Yang-Hee Cho

Phytochemical distribution and antioxidant activities of Korean adzuki bean (Vigna angularis) landraces

Total polyphenol content (TPC), total phenolic acid content (TPA), and total flavonoid content (TFC) in 209 Korean adzuki bean landraces were determined by colorimetric methods. Antioxidant effects were evaluated with the DPPH, ABTS, ferric reducing antioxidant power (FRAP), reducing power (RP), and SOD assays. TPC, TPA, and TFC in the 209 Korean adzuki bean landraces ranged from 1.1 to 11.7 mg gallic acid equivalents/g, 0.37 to 5.03 mg caffeic acid equivalents/g, and 0.17 to 0.91 mg quercetin equivalents/g, respectively. Antioxidant activities as assessed by the DPPH, ABTS, FRAP, PR, and SOD assays showed wide variation, ranging from 12.2 to 86.3 (IC50), 0.85 to 5.25 mg ascorbic acid equivalents (ASC)/g, 0.41 to 5.44 mg ASC/g, 0.54 to 1.83 mg ASC/g, and 60.4 to 142.8 (IC50), respectively. Using the relative antioxidant capacity index (RACI), we found that the IT189394 had the highest antioxidant activity. In clustering analysis, 209 Korean adzuki bean landraces were classified into three clusters. Among them, cluster I contained 22 landraces with higher antioxidant activities, TPC, TFC, and TPA and smaller seed sizes than the other clusters. We anticipate that these results will provide useful information for the development of adzuki bean-based functional foods.

Development of SSR Markers and Their Use in Studying Genetic Diversity and Population of Finger Millet (Eleusine coracana L. Gaertn.)

Finger millet (Eleusine coracana L. Gaertn.) is an important cereal crop in eastern Africa and southern India with excellent grain storage capacity and the unique ability to thrive in extreme environmental conditions. In this study, we analyzed the genetic diversity and population structure of finger millet using 12 developed microsatellites. By sequencing 815 clones from an SSR-enriched genomic DNA library, we obtained 12 polymorphic SSR markers, which also revealed successful amplicons in finger millet accessions. Using the developed SSR markers, we estimated genetic diversity and population structure among 76 finger millet accessions in Asia, Africa, and unknown origins. The number of alleles ranged from 2 to 9, with an average of 3.3 alleles. The mean values of observed heterozygosity and expected heterozygosity were 0.27 and 0.35, respectively. The average polymorphism information content was 0.301 in all 76 finger millet accessions. AMOVA analysis showed that the percentage of molecular variance among the populations was 1%, that among individuals was 5%, and that within individuals was 94%. In STRUCTURE analysis, the 76 finger millet accessions were divided into two subpopulations which had an admixture of alleles. There was a correspondence among PCoA, AMOVA, and population structure. This study may form the basis for a finger millet breeding and improvement program.

Comparison of eating quality and seed storage protein among Korean rice landraces

Improving eating quality and nutrition is one of the most important objectives in rice breeding program. Palatability factors and seed protein patterns of 69 Korean rice landraces were compared in this study. Of seven palatability factors, setback viscosity (SBV) had the largest variance, ranging from -144 to 45. Water content (WC) had the lowest variance, ranging from 11.0 to 13.0. In correlation analysis, eating quality was positively correlated with all palatability factors except gelatinization temperature (GT). In principal component analyses (PCA), the first PC with Eigen value of 5.06 explained 42.2% of the total variance. Cool paste viscosity (CPV) was the variable that had the largest positive loading. The second PC with Eigen value of 2.09 explained an additional 17.4% of the total variance. SBV was a variable that had the highest negative loading. Peak viscosity (PKV) had positive variance between PC1 and PC2. The 69 Korean rice landraces were clustered into four groups based on physicochemical properties and palatability factors, with groups I and II showing higher EQ than other groups. SDS-PAGE analyses revealed five seed storage patterns in the 69 Korean rice landraces. Among them, 84% (58 landraces) had pattern I. These results indicate that it is possible to develop high palatability cultivars using Korean rice landraces. In addition, screening of landraces based on variation in seed storage protein profile using SDS-PAGE could be highly effective for the identification of valuable rice genetic resources.