矮秆基因对水稻性状控制的机理探讨

1987-1988年，测定了13个我国籼粳稻品种的内源吲哚乙酸（IAA）和赤霉素（GA）类物质的含量。结果表明，我国矮化育种中所用的主要矮源及其衍生的半矮秆品种，其内源GA类物质和IAA的含量都远低于高秆品种的含量，矮秆品种的GA类物质只有高秆品种的70%-80%，而IAA只有高秆品种的20%左右。因此，我国育种家所用的矮性基因，不论是sd-1，sd-g或微效多基因，其所控制的3种性状（株高、分蘖性和叶片着生角）的表达不仅通过前人所述的GA类物质，而且还通过IAA调节，又矮秆品种在一生的各生育期，GA类物质含量都低于高秆者，说明矮生性基因在一生各时期都表达。

THE MECHANISM OF DWARF-GENE REGULATION ON RICE CHARACTERS

In 1987-1988, contents of endogenous indole-acetic acid (IAA) and gibberellin-like substances were assayed in plants of 13 cultivars. The results showed that the contents of endogenous GA-like substances and IAA of the major semidwarf-aneestors used by Chinese breeders and their semidwarf descendants were-much lower than those in their related tall ones; the contents of GA-like substances of semidwarfs Were70%-80% equivalent to those of the tall ones; and the contents of IAA in semidwarf euitivars were about 20% equivalent to those of the tall ones (Table 2). The contents of GA-like substances in semidwarf plants of different developmental stages were all lower than those in tall ones. Hence, the semidwarf genes used by Chinese breeders, whether sd-g or micro-regulated multiple genes, expressed their plant-type characters not only through regulation of GA-like substances as indicated by the former scientist, but also through regulation of IAA.