Search Results (19)

Single-stranded DNA (ssDNA) viruses are a diverse group of pathogens with broad host range, including bacteria, archaea, protists, fungi, plants, invertebrates, and vertebrates. Their small compact genomes have evolved to encode multiple proteins. This review focuses on the structure and functional diversity of the icosahedral capsids across the ssDNA viruses. To date, X-ray crystallography and cryo-electron microscopy structural studies have provided detailed capsid architectures for 8 of the 35 ssDNA virus families, illustrating variations in assembly mechanisms, symmetry, and structural adaptations of the capsid. However, common features include the conserved jelly-roll motif of the capsid protein and strategies for genome packaging, also showing evolutionary convergence. The ever-increasing availability of genomic sequences of ssDNA viruses and predictive protein modeling programs, such as using AlphaFold, allows for the extension of structural insights to the less-characterized families. Therefore, this review is a comparative analysis of the icosahedral ssDNA virus families and how the capsid proteins are arranged with different tessellations to form icosahedral spheres. It summarizes the current knowledge, emphasizing gaps in the structural characterization of the ssDNA capsidome, and it underscores the importance of continued exploration to understand the molecular underpinnings of capsid function and evolution. These insights have implications for virology, molecular biology, and therapeutic applications. Full article

Applying nitrogen fertilizers in agriculture can cause uncontrolled gas emissions, such as N₂O and CO_2, leading to global warming and serious climate changes. In this study, we evaluated the greenhouse gas emissions (GHGs) that are concomitant with applying different rates of N fertilization, i.e., 50, 75, 100, and 125% of the recommended dose (727 kg N ha⁻¹) for two cultivars (Balady and Sids-40) of Allium sativum L. grown under three planting dates (15 September, 1 October, and 15 October). For this purpose, two field experiments were carried out during the two growing seasons of 2020/2021 and 2021/2022. Treatments were arranged in a split–split plot design with three replicates: planting dates were set up in the main plots, nitrogen levels were conducted in the submain plots, and garlic varieties were in the sub-subplots. The obtained results can be summarized as follows: Planting on 15 September significantly increased vegetative growth parameters (i.e., plant height, leaves area, number of leaves plant⁻¹, and leaves dry weight) and total bulb yield, in both seasons. The application of the highest rate of N (125%) gave significantly higher records for vegetative growth parameters, while the 75% nitrogen treatment appeared to give the highest total bulb yield in both seasons. The means of plant growth characteristics and total bulb yield were significantly increased by the cultivation of the Balady cultivar. In addition, the results show that GHGs were positively correlated with increasing the rate of N fertilization. It could be recommended that planting on 15 September and fertilizing with 75% N fertilizer from the recommended dose for Balady cultivar achieve maximum yield and its components. Full article

Sugar beet is a critical crop for global sugar production, and optimizing its growth and yield requires a thorough understanding of the effects of agronomic practices such as sowing date and nitrogen fertilization. This study was conducted in the WULS-SGGW Experimental Field in Miedniewice, Poland, during two growing seasons. The aim of the research was to determine the impact of sowing dates and nitrogen fertilization on the morphometric features and photosynthetic performance of the Lubelska sugar beet variety grown in Luvisols soil. The experiments were arranged as split-plot designs (SPDs) with four replications. The factors of the experiment were the sowing date (optimal and delayed by two weeks) and nitrogen fertilization at doses of 0, 60, and 120 kg N·ha⁻¹. The photosynthetic activity of sugar beet plants was measured four times during the growing season using chlorophyll fluorescence (ChlF) parameters. Morphometric features were determined by collecting sugar beet plants after each chlorophyll fluorescence measurement. The obtained results demonstrate the significant effect of nitrogen doses on the morphometric parameters of aboveground biomass. Increasing nitrogen doses also differentiated chlorophyll fluorescence parameters, such as F_V/F₀, F_V/F_M, PI_ABS, ET₀/CS₀, and ET₀/CS_M. A two-week delay in sowing affected both the fluorescence parameters and morphometric features of sugar beet, highlighting the interaction between agronomic practices and plant physiology. Full article

In seasonal agricultural frozen soil areas, the straw return may influence the freeze–thaw characteristics by changing the soil organic matter and porosity. Monitoring moisture and heat in the freeze–thaw period is significant for preventing spring waterlogging and reasonable planting arrangements. However, the effect of long-term straw return on the soil freeze–thaw process is still unclear. In this study, we investigated the dynamics of soil temperature (ST) and soil moisture (SM) between straw-return cropland (SF) for 29 consecutive years and no-fertilization cropland (NF) during freeze–thaw progress in northeast China. The soil in both sites underwent unidirectional freezing and bidirectional thawing processes. The soil freezing and thawing dates in the NF of the profile occurred earlier than that in the SF. The NF had higher frozen depth and freezing rate than the SF and exhibited a larger range of ST variation and higher heat transmission efficiency. The SM showed a declining trend before the ST started to decrease to a freezing point at different depths in both sites. The migrated SM in most soil layers decreased during monitoring. The relationship between SM and negative ST was a power function at different frozen depths. The SM decreased rapidly in the range of −2–0 °C in both sites. During phase changes, the SF and NF consumed 33.0 and 43.6 MJ m⁻², respectively. The results can partially explain the response of straw return to soil hydrothermal variation during the freeze-thaw process. This study may provide an integral theory for effectively utilizing agricultural soil hydrothermal resource in northeast China. Full article

Forage sorghum is an alternative source for biofuel feedstock production and may also provide forage for livestock operations. Introducing biofuel feedstock as a dual-use forage to livestock operations has the potential to increase the adoption of biofuel feedstock production. However, additional technical agronomic information focusing on tillage, row arrangement, and harvest date for forage sorghum planted into pasturelands intended for dual use is needed. Three tillage treatments, disking and rototilling (RT), chisel plow (CP), and no tillage (NT), and two row arrangement treatments, single-row planting with 76.2 cm rows and twin rows of 17.8 cm on 76.2 cm centers, were tested for effects on forage sorghum yield in a 3-cut system. This study tested two sites in Booneville, AR, from 2010 to 2012. Several interactions with year were detected, likely due to large precipitation differences within and among years. The year greatly affected the yield, with greater (p < 0.05) yields in year 1 compared to years 2 and 3 in both locations. No till resulted in lower yields in some years and harvest dates, though no clear trend was detected among tillage treatments over years. Twin rows generally did not improve yield, except for the third harvest date at one location. No strong trends for tillage or row arrangement effects were observed in this study. Inconsistencies may have resulted from the strong influence of year or interactions of multiple factors, which may challenge producers interested in utilizing forage sorghum for biofuels and livestock feed. Full article

Phytotoxicity refers to the capacity of chemical substances or environmental factors to have a negative impact on plants. This is a crucial issue in both the context of crop cultivation and environmental protection. The research results were based on a 3-year field experiment conducted at an experimental station in Jadwisin (52°28′ N, 21°02′ E) on loamy soil. The experiment was set up using a randomized sub-block design in a split–split–plot arrangement with three replications. The first-order factor consisted of potato cultivars, while the second-order factors were weed control methods: (1) without protection; (2) mechanical weed control, extensive mechanical treatments to close rows; (3) Sencor 70 WG—pre-emergence (PRE) of potatoes; (4) Sencor 70 WG + Titus 25 WG + Trend 90 EC—PRE of potatoes; (5) Sencor 70 WG—post-emergence (POST) of potatoes; (6) Sencor 70 WG + Titus 25 WG + Trend 90 EC—POST of potatoes; (7) Sencor 70 WG + Fusilade Forte 150 EC—POST of potatoes; and (8) Sencor 70 WG + Apyros 75 WG + Atpolan 80 SC—POST of potatoes. The phytotoxic effects of herbicides on potato plants and weeds were assessed every 7 days, starting from the date when the first signs of damage appeared until they stabilized or disappeared. Phytotoxic damage to potato and weed plants was caused by the chemical weed control methods used. The response of potato plants to herbicides was significantly related to the genetic traits of the cultivars and meteorological conditions in the years of research. Phytotoxicity is an important aspect in both agriculture and environmental protection. Research on its mechanisms and impact will enable the development of effective plant protection strategies and the preservation of ecosystem balance. Full article

Getting accurate and up-to-date information on the cultivated land area and spatial arrangement of maize, an important staple crop in the Ningxia Hui Autonomous Region, is very important for planning agricultural development in the region and judging crop yields. This work proposes a machine-learning methodology to extract corn from medium-resolution photos obtained from the Sentinel-2 satellite. The Google Earth Engine (GEE) cloud platform is utilized to facilitate the process. The identification of maize cultivation regions in Huinong District in the year 2021 was performed through the utilization of support vector machine (SVM) and random forest (RF) classification techniques. After obtaining the results, they were compared to see if using the random forest classification method to find planting areas for maize was possible and useful. Subsequently, the regions where maize was cultivated were combined with image data from the Moderate Resolution Imaging Spectroradiometer (MODIS), which has a high temporal resolution. The Normalized Difference Vegetation Index (NDVI) contemporaneous difference method, which gives regular updates, was then used to track the growth of maize during its whole growth phase. The study’s results show that using the GEE cloud platform made it easier to quickly map out data about where to plant maize in Huinong District. Furthermore, the implementation of the random forest method resulted in enhanced accuracy in extracting maize planting areas. The confusion matrix’s evaluation of the classification performance produced an average overall accuracy of 98.9% and an average Kappa coefficient of 0.966. In comparison to the statistics yearbook of the Ningxia Hui Autonomous Region, the method employed in this study consistently yielded maize-planted area estimates in Huinong District with relative errors below 4% throughout the period spanning 2017 to 2021. The average relative error was found to be 2.04%. By combining MODIS image data with the NDVI difference model in the year 2021, the high-frequency monitoring of maize growth in Huinong District was successful. The growth of maize in Huinong District in 2021 exhibited comparable or improved performance in the seedling stage, nodulation stage, and the early stage of staminate pulling and spitting, possibly attributed to the impact of climate and other relevant elements. After that, the growth slowed down in August, and the percentage of regions with slower growth rates than in previous years gradually increased. However, overall, the growth of maize in Huinong District during the year 2021 showed improvement relative to the preceding years. The present study introduces a novel approach that demonstrates the capability to accurately extract corn crops in the Huinong District while simultaneously monitoring their growth at a high frequency. Full article

(1) Background: The participation of insects in the pollination of self-pollinating plants, such as coffee, is still controversial. This study determined the effect of flower-visiting insects on coffee berry set, yield, and quality. (2) Methods: Over 2 years, five evaluations in different locations, dates, and harvest times were carried out. Each evaluation consisted of eight treatments with 50 replicates each, arranged in a completely randomized experimental design. Treatments were established to identify the contribution of insects, wind, gravity, self-pollination, and cross-pollination to coffee yield and quality. (3) Results: The insects contributed 16.3% of the berry set, 26.9% of the berry coffee yield, and 30.6% of the weight of supremo-type beans. No differences were observed in the sensory quality of coffee produced with or without insects. For stigma receptivity, results indicate that there is a 6.3% probability of self-pollination during pre-anthesis. (4) Conclusions: The species Coffea arabica, despite being a self-pollinating plant, benefits from the presence of flower-visiting insects. During anthesis, arabica coffee flowers are ready for cross-pollination. Full article

Wheat (Triticum aestivum L.) is a staple and the most important food crop around the world. The growth and productivity of wheat are influenced by different factors, viz., sowing time, tillage system and nutrient application. The current field experiment consists of different boron (B) application rates, viz., B₀ = No application (Control), B₁ = soil applied (2 kg ha⁻¹), B₂ = foliar applied (2 kg ha⁻¹), B₃ = water spray; two tillage systems, viz., zero tillage (ZT) and conventional tillage (CT); and three sowing dates (S₁ = 15 November; S₂ = 5 December and S₃ = 25 December). It was conducted during the years 2019–2020 and 2020–2021 under a split-split plot arrangement. The results showed that sowing dates and boron had beneficial impacts on the growth and productivity of wheat. The wheat crop sown on 15 November showed the highest plant height, chlorophyll contents, grains per spike, and grains’ boron content. Similarly, the application of boron under late sown conditions also improved the plant height (83.8 cm), chlorophyll contents (45.6), biological (5418 kg ha⁻¹) and grain (4018 kg ha⁻¹) yield as compared to control during both years. Furthermore, the higher crop growth and yield parameters were noted with the foliar application of boron at 2 kg ha⁻¹. However, wheat crop growth and yield characteristics were not significantly affected by tillage techniques, h. In conclusion, the application of boron @ 2 kg ha⁻¹ could be a suitable option for achieving higher wheat grain yield and productivity under late-sown conditions. Full article

Two-line hybrid rice production requires environmental genetic male-sterile (EGMS) lines that become sterile in certain environmental conditions. In this study, we aimed to identify the genetic type(s), sterility thresholds, optimum planting date, and efficient seeding density of eight male-sterile lines, including four lines developed at the University of Arkansas, Rice Research and Extension Center (RREC) and four at the Dale Bumpers National Rice Research Center (DBNRRC) both located in Stuttgart, AR, USA. The lines were screened in growth chambers using different temperatures and day lengths to identify the type of EGMS line and sterility thresholds. A single location was used in testing the first year of the study and three locations used in the second year of the planting date study. All experiments were arranged in randomized blocks with three replications to identify the optimum planting date and seeding rate. Three planting dates were tested each year for the planting date experiment, and three seeding densities were used in the seed density study. The growth chamber study showed that all RREC lines were thermosensitive genic male-sterile lines, and the sterility threshold temperature for one of these lines was >32.2 °C while that of others was >29.4 °C. The type of sterility and threshold of DBNRRC lines were inconclusive due to their genetic heterogenicity and environmental response inconsistency. In Arkansas, April 25 was the optimum planting date for sterile conditions, and a 431 seed/m² seeding rate was required to produce an adequate number of panicles for hybrid seed production while avoiding wasting expensive male-sterile seeds. Full article

Teosinte (Euchlaena mexicana L.) is a popular herbage crop in Nepal. Although farmers produce teosinte seeds, management for maximizing seed yield is unknown. A study was undertaken to investigate teosinte seed yield in order to explore the seed production potential of teosinte for maximizing herbage yield. There were four different sowing dates (30 March, 30 April, 30 May and 30 June), four seed rates (20, 40, 60 and 80 kgha⁻¹) and three herbage cuttings (nil, once at 45 days after sowing (DAS), twice at 45 and 75 DAS) arranged in a split-split plot design. In both years, the highest seed yield was obtained from the two earliest sowings because they had taller plants, more tillers, a higher leaf area index (LAI) and more cobs per plant, ears per cob and seeds per ear than later sown plants. In 2017, seed yield did not differ among the seed rates because of adverse climatic conditions; however, in 2018 the two lower seed rates out yielded the two highest seed rates. Cutting twice significantly reduced seed yield in both years; one cut did not reduce seed yield in 2017 but it did so in 2018. These results suggest teosinte seed crops should be sown early at a seed rate between 20 to 40 kgha⁻¹. An economic analysis indicated that the traditional farmer practice of taking one herbage cut from their seed crop would not affect the gross margin. Full article

Determining the effect of irrigated and rainfed conditions on light interception, light extinction coefficient (k), radiation use efficiency (RUE), biomass, and storage root accumulation of cassava was the objective of this study. The field experiment was arranged in a randomized complete block design (RCBD) with four replications. The effect of irrigated and rainfed water conditions in cassava were evaluated under two planting dates for two years. Light interception depended on k and LAI which affected solar radiation accumulation and thus biomass production for cassava. The k values ranged from 0.49 to 0.93 a nd 0.46 to 0.86 for irrigated and rainfed crops, respectively. The RUE_bi and RUE_sr depended on water conditions and crop growth stages and seasons, whereas rainfed crops in the May planting were slightly lower in RUE_bi than irrigated crops. RUE_bi of the crop planted in November was not significantly different for irrigated and rainfed crops. Irrigation at the late growth stage could maintain higher LAI, light interception, and RUE for the crop planted in May, whereas those in November planting were not significantly different. Full article

Rice false smut is known as the cancer of rice. The disease is becoming increasingly prominent and is one of the major diseases in rice. However, prevention and treatment of this disease relies on “Centralized pesticide spraying”. However, indiscriminate spraying leads to more pesticide residue, and impacts ecological and food safety. To obtain more objective results, different experimental planting forms are necessary. This study collected data at a complex planting environment based on “near earth remote sensing” using a frame-based hyperspectral device. We used mixed detection methods to differentiate between healthy rice and U. virens infected rice. There were 49 arrangements and more than 196 differentiation models between healthy and diseased rice, including 7 sowing data plots, 2 farm management types, and 23 pattern recognition methods. Finally, the real accuracy was mostly above 95%. In particular, with the increase of epoch and iteration, feature sequences based on deep learning could achieve better results; most of the accuracies were 100% with 100 epochs. We also found that differentiation accuracy was not necessarily correlated with the sowing dates and farm management. Finally, the detection method was verified according to the actual investigation results in the field. The prescription map of disease incidence was generated, which provided a theoretical basis for the follow-up precision plant protection work. Full article

Morphology and nomenclature are essential issues of botany, in which both extant and fossil plant taxa follow the same nomenclature code. Devonian (419.2–358.9 Ma) herbaceous lycopsid Barsassia, one of the earliest coal-forming plants in geological history, possesses a characteristic, easily recognized, step-like stem and has been thought to be an index fossil for dating and correlating the Middle Devonian strata, especially those in the paleoblocks of Siberia, Kazakhstan, Xinjiang, and North China. Here, we systematically study the Devonian lycopsid Barsassia in terms of its morphology and nomenclature, based on the new materials from the Middle Devonian Hujiersite Formation of West Junggar, Xinjiang, China, and the International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code). Barsassia ornata is determined as the type species of the genus, and a neotype is designated for that name. Barsassia ornata consists of fan- or rectangular-shaped leaves with awl-shaped or finger-like distal tips. Its leaves are pseudo-whorls and imbricately arranged on the stem surface forming distinct step-like structure. Full article

The genus Chlorophytum includes many economically important species well-known for medicinal, ornamental, and horticultural values. However, to date, few molecular genomic resources have been reported for this genus. Therefore, there is limited knowledge of phylogenetic studies, and the available chloroplast (cp) genome of Chlorophytum (C. rhizopendulum) does not provide enough information on this genus. In this study, we present genomic resources for C. comosum and C. gallabatense, which had lengths of 154,248 and 154,154 base pairs (bp), respectively. They had a pair of inverted repeats (IRa and IRb) of 26,114 and 26,254 bp each in size, separating the large single-copy (LSC) region of 84,004 and 83,686 bp from the small single-copy (SSC) region of 18,016 and 17,960 bp in C. comosum and C. gallabatense, respectively. There were 112 distinct genes in each cp genome, which were comprised of 78 protein-coding genes, 30 tRNA genes, and four rRNA genes. The comparative analysis with five other selected species displayed a generally high level of sequence resemblance in structural organization, gene content, and arrangement. Additionally, the phylogenetic analysis confirmed the previous phylogeny and produced a phylogenetic tree with similar topology. It showed that the Chlorophytum species (C. comosum, C. gallabatense and C. rhizopendulum) were clustered together in the same clade with a closer relationship than other plants to the Anthericum ramosum. This research, therefore, presents valuable records for further molecular evolutionary and phylogenetic studies which help to fill the gap in genomic resources and resolve the taxonomic complexes of the genus. Full article