Search Results (71)

Rice blast disease, caused by the ascomycete fungus Magnaporthe oryzae (syn. Pyricularia oryzae), poses a severe threat to global rice production. Southern China, a major rice-growing region characterized by diverse agroecological conditions, faces substantial challenges from blast disease, yet our understanding of the genetic structure of M. oryzae populations in this region remains limited. Here, we analyzed 885 M. oryzae strains from 18 nurseries across four rice ecological regions in Southern China using a panel of genome-wide SNP markers. Phylogenetic and principal component analyses revealed three distinct clonal lineages: lineage I (58.19%), lineage II (21.36%), and lineage III (20.45%). Lineage I exhibited a broader geographic distribution compared to the other two lineages. Host-adapted divergence was observed across rice subspecies, with lineage III predominantly associated with japonica growing-regions, while lineages I and II mainly colonized indica rice-growing regions. Genetic diversity exhibited significant spatial heterogeneity, with the nucleotide diversity (π) ranging from 0.17 in South China to 0.32 in the Middle–Lower Yangtze River region, reflecting differential cropping systems. The predominantly negative Tajima’s D values across populations suggested recent expansion or selective sweeps, likely driven by host resistance pressures. High genetic differentiation between lineage I and other lineages contrasted with low divergence between lineages II and III, indicating distinct evolutionary trajectories. Furthermore, an uneven distribution of mating types among three genetic lineages was observed, suggesting limited sexual recombination within clonal lineages. The information obtained in this study may be beneficial in devising suitable strategies to control rice blast disease in Southern China. Full article

Sclerotinia sclerotiorum is a globally distributed fungal pathogen responsible for significant agricultural losses across a wide range of crops. This study aimed to develop polymorphic simple sequence repeat (SSR) markers by whole-genome resequencing of three Korean isolates and a public reference genome. A total of 16,885 SSR motifs were identified, of which 368 overlapped with polymorphic insertion–deletion (InDel) sites across the four genomes. From these, 12 SSR markers were selected based on polymorphism information content and amplification quality. Validation across the 28 isolates in Korea revealed high levels of genotypic diversity, suggesting that each isolate is a unique haplotype, although S. sclerotiorum is homothallic and clonally propagated. This multi-genome approach provides robust resources for genotyping, molecular diagnostics, and epidemiological surveillance of S. sclerotiorum. Full article

The production of carrot (D. carota L.) doubled haploids (DH) for the acceleration of this important vegetable crop breeding requires genome doubling of haploid regenerants. If spontaneous doubling does not occur, artificial chromosome doubling can be complicated by the lack of efficient genome-doubling protocols. We tested an antimitotic agent treatment of carrot at the embryo stage. It allowed us to produce and treat a large number of clonal carrot embryos (at least 30 embryos per treatment condition) in small volumes with minimal reagent amounts. We showed that 0.01–1 g/L colchicine did not perturb carrot development. Trifluralin showed no signs of toxicity at 0.001 and 0.01 g/L concentrations, but 0.1 g/L trifluralin reduced survival by 40% and delayed plantlet regeneration. We showed via DNA content flow cytometry that 0.01–1 g/L colchicine and 0.001–0.1 g/L trifluralin could double the carrot genome. The highest diploid percent was observed at 1 g/L colchicine (34%) and 0.1 g/L trifluralin (28%). The highest percent of diploids together with mixoploids (partial diploids) was at 0.01 and 0.1 g/L trifluralin (over 70%), followed by 1 g/L colchicine (56%). To our knowledge, this is the first report on trifluralin application for genome doubling in Apiaceae. In our study, we determined colchicine and trifluralin toxicity and doubling efficiency at different concentrations that can be used for carrot DH-line production and further improvement of genome doubling methods. Full article

Oil palm (Elaeis guineensis Jacq.) is the leading global oil-producing crop due to its high oil yield. Increasing global demands for palm oil require efficient propagation. Conventional breeding is practical but slow, making micropropagation an attractive alternative for rapidly multiplying superior genotypes. However, transitioning from in vitro to ex vitro conditions causes physiological stress, restricting survival and productivity. This study assessed gas exchange and chlorophyll fluorescence dynamics during acclimatization from in vitro conditions to field establishment, comparing the seedlings obtained in vitro with conventional seed-derived palm seedlings to conventional seed-derived palms. A pronounced photosynthetic efficiency decline occurred after transfer from in vitro culture, followed by a gradual recovery. The photosynthetic rate (A) increased from 0.86 µmol m⁻² s⁻¹ early in acclimatization to 15.43 µmol m⁻² s⁻¹ in field-established seedlings. Physiological characterization using CO₂ and light response curves identified the reductions in carboxylation efficiency and overall quantum yield CO₂. These biochemical constraints gradually diminished during acclimatization, facilitating a transition from heterotrophic to autotrophic growth. Chlorophyll fluorescence analysis revealed remarkable photoinhibition during initial ex vitro stages, indicated by a decreased maximum quantum efficiency of photosystem II. However, the seedlings progressively restored photochemical function throughout subsequent acclimatization phases. These findings highlight the importance of carefully regulating environmental parameters—particularly irradiance, humidity, and carbon availability—during early seedling acclimatization. The effective management of growth conditions significantly mitigates physiological stress, ensuring robust photosynthetic activity and optimized stomatal regulation. The improved acclimatization practices, therefore, can substantially enhance seedling survival rates, physiological resilience, and the overall field performance of micropropagated oil palms. Future research should focus on refining acclimatization protocols, emphasizing targeted physiological interventions to maximize the efficiency, commercial viability, and sustainability of oil palm clonal propagation. Full article

Globally, people are cultivating finger millet, an important cereal, to improve food availability and health benefits for humans. However, the biotechnological research on this millet is limited and insufficient in this field. The primary focus of this study is to optimize an efficient regenerated protocol for initiating further plant transformation studies, using the shoot apex as an explant and various growth regulators. For example, three cytokinins (BAP, TDZ, and Kin) at different concentrations were used to induce multiple shoots of finger millet. Among these, TDZ (4.5 µM) provided the maximum number (17.3) of shoots as compared to BAP and Kin. IBA (2.46 µM), along with MS medium, was used for the induction of roots, where 5.6 roots were produced in an individual shoot and the length of the root was longer with a size of 8.2 cm after two weeks of incubation. The clonal fidelity of the in vitro regenerated plantlets of finger millet was confirmed by ISSR primers. Overall, the present work developed a robust and reliable procedure for the establishment of efficient and reproducible regeneration through the shoot apex that will be useful for the genetic improvement of this crop. The genetic enhancement of these millets as well as the successful creation of transgenic plant varieties modified for resistance to biotic and abiotic challenges in the near future would be aided by this study. Full article

In vitro shoot culture and cryopreservation (CP) are techniques essential for the ex situ preservation of genetic resources and the production of plant propagation material of clonally propagated horticultural crops. Changes in plant-associated microbiota diversity and composition induced by in vitro cultivation and CP treatment could have a negative effect on the growth and ex vitro adaptation of the in vitro propagated shoots. Therefore, the aim of the present study was to assess changes in endophytic bacteria diversity in domestic apple tissues induced by in vitro cultivation and CP treatment and to investigate the potential of the bacterial inoculum to improve the rooting and ex vitro acclimatisation of the propagated shoots. Metataxonomic analysis revealed a variation in the endophytic bacteria diversity and taxonomic composition between the field-grown tree dormant bud and the in vitro propagated or CP-treated shoot samples of apple cv. Gala. Whereas Sphingobacteriaceae, Sphingomonadaceae, Pseudomonadaceae, and Beijerinckiaceae families were the most prevalent families in the bud samples, Enterobacteriaceae, Bacillaceae, and Lactobacillaceae were dominant in the in vitro shoots. The bacterial inoculum effect on rooting and ex vitro acclimatisation was assessed using four isolates selected by screening the endophytic isolate collection. Bacillus sp. L3.4, B. toyonensis Nt18, or a combined inoculum resulted in a 21%, 36%, and 59% increase in cumulative root length and a 41%, 46%, and 35% increase in the biomass accumulation of ex vitro acclimatised plantlets, respectively. Root zone microbiota functional diversity analysis implied that growth stimulation was not related to improved nutrient uptake but could involve a pathogen-suppressing effect. The results demonstrate that the application of plant growth-promoting bacteria can potentially improve the performance of the in vitro propagated germplasm. Full article

This study aimed to investigate: (1) the bioactive profile of seeds, husks, and leaves of selected conilon coffee genotypes (n = 42) from three consecutive crops for the selection of plants to meet health interests, (2) the variability in the content of these bioactive compounds over the crops, and (3) possible correlations among the contents of the evaluated compounds in the different parts of the plant. Selected conilon plants were reproduced by clonal propagation. Bioactive compounds were analyzed using HPLC-DAD. Eight chlorogenic acids (CGA), caffeine, trigonelline, and minor phenolic compounds were quantified (dry basis) in all extracts. CGA contents in seeds, husks, and leaves ranged between 3.71 and 9.71 g/100 g, 0.43 and 1.65 g/100 g, and 0.80 and 2.22 g/100 g, respectively. Caffeine contents ranged between 1.21 and 2.63 g/100 g, 0.13 and 0.84 g/100 g, and 0.33 and 2.01 g/100 g in seeds, husks, and leaves, respectively. Trigonelline contents ranged between 0.83 and 1.12 g/100 g, 0.59 and 1.24 g/100 g, and 0.74 and 1.84 g/100 g, respectively. Variation among the three crops was observed to be higher for CGA. A discrete correlation between CGA and caffeine was observed in the seeds (r: 0.72, p = 0.003). Some of the genotypes showed consistently higher contents of these bioactive compounds than others (not only in the seeds but also in the husks and leaves), being good candidates for cultivar registration to meet various market demands in the food and pharmaceutical industries. Studies that evaluate the potential use of new genotypes and byproducts are important for diversification and maximum use of coffee plants, promoting sustainability and financial return to the farmers and the producing country. Full article

Mycorrhizal fungi contribute to crop growth, yields, and stress tolerance. In forests, common mycorrhizal networks are suggested to function as carbon storage and to transfer substances and signals between trees, thus likely contributing to their resilience. Such properties are crucial under increasing environmental stresses, particularly for clonal forestry. However, mycorrhizal communities in relation to tree field performances have been scarcely studied. In this study, mycorrhizal communities on the roots of clones of silver birch and hybrid aspen growing in distinct trials in deep automorphous mineral soils (podzolic and fluvic) under hemiboreal conditions were assessed using internal transcribed spacer sequencing, bioinformatics, and community analysis. The mycorrhizal communities were moderately rich/diverse and were mostly formed by generalist taxa (prevailingly ectomycorrhizal) common for the region. The differences in communities among the tree clones were estimated for silver birch, while for hybrid aspen, the productivity of clones was inversely related to the richness and diversity of the communities, suggesting a top-down effect of the host. Accordingly, some mycorrhizal taxa (e.g., Hyaloscypha sp.) showed clone-specific abundances indicating a preference for a specific host. These findings prompt further functional studies and highlight the need to consider genetic differences of forest regenerative material for maximizing mycorrhizal diversity, as well as for more effective inoculation. Full article

Modern agricultural research, including fruit tree rootstock evaluations, began in England. In the mid-1800s, field plots were established at the Rothamsted Research Station to evaluate cultivars and fertilizer treatments for annual crops. By the early 1900s, farmers questioned the value of field experimentation because the results were not always valid due to inadequate randomization and replication and poor data summarization. During the first half of the 20th century, Rothamsted statisticians transformed field plot experimentation. Field trials were tremendously improved by incorporating new experimental concepts, such as randomization rather than systematically arranging treatments, the factorial arrangement of treatments to simultaneously test multiple hypotheses, and consideration of experimental error. Following the classification of clonal apple rootstocks at the East Malling Research Station in the 1920s, the first rootstock trials were established to compare rootstocks and evaluate rootstock performance on different soil types and with different scion cultivars. Although most of the statistical methods were developed for annual crops and perennial crops are more variable and difficult to work with, rootstock researchers were early adopters of these concepts because the East Malling staff included both pomologists and statisticians. Many of the new statistical concepts were incorporated into on-farm demonstration plots to promote early farmer adoption of new practices. Recent enhancements in computing power have led to the rapid expansion of statistical theory, the development of new statistical methods, and new statistical programming environments, such as R. Over the past century, in many regions of the world, the adoption of new statistical methods has lagged their development. This review is intended to summarize the adoption of error-controlling experimental designs by rootstock researchers, to describe statistical methods used to summarize the resulting data, and to provide suggestions for designing and analyzing future trials. Full article

Various rapid propagation strategies have been discovered, which has facilitated large-scale plant reproduction and cultivar development. These methods, in many plant species, are used to rapidly generate large quantities (900 mini-tubers/m²) of high-quality propagule (free from contamination) at a relatively low cost in a small space. They are also used for plant preservation. This review article aims to provide potential applications for regeneration and clonal propagation. Plant propagation using advanced agrotechnology, such as aeroponics, is becoming increasingly popular among academics and industrialists. The advancement of asexual aeroponic propagation has been achieved through advancements in monitoring and control systems using IoT and smart sensor technology. New sensor technology systems have gained substantial interest in agriculture in recent years. It is used in agriculture to precisely arrange various operations and objectives while harnessing limited resources with minimal human intervention. Modern intelligent technologies and control systems simplify sensor data collection, making it more efficient than manual data collection, which can be slow and prone to errors. Specific ambient variables like temperature, humidity, light intensity, stock solution concentrations (nutrient water), EC (electrical conductivity), pH values, CO₂ content, and atomization parameters (frequency and interval) are collected more effectively through these systems. The use of intelligent technologies provides complete control over the system. When combined with IoT, it aids in boosting crop quality and yield while also lowering production costs and providing data directly to tablets and smartphones in aeroponic propagation systems. It can potentially increase the system’s productivity and usefulness compared to the older manual monitoring and operating methods. Full article

Moringa oleifera L. is a valuable multipurpose tree species widely planted for centuries due to its high medicinal value and antifungal, antiviral, antidepressant, and anti-inflammatory properties in the food industry. However, its cultivation is hindered by production constraints such as the unavailability of planting material and the inadequate number of high-yielding clones. Thus, a study was initiated to select high-yielding clones in terms of growth and chemical content for the mass propagation of superior moringa trees. Screening on high-yielding clones with high astragalin content was conducted through the high-performance liquid chromatography (HPLC) analysis of moringa leaf extract. Selected genotypes were evaluated for their anti-inflammatory potential through in vitro bioactivity assays of leaf methanol extract. The effects of the rooting hormone, rooting substrates, and size of the cutting on the rooting response of branch cuttings of moringa were investigated. Results found that samples collected from different ecological zones of Peninsular Malaysia show significant variation in terms of astragalin content. The extracts were observed to show considerable variation in biological activity against the pro-inflammatory enzymes. The size of the cuttings had significant effects on the rooting of the cuttings as longer cuttings with bigger diameters rooted better than shorter cuttings with smaller diameters. Several genotypes of M. oleifera with superior phenotypic characteristics and bioactive compounds have been identified. Factors affecting the rooting efficiency and optimal conditions of rooting are suggested, which provides valuable information for the propagation of the superior planting material of moringa. This effort will ensure the sustainable production and supply of good quality raw materials for the production of quality end-products for the food and pharmaceutical industry. Full article

Deciphering the genetic mechanisms underlying key agronomic and quality traits in potato (Solanum tuberosum L.) is essential for advancing varietal improvement. Phenotypic instability in early clonal generations and inbreeding depression, coupled with the complexity of tetrasomic inheritance, pose significant challenges in constructing mapping populations for the genetic dissection of complex traits. Genome-wide association studies (GWASs) offer an efficient method to establish trait–genome associations by analyzing genetic recombination and mutation events in natural populations. This review systematically examines the application of GWASs in identifying agronomic traits in potato, such as plant architecture, yield components, tuber shape, and resistance to early and late blight and nematodes, as well as quality traits including dry matter, starch, and glycoalkaloid content. Some key chromosomal hotspots identified through GWASs include chromosome 5 associated with tuber yield, starch content, and late blight resistance; chromosome 4 and 10 associations with tuber shape and starch content; chromosomes 1, 9, and 11 associated with plant height, tuber number, glycoalkaloid content, and pest resistance. It elucidates the advantages and limitations of GWASs for genetic loci identification in this autotetraploid crop, providing theoretical insights and a reference framework for the precise localization of key genetic loci and the discovery of underlying genes using GWASs. Full article

Dianthus cruentus Griseb. (Caryophyllaceae) is an herbaceous perennial native to Greece with a strong ornamental potential when used as a pollinator-friendly component of xeric gardens and green roofs, where it is valued for its tolerance of poor, dry soils, and its showy colorful inflorescences. Aiming to develop an efficient mass propagation protocol appropriate for the introduction of the species as a novel floricultural crop, the in vitro seed and clonal propagation of a Greek native xeric ecotype were investigated in this paper for the first time. A total of 90–100% of the seeds, after being stored in the dark at room temperature for 12 months, germinated when incubated at 10 to 25 °C after their surface sterilization and transfer in vitro. Sixty-day-old seedlings grown in vitro were then used as a source of nodal explants for the initial establishment of micropropagation cultures, more efficiently on MS medium with 0.1 mg L⁻¹ 6-benzylaminopurine (BA). In the multiplication stage, either normal or hyperhydric micro-shoots were used as explant sources, assessing the possibility of incorporating usually discarded material in the propagation procedure. Different solid media were tested, with the highest multiplication indices (5.1) recorded in an MS medium containing 0.1 mg L⁻¹ BA and 0.05 mg L⁻¹ NAA, regardless of explants’ hyperhydricity, while an MS medium containing 0.1 mg L⁻¹ BA and 12 g L⁻¹ agar proved optimal for the effective reversal of hyperhydric explants (MI: 5.2). Despite higher hyperhydricity and reaction rates being observed when hyperhydric explants were used, modifications in the multiplication medium proved to be highly effective in controlling hyperhydricity, with the highest number of normal shoots (2.4–2.6) produced in BA-containing media. Micro-shoots rooted readily in ½ MS medium (60–100%), with rooting rates and quality positively affected by the presence of 0.5 mg L⁻¹ IBA in the rooting medium and the absence of cytokinins in the multiplication one. Rooted micro-shoots were successfully acclimatized ex vitro at high rates (65–100%), their origin influencing their acclimatization and morphology. Thus, the concurrent use of normal and hyperhydric shoots in the proposed micropropagation protocol is proven to be both feasible and desirable, as it is able to significantly increase efficiency and facilitate the sustainable exploitation and dissemination of D. cruentus as a promising multivalent horticultural crop. Full article

Grafting, the careful selection of rootstocks and scions, has played a crucial role maintaining Chilean avocado fruit quality standards in a scenario in which climate change and drought-related issues have considerably decreased avocado fruit production in the last fifteen years. The historical use of seedling rootstocks in Chile has experienced a recent shift towards clonal rootstocks, driven by the potential to produce more consistent and predictable crops. This research aims to compare Hass avocado plants grafted on Mexicola seedling and Dusa^® clonal rootstocks in a soilless and protected system using (i) a differential expression analysis of root and leaf samples and (ii) a fruit transcriptomic and metabolomic integration analysis to improve our understanding of rootstock–scion interaction and its impact on avocado tree performance and fruit quality. The results demonstrated that no significant transcriptomic and metabolomic differences were identified at fruit level in the ready-to-eat (RTE) stage for Hass avocado fruit from both rootstocks. However, Hass avocados grafted on the clonal rootstock showed greater aerial growth and slightly increased fruit size than the seedling rootstock due to the enrichment of cell wall-remodeling genes as revealed in leaves and fruit at harvest stage. Full article

Late blight is a destructive disease of solanaceous crops such as tomato (Solanum lycopersicum L.), caused by the Oomycete Phytophthora infestans (Mont.) de Bary. Late blight is generally controlled by fungicide applications, which quickly become ineffective due to the appearance of new P. infestans genotypes that can overcome the resistance of improved tomato cultivars and cause total production losses. The aim of this study is to assess the resistance level of tomato cultivars under controlled conditions and inoculations were carried out on detached leaflets (cvs. Trakia, Saint Pierre and Marmande) using inoculums of the major P. infestans clonal lineages found in Algeria such as EU_13_A2 (n = 1), EU_23_A1 (n = 2) and EU_2_A1 (n = 1) (three replicates of each isolate). This investigation showed that the choice of resistant cultivars can help control late blight and provide economic and environmental advantages by reducing the use of inputs. Full article