Morphological variation was investigated among 31 maize landrace accessions collected from the fields of various farmers in South Sudan by examining 7 quantitative agronomic characteristics. A significant positive correlation was found between days to tasseling (DT) and days to silking (DS), between plant height (PH) and ear height (EH) and stem width (SW), and between EH and SW and leaf length (LL). First and second principal components accounted for 69% of the total variance (40.9% and 28.6%, respectively). PH, EH, SW, LL, and leaf width (LW) were clearly characterized in a positive direction on the first axis. DT and DS were clearly characterized in a positive direction on the second axis. A scatter plot based on phenotypic data revealed the existence of 3 groups based on the most discriminating characteristics: Group I included 5 maize landrace accessions, Group II comprised 14 maize landrace accessions, and Group III included 10 maize landrace accessions. In principal component analysis, generally the investigated genotypes were not clearly grouped into their geographical origins owing to a weak geographic relationship among the accessions. In conclusion, even though the morphological characterization studies were conducted in the South Korean climate, this study revealed significant phenotypic variation among the explored maize landrace accessions collected from South Sudan. Therefore, this information about phenotypic divergence may be very useful for future breeding research programs as well as for genetic improvement of South Sudan maize accessions.
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Bakanae disease is an important fungal disease caused by
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In order to estimate genetic diversity of Korean rice landraces, rice characters and SSR markers of 76 rice germplasms were analyzed. Of 12 rice characters, amylose content (AC) showed as largest variance (4.9 to 28.9%), whereas grain length (GL) showed as the lowest variance (4.4 to 5.9 mm). In principal component analyses (PCA), the first principal component explained 60.3% of total variance, in which culm length (CL) and growth period (GP) showed as positive variance and AC showed as negative variance. The second principal component explained an additional 22.4% of the total variance, in which GP and AC showed highly positive variables and CL showed a negative variable. Forty nine SSR markers produced a total of 473 alleles with an average of 9.65 alleles. Polymorphism information content (PIC) was in the range of 0.11 to 0.93. Average observed heterozygosity ranged from 0.12 to 0.39, with an average value of 0.61. As a result of STRUCTURE analysis, 76 Korean rice landraces showed two subpopulations. In clustering analysis, rice characters and SSR markers were clustered into four groups and three groups, respectively. However, they were not significant different from each other. These results provided insight into the characteristics of Korean rice landraces, thus improving our knowledge on rice breeding.
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Indian spinach (
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Brown rice contains beneficial phytonutrients such as antioxidants, anthocyanins and oryzanol, and oryzanol is one of the major components. However, the information of oryzanol contents and genetic data are limited in Korean rice landraces to use the genetic resources. This study was conducted to investigate varietal differences of the oryzanol content and analyze the genetic diversity using SSR marker about 196 Korean rice landraces. Among tested germplasm, the total γ-oryzanol values showed the high variation ranged from 9.8 to 55.9 mg 100g−1 and an average content value was 27.2 mg 100g−1. Particularly, IT007903, IT007714, IT006622 and IT006125 accessions were showed γ-oryzanol contents higher than 50mg 100g−1. The 24-methylene cycloartenyl ferulate was the most prevalent with an average value of 29.9% among the total γ-oryzanol components, and followed by cycloartenyl ferulate (26.7%). Genetic diversity among 196 landrace accessions was evaluated based on 46 SSR markers carrying total 396 alleles. The mean values of observed (HO) and expected heterozygosities (HE) were 0.009 and 0.497, respectively, indicating a considerable amount of polymorphism within this collection. A genetic distance-based phylogeny grouped into seven clusters with genetic distance (GD) value was 0.6. According to the phylogenetic analysis, roughly 7 clusters were divergent, and the γ-oryzanol content values showed statistical differences by the four groups (
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