水稻 量的形質에 關한 遺傳硏究 第1報 水稻 입형에 粒型 關한 遺傳分析

Studies on the Inheritance of Quantitative Characteristics in Rice 1. Studies on the Inheritance of Grain Size in Rice

For clarifing the inheritance of morphological traits such as length, width, thickness and weight of rice grain, F₁ progenies of seven crosses and four F₂ populations from five parents were empoloyed in greenhouse and field at Suweon in 1983. No significant difference was found between reciprocal crosses in the grain characteristics of F₁ progenies. Segregation mode of grain length in F₂ population showed nearly normal distribution under both field and greenhouse except that of width and thickness, which were slightly propended to the narrower and the thinner parents. However, the distribution of grain weight in F₂ segregation was skewed toward the lighter parents so that light grains appeared to be partially dominant over heavy grains. The heritability estimates of the grain characteristics were considerably high and the order of magnitude was weight > width > length > thickness in field, but was width > weight> length > thickness in greenhouse, respectively. Grain weight showed highly positive correlations with length, width and thickness in both environments. Direct effects of grain characteristics for the increase of grain weight in path analysis were higher in the order of thickness>grain length/width ratio in field, but length>thickness> width in greenhouse.