水稻 品種間 交雜에 있어서 稈長의 遺傳分離 ⅩⅡ. 優性短桿 遺傳子 D-53의 遺傳分離

The segregation mode of plant height in the crosses of rice cultivars ⅩⅡ. Genetic segregation of dominant dwarf gene D-53

A rice genetic stock F₁ 282, which has D-53 gene (formerly reported as Dk-3 by Iwata), was crossed with three dwarf cultivars Seolak, Fukei 71 and Waesung #5, one recessive tall cultivar Davis 80 and two ordinary cultivars PI #1 and Onne mochi, and their culm and internode lengths were tested for their parents, F₁S and F₂S. The culm length of F₁S plants of the crosses F₁ 282/PI #1 and F₁ 282/Davis 80 were shorter than their dwarf parent, meaning that the dwarfness of F₁ 282/Waesung #5 and F₁ 282/Onne mochi were taller than their taller parent, implying that there are some genetic interactions between the two parental genotypes. The F₁ plants of the crosses F₁ 282/Seolak and F₁ 282/Fukei 71 were as short as their parents. For the culm length of F₂S, in the crosses F₁282/Seolak and F₁282/Fukei 71, the segregation ratio of short;tall=13;3 were observed. In the cross of F₁ 282/PI #1, the ratio was short;tall=3 : 1, and in the cross F₁ 282/Davis 80 it was short : tall =15 : 1. In the cross of F₁ 282/Waesung #5 the ratio was short : tall= 3 : 13, and in the cross F₁ 282/Onne mochi no distinct segregation pattern was observed. In all the crosses, the liguless segregated normally. This may imply that no distorted segregation due to gametic competition or improper population size etcetra was involved.