To better understand the morphological variation in the 189 accessions of cultivated var. frutescens of Perilla crop preserved at the RDA-Genebank in South Korea, morphological characteristics were investigated using seven traits related to leaf quality. In the principal component analysis (PCA), the first and second principal components accounted for 28.9% and 19.7% of the total variance, respectively. In the first component, leaf color (QL1) and stem color (QL3) contributed positively, whereas the flowering period (QL5) and degree of pubescence (QL6) contributed in a negative manner. In the second component, QL5 and QL6 contributed positively, whereas the fragrance of plants (QL7) contributed negatively. The results of PCA showed that the 189 Perilla accessions were clearly divided into three groups based on the 1st axis (X-axis), except for some accessions. However, the Perilla accessions collected in South Korea and abroad did not show a clear geographical distribution between the collection areas. Correlation analysis among the seven traits of 189 Perilla accessions showed a positive correlation coefficient for the combination of QL1 and QL3, and QL5 and QL6, and a negative correlation for the combination of color of the reverse side of the leaf and QL6, and QL5 and QL7. Therefore, the results of this study will provide useful information for the selection of useful resources for the development of leafy vegetable varieties of the Perilla crop and the preservation and management of genetic resources of the Perilla crop preserved at the RDA-Genebank in South Korea.

In this study, 14 agricultural and phenotypic traits were used to analyze morphological variations among 10 near-isogenic lines (NILs) of colored waxy maize and 2 parental lines (HW3 and HW9) of the hybrid cultivar “Mibaek 2.” The results of principal component analysis indicated that on the first principal component axis, seed coat color, R value, V value, days of tasseling, L* value, and days of silking greatly contributed to the positive direction, whereas anthesis–silking interval and leaf width greatly contributed to the negative direction. On the second principal component axis, kernel row number and tassel color contributed to the positive direction, whereas setted ear length, ear length, and 100-kernel weight contributed to the negative direction. Thus, the morphological characteristics that greatly contributed to the first and second principal components might be useful for discrimination among the 10 NILs and 2 parental lines of “Mibaek 2.” Of the 10 NILs analyzed, 16CLP26 and 16CLP16 were considered useful breeding material for the development of colored waxy maize varieties with relatively high amounts of yield and anthocyanin. Collectively, these results are expected to provide useful information for the development and selection of lines for breeding colored waxy corn varieties at the Maize Research Institute, Gangwon-do Agricultural Research and Extension Services.

In this study, genetic analysis was conducted on the inheritance of qualitative traits, such as leaf color, flower color, seed size, and seed hardness, in the F₂ population derived from the cross between var. frutescens and var. crispa. As determined by the separation pattern of each trait in the F₂ population, F₂ plants with a green color were more common than those with a purple color on the leaf surface, whereas F₂ plants with a purple color were more common than those with a green color on the reverse side of the leaf. For flower color, more F₂ plants were observed to have a white color. For seed size, more F₂ plants were observed to have a seed size of above 2 mm, and for seed hardness, more F₂ plants were observed to have characteristics of seed hardness. Our examination of the genetic separation ratios with respect to Mendel’s law of genetics revealed that three traits, leaf color (surface and reverse side) and flower color, did not follow the separation ratio of 1:2:1, and the seed size did not follow the segregation ratio of 3:1, but seed hardness was found to follow the separation ratio of 3:1. The results of this study are expected to provide basic information to help understand the genetic segregation of leaf and seed characteristics in the F₂ population derived from the cross between var. frutescens and var. crispa, and also to provide useful information for breeding studies to assist the development of varieties of Perilla crop.

We collected 32 maize inbred lines from eastern cereal and oilseed research center in Canada to develop new maize varieties. We also evaluated genetic diversity, genetic relationships, and population structure using 35 SSR markers. A total of 269 alleles were revealed in 35 loci with an average of 7.69 and a range between 3 and 15 alleles per locus. The genetic diversity values varied from 0.176 to 0.889 with an average of 0.691. The polymorphic information content varied from 0.171 to 0.879 with an average of 0.659. Population structure analysis indicated that 32 Canadian maize inbred lines comprised four major groups and one admixed group based on a membership probability threshold of 0.80. The four major groups contained 13, 2, 5 and 2 maize inbred lines, respectively. From genetic relationships analysis, the all inbred lines were divided into three main groups at 26% genetic similarity. Group I included 22 inbred lines, and Group II included 9 inbred lines. Group III consist of only one inbred line. The results in this study would be useful for the improvement and development of new cultivars, planning crosses for hybrids or development of inbred line in maize breeding program

In order to develop a core set and new corn variety in Korea, we evaluated the morphological characteristics of 194 maize accessions by examining eight quantitative characteristics. On the evaluation of quantitative traits for 194 maize accessions, they showed the morphological variations in tassel length (35.1±5.0 cm), plant height (226.1±33.7 cm), ear height (86.3±22.6 cm), stem diameter (2.3±0.6 cm), leaf width (9.3±1.1 cm), ear length (14.5±2.4 cm), ear row number (14.1±1.9 row), and 100 kernel weight (24.9±4.4 g). The results of principal component analysis (PCA) indicated that the tassel length, plant height, and ear height greatly contributed to positive direction on the first principal component axis. One-hundred kernel weight contributed to negative direction on the second principal component axis. Thus these morphological characteristics, which contributed greatly in the first and second principal components, might be useful for discrimination among 194 maize accessions. In our study, seven accessions, such as IT026357, IT026441, IT027321, IT033271, IT033591, IT033597 and IT124273, particularly were measured high on yield-related traits. Consequently, the 194 maize accessions used in this study could be used as promising materials for maize breeding programs such as development of new hybrid in Korea.

Grain yield, agronomic traits, and correlation between genetic distance of 36 F₁ hybrids produced by half-diallel crosses using nine maize inbred lines were analyzed. In the analyses of F₁ hybrids and their mid-parent heterosis (MPH) for agronomic traits, grain yield showed highest MPH value of 156%. One-hundred kernel weight showed the lowest value of 7%. In addition, when genetic distance based on agronomic traits was estimated, parental inbred lines did not agree with their own pedigree. Therefore it had the limitation to estimate genetic distance using agronomic traits. In this study, 92 SSR markers were used to calculate genetic distance at DNA level. However we did not confirm their own pedigree of nine parental inbred lines. There was no correlation between grain yield and SSR markers. Therefore molecular marker selection was conducted in relation with grain yield by the step-by-step method using 92 SSR markers. The selected nine SSR markers showed a significant positive correlation (r²=0.703**) between grain yield and SSR markers. The correlations between the selected SSR markers and agronomic traits of ear length, ear width, plant height, and ear height were particularly showed positively correlated. The nine SSR markers selected in this study would help predicting heterosis and planning crosses for hybrids in maize breeding programs.