This study was carried out to find relationships of genetic distance and heterosis expression degree in the developed CNU waxy corn lines. The used material were developed in Corn Breeding Laboratory, Coll. of Agri. & Life Sci., CNU. Total 10 primers used for SSR maker analysis. In genetic distance, the used lines divided into four groups; A group has two lines, B group has one line, C group has ten lines and D group has eleven lines, respectively. Among used lines, CNU427 and CNU588 were very closed as a 74, while CNU451 and CNU429 were remote as a 40 inbred coefficient, respectively. While heterosis degree were very variable not only hybrids but also cross parents. Average heterosis of most cross-parent was high in plant height, ear height, flowering day and ear length. Especially, CNU H09-23 hybrid was high as 79.4% than other hybrids. Here, we gained the fact has closely relationship between genetic distance and heterosis.

반이면 교잡을 통해 얻어진 36개의 F1 교잡종들에 대하여 수량 및 농업관련 형질에 대하여 조사하였다. 36개 교배조합 의 F1과 교배친의 잡종강세를 조사한 결과, F1의 잡종강세 정 도는 종실수량에서 156%로 가장 컸고, 100립중이 가장 작은 7%로 나타났다. 농업형질에 의한 교배친들 사이의 표현형적 거리는 육성된 계보와 차이가 있었으며, 농업형질만으로 유전 적 거리를 측정하는 것은 한계가 있었다. SSR 분석에 의한 유전적 거리와 농업형질과의 상관을 확인하기 위하여 9개의 자식계통에 대한 92개의 SSR primer를 확인한 결과, 육성 계 보에 의한 유연관계를 명확하게 나타내지 못하여 표현형적 거리와 SSR 마커에 의한 유전적 거리에서도 유의성을 찾을 수 없었다. 본 연구에서는 옥수수 종실수량과 SSR 분석을 통 한 유전적 거리 사이의 유의성이 없었다. 따라서 종실수량과 정의 상관을 보이는 9개의 primer 조합을 선발하였다. 9개의 SSR primer들을 이용한 계통유연관계를 분석에서 옥수수 계 통들의 계보와 선발된 SSR을 이용한 유전적 거리는 연관성 을 찾을 수 없었지만, 종실수량과 선발된 9개의 SSR primer 를 이용한 유전적 거리와는 고도의 정의 상관을 보였다 (R2=0.703**). 선발된 SSR primer를 이용한 유전적 거리와 교잡종의 주요 농업형질의 상관 분석 결과, 교잡종 자체의 수 량구성의 모든 요소뿐만 아니라 간장, 착수고도 유의성을 보 였고, 평균에 대한 잡종강세와는 종실수량이 정의 상관을 보 였다. 본 연구에서 선발한 9개의 SSR primer들은 옥수수 육 종연구에서 교배조합 구성을 위한 잡종강세 예측에 도움을 줄 것으로 생각된다.

Heterosis is very important for breeding hybrid cultivars and is intensively used to increase the productivity of crop plants. But the molecular basis of heterosis is still unrevealed to the scientists. This study selected 51 heterosis associated genes of Arabidopsis of different family on the basis of their high differential expression in a hybrid compared to its midparent value and identified their orthologues in Brassica oleracea. Then the selected B. oleracea genes were characterized based on their structural properties, recognized functions and expression patterns in a cabbage hybrid progeny (Cabbage-36) of crosses between Cabbage-34 and Cabbage-35 accessions. Among these genes, a good number were found to express highly in the hybrid then the midparent value and better parent in some cases. Moreover, these highly expressed genes are mostly related to the yield contributing characters. Cotyledon and young leaf sizes of these three genotypes also well correlated with gene expression. Thus, it can be said that, the identified genes might be associated with the mechanism of heterosis of B. oleracea hybrid and provide a foundation for the exploration of gene regulatory networks associated with the specification of the phenomenon heterosis in the plant life cycle. Subsequently, these genes would be useful resources for molecular hybrid breeding in Brassica crops as well.

This study was carried out to analyze correlation between heterosis of F1 hybrids and the genetic distance of parental lines. Growth characteristics such as number of leaves, plant height, bulb diameter, bulb height, bolting rate and marketable yield were examined in 15 F1 hybrids. The genetic distance among one male sterile line and fifteen restorer lines were analyzed with SSR markers. 21 primer pairs amplified polymorphic band and the average number of polymorphic allele was 3.4. As a result of UPGMA cluster analysis, the similarity coefficient value among parental lines ranged from 0.43 to 0.63. Combination of M1 and R14 is high similarity and number of leaves, plant height and yield are 10.2, 66.7cm and 6,818kg·10a-1. The case of the lowest value combination, they are 9.0 and 63.7cm and 7,728kg·10a-1, respectively. The results showed that there are no significant correlations between genetic distance and heterosis of F1 hybrids and only molecular marker does not predict growth traits and yield of onion.

Heterosis describes the increased performance of F1 hybrid plants in terms of increased biomass, yield, vegetative growth rate, and tolerance against biotic and abiotic stresses as compared with their inbred parents. Two sets of rice materials, 166 RILs derived from a cross between Milyang 23 (Korean indica-type rice) and Tong 88-7 (japonica Rice), and BC1F1 hybrids derived from crosses between the RILs and the female parent, Milyang 23, were produced to identify QTLs for heterosis of yield and yield-related traits. The QTLs were detected from three different phenotype data sets including the RILs, BC1F1 hybrids, and mid-parental heterosis data set. A total of 57 QTLs were identified for nine traits. Of eight QTLs detected for yield heterosis, five overlapped with other heterosis QTLs for yield-related traits such as spikelet number per panicle, days to heading, and spikelet fertility. Four QTLs for yield heterosis, gy1.1, py6, gy10, and py11, were newly identified in this study. We identified a total of 17 EpQTLs for yield heterosis that explain 21.4 ~ 59.0 % of total phenotypic variation, indicating that epistatic interactions may play an important role in heterosis.

본 연구는 목화의 실용형질 향상으로 새로운 품종 육성을 위한 기초자료를 얻고자 육지면 5개 품종과 이들을 이면교잡 하여 얻은 F1 10개 조합을 재료로 주당 수량, 주당 삭수, 1삭 종자수, 종자장, 종자폭, 1삭 조면중 등 6개 형질에 대한 잡종강세, 조합 능력, 유전성분, 유효유전자수, 유전력 등을 분석한 것으로 그 결과를 요약하면 다음과 같다. Heterosis와 heterobeltiosis는 주당 수량, 주당 삭수, 종자장, 1삭 조면중에서 부의 방향으로 유의하였다. GCA와 SCA는 모든 형질에서 고도로 유의하였다. 평균우성정도는 주당수량, 주당 삭수, 1삭 종자수 및 종자폭에서 초우성으로 나타났고, 종자장은 완전우성, 1삭 조면중은 부분우성으로 나타났다. 유효유전자수는 주당 수량, 주당 삭수, 종자장에서 2개, 1삭 종자수, 종자폭 그리고 1삭 조면중에서 1개로 추정되었다. 협의의 유전력은 주당 수량, 주당 삭수 및 1삭 종자수에서는 낮았으나 종자폭에서는 높았다. 광의의 유전력은 1삭 조면중을 제외한 모든 형질에서 높았다.

The genetic basis underlying heterosis for agronomic traits of rice under cold water irrigated field condition was investigated in the 143 RILs and 286 BC₁F₁ lines from the cross between a cold-susceptible variety, Milyang23 and a co

Forty-four F₁ hybrids derived from crosses among eleven temperate japonica rice cultivars were grown and evaluated for traits related to cold tolerance including days to heading and spikelet fertility in the cold-water irrigated plot (17℃) and

Improving grain yield and quality of japonica rice continues to be a major breeding objective in Korea. In this study we evaluated genetic divergence among four japonica rice cultivars and assessed the relationship between genetic distance and hybrid perf