Germplasm Accessions Research Articles

Utilization of 16Sr RNA and secA genes for molecular discernment of 'Candidatus Phytoplasma australasiaticum' strain associated with linseed germplasm in India.

The growing prevalence of phytoplasma associated symptoms on linseed or flax (Linum usitatissimum L.) germplasm at Indian Council of Agricultural Research- National Bureau of Plant Genetic Resources (ICAR-NBPGR) fields was noticed during the 2019-22 growing seasons. The characteristic phytoplasma symptoms of phyllody, stem fasciation, stunting, along with floral and capsule malformations were observed in 41 linseed accessions grown at experimental fields of ICAR-NBPGR, Delhi. During 3years, the presence of phytoplasma in symptomatic linseed accessions was confirmed by nested-PCR assays utilizing 16S rRNA and secA gene-specific primers. The 16S rRNA and secA gene sequences of linseed phytoplasma strains from the representative symptomatic 41 linseed accessions exhibited 100% sequence identity among themselves and 99.93% and 99.82% sequence homology with reference strain, 'Candidatus Phytoplasma australasiaticum' (GenBank Accession: Y10097). Phylogenetic analysis of 16S rRNA and secA gene sequences clustered the linseed isolates with the peanut witches' broom group belonging to 'Ca. P. australasiaticum' strains. The virtual RFLP analysis of 16S rRNA F2nR2 fragment (~1.2kb) of linseed phytoplasma strains further classified it into 16Sr group II, subgroup D. Our results suggested confirmation of the association of 'Ca. P. australasiaticum' strain (16SrII-D) in the linseed germplasm accessions from North India, which is the first report from India. The phytoplasma infection also reduced the growth and yield parameters of two linseed accessions (IC0498748 and EC0718851).

Variability in predicted deleterious mutations among barley accessions conserved ex situ

AbstractUnderstanding the genetic cost for long‐term conservation of more than 7 million plant germplasm accessions in 1750 genebanks worldwide requires knowledge about the extent and variation of deleterious mutations within and among conserved germplasm collections. Our recent study revealed a wide range of mutations predicted to be deleterious to gene function and averaged sample‐wise mutation burden per deleterious locus across barley, wheat, oat, soybean, maize, rapa, and sunflower germplasm collections. Here we report the extent and variation of predicted deleterious mutations among nine accessions of a barley (Hordeum vulgare L.) collection from an RNA‐Seq analysis of 16 individual samples of each accession. The assayed accessions were found to vary significantly in the number and proportion of single nucleotide polymorphisms (SNPs) predicted to be deleterious mutations (ranging from 242 to 314 with a mean of 270 and from 0.00073 to 0.00099 with a mean of 0.00086, respectively). Similarly, a significant variation was also observed in the averaged sample‐wise mutation burden estimates per deleterious locus, ranging from 0.541 to 0.747 with a mean of 0.681. Cultivar accessions had higher averages in the proportions of the predicted deleterious SNPs and in the averaged sample‐wise mutation burden estimates than landrace accessions (0.00090 vs. 0.00082 and 0.695 vs. 0.663, respectively). The estimates of deleterious base‐substitution mutations (×10−8) for the nine accessions varied from 0.313 to 0.406 with a mean of 0.349. These within‐collection findings are useful for understanding the genetic cost in conserved germplasm and have implications for long‐term germplasm management and conservation.

Molecular insights into the oleic acid accumulation in safflower

AbstractMost of the Indian safflower (Carthamus tinctorius L.) varieties produce oil rich in linoleic acid (LA, ~75%) and low in oleic acid (OA, ~15%). In the fatty acid biosynthetic pathway, the fatty acid desaturase 2 (FAD2) enzyme converts OA to LA. Safflower is reported to have 12–20 FAD2 genes. Gene expression analysis of four FAD2 genes during seed development in a high LA variety, PBNS‐12, revealed high expression of FAD2‐1 at 21 days after flowering (DAF), correlating with high LA accumulation. Fatty acid profiling of 448 Indian safflower germplasm accessions revealed four lines to have high (58%–77%) OA content, with NASF‐39 having the highest OA content. Interestingly, all four high OA lines showed the same mutation in the FAD2‐1 gene. The DNA sequence of FAD2‐1 from the four high OA lines showed a deletion of C at the +606 position, resulting in a premature stop codon at the +733 position and a truncated protein of 244 amino acids. Hence, despite the high expression levels of FAD2‐1 in NASF‐39 at 18–21 DAF, it exhibited high OA (77%). The dysfunctional nature of the truncated FAD2‐1 in NASF‐39 was evident in molecular docking studies with 1‐stearoyl‐2‐oleoyl phosphatidylcholine. We also sequenced FATB, a thioesterase responsible for releasing stearic acid from acyl carrier protein for further desaturation to oleic acid, where an A773G substitution was observed. This resulted in E258G substitution in NASF‐39 FATB compared to that of PBNS‐12. This probably made the acyl‐binding pocket of NASF‐39 FATB unstable, contributing to high OA accumulation. Thus, the outcomes of this study can help develop super and ultra‐high oleic safflower varieties through various genetics and genomics approaches.

Identifying Genetic Loci Determining Grain Yield Under Drought Stress in Rice (Oryza sativa L.)

ABSTRACTIdentifying the genomic regions (quantitative trait loci (QTL)) significantly linked to grain yield under drought stress could expedite the development of novel rice cultivars suited for rainfed areas through marker‐assisted breeding. This study identified QTL regions linked to plant phenology and production traits by evaluating 122 recombinant inbred lines (RILs) of Danteshwari × Daggaddeshi under different environmental conditions. A consistent QTL region associated with grain yield under water stress (60.4 Mbp) was mapped on chromosome 1 between RM428 and RM24 with an LOD score of 4.0. Another QTL region (9.4 Mbp) linked to plant height under all environmental conditions was mapped on chromosome 1 between RM1‐HvSSR1‐87 with a LOD score of 7.5 and phenotypic variance of 25%. A core set of 402 diverse rice accessions was also evaluated under water stress conditions and subjected to genome‐wide association analysis. Twelve markers linked to grain yield under drought were identified, out of which five were significantly associated with grain yield and days to flowering under drought. The markers linked to grain yield were compared between the bi‐parental population and germplasm accessions to identify the common markers. Three markers (RM1, RM259 and RM201) were found to be consistently linked to drought stress across the seasons in both bi‐parental population and germplasm accessions studied and could be potential candidates for application in marker‐assisted selection for improving grain yield under drought stress in rice.

Genetic Variability and Diversity Analysis in Yard Long Bean [Vigna unguiculata (L.) walp subsp. sesquipedalis (L.) verdcourt] Accessions under Coastal Saline Ecosystem

Background: Yard long bean despite being highly nutritive summer legume vegetable crop, it is not cultivated on large scale due to seasonal constraints with progressing research activities, Tamil Nadu is yet to came up with a suitable commercial variety of yard long bean with higher yield and superior pod quality. Considering this, the present study with 30 yard long bean germplasm accessions was undertaken to estimate the genetic parameters and deciphering the extent of genetic divergence for nine quantitative traits in yard long bean. Methods: The genetic material comprising 30 different sources of germplasm accessions were evaluated for various quantitative traits in randomized block design (RBD) with triplicate replication at the Garden land, Department of Horticulture, Faculty of Agriculture, Annamalai University during 2022. TNAUSTAT and R Software has been used for data analysis. Result: Analysis of variance exhibited significant differences among the accessions for all the nine quantitative traits indicating the presence of genetic variability. The magnitude of high phenotypic and genotypic coefficient of variation was obtained for all the traits except days to maturity and days to fifty per cent flowering. High heritability coupled with genetic advance per cent as mean was observed for pod yield per plant followed by number of pods per plant, test weight, pod girth, number of seeds per pod, plant height and pod length indicating the predominance of additive gene action. Direct selection for above indicate traits could be valuable for yield improvement programme. Further, genetic divergence analysis revealed that seven clusters could be identified from 30 genotypes. The cluster I was largest having twelve genotypes. The maximum inter cluster distance was found between cluster I and cluster VII followed by cluster I and IV and the intra cluster distance was noted in cluster III followed by cluster I. Among the yield contributing traits, maximum contribution towards genetic divergence existed for pod length followed by test weight, days to maturity and pod yield per plant. Hence, hybridization between cluster VII (IC-630381), V (IC-630379), IV (IC-630383) and I (IC-626143) could be utilized for superior recombinants with desirable traits in segregating generations of yard long bean.

Genetic Variability Studies for Morpho-Physiological and Yield-attributing Traits in Foxtail Millet (Setaria italica L. Beauv.)

Foxtail millet is an underutilized crop which has high nutritional values and wide genetic resources, possessing the ability to tolerate several abiotic stresses efficiently. Those resources must be used in order to improve desired traits, primarily yield attributes. This investigation was carried out to assess the genetic parameters, such as variability, per se performance, heritability and genetic advance as percent of mean (GAM) for sixteen morpho-physiological, yield-attributing traits in fifty foxtail millet germplasm accessions at the Regional Agricultural Research Station, Nandyal during Rabi, 2023-2024. The study revealed the wide range of variation for all studied traits and that the accessions SiA 3290, SiA 4345, and SiA 4391 had potential for most traits and a high grain yield per plant. Thus, after multilocation testing, these accessions might be exploited for commercial cultivation. The assessment revealed that the phenotypic coefficient of variation (PCV) was slightly greater than the corresponding genotypic coefficient of variation (GCV), indicating the influence of the environment on the manifestation of these traits. It was also observed that the traits viz.., photosynthetic rate, transpiration rate, stomatal conductance, abortive grain rate, and grain yield per plant had high PCV and GCV and these traits significantly contributed to the overall variability and scope for selection. High heritability in combination with high GAM was observed for photosynthetic rate, transpiration rate, stomatal conductance, 1000-grain weight, fodder yield per plant and grain yield per plant. This indicates that, these traits are mostly governed by additive genes and thus making them suitable for simple direct selection to improve these traits and further breeding efforts focused on increasing yields.

Genetic variability, association and diversity analysis of yield and its component traits in rice (Oryza sativa) germplasm

An experiment was conducted during winter (rabi) season of 2022 at ICAR-Indian Institute of Rice Research, Hyderabad, Telangana to evaluate extent of genetic variability, heritability, diversity and the relationship between yield and its component traits in a collection of 60 rice germplasm accessions. Results showed that germplasm accessions exhibited ample genetic variability and diversity for yield traits. Based on per se performance, inter crosses between the genotypes IC458483 with high grain yield, IC210775 with more panicle length, IC75919 with high 100-grain weight, IC75980 with more productive tillers and IC75965 with high protein content could produce positive transgressive segregants for improving respective traits. Plant height, total and effective tillers, grain yield and 100-grain weight traits which exhibited the highest heritability and genetic advance could be vital for selection in hybridization programmes. Crossing among genotypes of diverse clusters specifically VI, VII and VIII is suggested as this could create a broad variation useful for selecting genotypes with both high yield and long panicles.

Assessing the genetic diversity of taro germplasm collection in Vietnam using simple sequence repeat markers

ABSTRACT This study evaluated the genetic diversity of 253 taro (Colocasia esculenta (L.) Schott) germplasm accessions collected in Vietnam at the molecular level using 20 Simple Sequence Repeat (SSR) markers. High genetic diversity in the taro germplasm accessions were detected with 100% polymorphic SSR loci, and 89 alleles were obtained at the 20 SSR loci with an average of 4.45 alleles per locus, of which 14 markers had high polymorphism (3 alleles/locus). Polymorphic Information Content (PIC) values obtained at 20 SSR loci ranged from 0.31 (Ce0078) to 0.85 (HK34), with an average of 0.65. The genetic similarity coefficient within the accessions ranged from 0.39 to 1.00. All 253 accessions were classified into 2 groups at a genetic similarity level of 0.60; one of the groups (group 2) was divided into 8 sub-groups at a genetic similarity level of 0.64. Some accessions (such as 28279 and SP-19-009; SP-19-061 and SP-19-023; 28278 and SP-19-006) with a high genetic similarity coefficient (1.00) showed a very close genetic relationship, while others (such as 10063 and 11544) with a low genetic similarity coefficient (0.39) showed a fairly distant genetic relationship. The study’s results provide a foundation for preserving and breeding taro in Vietnam. Five taro accessions (28211, SP-19-017, T.3578, T.3515, and 10098) carrying specific alleles that could be identified by 6 SSR markers (uq55–112, uq73–164, HK35, Ce0078, HK22, and HK31) were detected. Furthermore, the SSR marker approach showed the potential application in identifying genetic relationships and distinguishing different taro cultivars.

Genome-wide association study of stem structural characteristics that extracted by a high-throughput phenotypic analysis "LabelmeP rice" in rice.

Stem is important for assimilating transport and plant strength; however, less is known about the genetic basis of its structural characteristics. In this study, a high-throughput method, "LabelmeP rice" was developed to generate 14 traits related to stem regions and vascular bundles, which allows the establishment of a stem cross-section phenotype dataset containing anatomical information of 1738 images from hand-cut transections of stems collected from 387 rice germplasm accessions grown over two successive seasons. Then, the phenotypic diversity of the rice accessions was evaluated. Genome-wide association studies identified 94, 83, and 66 significant single nucleotide polymorphisms (SNPs) for the assayed traits in 2 years and their best linear unbiased estimates, respectively. These SNPs can be integrated into 29 quantitative trait loci (QTL), and 11 of them were common in 2 years, while correlated traits shared 19. In addition, 173 candidate genes were identified, and six located at significant SNPs were repeatedly detected and annotated with a potential function in stem development. By using three introgression lines (chromosome segment substitution lines), four of the 29 QTLs were validated. LOC_Os01g70200, located on the QTL uq1.4, is detected for the area of small vascular bundles (SVB) and the rate of large vascular bundles number to SVB number. Besides, the CRISPR/Cas9 editing approach has elucidated the function of the candidate gene LOC_Os06g46340 in stem development. In conclusion, the results present a time- and cost-effective method that provides convenience for extracting rice stem anatomical traits and the candidate genes/QTL, which would help improve rice.

Freezing Points of Fruit from Different Kiwifruit Genotypes at Harvest and during Cold Storage

Fruit storage is optimized at the lowest safe temperature to maximize storage life whilst avoiding chilling or freezing injury. The few published studies of freezing in kiwifruit (Actinidia spp.) have been conducted with A. chinensis var. deliciosa ‘Hayward’ fruit, with freezing temperatures reported in the range of −1.5 °C to −2.5 °C. In China, a large number of kiwifruit cultivars have been commercialized recently, with at least ten being commonly planted. In this research, freshly harvested fruits from 45 kiwifruit germplasm accessions were measured for freezing point, soluble solids content (SSC) and water content (WC). The difference in freezing point of different tissue zones within a fruit and after different periods of cold storage were determined for the fruit of three representative main cultivars: the green-fleshed ‘Hayward’, the red-fleshed A. chinensis var. chinensis ‘Donghong’, and the yellow-fleshed interspecific hybrid A. eriantha × A. chinensis ‘Jinyan’. The the freezing point of kiwifruit was found to be highly correlated with the SSC. This relationship was found irrespective of whether the measurement was made at harvest, at different places in the fruit, or after ripening during storage. These findings agree with previous reports for kiwifruit and other fruits, although it appears that the relationship may differ among kiwifruit cultivars, something not previously reported and which requires further confirmation.

Identification of cowpea [Vigna unguiculata (L.) Walp.] germplasm accessions resistant to yellow mosaic disease

Yellow mosaic disease (YMD) of cowpea, predominantly caused by mungbean yellow mosaic India virus (MYMIV) and mungbean yellow mosaic virus (MYMV) is a major constraint to the production of cowpea (Vigna unguiculata L.) in India resulting in significant yield reductions. The present study extensively evaluated 1127 cowpea germplasm accessions from the National Gene Bank of India, New Delhi, at two hotspot locations (Hyderabad and Delhi) for their response to YMD. About 181 accessions showed no symptoms in field screening at both locations and were considered putatively resistant. A set of the best 100 out of 181 was selected for further confirmation of resistance to MYMIV through whitefly-mediated screening along with 40 accessions known to be susceptible to YMD. The results of whitefly-mediated transmission confirmed MYMIV resistance in 20 accessions with a disease score of zero. Further, the YMD-associated Begomovirus was characterized using rolling circle amplification coupled with sequencing of the full DNA-A genome of MYMIV, which shared an identity of 99.02% with the MYMIV isolate infecting cowpea in Pakistan. The 20 cowpea accessions identified as novel resistant sources to MYMIV in the present study could be used for mapping resistance genes and as donors in resistance breeding for yellow mosaic disease

Genome Size Variation in Sesamum indicum L. Germplasm from Niger.

Sesamum indicum L. (Pedaliaceae) is one of the most economically important oil crops in the world, thanks to the high oil content of its seeds and its nutritional value. It is cultivated all over the world, mainly in Asia and Africa. Well adapted to arid environments, sesame offers a good opportunity as an alternative subsistence crop for farmers in Africa, particularly Niger, to cope with climate change. For the first time, the variation in genome size among 75 accessions of the Nigerien germplasm was studied. The sample was collected throughout Niger, revealing various morphological, biochemical and phenological traits. For comparison, an additional accession from Thailand was evaluated as an available Asian representative. In the Niger sample, the 2C DNA value ranged from 0.77 to 1 pg (753 to 978 Mbp), with an average of 0.85 ± 0.037 pg (831 Mbp). Statistical analysis showed a significant difference in 2C DNA values among 58 pairs of Niger accessions (p-value < 0.05). This significant variation indicates the likely genetic diversity of sesame germplasm, offering valuable insights into its possible potential for climate-resilient agriculture. Our results therefore raise a fundamental question: is intraspecific variability in the genome size of Nigerien sesame correlated with specific morphological and physiological traits?

Patterns of the Predicted Mutation Burden in 19,778 Domesticated Barley Accessions Conserved Ex Situ.

Long-term conservation of more than 7 million plant germplasm accessions in 1750 genebanks worldwide is a challenging mission. The extent of deleterious mutations present in conserved germplasm and the genetic risk associated with accumulative mutations are largely unknown. This study took advantage of published barley genomic data to predict sample-wise mutation burdens for 19,778 domesticated barley (Hordeum vulgare L.) accessions conserved ex situ. It was found that the conserved germplasm harbored 407 deleterious mutations and 337 (or 82%) identified deleterious alleles were present in 20 (or 0.1%) or fewer barley accessions. Analysis of the predicted mutation burdens revealed significant differences in mutation burden for several groups of barley germplasm (landrace > cultivar (or higher burden estimate in landrace than in cultivar); winter barley > spring barley; six-rowed barley > two-rowed barley; and 1000-accession core collection > non-core germplasm). Significant differences in burden estimate were also found among seven major geographical regions. The sample-wise predicted mutation burdens were positively correlated with the estimates of sample average pairwise genetic difference. These findings are significant for barley germplasm management and utilization and for a better understanding of the genetic risk in conserved plant germplasm.

Morphological and Agronomical Characterization in Bread Wheat (Triticum aestivum L.) Germplasm and Combined Study of Heritability, Genetic Variance, Genetic Advances and Association of Characters

The present experiment was carried out during Rabi 2021-2022 at Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture &amp; Technology, Meerut-250110 (U.P.). The material used in the present study comprised 103 germplasm accessions of Wheat (Triticum aestivum L.) having variability for various agronomic and morphological characters were obtained from the available germplasm in the Department of Genetics &amp; Plant Breeding, SVPUA&amp;T, Meerut. The number of genotypes are 103 including four check (DBW-71, DBW-222, DBW-173, HD-3226), the Plot size is10 row 2.5m length spaced at 0.25m and the date of sowing is 20 December, 2021 on Augmented experimental design. Twelve observations were recorded. In each plot, five plants from each genotype were arbitrarily selected and tagged to record the observations studied characteristics except days to 50 % flowering and days to maturity they were recorded on plot basis. The highest value of biological yield per plant was estimated in CSW-18 (45.16g), DBW-621 (51.45%) recorded a high value of harvest index and the maximum grain yield is from CSW-18 (15.94) g. High heritability coupled with high genetic advance observed for gluten content, grain yield per plant, biological yield per plant, harvest index and number of productive tillers per plant.

Germplasm Screening for Identification of BCMV Resistance Sources from Diverse Cowpea [Vigna unguiculata (L.) Walp.] Germplasm using Serological and Molecular Diagnostics

Background: Bean common mosaic disease (BCMD) caused by Bean common mosaic virus (BCMV) has been regarded as one of the most important seed-borne and aphid vector transmitted destructive disease of cowpea not only affecting its yield but also reducing its grain quality globally. Since the dawn of crop improvement, germplasm served as the source of resistance for various biotic stresses. Currently, host plant resistance is the best, reliable, economic and environmental friendly practice of virus disease management. The objective of this study was to assess the response of diverse cowpea germplasm against BCMV under natural and controlled conditions followed by serological and molecular detection. Methods: In this study, 85 cowpea germplasm accessions and one known BCMV susceptible (C152) and one resistant (CP55) varieties are evaluated for their response to the BCMD in augmented block design (ABD). The reaction of cowpea accessions were assessed using percent disease incidence (PDI). Transmission Electron microscopy (TEM), Direct Antigen Coating-Enzyme-linked Immunosorbent Assay (DAC-ELISA) and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) were used for confirming the BCMV. Result: Natural and controlled condition screening data analysis revealed a significant difference among diverse cowpea germplasm for BCMV diseases incidence. Based on field screening at Ranchi and New Delhi (2019 and 2020) and artificial confirmation. 24 out of 85 accessions were found to be immune and confirmed through DAC-ELISA and RT-PCR. As a consequence these accessions could be a potential new source of disease resistance for BCMV in breeding programs.Further, DAC ELISA of seed coat and Embryo revealed the presence of virus in 5% and 15% of samples tested. Accession IC418505 recorded highest disease incidence (40.0%).

Expression analysis and characterization of resistance (R) genes in contrasting Fusarium wilt resistant chickpea genotypes

Fusarium wilt is one of the most notorious diseases of crop plants. This disease leads to huge crop losses in chickpea with substantial monetary value worldwide. The objective of the current study was to characterise Fusarium oxysporum f. sp. cicris (Foc), the causal agent of chickpea wilt, on morphological basis followed by the assessment of resistance of thirty chickpea germplasm accessions to Foc in a pot experiment. The second objective of this research was to study gene expression and characterisation of specific resistance (R) genes in different Fusarium wilt-resistant chickpea genotypes. The morphological identification and characterization of Foc was done by culturing the fungus potato dextrose agar (PDA) medium. Fusarium wild resistance was assessed by challenging 30 chickpea genotypes to artificial inoculum of Foc by using a pre-defined disease rating scale. Different resistance levels were showed by different chickpea genotypes ranging from highly resistant to highly susceptible. Two accessions demonstrated resistance, 15 were moderately resistant and the rest of the genotypes were moderately susceptible to susceptible. The in-silico expression analysis of R genes showed that two R genes, LOC101499430 and LOC101499568 were upregulated in chickpea roots, indicating their probable role in Fusarium wilt resistance. The genes were further assessed for their expression in response to Fusarium inoculation in contrasting Fusarium wilt resistant and susceptible chickpea genotypes. The resistant genotypes showed significantly higher expression levels of the selected R genes in comparison with susceptible genotypes. This study provides valuable insights into evaluating chickpea germplasm for Fusarium wilt resistance and identification of candidate resistance genes which could be employed for enhancement of Fusarium wilt resistance in chickpea.

The plant germplasm and herbarium (WIR) collections maintained at VIR as contributors to grape genetic diversity conservation, expansion and utilization

Improving the standards of collecting and maintaining valuable genetic resources accessions and information about them is currently of crucial importance for the successful development of the world viticulture in the light of the challenges caused by the spread of grape diseases and climate change. This review briefly characterizes the global grapevine gene pool, approaches to its conservation, including base and duplicate conservation techniques, and the current status and prospects of the progress in in vitro and cryogenic preservation methods. The genetic potential of grape wild relatives is assessed focusing on particular species as sources of resistance genes to biotic and abiotic stressors. Achievements in the application of gene editing technologies to increase grape resistance to diseases are discussed. It is noted that a common practice at this stage is to knock out the genes responsible for grapevine susceptibility to diseases, whereas a more advantageous approach in the future will be to make targeted changes in the grape genome based on the knowledge of resistance genes in its wild relatives. Therefore, grape wild relatives need to be studied thoroughly using modern methods of forward and reverse genetics. Regarding the issues of grape genetic diversity conservation and expansion at the current technological stage, the status and significance of the plant germplasm and herbarium (WIR) collections held by VIR are scrutinized in detail. Authentication of grape germplasm accessions is marked as important, along with the role of the WIR herbarium, a unique collection incorporating physical carriers of reference genetic information on the national grapevine gene pool. Promising trends in the development of the WIR herbarium are outlined in connection with the establishment and preservation of nomenclature standards for domestic grape cultivars.

Effectiveness of ISSR markers for detecting genomic variability in &lt;I&gt;Panicum miliaceum&lt;/I&gt; L. accessions

Background. Millet is one of the main cereal crops with a wide area of cultivation. Over the past decade, there has been a significant increase in the consumption of millet and its processed products. As a result, the breeding of cultivars with high consumer properties is becoming relevant, requiring knowledge of the genetic diversity of germplasm accessions to identify donors of valuable agronomic traits and select parental forms using ISSR markers.Materials and methods. The analysis with 8 ISSR primers included 21 accessions of Panicum miliaceum L. of various origin from the VIR collection. The DNA of each accession was isolated by the CTAB method, and ISSR analysis was performed in a ­BioRad T100 Thermal Cycler. Statistical processing was made in the DARwin program (version 6.0.21).Results and conclusion. Eight primers were used to amplify 116 fragments, 62 (53.4%) of which turned out to be polymorphic. To assess the effectiveness of the analyzed primers and identify the polymorphism of millet, basic indicators of their informativeness were calculated and assessed by quantifying four marker parameters. Average PIC (0.27–0.36), EMR (1.38–14.5) and MI (0.12–4.87) values were obtained for most ISSR primers. Four ISSR primers had high Rp values (3.52–6.76) and were the most informative for genotyping. The selected ISSR markers were used to assess the genetic variability of the accessions and identify them. The values of genetic distances (GD) were 0.05–0.21. It was shown that four ISSR markers with the best informativeness values provided sufficient polymorphism to assess the genetic diversity of the analyzed P. miliaceum genotypes and could be recommended for identification of the variability in the genome of millet accessions.

Registration of the “Woodies” multi–rust‐resistant barley germplasm

AbstractSelection for resistance to plant diseases is a continuous effort on the part of plant breeders. Sources of genetic resistance are often limited, despite considerable discovery efforts. Stem rust and stripe rust are two diseases of particular importance in barley (Hordeum vulgare L.) production. The present work aims to develop and deploy genotypes with resistance to these diseases that can be used in future breeding efforts. The Woodies, Woody‐1 (DH160733; Reg. no. GP‐218, PI 704479) and Woody‐2 (DH160754; Reg. no. GP‐219, PI 704480), are two doubled‐haploid genotypes produced via F1 anther culture named in honor of the late Lynn “Woody” Gallagher. These two‐row spring habit barley germplasm accessions were released by the Oregon Agricultural Experiment Station in 2023. These genotypes have demonstrated resistance to both stem and stripe rust at the seedling and adult plant stage in trials conducted between 2018 and 2023. The genetic basis of this resistance appears to be a novel quantitative trait locus conferring resistance to both diseases on chromosome 5H that is different from the known rpg4/Rpg5 complex for stem rust resistance found on the same chromosome. Seed can be requested from the Oregon State University Barley Breeding Program or from the NLGRP Germplasm repository.

Ability of Genomic Prediction to Bi-Parent-Derived Breeding Population Using Public Data for Soybean Oil and Protein Content.

Genomic selection (GS) is a marker-based selection method used to improve the genetic gain of quantitative traits in plant breeding. A large number of breeding datasets are available in the soybean database, and the application of these public datasets in GS will improve breeding efficiency and reduce time and cost. However, the most important problem to be solved is how to improve the ability of across-population prediction. The objectives of this study were to perform genomic prediction (GP) and estimate the prediction ability (PA) for seed oil and protein contents in soybean using available public datasets to predict breeding populations in current, ongoing breeding programs. In this study, six public datasets of USDA GRIN soybean germplasm accessions with available phenotypic data of seed oil and protein contents from different experimental populations and their genotypic data of single-nucleotide polymorphisms (SNPs) were used to perform GP and to predict a bi-parent-derived breeding population in our experiment. The average PA was 0.55 and 0.50 for seed oil and protein contents within the bi-parents population according to the within-population prediction; and 0.45 for oil and 0.39 for protein content when the six USDA populations were combined and employed as training sets to predict the bi-parent-derived population. The results showed that four USDA-cultivated populations can be used as a training set individually or combined to predict oil and protein contents in GS when using 800 or more USDA germplasm accessions as a training set. The smaller the genetic distance between training population and testing population, the higher the PA. The PA increased as the population size increased. In across-population prediction, no significant difference was observed in PA for oil and protein content among different models. The PA increased as the SNP number increased until a marker set consisted of 10,000 SNPs. This study provides reasonable suggestions and methods for breeders to utilize public datasets for GS. It will aid breeders in developing GS-assisted breeding strategies to develop elite soybean cultivars with high oil and protein contents.