二面交雜에 의한 水稻 節間直徑의 遺傳分析

A diallel analysis of internode diameter in rice

A genetic study on the upper internode diameters in Oriza stativa was carried out by means of a 5×5 diallel cross. The five parental varieties were Raekyung, Nongbaek, Yushin, Yeongnamjosaeng and Honenwase. Kernel number per panicle, upper five internode diameter and the number of second branch per first branch were heighly correlated positively one another. Non-allelic interaction was not. In the degrees of dominance, the first and the second internode diameter were by partial-dominance, while the third, the fourth and the fifth internode diameter by over-dominance. The more thick internode diameter were appeared to be dominant to the more thin. The genetic variation of internode diameter were much more influenced by additive effect on upper first and second internode, while those of lower third, fourth, fifth internode were due to dominant effect, and those were controlled by 2-7 major genes. Heritabilities (h²B) in broad sense were very high in all characters, but narrow sense heritabilities (h²N) were ranged from 0.279 to 0.856 according to characters. Effects of GCA were large than SCA effect, and Raekyung and Yushin had high positive GCA, but Nongbaek and Honenwase had high negative GCA in all characters. The best combinations were Nongback x Yushin and Nongbaek x Yeongnamjosaeng, which included Nongbaek as Japonica parent and had the highest SCA, in all characters.