazine and Florfenicol in an Entisol of a Chicken-Raising Orchard: Impact of Manure-Derived Dissolved Organic Matter
Agronomy 2022, 12(12), 3228; https://doi.org/10.3390/agronomy12123228 - 19 Dec 2022
Viewed by 408
Abstract
Antibiotic pollution from manured farmland soils is a major public concern, and their potential interaction with manure particles and/or manure–dissolved organic matter (DOM) often complicates their leaching behaviour. This study investigated the leaching of sulfadiazine (SDZ) and florfenicol (FFC) with manure-DOM in undisturbed [...] Read more.
Antibiotic pollution from manured farmland soils is a major public concern, and their potential interaction with manure particles and/or manure–dissolved organic matter (DOM) often complicates their leaching behaviour. This study investigated the leaching of sulfadiazine (SDZ) and florfenicol (FFC) with manure-DOM in undisturbed field lysimeters and repacked soil columns under natural and simulated rainfall conditions. The results showed that manure-DOM reduced SDZ mass flux, but soil hydrological processes and heavy rainfall events led to accelerated leaching. FFC was more prone to leaching in a manured plot (0.48 µg m−2 h−1) compared to the control (0.12 µg m−2 h−1), suggesting DOM facilitated transport of FFC in the field lysimeter study via cotransport mechanisms favored by abundant macropores in the study site. In contrast, SDZ and FFC mobility were reduced in repacked soil columns under manure-DOM conditions, suggesting complexation and adsorption in matrix pores. Two kinetic site models and two-site nonequilibrium adsorption models revealed the existence of nonequilibrium conditions and kinetic sorption processes in the repacked column. FFC exhibited lower leaching potential compared to SDZ in both the repacked column and natural field conditions. Redundancy analyses revealed that FFC had a close relationship with humic-like components (C1 and C3), but SDZ was more related to the protein-like components (C2) of DOM. The presence of manure-DOM may decrease the ecological risks of highly mobile antibiotics under matrix flow through complexations and adsorption. However, a similar scenario in macroporous flow under heavy rainfalls may lead to accelerated leaching. Full article
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Article
Metabolomics Analysis Reveals Dynamic Accumulation of Sugar and Acid during Stem Development of Brassica juncea
Agronomy 2022, 12(12), 3227; https://doi.org/10.3390/agronomy12123227 - 19 Dec 2022
Viewed by 568
Abstract
The composition and content of sugar and acid are important indicators of organ development and the quality of horticultural products. B. juncea is an important vegetable in the cruciferous family, with a swollen fleshy stem as the edible organ. Elucidating the characteristics of [...] Read more.
The composition and content of sugar and acid are important indicators of organ development and the quality of horticultural products. B. juncea is an important vegetable in the cruciferous family, with a swollen fleshy stem as the edible organ. Elucidating the characteristics of sugar and acid accumulation during stem expansion of stem mustard and its regulatory mechanism could enhance stem quality. In this study, physiological indicators such as dry matter content, sugar–acid content and related enzyme activities were measured in eight stages of the tumorous stem. The results showed that the sugar and sucrose contents initially increased and then decreased during stem development: Sucrose exhibited a positive correlation with sucrose synthase and sucrose phosphate synthase, while acid content was highly positively correlated with malate dehydrogenase. Further analysis of the dynamic patterns of sugar and acid metabolite contents using metabolomics showed that 1097 metabolites were detected, including 229 organic acids and derivatives, 109 lipids, and other metabolites. Metabolic pathway enrichment analysis showed that metabolites were significantly enriched in organic acids, amino acids, glycolysis/gluconeogenesis, starch, and sucrose metabolism. Analysis of the sugar pathway and the tricarboxylic acid cycle revealed obvious differences in the content and type of metabolites, with most upregulated metabolites in S3 and S4. The expression patterns of enzyme genes associated with the biosynthesis and accumulation of sugar and acid metabolites were found based on differentially expressed genes at different developmental stages, and gene expression levels were verified by qPCR, which showed that the expression patterns of enzyme genes associated with this pathway were highly consistent with the metabolite accumulation. These results suggest that amino acids, sugars, and acids play a critical role in regulating the development of tumorous stems. Results of the present study offer a theoretical basis to improving the quality of mustard by using a metabolomics approach to determine the dynamics of metabolites and related regulatory enzymes during development and the correlation between these levels, which provides novel insights into the potential mechanisms underlying sugar and acid metabolism. Full article
(This article belongs to the Special Issue Recent Advances in Horticultural Crops-from Omics to Biotechnology)
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Article
Beneficial Effect of Exogenously Applied Calcium Chloride on the Anatomy and Fast Chlorophyll Fluorescence in Rhododendron × pulchrum Leaves Following Short-Term Heat Stress Treatment
Agronomy 2022, 12(12), 3226; https://doi.org/10.3390/agronomy12123226 - 19 Dec 2022
Viewed by 614
Abstract
The heat tolerance of plants can be improved by using exogenous calcium chloride (CaCl2) to cope with temperature fluctuations. Since global climates continue to warm, it is important to further explore the way in which plants respond to heat stress with [...] Read more.
The heat tolerance of plants can be improved by using exogenous calcium chloride (CaCl2) to cope with temperature fluctuations. Since global climates continue to warm, it is important to further explore the way in which plants respond to heat stress with the use of CaCl2. We aimed to explore the effect of exogenous CaCl2 on the leaf microstructure, leaf epidermal ultrastructure, and chlorophyll a fluorescence of Rhododendron × pulchrum (R. × pulchrum) under heat stress. In the leaves of R. × pulchrum treated with exogenous CaCl2, compared to the control, the thickness of the epidermis, spongy tissues, and stomatal aperture increased, whereas the stomata density and ratio of closed/open stomata decreased. In the leaves of R. × pulchrum under heat stress conditions, compared to the control, the values of the maximal photochemical efficiency of photosystem II (Fv/Fm), the performance index on an absorption basis (PIABS), the quantum yield for the reduction of terminal electron acceptors on the acceptor side of PSI (φRo), and the energy absorbed per unit cross-section of a photosynthesizing object at the moment of achieving the fluorescence maximum (ABS/CSM) all decreased, whereas the quantum yield of the energy dissipation (φDo) increased significantly. However, these differences disappeared when R. × pulchrum was treated with exogenous CaCl2. This suggests that exogenous CaCl2 can improve the heat tolerance in R. × pulchrum by regulating the leaf anatomical structure and the behavior of epidermal cells and stomata in leaves, protecting the stability of photosystems I and II and improving the electron transfer from QA to QB. Our study could provide a theoretical basis for the breeding, further research, and utilization of Rhododendron in the context of global warming. Full article
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Article
Effects of Phosphorus Supply on Seed Yield and Quality in Flax
Agronomy 2022, 12(12), 3225; https://doi.org/10.3390/agronomy12123225 - 19 Dec 2022
Viewed by 464
Abstract
Flaxseed, which is rich in lignan, α-linolenic acid, dietary fiber, and several minerals, is an important food and nutrition source. In this study, trials were conducted at Yongdeng over two consecutive years (2018 and 2019), with three cultivars (Longyaza 1, Longya 14, and [...] Read more.
Flaxseed, which is rich in lignan, α-linolenic acid, dietary fiber, and several minerals, is an important food and nutrition source. In this study, trials were conducted at Yongdeng over two consecutive years (2018 and 2019), with three cultivars (Longyaza 1, Longya 14, and Zhangya 2) and five application rates of phosphorus (P) (0, 40, 80, 120, and 160 kg P2O5 ha−1). We examined the effects of P on the seed yield, and the yields and contents of dietary fiber, lignan, iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu). We found that P fertilization positively influenced yields of seed and levels of lignan, Fe, and Cu, showing average increases of 15, 20, 24, and 28%, respectively, compared with plants not given P over the 2-year study. Additionally, P fertilization resulted in increased concentrations of Fe and Cu in flaxseed of 8 and 2%, respectively. P fertilization negatively affected the levels of dietary fiber, Zn, and Mn, which were reduced by 7, 11, and 7%, respectively, in comparison with the control. In conclusion, the results demonstrated that appropriate P application is an effective strategy for improving yields of seed, lignan, Fe, and Cu in flax production and for enhancing concentrations of Fe and Cu in flax. Full article
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Article
Microbacterium oxydans Regulates Physio-Hormonal and Molecular Attributes of Solanum lycopersicum under Drought Stress
Agronomy 2022, 12(12), 3224; https://doi.org/10.3390/agronomy12123224 - 19 Dec 2022
Viewed by 534
Abstract
Among the types of abiotic stresses, drought is one of the most serious growth limiting factors for crop plants. In recent years, various strategies have been employed to alleviate the adverse effects of drought stress in crops, but the use of plant growth-promoting [...] Read more.
Among the types of abiotic stresses, drought is one of the most serious growth limiting factors for crop plants. In recent years, various strategies have been employed to alleviate the adverse effects of drought stress in crops, but the use of plant growth-promoting rhizobacteria (PGPR) is among the standout techniques. Currently, we have isolated 55 strains of bacteria from the rhizosphere of Achyranthes aspera L. and Calotropis procera (Aiton). However, AGH3, AGH5, and AGH9 produced significant (p = 0.05) amounts of plant hormones and exhibited siderophore and phosphate solubilization activities. Bioassay experiments on Waito-C rice demonstrated an enhanced growth in the presence of the isolate AGH3. Moreover, the isolate AGH3 promoted the growth of Solynum lycopersicum L. under drought stress. The results revealed that AGH3-associated S. lycopersicum plants showed significantly (p = 0.05) reduced production of abscisic acid (ABA) and jasmonic acid (JA) as compared with the AGH3-free plants under polyethylene glycol (PEG) stress. In addition, high expressions of SlmiR 159 (from 6- to 10-fold), SlHsfA1a (from 1- to 4-fold), and SlHAKT1 (from 0.26- to 1-fold) genes were noticed in AGH3-associated S. lycopersicum plants under drought stress. From the results, it is concluded that rhizobacteria (AGH3) can be used as a pragmatic biofertilizer to ensure organic farming under normal as well as drought conditions. Full article
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Article
Rapid Nondestructive Detection of Chlorophyll Content in Muskmelon Leaves under Different Light Quality Treatments
Agronomy 2022, 12(12), 3223; https://doi.org/10.3390/agronomy12123223 - 19 Dec 2022
Viewed by 692
Abstract
In order to select the light quality suitable for plant growth, a quantitative detection model of chlorophyll content in muskmelon leaves was established to monitor plant growth quickly and accurately. In the paper, muskmelon “Boyang 91” was used as the experimental material, and [...] Read more.
In order to select the light quality suitable for plant growth, a quantitative detection model of chlorophyll content in muskmelon leaves was established to monitor plant growth quickly and accurately. In the paper, muskmelon “Boyang 91” was used as the experimental material, and six different light proportion treatments were set up. Through measuring plant height, stem diameter, number of leaves, nodes, and other growth indicators, in addition to leaf chlorophyll content, the response difference of muskmelon to different light qualities was explored in a plant factory. The hyperspectral imaging technology was used to establish the prediction model for the chlorophyll content of muskmelon. The original spectrum was preprocessed and optimized by five pretreatments, and then the characteristic wavelengths were extracted by six methods. Partial least squares regression (PLSR), least squares support vector machine (LSSVM), and convolutional neural network (CNN) were established for optimal feature wavelength. The results showed that the plant height and stem diameter of the T3 treatment were higher than those of other treatments, and their values were 14.48 (cm) and 5.02 (mm), respectively. The chlorophyll content of the T3 treatment was the highest, and its value was 40.16 (mg/g), which was higher than that of other treatments. Through comprehensive analysis, the T3 treatment (light ratio: 6R/1B/2W, light quantum flux: 360 μmol/(m2·s), photoperiod: 12 h) was optimal. Meanwhile, the average spectral reflectance data of 216 leaf samples were extracted, and the S-G preprocessing method was selected to preprocess the original spectral data (Rc = 0.860, RMSEC = 1.806; Rcv = 0.790, RMSECV = 2.161). By comparing and analyzing the correlation coefficients and root mean square errors of six feature wavelength extraction methods, it was concluded that the variable combination population analysis (VCPA) method had the best model effect for feature wavelength extraction (RP = 0.824, RMSEP = 1.973). Ten characteristic wavelengths ( 396, 409, 457, 518, 532, 565, 687, 691, 701, and 705 nm) extracted by the VCPA method were used to establish the chlorophyll content prediction model, and the chlorophyll content prediction model of S-G-VCPA-CNN had the best performance (Rc = 0.9151, RMSEC = 1.445; Rp = 0.811, RMSEP = 2.055). The results of this study provide data support and a theoretical basis for screening the light ratio of other crops, and also present technical support for online monitoring of crop growth in plant factories. Full article
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Article
Influence of N, K, and Seaweed Extract Fertilization on Biomass, Photosynthetic Pigments, and Essential Oil of Thymus vulgaris: Optimization Study by Response Surface Methodology
Agronomy 2022, 12(12), 3222; https://doi.org/10.3390/agronomy12123222 - 19 Dec 2022
Viewed by 454
Abstract
Nutrient management has a decisive impact on the biomass and essential oil yield of medicinal plants. This study aimed to determine the optimal levels of nitrogen, potassium, and seaweed extract fertilizers to maximize the yield and quality of thyme using the response surface [...] Read more.
Nutrient management has a decisive impact on the biomass and essential oil yield of medicinal plants. This study aimed to determine the optimal levels of nitrogen, potassium, and seaweed extract fertilizers to maximize the yield and quality of thyme using the response surface methodology (RSM). The experiment was laid out as a Box-Behnken design with three replications and three experimental factors, including nitrogen (urea) (0, 200, and 400 kg ha−1), and foliar application of potassium (Flourish Sulfopotash) (0, 6, and 12 kg ha−1) and seaweed extract (0, 3, and 6 L ha−1). The generated models were statistically significant for all measured traits except for γ-terpinene and p-cymene. While the influence of N on the amount of photosynthetic pigments followed a quadratic trend, the response of total chlorophyll and carotenoids to increasing potassium was linear. The response of biomass yield to N and seaweed was quadratic and linear, respectively. Potassium application had no significant influence on biomass. Essential oil yield reached its peak value (12 kg ha−1) when N and seaweed were applied at their intermediate levels and with the maximum application rate of potassium. Thymol was identified as the highest essential oil component (46.1%), followed by γ-terpinene (19.2%), p-cymene (14.1%), and carvacrol (5.6%). The optimization results suggested that the application of 162 kg ha−1 urea, 12 kg ha−1 Flourish Sulfopotash, and 4 L ha−1 seaweed extract was sufficient to produce the maximum dry matter (1247 kg ha−1), and more than 11 kg ha−1 of essential oil, with a concentration of 1%. Through optimization, the amounts of thymol and carvacrol were estimated to be as much as 44.2% and 6.2%, respectively. The results of the study suggested that resource optimization through RSM can be used as an efficient method to manage the consumption of fertilizers in thyme production. Full article
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Article
Insights into Long-Term Acclimation Strategies of Grapevines (Vitis vinifera L.) in Response to Multi-Decadal Cyclical Drought
Agronomy 2022, 12(12), 3221; https://doi.org/10.3390/agronomy12123221 - 19 Dec 2022
Viewed by 423
Abstract
Changing climatic conditions across Australia’s viticulture regions is placing increasing pressure on resources such as water and energy for irrigation. Therefore, there is a pressing need to identify superior drought tolerant grapevine clones by exploring the extensive genetic diversity of early European clones [...] Read more.
Changing climatic conditions across Australia’s viticulture regions is placing increasing pressure on resources such as water and energy for irrigation. Therefore, there is a pressing need to identify superior drought tolerant grapevine clones by exploring the extensive genetic diversity of early European clones in old vineyards. Previously, in a field trial, we identified drought-tolerant (DT) dry-farmed Cabernet Sauvignon clones that had higher intrinsic water use efficiency (WUEi) under prolonged soil moisture deficiency compared to drought-sensitive (DS) clones. To investigate whether the field-grown clones have been primed and confer the drought-tolerant phenotypes to their subsequent vegetative progenies, we evaluated the drought responses of DT and DS progenies under two sequential drought events in a glasshouse alongside progenies of commercial clones. The DT clonal progenies exhibited improved gas exchange, photosynthetic performance and WUEi under recurrent drought events relative to DS clonal progenies. Concentration of a natural priming agent, γ-amino butyric acid (GABA), was significantly higher in DT progenies relative to other progenies under drought. Although DT and commercial clones displayed similar drought acclimation responses, their underlying hydraulic, stomatal and photosynthetic regulatory mechanisms were quite distinct. Our study provides fundamental insights into potential intergenerational priming mechanisms in grapevine. Full article
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Article
Assessment of Potential Heavy Metal Contamination Hazards Based on GIS and Multivariate Analysis in Some Mediterranean Zones
Agronomy 2022, 12(12), 3220; https://doi.org/10.3390/agronomy12123220 - 19 Dec 2022
Viewed by 505
Abstract
One of the most significant challenges that global decision-makers are concerned about is soil contamination. It is also related to food security and soil fertility. The quality of the soil and crops in Egypt are being severely impacted by the increased heavy metal [...] Read more.
One of the most significant challenges that global decision-makers are concerned about is soil contamination. It is also related to food security and soil fertility. The quality of the soil and crops in Egypt are being severely impacted by the increased heavy metal content of the soils in the middle Nile Delta. In Egypt’s middle Nile Delta, fifty random soil samples were chosen. Inverse distance weighting (IDW) was used to create the spatial pattern maps for four heavy metals: Cd, Mn, Pb, and Zn. The soil contamination levels in the research area were assessed using principal component analysis (PCA), contamination factors (CF), the geoaccumulation index (I-Geo), and the improved Nemerow pollution index (In). The findings demonstrated that using PCA, the soil heavy metal concentrations were divided into two clusters. Moreover, the majority of the study region (44.47%) was assessed to be heavily to extremely polluted by heavy metals. In conclusion, integrating the contamination indices CF, I-Geo, and In with the GIS technique and multivariate model, analysis establishes a practical and helpful strategy for assessing the hazard of heavy metal contamination. The findings could serve as a basis for decision-makers to create effective heavy metal mitigation efforts. Full article
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Article
Morphological, Physiological and Quality Performances of Basil Cultivars under Different Fertilization Types
Agronomy 2022, 12(12), 3219; https://doi.org/10.3390/agronomy12123219 - 19 Dec 2022
Cited by 1 | Viewed by 620
Abstract
The prospect of replacing traditional chemical fertilization with organic and microorganism-based fertilization meets the current demand for more sustainable cropping systems and healthy food. In this respect, research was carried out to evaluate the effects of the factorial combination between four basil cultivars [...] Read more.
The prospect of replacing traditional chemical fertilization with organic and microorganism-based fertilization meets the current demand for more sustainable cropping systems and healthy food. In this respect, research was carried out to evaluate the effects of the factorial combination between four basil cultivars (‘Aromat de Buzau’, ‘Macedon’, ‘Cuisoare’ and ‘Serafim’) and three types of fertilization, namely chemical fertilization (with a solid chemical fertilizer), organic fertilization (with chicken manure formulate) and microorganisms’ fertilization (with microorganisms formulate), on basil yield, biochemical and physiological parameters and essential oil composition. The results showed that the biometric parameters (plant height, number of stems and leaves and leaf area) were significantly influenced by the cultivar; ‘Macedon’ obtained the highest values of plant height (64.7 cm) and number of stems (20.33) and leaves (618.3) and ‘Serafim’ the largest leaf area (4901.7 cm2 per plant), while the type of fertilization did not affect these parameters. Regarding the biomass, the influence of the cultivar was not significant on fresh biomass but was significant on dry biomass, with ‘Macedon’ showing the highest value (56.4 g·plant−1 dry biomass). The mentioned parameters were significantly influenced by the type of fertilization, with the highest values recorded with chemical fertilization. Both the cultivar and the fertilization type significantly influenced the physiological parameters (the total content of assimilatory pigments and photosynthesis). Five phenolic compounds were quantified from leaf extracts by HPLC-MS (caffeic acid, hyperoside, isoquercitrin, rutin and quercitrin). Hyperoside was identified only in ‘Macedon’, while the rest of the compounds were found in all the cultivars and varied depending on the cultivar and fertilization type. Regarding the composition of the essential oil, variation was found depending on the cultivar and fertilization type. In ‘Aromat de Buzau’, the main compounds were methyl chavicol and β-linalool; in ‘Macedon’, geranial and neral; and in ‘Cuisoare’ and ‘Serafim’, β-linalool. Moreover, the PCA showed that the ‘Serafim’ cultivar has exclusive properties compared to the other cultivars. Our results highlight that identifying the most effective interaction between genotype and fertilization type allows to optimize yield and quality targets for sweet basil. Full article
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Communication
CRISPR/Cas9-Mediated Mutagenesis of GmFAD2-1A and/or GmFAD2-1B to Create High-Oleic-Acid Soybean
Agronomy 2022, 12(12), 3218; https://doi.org/10.3390/agronomy12123218 - 19 Dec 2022
Viewed by 500
Abstract
Soybean (Glycine max (L.) Merr.) oil is an important source of vegetable oil for supporting the human diet. However, the high level of polyunsaturated fatty acids in natural soybean oil renders the oil unstable and thus susceptible to the development of unpalatable [...] Read more.
Soybean (Glycine max (L.) Merr.) oil is an important source of vegetable oil for supporting the human diet. However, the high level of polyunsaturated fatty acids in natural soybean oil renders the oil unstable and thus susceptible to the development of unpalatable flavors and trans fatty acids. Therefore, reducing the content of polyunsaturated fatty acids and increasing the content of monounsaturated fatty acids is a longstanding and important target for soybean breeding. However, soybean varieties with a high oleic acid content are rare in soybean germplasm resources, which introduces substantial difficulties in the cultivation of high-oleic-acid soybeans. In this study, CRISPR/Cas9-mediated gene-editing technology was used to create targeted knockout of the soybean fatty acid desaturase encoding genes GmFAD2-1A and GmFAD2-1B that contribute to the formation of polyunsaturated fatty acids. We obtained fad2-1a, fad2-1b, and fad2-1a/fad2-1b homozygous mutants using two sgRNAs. We found that the oleic acid content increased from 11% to 40-50% in the fad2-1a and fad2-1b mutants and to 85% in the fad2-1a/fad2-1b mutants. We also generated transgene-free double mutants that conferred higher oleic acid, and the fad2-1a/fad2-1b mutant had no adverse phenotyping compared with the wild type. Our study provided new materials for the selection and breeding of high-oleic-acid soybean varieties. Full article
(This article belongs to the Special Issue New Advances in Soybean Molecular Biology)
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Article
Assessing the Suitability of Selection Approaches and Genetic Diversity Analysis for Early Detection of Salt Tolerance of Barley Genotypes
Agronomy 2022, 12(12), 3217; https://doi.org/10.3390/agronomy12123217 - 19 Dec 2022
Viewed by 582
Abstract
Assessment of the salt tolerance of a large genotype collection at the early growth stages may assist in the fast-tracking improvement of salt-tolerant barley genotypes in breeding programs. This study aimed to investigate the ability of traits related to seed germination ability and [...] Read more.
Assessment of the salt tolerance of a large genotype collection at the early growth stages may assist in the fast-tracking improvement of salt-tolerant barley genotypes in breeding programs. This study aimed to investigate the ability of traits related to seed germination ability and seedling growth performance with helping of nine sequence-related amplified polymorphism (SRAP) markers to detect the salt tolerance of 70 barley genotypes during the early growth stages. The different genotypes were exposed to three salt concentrations (0, 100, and 200 mM NaCl) and evaluated for salt tolerance by looking at germination percentage, germination index, and mean germination time during eight days as well as the lengths and weights of seedling shoot and root after 21 days from sowing. The results showed that genotypic variations in germination ability and seedling growth performance obviously appeared under 200 and 100 mM NaCl, respectively. The germination traits exhibited a strong correlation among themselves, whereas they had a poor correlation with seedling traits. A strong and positive correlation was only observed for shoot fresh weight with shoot length and root fresh weight under salinity conditions. Principal component analysis revealed that the first two components, which explained 53% of the total variability, succeeded to identify the genotypes with high salt tolerance during only one stage (germination or seedling stage) and both stages. Cluster analysis based on the stress tolerance index of germination and seedling traits grouped 70 genotypes into four key clusters, with genotypes grouped in cluster 1 and cluster 2 being salt tolerant during the germination stage and moderately tolerant during the seedling stage; the opposite was found with the genotypes grouped in cluster 4. According to Ward’s method, the salt tolerance of genotypes that ranked as most salt-tolerant (T) or salt-sensitive (S) remained almost unchanged during germination and seedling stages. In contrast, a change in salt tolerance with both stages was found for the genotypes that ranked as moderately salt-tolerant (MT) and salt-sensitive (MS) genotypes. The nine SRAP markers divided the tested genotypes into two distinct clusters, with clusters B had the most T and MT genotypes. Finally, using appropriate statistical methods presented in this study with SRAP markers will be useful for assessing the salt tolerance of a large number of barley genotypes and selecting the genotypes tolerant of and sensitive to salinity at the early growth stage. Full article
(This article belongs to the Special Issue Crop Tolerance under Biotic and Abiotic Stresses)
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Communication
Genome-Wide Association Study for Non-Photochemical Quenching Traits in Oryza sativa L.
Agronomy 2022, 12(12), 3216; https://doi.org/10.3390/agronomy12123216 - 18 Dec 2022
Viewed by 599
Abstract
Manipulating the photoprotective mechanism has been demonstrated to be an effective way to enhance the photosynthetic productivity of crop plants. NPQ(T) is a chlorophyll fluorescence parameter for rapid estimation and imaging of non-photochemical quenching (NPQ) of excitons in the photoprotective mechanism. However, the [...] Read more.
Manipulating the photoprotective mechanism has been demonstrated to be an effective way to enhance the photosynthetic productivity of crop plants. NPQ(T) is a chlorophyll fluorescence parameter for rapid estimation and imaging of non-photochemical quenching (NPQ) of excitons in the photoprotective mechanism. However, the variation and genetic basis of NPQ(T) are rarely reported in the Oryza sativa L. In this study, we collected 173 rice cultivars and investigated the NPQ(T) value. We found that the NPQ(T) has a wide variation, although it had not been under-selected in the different subspecies. A genome-wide association study (GWAS) utilizing 1,566,981 high-quality SNPs identified three significant associated signals on chromosomes 02, 05, and 07. Furthermore, one likely candidate gene Os02g0184100, underlying the associated signal on chromosome 02, was uncovered by identifying the expression pattern in flag leaves and testing the correlation between functional polymorphisms and phenotypic variation. The significant SNPs and candidate genes identified in this study provide us a comprehensive understanding of the genetic architecture of NPQ(T) and could be used for genetic improvement of rice photoprotection. Full article
(This article belongs to the Special Issue Plant Photosynthesis: From Molecules to Remote Sensing)
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Article
Applied Selenium as a Powerful Antioxidant to Mitigate the Harmful Effects of Salinity Stress in Snap Bean Seedlings
Agronomy 2022, 12(12), 3215; https://doi.org/10.3390/agronomy12123215 - 18 Dec 2022
Viewed by 535
Abstract
Selenium (Se) plays several significant roles in regulating growth, development and plant responses to various abiotic stresses. However, its influence on sulfate transporters (SULTRS) and achieving the harmony with other salt-tolerance features is still limited in the previous literatures. This [...] Read more.
Selenium (Se) plays several significant roles in regulating growth, development and plant responses to various abiotic stresses. However, its influence on sulfate transporters (SULTRS) and achieving the harmony with other salt-tolerance features is still limited in the previous literatures. This study elucidated the effect of Se supplementation (5, 10 and 20 µM) on salt-stressed (50 mM NaCl) snap bean seedlings. Generally, the results indicated that Se had dual effects on the salt stressed seedlings according to its concentration. At a low level (5 µM), plants demonstrated a significant improvement in shoot (13.8%) and root (22.8%) fresh weight, chlorophyll a (7.4%), chlorophyll b (14.7%), carotenoids (23.2%), leaf relative water content (RWC; 8.5%), proline (17.2%), total soluble sugars (34.3%), free amino acids (FAA; 18.4%), K (36.7%), Ca (33.4%), K/Na ratio (77.9%), superoxide dismutase (SOD; 18%), ascorbate peroxidase (APX;12.8%) and guaiacol peroxidase (G-POX; 27.1%) compared to the untreated plants. Meanwhile, most of these responses as well as sulfur (S), Se and catalase (CAT) were obviously decreased in parallel with increasing the applied Se up to 20 µM. The molecular study revealed that three membrane sulfate transporters (SULTR1, SULTR2 and SULTR 3) in the root and leaves and salinity responsive genes (SOS1, NHX1 and Osmotin) in leaves displayed different expression patterns under various Se treatments. Conclusively, Se at low doses can be beneficial in mitigating salinity-mediated damage and achieving the functioning homeostasis to tolerance features. Full article
(This article belongs to the Special Issue Antioxidant Defenses in Crop Plants)
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Perspective
Arbuscular Mycorrhiza Symbiosis as a Factor of Asteraceae Species Invasion
Agronomy 2022, 12(12), 3214; https://doi.org/10.3390/agronomy12123214 - 18 Dec 2022
Viewed by 534
Abstract
Invasive weeds of the Asteraceae family are widespread in the world. Arbuscular mycorrhiza (AM) is one of the main factors contributing to the successful distribution of these species that is most clearly manifested in the subfamily Asteroideae. The benefits of plant-AMF symbiosis are [...] Read more.
Invasive weeds of the Asteraceae family are widespread in the world. Arbuscular mycorrhiza (AM) is one of the main factors contributing to the successful distribution of these species that is most clearly manifested in the subfamily Asteroideae. The benefits of plant-AMF symbiosis are most significant under unfavorable biotic and abiotic conditions. The specificity of the relationship between arbuscular mycorrhizal fungi (AMF) communities and plants and is determined at the presymbiotic stage. The AMF colonization level is higher in invasive species than in native ones, but AMF communities associated with Asteraceae invasive species are less diverse. AMF communities of Asteraceae invaders often include fewer common species (e.g., species belonging to Diversisporales). Invaders also reduce native AMF species richness in new areas. Arbuscular mycorrhizal fungi can form mycorrhizal networks that allow the redistribution of nutrients in plant communities. The most significant influence of AMF associated with invasive Asteraceae plants is seen in the formation of soil and rhizosphere microbiota, including the suppression of beneficial soil bacteria and fungi. This review could be useful in the development of practical recommendations for the use of AMF-based fertilizers. Full article
(This article belongs to the Special Issue Applications of Soil Microorganisms for Sustainable Crop Production)
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Article
Evaluation of the Sustainability of Vineyards in Semi-Arid Climates: The Case of Southeastern Spain
Agronomy 2022, 12(12), 3213; https://doi.org/10.3390/agronomy12123213 - 18 Dec 2022
Viewed by 426
Abstract
Vineyards in southeastern Spain, although subjected to a semi-arid climate, generate multiple environmental and socioeconomic benefits. However, they have an uncertain future, mainly due to the price of grapes, as well as the limited water resources and the effects of climate change. For [...] Read more.
Vineyards in southeastern Spain, although subjected to a semi-arid climate, generate multiple environmental and socioeconomic benefits. However, they have an uncertain future, mainly due to the price of grapes, as well as the limited water resources and the effects of climate change. For this reason, in this work a sustainability evaluation was carried out through life cycle costing analysis (LCC) combined with life cycle assessment (LCA) for four vineyard models characteristic of the area: two rainfed (conventional and organic) and two irrigated (conventional and organic). The greatest differences in the cost structure between the rainfed and irrigated systems are due to the amortization of the infrastructure of the irrigated vineyards, which requires high gross production, via productivity in kilos or in a grape price that prioritizes quality. In addition, the environmental impacts are greater due to this infrastructure. The differences between conventional and organic production for each type of vineyard are of little relevance. The inputs of this crop are minimized, to lower costs, and this entails low economic and environmental costs. However, conventional management entails slightly higher impacts than organic management. Full article
(This article belongs to the Section Farming Sustainability)
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Communication
Effects of Packing Density and Inoculation with Lactic Acid-Producing Bacteria to Evaluate the Potential for North American Elderberry (Sambucus canadensis L.) Fodder as Silage
Agronomy 2022, 12(12), 3212; https://doi.org/10.3390/agronomy12123212 - 18 Dec 2022
Viewed by 495
Abstract
Commercial elderberry production requires complete pruning in late fall to maintain productive canes. For integrated farms (livestock and crops), this biomass has potential as ensiled fodder for ruminant livestock. The objectives of this study were to determine the forage nutritive value of late-season [...] Read more.
Commercial elderberry production requires complete pruning in late fall to maintain productive canes. For integrated farms (livestock and crops), this biomass has potential as ensiled fodder for ruminant livestock. The objectives of this study were to determine the forage nutritive value of late-season (November) pruned elderberry (Sambucus canadensis L. “Rogersville”) fodder when ensiled. A 2 × 2 factorial laboratory silo experiment was conducted testing two packing densities with or without inoculation with lactic acid-producing bacteria silage inoculant to determine effects on silage nutritive values and fermentation parameters. Pre-ensiled elderberry fodder, composited from plants over 2000 m2, averaged 5.6% crude protein, 62.5% acid detergent fiber (ADF), 72.5% neutral detergent fiber, 11.4% non-fiber carbohydrates, 53% total digestive nutrients, and 52% relative feed value (RFV). The two packing densities were 160.2 kg dry matter/m3 and 240.3 kg dry matter/m3. Packing density did not affect any nutrient characteristics of the ensiled fodder. Acid detergent fiber was greater (p = 0.01) in un-inoculated silage, resulting in lower (p < 0.01) RFV for un-inoculated silage. Only lactic acid concentration was affected by packing density with greater concentrations (p = 0.04) in high-density silos. Inoculant affected several fermentation parameters with greater concentrations of (p < 0.01) propanediol, (p = 0.01) propanol, and (p < 0.01) acetic acid, while un-inoculated silages had greater concentrations of (p = 0.03) ammonia-nitrogen, (p < 0.01) lactic acid, (p = 0.02) succinic acid, and (p < 0.01) ethanol. Overall, late-season elderberry fodder was successfully ensiled, but nutritive value was low. Packing density did not affect nutritive value but did increase lactic acid concentration. Inoculation improved the RFV by reducing ADF, and though acetic acid production was greater in inoculated silage, total acid concentration was not affected. Full article
(This article belongs to the Special Issue Silvopastoralism and Agroforestry for Forage Production)
Review
Protein-Based Biostimulants to Enhance Plant Growth—State-of-the-Art and Future Direction with Sugar Beet as an Example
Agronomy 2022, 12(12), 3211; https://doi.org/10.3390/agronomy12123211 - 18 Dec 2022
Viewed by 1117
Abstract
Protein-based biostimulants (PBBs) are derived from the hydrolysis of protein-rich raw materials of plant and/or animal origins, usually by-products or wastes from agro-industries. The active ingredients (AIs) produced by hydrolysis have the capacity to influence physiological and metabolic processes in plants, leading to [...] Read more.
Protein-based biostimulants (PBBs) are derived from the hydrolysis of protein-rich raw materials of plant and/or animal origins, usually by-products or wastes from agro-industries. The active ingredients (AIs) produced by hydrolysis have the capacity to influence physiological and metabolic processes in plants, leading to enhanced growth, nutrient and water-use efficiency, tolerance to abiotic and biotic stresses, and improved crop yield and quality. This paper reviews the state-of-the-art and future opportunities for use of PBBs, based on potential effects on the soil, crops, and sustainability (social, economic, environmental). In this case, two examples of PBBs (hydrolyzed wheat gluten and potato protein) and their effects on the early growth of three sugar beet varieties are described and discussed. Both PBBs have a significant stimulating effect on early sugar beet growth and development. The opportunity to develop PBBs into superabsorbent polymers (SAPs) is discussed. To conclude, PBBs/SAPs developed from agro-industrial wastes have the potential for sustainably supplying water and nutrients in agricultural systems and for enhancing plant growth and development over a substantial period. Full article
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Article
Genotype × Environment Interaction Influence Secondary Metabolite in Cowpea Infested by Flower Bud Thrips
Agronomy 2022, 12(12), 3210; https://doi.org/10.3390/agronomy12123210 - 18 Dec 2022
Viewed by 631
Abstract
Secondary metabolites are among the major contributors of host-plant resistance. Cowpea produces secondary metabolites that are known to enhance resistance to insect pests including flower bud thrips. However, environmental conditions tend to affect the production of secondary metabolites, thereby affecting the response of [...] Read more.
Secondary metabolites are among the major contributors of host-plant resistance. Cowpea produces secondary metabolites that are known to enhance resistance to insect pests including flower bud thrips. However, environmental conditions tend to affect the production of secondary metabolites, thereby affecting the response of the host plants to insect pest. The objective of this study was to determine the effect of the genotype × environment interaction on the production of secondary metabolites and flower bud thrips resistance in cowpea. Six cowpea genotypes were evaluated for flower bud thrips damage and the contents of flavonoids, antioxidants, phenolics, proteins, lignin, tannins and reducing sugars in four environments with varying temperatures and rainfall patterns. The data collected were subjected to the analysis of variance and genotype and genotype × environment (GGE) analysis. Flower thrips damage, and the contents of flavonoids, antioxidants, lignin, tannins and reducing sugars varied significantly (p < 0.001) among genotypes. Genotype Sanzi produced high levels of antioxidants, while TVU-9820 led in phenolic concentrations respectively. Metabolite contents were significantly (p < 0.001) different among environments, with the long rain season of field experiments led to increased production of flavonoids, proteins, lignin and tannins. A resistant genotype, TVU-3804, produced relatively stable contents of flavonoids, antioxidants, phenolics, proteins and reducing sugars across environments. In this study, the environment influenced the concentration of the metabolites, which in turn affected the cowpea’s resistance to flower bud thrips. Full article
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Article
A Dynamic Detection Method for Phenotyping Pods in a Soybean Population Based on an Improved YOLO-v5 Network
Agronomy 2022, 12(12), 3209; https://doi.org/10.3390/agronomy12123209 - 17 Dec 2022
Viewed by 451
Abstract
Pod phenotypic traits are closely related to grain yield and quality. Pod phenotype detection in soybean populations in natural environments is important to soybean breeding, cultivation, and field management. For an accurate pod phenotype description, a dynamic detection method is proposed based on [...] Read more.
Pod phenotypic traits are closely related to grain yield and quality. Pod phenotype detection in soybean populations in natural environments is important to soybean breeding, cultivation, and field management. For an accurate pod phenotype description, a dynamic detection method is proposed based on an improved YOLO-v5 network. First, two varieties were taken as research objects. A self-developed field soybean three-dimensional color image acquisition vehicle was used to obtain RGB and depth images of soybean pods in the field. Second, the red–green–blue (RGB) and depth images were registered using an edge feature point alignment metric to accurately distinguish complex environmental backgrounds and establish a red–green–blue-depth (RGB-D) dataset for model training. Third, an improved feature pyramid network and path aggregation network (FPN+PAN) structure and a channel attention atrous spatial pyramid pooling (CA-ASPP) module were introduced to improve the dim and small pod target detection. Finally, a soybean pod quantity compensation model was established by analyzing the influence of the number of individual plants in the soybean population on the detection precision to statistically correct the predicted pod quantity. In the experimental phase, we analyzed the impact of different datasets on the model and the performance of different models on the same dataset under the same test conditions. The test results showed that compared with network models trained on the RGB dataset, the recall and precision of models trained on the RGB-D dataset increased by approximately 32% and 25%, respectively. Compared with YOLO-v5s, the precision of the improved YOLO-v5 increased by approximately 6%, reaching 88.14% precision for pod quantity detection with 200 plants in the soybean population. After model compensation, the mean relative errors between the predicted and actual pod quantities were 2% to 3% for the two soybean varieties. Thus, the proposed method can provide rapid and massive detection for pod phenotyping in soybean populations and a theoretical basis and technical knowledge for soybean breeding, scientific cultivation, and field management. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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Article
Effects of Phenological Changes on Plant Production—From the View of Stipa krylovii
Agronomy 2022, 12(12), 3208; https://doi.org/10.3390/agronomy12123208 - 16 Dec 2022
Viewed by 707
Abstract
Global warming has changed plant phenology and induced variations in the productivity of terrestrial ecosystems. Recent studies have shown inconsistent results regarding the influence of phenological changes on plant production. We carried out a three-year in situ experiment in Inner Mongolia and used [...] Read more.
Global warming has changed plant phenology and induced variations in the productivity of terrestrial ecosystems. Recent studies have shown inconsistent results regarding the influence of phenological changes on plant production. We carried out a three-year in situ experiment in Inner Mongolia and used Stipa krylovii as an example to examine the phenological changes and their importance to plant production under changes in temperature and precipitation. We found that precipitation, temperature, and their interactions had no significant impact on the start of the growing season (SOS) or vegetative growth length (VGL). Precipitation had significant impacts on the end of the growing season (EOS), the length of the growing season (LOS), and reproductive growth length (RGL). The precipitation addition treatments of T2.0W + 50% (2 °C warming and 50% precipitation addition) and T1.5W + 50% (1.5 °C warming and 50% precipitation addition) significantly delayed the EOS by 6.7 d and 5.4 d, and significantly prolonged the LOS by 9.3 d and 9.3 d, respectively. Precipitation significantly changed the net CO2 assimilation rate (Pn) of the heading stage. There was no significant difference in the dry mass among all the treatments. The SOS and VGL had significant negative impacts on the dry mass of Stipa krylovii, while temperature, precipitation, and the EOS had no significant direct effect on it. Our results imply that the SOS was more important than the EOS in regulating the plant production of Stipa krylovii. This study can facilitate the understanding of the response of productivity to phenological dynamics and improve the accuracy of simulating the terrestrial ecosystem carbon budget. Full article
(This article belongs to the Section Grassland and Pasture Science)
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Article
Analysis of Photosynthetic Differences of Rice Germplasm in Southeast Asia Based on Leaf-Tissue Structure, Physiology, and iTRAQ
Agronomy 2022, 12(12), 3207; https://doi.org/10.3390/agronomy12123207 - 16 Dec 2022
Viewed by 508
Abstract
Photosynthesis is responsible for 90–95% of organic matter in crop yield. The light energy utilization rate of high-yielding rice varieties is 1.0–1.5%, but the ideal value is about 3–5%. Yield can be further improved by improving photosynthetic function. Through the initial screening and [...] Read more.
Photosynthesis is responsible for 90–95% of organic matter in crop yield. The light energy utilization rate of high-yielding rice varieties is 1.0–1.5%, but the ideal value is about 3–5%. Yield can be further improved by improving photosynthetic function. Through the initial screening and re-screening of 220 Southeast Asian germplasm resources, we found that the net photosynthetic rate of Southeast Asian germplasm resource C1 was 36.96 μmol m−2 S−1, which is close to that of C4 plant maize and 3.26 times higher than that of Southeast Asian germplasm resource G164 at 11.26 μmol m−2 S−1. Using C1 and G164 as materials, we compared the tissue structure, chloroplast ultrastructure, photosynthetic physiological indicators, and proteomics of sword leaves to determine the factors affecting photosynthetic function. Compared with G164, C1 exhibited increased number of vascular bundles, increased stomatal size and density, more abundant and neatly arranged chloroplasts and thylakoid grana, and higher chlorophyll fluorescence parameters. The activities and contents of the key photosynthetic enzyme Rubisco were higher in C1 than in G164. The two germplasm resources were subjected to iTRAQ analysis, and the results showed that compared with C1, nine proteins were down-regulated and one protein was up-regulated and associated with photosynthetic electron transport in G164; a total of 17 differential proteins were associated with CO2 fixation, and nine were up-regulated and eight differential proteins were down-regulated in G164. The identified genes encode proteins in the photosynthesis and carbon fixation pathways, and the changes in gene expression were verified by real-time qPCR. The gene expression patterns were consistent with the protein expression patterns. The results suggest that most differential proteins are involved in electron transfer from PSII to PSI and in the CO2 fixation pathway, and increasing the levels of such proteins can effectively enhance the photosynthetic efficiency. C1 can be used as a donor material for selection of high light efficiency varieties and in-depth photosynthesis studies. Full article
(This article belongs to the Special Issue In Memory of Professor Longping Yuan, the Father of Hybrid Rice)
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Article
Multilocation Evaluation of Virginia and Runner -Type Peanut Cultivars for Yield and Grade in Virginia–Carolina Region
Agronomy 2022, 12(12), 3206; https://doi.org/10.3390/agronomy12123206 - 16 Dec 2022
Viewed by 630
Abstract
The peanut is mostly grown in semi-arid tropical regions of the world, characterized by unpredictable rainfall amounts and distribution. Average annual precipitation in the Virginia–Carolina (VC) region is around 1300 mm; however, unpredictable distribution can result in significant periods of water deficit and [...] Read more.
The peanut is mostly grown in semi-arid tropical regions of the world, characterized by unpredictable rainfall amounts and distribution. Average annual precipitation in the Virginia–Carolina (VC) region is around 1300 mm; however, unpredictable distribution can result in significant periods of water deficit and subsequent reduction in yield and gross income. The development of new peanut cultivars with high yield and acceptable levels of yield stability across various water-availability scenarios is an important component of the peanut breeding program in Virginia and the Carolinas, where the large-seeded Virginia-type peanut is the predominantly grown market type. In addition, the simultaneous use of runner cultivars developed in the dryer southeastern region has been proposed as a practical solution to limited irrigation availability in the VC region. Still, the identification and adequate utilization of available commercial cultivars with the best combination of yield, drought tolerance, and gross income is more immediately beneficial to the peanut industry, yet this assessment has not been carried out to date. The aim of this study was to identify cultivars that maintain high yield and grade, therefore gross income, across a wide range of environmental conditions. We evaluated five commercially available Virginia and runner-type peanut cultivars for pod yield stability using multilocation trials over four years across 13 environments. Additive main effects and multiplicative interaction (AMMI) and different stability approaches were used to study genotype (G), environment (E), and their interaction (G × E) on pod yield. Pod yield stability was specifically assessed by using the Lin and Binn approach, Wricke’s ecovalence, Shukla’s stability, and the Finlay–Wilkinson approach. The combined analysis of variance showed highly significant effects (p ≤ 0.001) for genotypes, environments, and G × E for pod yield. The environments varied in yield (2840–8020 kg/ha). Bailey, Sullivan, and Wynne are Virginia-type cultivars. The grade factors SMK, SS, and TK changed with water regime within both market types. Among the runner cultivars, TUFRunner 297 presented high mean productivity; however, it showed specific adaptation to limited environmental conditions. Based on different stability approaches, this study concludes that Sullivan and Bailey are the most stable and adaptable cultivars across the testing environments, whereas Wynne exhibited specific adaptability to some environments. These findings have important implications for peanut cultivar recommendations in terms of meeting peanut industry standards for yield, grading quality, and breeding progress. Full article
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Concept Paper
Biostimulants and Herbicides: A Promising Approach towards Green Deal Implementation
Agronomy 2022, 12(12), 3205; https://doi.org/10.3390/agronomy12123205 - 16 Dec 2022
Viewed by 382
Abstract
Biostimulants are products that can increase crop growth and can be applied either to the soil or to the plant and seed of a wide range of crops. However, there is a large gap in knowledge regarding the potential interactions of biostimulants with [...] Read more.
Biostimulants are products that can increase crop growth and can be applied either to the soil or to the plant and seed of a wide range of crops. However, there is a large gap in knowledge regarding the potential interactions of biostimulants with plant protection products like herbicides. The present review aims to highlight various effects of the combined use of biostimulants with herbicides in terms of weed management, crop yield and quality parameters. Special emphasis is given to the comparison between the combined use of biostimulants with herbicides and herbicides used alone (without biostimulants). In wheat and potato, the combined use of biostimulants with herbicides can in some cases be beneficial for the crop compared with herbicides alone, with recorded yield increases of up to 14.7% depending on the biostimulant, the herbicide, the year and the method of application (mixture or sequentially). Combining herbicides and biostimulants shows potential to achieve good weed management while improving crop yields and quality and thus lower herbicide rates could be probably used for sufficient weed control in full agreement with the goals of Green Deal and agroecology approaches. Full article
(This article belongs to the Special Issue The Future of Weed Science—Novel Approaches to Weed Management)
Article
Antifungal Effect of Plant Extracts on the Growth of the Cereal Pathogen Fusarium spp.—An In Vitro Study
Agronomy 2022, 12(12), 3204; https://doi.org/10.3390/agronomy12123204 - 16 Dec 2022
Viewed by 666
Abstract
The aim of the study was a laboratory evaluation of the antifungal effect of leaf extracts from yarrow (Achillea millefolium L.), tansy (Tanacetum vulgare L.), sage (Salvia officinalis L.) and wormwood (Artemisia absinthium L.) on fungi of the genus [...] Read more.
The aim of the study was a laboratory evaluation of the antifungal effect of leaf extracts from yarrow (Achillea millefolium L.), tansy (Tanacetum vulgare L.), sage (Salvia officinalis L.) and wormwood (Artemisia absinthium L.) on fungi of the genus Fusarium, major cereal pathogens. The study used 5%, 10%, and 20% concentrations of plant extracts, evaluating their effect on the linear growth of Fusarium avenaceum, F. culmorum, F. graminearum, F. sporotrichioides and the percentage of their growth inhibition compared to control. The study also included the assessment of the content of selected biologically active compounds in plant extracts and their impact on the development of the aforementioned pathogenic fungi. The total content of polyphenols and flavonoids in the extracts was assessed by spectrophotometry, and antioxidant activity was determined using the synthetic 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Plant extracts from sage were characterized by the highest polyphenol contents (81.95 mg/mL) and flavonoids (21.12 mg/mL) compared to other plant extracts, and also showed the highest antioxidant activity (102.44 mM Trolox). Wormwood extract contained the lowest amount of phenolic compounds (flavonoids—5.30 mg/mL, polyphenols—43.83 mg/mL). Plant extracts inhibited the mycelia growth of fungal pathogen depending upon the fungus species, type of extract and its concentration. The extracts of sage (S) and tansy (T) plants at a concentration of 20% demonstrated strong inhibitory effect against the tested fungi (the highest inhibition coefficient for S20: 83.53%; T20: 72.58%), while 10% and 5% extracts of these plants were less effective in inhibiting the growth of Fusarium (highest inhibition coefficient for S10: 71.33%; S5: 54.14%; T10: 56.67%; T5: 38.64%). Yarrow (Y) and wormwood (W) extracts showed low fungistatic effect. Their 20% concentration inhibited the development of mycelia growth of fungi at the level of 63.82% (W20) and 67.57% (Y20). The 5% and 10% concentrations of these plant extracts had the weakest effect on the tested fungi (Y5: 34.09; W5: 42.06%; Y10: 45.01%; W10: 57.44%), even stimulating the Fusarium growth compared to the control (Y5: −23.7%). Based on the study, it was found that each species of fungus reacted differently to the addition of the extract to the culture medium and its concentration, however F. avenaceum and F. culmorum were the most sensitive fungi, while the least sensitive was F. graminearum. The results of the research are the preliminary phase for further field tests to determine the fungistatic effect of plant extracts in field conditions, their phytotoxicity and biological stability, as well as the possibility of producing a biopreparation to protect plants against fusariosis. Full article
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Article
Deciphering Early Movements and Domestication of Coffea arabica through a Comprehensive Genetic Diversity Study Covering Ethiopia and Yemen
Agronomy 2022, 12(12), 3203; https://doi.org/10.3390/agronomy12123203 - 16 Dec 2022
Cited by 1 | Viewed by 1607
Abstract
The coffee species Coffea arabica is facing numerous challenges regarding climate change, pests and disease pressure. Improved varieties will be part of the solution. Making optimal use of the scarce genetic diversity of the species is hence essential. In this paper, we present [...] Read more.
The coffee species Coffea arabica is facing numerous challenges regarding climate change, pests and disease pressure. Improved varieties will be part of the solution. Making optimal use of the scarce genetic diversity of the species is hence essential. In this paper, we present the first study of C. arabica genetic diversity covering its complete native habitat in Ethiopia together with its main domestication centers: Yemen and Hararghe region in Ethiopia. All in all, 555 samples were analyzed with a set of Single Sequence Repeat markers. Through admixture genetic analysis, six clusters were identified. A total of two “Core Ethiopian” clusters did not participate in the domestication of the species. There were four clusters that were part of the “Domestication Pathway” of C. arabica. The first one was named “Ethiopian Legacy” as it represents the genetic link between “Core Ethiopia” and the “Domestication Pathway” in Yemen and Hararghe. The geographic origin of this cluster in Ethiopia was the south of Ethiopia, namely Gedio, Guji and Sidama, which hence appears as the source of coffee seeds that led to the domestication of C. arabica. In Yemen, in addition to the “Ethiopian Legacy” cluster, we confirmed the “Typica/Bourbon” and “New-Yemen” clusters. In Hararghe, the “Harrar” cluster, never described before, likely originates from a re-introduction of domesticated coffee from Yemen into this region of Ethiopia. Cultivated varieties around the world today originate from the “Ethiopian Legacy” and “Typica/Bourbon” clusters and but none are related to the “new-Yemen” and “Harrar” clusters. Implications for breeding strategies are discussed. Full article
(This article belongs to the Special Issue Genetic Diversity and Population Structure in Crop and Woody Plants)
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Article
Comparative Transcriptomic Analysis of Head in Laodelphax striatellus upon Rice Stripe Virus Infection
Agronomy 2022, 12(12), 3202; https://doi.org/10.3390/agronomy12123202 - 16 Dec 2022
Viewed by 411
Abstract
Rice stripe virus (RSV) is transmitted by the small brown planthopper (SBPH), Laodelphax striatellus, in a circulative-propagative manner. Multiple studies have proved that RSV can manipulate vector insects to facilitate its transmission and can alter the gene expressions in viruliferous SBPH. However, to [...] Read more.
Rice stripe virus (RSV) is transmitted by the small brown planthopper (SBPH), Laodelphax striatellus, in a circulative-propagative manner. Multiple studies have proved that RSV can manipulate vector insects to facilitate its transmission and can alter the gene expressions in viruliferous SBPH. However, to the best of our knowledge, nobody has investigated the gene expressions in the head of SBPH after RSV acquisition. In this study, to investigate the genes and gene functions regulated by RSV infection in the head of SBPH, we used RNA sequencing to compare the transcriptional profiles between SBPH head samples that acquired RSV or not. Compared with the non-viruliferous SBPH, a total of 336 differentially expressed genes (DEGs) were identified in the head samples of viruliferous SBPH groups, including 186 up-regulated and 150 down-regulated genes. Here, we focused on DEGs that may be involved in RSV replication or transmission, primarily genes associated with the nervous system, cytochrome P450s, sugar metabolism, the olfactory system, and cuticular process, as well as genes that have been previously reported to affect virus transmission in insect vectors including ubiquitin-protein ligase (E3), ecdysone response gene (E74A), and vitellogenin receptor (VgR). Finally, we verified the accuracy of the transcriptome sequencing results using qRT-PCR by selecting 16 DEGs. Our results can contribute to the understanding of the effects of RSV infection on gene regulation in the head of SBPH and provide insight into the control of plant virus transmission and insect vectors. Full article
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Article
Selection of Reference Genes for Transcription Studies Considering Co-Regulation and Average Transcriptional Stability: Case Study on Adventitious Root Induction in Olive (Olea europaea L.) Microshoots
Agronomy 2022, 12(12), 3201; https://doi.org/10.3390/agronomy12123201 - 16 Dec 2022
Viewed by 368
Abstract
Selection of reference genes (RGs) for normalization of PCR-gene expression data includes two crucial steps: determination of the between-sample transcriptionally more stable genes, and subsequent choosing of the most suitable genes as internal controls. Both steps can be carried out through generally accepted [...] Read more.
Selection of reference genes (RGs) for normalization of PCR-gene expression data includes two crucial steps: determination of the between-sample transcriptionally more stable genes, and subsequent choosing of the most suitable genes as internal controls. Both steps can be carried out through generally accepted strategies, each having different strengths and weaknesses. The present study proposes reinforcement of the normalization of gene expression data by integrating analytical revision at critical steps of those accepted procedures. In vitro olive adventitious rooting was used as an experimental system. Candidate RGs were ranked according to transcriptional stability according to several methods. An algorithm of one of these programs (GeNorm) was adapted to allow for partial automatization of RG selection for any strategy of transcriptional-gene stability ordering. In order to choose the more appropriate set of RGs, the achieved results were analytically revised, with special emphasis on biasing effects such as co-regulation. The obtained putative RG sets were also tested for cases restricted to fewer variables. The set formed by the genes H2B, OUB and ACT is valid for normalization in transcriptional studies on olive microshoot rooting when comparing treatments, time points and assays. Such internal reference is now available for wider expression studies on any target gene in similar biological systems. The overall methodology aims to constitute a guide for general application. Full article
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