Buckwheat (Fagopyrum esculentum Moench), one of the minor crops grown in Korea belonging to the Polygonaceae family, is an annual crop widely cultivated in Asia, Europe, and America and has a character of outcrossing and self-incompatibility. The objective of this study was to analyze the genetic variability, phylogenetic relationships and population structure of buckwheat landraces of Korea using SSR markers. Ten microsatellite markers have been detected from a total of 79 alleles among the 179 buckwheat accessions were collected from Korea. The number of allele per marker locus (NA) ranged from 2 (GB-FE-001, GB-FE-043 and GB-FE-055) to 31 (GB-FE-035) with an average of 7.9 alleles. GB-FE-035 was the most polymorphic with the highest PIC value 0.93. Major allele frequencies (MAF) for the 10 polymorphic loci varied from 0.12 to 0.97 with a mean allele frequency of 0.57. The expected heterozygosity (HE) values ranged from 0.05 to 0.94 with an average of 0.53. The observed heterozygosity (HO) ranged from 0.06 to 0.92 with an average of 0.42. The overall polymorphic information contents (PIC) values ranged from 0.05 to 0.93 with an average of 0.48. The landrace accessions of buckwheat used in the present study were not distinctly grouped according to geographic distribution. The study concludes that the results revealed genetic differentiation was low according to the geographic region because of outcrossing and self-incompatibility. We reported that our analyses on the genetic diversity of common buckwheat cultivars of Korea were performed by using of microsatellite markers.

Fusarium head blight (FHB) is the most important disease of wheat that may cause serious yield and quality losses and leads to harmful contamination of the grain with fungal toxins. Korean wheat cultivars showed much less resistant to FHB than Sumai3, which known as resistance to FHB, evaluated by spray inoculation in our companion report. Many DNA-marker studies, including sequence tagged site (STS) and simple sequence repeat (SSR) markers and qualitative trait loci (QTL) associated with FHB resistance have been identified and mapped on the specific chromosome, especially 3BS, by many previous studies. However, there was no application of DNA-markers to select FHB resistance lines in Korean wheat breeding programs. 3 SSR markers and 6 STS markers linked to major QTL on chromosome arms 3BS found in Sumai3 and its derivatives were used to screen FHB resistance in Korean wheat cultivars. All markers known to be most significant markers based on previous research (Liu and Anderson 2003). There was general lack of marker polymorphism for Korean wheat cultivars used in this study. However, STS3B-138 marker only showed the polymorphism in Korean wheat cultivars. Allele size of STS3B-138 is 355 bp in Sumai 3 and 12 of 24 cultivar showed this allele. The range in Type II resistance rating was 1-5 and average of these 12 cultivars have 355bp allele was grade 2.4. The most resistant cultivars under the 2 grade, Gobun, Jinpoom, Milseong and Namhae also showed 355bp allele. Therefore, These results provide potential for development of wheat cultivars with improved Fusarium head blight resistance through use of effective FHB screen methods and marker - assisted selection.

The rice sucrose synthase 3 (RSUS3) localized predominantly inrice seed endosperm may play an important role in the starch filling in the milky stage of rice seed. As the genetic diversity at this locus is not known yet, forty three rice varieties/accessions were objected to amplify full sequence of the RSUS3 to examine the distribution of DNA polymorphisms. A total of 254 sequence variants, including 82, 150 and 22SNP sand indels, were successfully identified in whole length of 7,733bp sequence comprising promoter, exon and intron, and 3’ down stream non transcribed region(NTR). Eleven haplotypes were distinguishable among 43 rice varieties based on the nucleotide variation on the three defined regions (5’NTR, transcript and 3’NTR). The promoter region showed the occurrence of a base change on a cis-element which might involve a functional role of the motif in seed-specific expression. Non random process seemed to be acted in the genetic diversity of RSUS3geneamongricegermplasmusedinthisstudy. The analysis of polymorphism sites indicated a history of eleven minimum recombination mostly occurred in the transcribed region. This result might provide an insight for a clasditic approach for establishing future genetic association studies of RSUS3locus.

The SSR markers were generally used to analysis the plant genetic diversity, but it have been rarely reported in case of castor bean. We constructed the microsatellite-enriched genomic library and sequenced totally 775 clones to obtain the microsatellite sequence information of the castor bean. Among the sequenced clones, one hundred fifty clones (19.3%) were redundant and four hundred twenty (67.2%) were found to contain microsatellite sequences within the remaining 625 unique clones. A total of 237 primer pairs were designed based on the sequenced microsatellite clones information and evaluated for polymorphism in ten castor bean accessions. Twenty-eight SSR markers produced reproducible polymorphic bands and were further characterized using a diverse set of 25 castor bean accessions. The majority of unique SSRs revealed dinucleotide motives (84%) on the other hand the ratio of trinucleotide motives was 15%. A microsatellite enriched library from the Ricinus communis L. was mainly consisted of [(AG), (GA)/(CT), (TC)] and [(CTT)/(AAG)] microsatellite motifs. The length of dinucleotide SSRs ranged from 4 to 50 repeats with an average 12.4, and that of trinucleotide SSRs from 4 to 56 with an average of 7.35 repeats. These newly developed microsatellite markers will be useful for breeding system and classification of Ricinus communis L.

The genus Allium which is one of the biggest plant genera comprises around 750 species that show the various morphological and ecological diversity with various taxonomic and geographical groups. The species of genus Allium has not been clearly distinguished because of extraordinary large amount of variation. We developed 8 simple sequence repeat markers (SSRs) which showed polymorphism within A. sativum accessions, but it was insufficient in transferability analysis of other Allium species. In this regard, we finally selected 50 primer pairs which was applicable to other Allium species adding to 8 primer pairs. According to results from application of 50 SSR markers to 9 Allium species, the average number of alleles ranged from 1.400 (A. porrum) to 1.889 (A. tuberrosum) and A. tuberosum (2n=32) has maximum 9 alleles. The lowest transferability value was 42.0% ( A. cepa and A. chinense) while A. sativum showed 96.7%. The A. porrum conceived to be close relationship to A. sativum as Allium subgenera revealed higher transferability (73%) rather than other Allium species. According to PCA analysis, three groups were divergent, and the A. fistulosum and A. sativum revealed the distinct groups and the rest 7 species formed another group.

The present study was carried out to assess the genetic diversity, population structure and linkage disequilibrium in Korea. In model-based population, Korean rice germplasm were classified into four subpopulaton designated as indica cultivated, japonica cultivated, indica weedy, and japonica weedy were identified. Pair-wise estimates of FST indicated a different degree of differentiation between the four model-based populations with values ranging from 0.073 (between japonica cultivated and japonica weedy) and 0.474 (between japonica weedy and indica weedy). The indica weedy population appeared to be highly differentiated as compared to other populations. The indica cultivated have the highest gene diversity (0.58), followed by japonica cultivated (0.50), japonica weedy (0.42) and indica weedy (0.35). The total number of specific alleles in indica weedy and japonica weedy populations was 39 alleles (23 markers) and 55 alleles (22 markers), respectively. An average of LD (r2) value of indica weedy and japonica weedy type was higher than two other populations, both in inter- and intra-chromosome, indicating the possible reproductive and geographical isolations of sub-populations in cultivated rice fields.

The present study reports isolation and characterization of ten polymorphic SSR markers developed from common buckwheat (Fagopyrum esculentum Moench). These SSR markers produced a total of 59 alleles across 41 common buckwheat accessions with an average of 5.9 alleles per locus. Values for observed (HO) and expected (HE) heterozygosities ranged from 0.071 to 0.924 (mean=0.53) and from 0.073 to 0.902 (mean=0.412), respectively. At significance threshold (P<0.05), seven loci deviated from Hardy-Weinberg equilibrium (HWE), whereas significant linkage disequilibrium (LD) values were observed between 5 pairs of loci. These markers are currently being used for programming of the genetic conservation and classification of common buckwheat germplasm collection.

There are about 16 species included in Fagopyrum (Polygonaceae) genus and some of them have been found recently and named. Fagopyrum genus is generally divided into two major groups: cymosum and urophyllum group. This study is to analyze the genetic diversity of Fagopyrum genus, to compare with the phylogeny result of Fagopyrim using previous analysis results, and to provide the information of each species specific marker by executing the cross-amplification on 3 species and 2 sub-species among cymosum group and 5 species among urophyllum using 136 SSR markers newly developed from common buckwheat. Cluster analysis using UPGMA showed two main clusters, each of the cymosum and urophyllum group. This result agree well with the previous findings on species relationships in Fagopyrum using different method approachs. In cross species amplification, our results revealed significant transferability of F. esculentum microsatellites to the 4 cymosum species (96.3% in F. esculentum ssp. Ancestral, 61.0% in F. tataricum ssp. tataricum, 36.0% in F. tataricum ssp. potanini, 97.1% in F. homotropicum). However, the percentage of 136 SSR markers were amplified in the urophyllum species (50.7% in F. urophyllum, 50% in F. lineare, 60.3% in F. leptopodum, 66.9% in F. capillatum, 66.2% in F. gracilipes) was lower than cymosum species, except F. tataricum. In addition, we identified 61 species specific markers among each species. These results demonstrate wide potential applicabilityof these markers for the study of inter-specific genetic diversity as well as evolutionary relationships among cultivated and wild buckwheat.