Vetch (Vicia sativa L.) is one of the most important annual forage legumes in the World due to its multiple uses (i.e., hay, grain, silage and green manure) and high nutritional value. However, detrimental cyanoalanine toxins in its plant parts including seeds and its vulnerability to hard winter conditions are currently reducing the agronomic values of vetch varieties. Moreover, the existence in the public domain of very few genomic resources, especially molecular markers, has further hampered breeding efforts. Polymorphic simple sequence repeat markers from transcript sequences (cDNA; simple sequence repeat [SSR]) were developed for Vicia sativa subsp. sativa. We found 3,811 SSR loci from 31,504 individual sequence reads, and 300 primer pairs were designed and synthesized. In total, 65 primer pairs were found to be consistently scorable when 32 accessions were tested. The numbers of alleles ranged from 2 to 19, frequency of major alleles per locus were 0.27-0.87, the genotype number was 2-19, the overall polymorphism information content (PIC) values were 0.20-0.86, and the observed and expected heterozygosity values were 0.00-0.41 and 0.264-0.852, respectively. These markers provide a useful tool for assessing genetic diversity, population structure, and positional cloning, facilitating vetch breeding programs.

A genetic evaluation of safflower germplasm collections derived from different geographical regions and countries will provide useful information for sustainable conservation and the utilization of genetic diversity. However, the molecular marker information is limited for evaluation of genetic diversity of safflower germplasm. In this study, we acquired 509 putative genomic SSR markers for sufficient genome coverage using next-generation sequencing methods and characterized thirty polymorphic SSRs in safflower collection composed of 100 diverse accessions. The average allele number and expected heterozygosity were 2.8 and 0.386, respectively. Analysis of population structure and phylogeny based on thirty SSR profiles revealed genetic admixture between geographical regions contrary to genetic clustering. However, the accessions from Korea were genetically conserved in distinctive groups in contrast to other safflower gene pool. In conclusion, these new genomic SSRs will facilitate valuable studies to clarify genetic relationships as well as conduct population structure analyses, genetic map construction and association analysis for safflower.

The numbers of SSR markers and their utilization have not been determined and investigated as extensively in Fagopyrum species as compared to other crop species. The current report presents 136 new SSR markers in Fagopyrum esculentum ssp. esculentum and their application to related species in the genus Fagopyrum. Of the 136 SSRs, 10 polymorphic SSR markers were utilized in a genetic diversity analysis of a common buckwheat population consisting of 41 accessions of diverse origin. The study showed observed (H(O)) and expected (H(E)) heterozygosities ranging from 0.071 to 0.924 (mean = 0.53) and from 0.073 to 0.902 (mean = 0.412), respectively. Forty-one of the 136 SSRs amplified sequences in other Fagopyrum species, including the cymosum and urophyllum groups. The phylogenetic relationships revealed using the SSRs was consistent with results obtained using other marker systems, with one exception. The sequence and diversity information obtained using these new SSRs and their cross-transferability to related Fagopyrum species will increase our understanding of genetic structures and species relationships within the Fagopyrum genus.

This study was carried out to assess the genetic diversity and to analyze the population genetic structure for a total of 692 mungbean accessions preserved at National Agrobiodiversity Center (NAC) of the Rural Development Administration (RDA), Korea. Mungbean accessions were collected from 27 countries in nine different geographic regions, and were genotyped using 15 microsatellite markers, which were developed in our previous study. A total of 66 alleles were detected among 692 accessions at all the loci with an average of 4.4 alleles per locus. All the microsatellite loci were found to be polymorphic. The expected heterozygosity (HE) and polymorphism information content (PIC) ranged from 0.081 to 0.588 (mean = 0.345) and from 0.080 to 0.544 (mean = 0.295), respectively. Of the 66 alleles, 17 (25.8%) were common (frequency range between 0.05 and 0.5), 15 (22.7%) were abundant (frequency range > 0.5), and 34 (51.5%) were rare (frequency range < 0.05). Locus GB-VR-7 provided the highest number of rare alleles(eight), followed by GB-VR-91(six) and GB-VR-113(four). Country-wide comparative study on genetic diversity showed that accessions from the USA possessed the highest genetic diversity (PIC) followed by Nepal, Iran, and Afghanistan. And region-wide showed that accessions from Europe possessed the highest average genetic diversity, followed by accessions from the USA, South Asia, West Asia, and Oceania. Twenty-seven countries were grouped into seven clades by phylogenetic relationship analysis, but clustering pattern did not strictly follow their geographical origin because of extensive germplasm exchange between/among countries and regions. As a result of a model-based analysis (STRUC-TURE) of microsatellite data, two distinct genetic groups were identified which shared more than 75% membership with one of the two genetic groups. However the genetic group pattern did not reflect their geographical origin. The Duncan's Multiple Range Test among these two genetic groups and an admixed group, with a mean of 16 phenotypic traits, showed significant difference in 12 quantitative and qualitative traits on the basis of ANOVA. These 15 newly developed SSR markers proved to be useful as DNA markers to detect genetic variation in mungbean germplasm for reasonable management and crossbreeding purposes.

Bacterial wilt of tomatoes caused by Ralstonia solanacearum is a devastating disease that limits the production of tomato in Korea. The best way to control this disease is using genetically resistant tomato plant. The resistance degree to R. solanacearum was evaluated for 285 tomato accessions conserved in the National Agrobiodiversity Center of Rural Development Administration. These accessions of tomato were originated from 23 countries. Disease severity of tomato accessions was investigated from 7 days to 14 days at an interval of 7 days after inoculation of R. solanacearum under greenhouse conditions. A total of 279 accessions of tomato germplasm were susceptible to R. solanacearum, resulting in wilt and death in 70 to 90% of these plants. Two tomato accessions were moderately resistant to R. solanacearum. Only four accessions showed high resistance against R. solanacearum. No distinct symptom of bacterial wilt appeared on the resistant tomato germplasms for up to 14 days after inoculation of R. solanacearum. Microscopy of resistant tomato stems infected with R. solanacearum revealed limited bacterial spread with thickening of pit membrane and gum production. Therefore, these four resistant tomato germplasms could be used in tomato breeding program against bacterial wilt.