水稻品種의 二面交雜에 의한 量的形質의 遺傳分析 Ⅰ. 자포니카 水稻品種의 雜種强勢 및 主要形質間의 相關

Heterosis and correlations between major characters in diallel cross of rice Ⅰ. Heterosis and correlations between major characters in japonica rice

This work has been performed to get the useful informations regarding the degree of heterosis and correlations between quantitative characters related to sink and source in Japonica rice varieties. Heterosis for days to flowering in F1 generation was mostly significant to late maturing, however, cross combination in which Ishiokamochi 7 crossed with Shin # 2 showed hetersois for days to flowering to early maturing. Degree of heterosis for culm length in F1 was greater than that of in F2 generation and the direction of heterosis and heterobeltiosis was tall culm length in case of cross combination in which Ishiokamochi 7 crossed with Samnambyeo. Almost all F1 generation in which had Ishiokamochi 7 as parent showed high heterosis for the number of panicles, 1000 grain weight and number of spikelets per panicle. Degree of heterosis to the productivity score in F₁, generation mostly showed high and positive direction. Significant positive heterosis and heterobeltiosis for leaf area index was found in the cross combination involved Ishiokamochi 7, Shin # 2 and Samnambyeo as their parent. In general, genotypic correlation coefficient was higher than environmental correlation coefficient and characters such as 1000 grain weight, number of spikelets per panicle and productivity score showed highly significant genotypic correlation with yield. The genotypic, phenotypic and environmental correlation coefficients between dry matter and harvest index in F1 generation showed highly negative significant. Significant positive genotypic and phenotypic correlation were found for crop growth rate and relative growth rate.