Abstract: Sensitivities of different height genes of rice to GA₃ and their relationships with enzymes were studied using three pairs of isogenic lines. The results indicated that the sensitivities of the genes to GA₃ were in the order: eui>sd1>Sd1>sds(t). The gene sd1was more sensitive in indica than in japonica. Sensitivities of the endosperms with the different height genes to GA₃ quitely accorded with these of the seedlings. Assay of peroxidase showed that activity of the enzyme was higher in the tall lines than in the short lines in seedlings of 4 days, and higher in the short lines than in the tall ones in seedlings of 8 days. The enzyme was lower activity in sensitive lines treated with GA₃ for 4 and 8 days. The isozyme band 8 of peroxidase and the band 7 of esterase on the electrophoresis gel were related to the sensitivity of the height genes to GA₃.

Key words: Rice, Plant height genes, Sensitivity to GA3, Enzyme

摘要： 用3对水稻植株高度近等基因对，研究了株高基因对GA₃ 敏感性和酶的影响。结果表明，株高基因在苗期对GA₃ 敏感性强弱顺序为eui>sd1>Sd1>sds(t)；其中梗稻的Sd1敏感性强于籼稻的。 用胚乳培养法快速鉴别水稻株高基因对GA₃敏感性的结果与幼苗鉴定的一致，说明这种方法是有效的。 在酶活性方面，4 d的幼苗中高秆品系的过氧化物酶活力比矮秆品系的高， 而8 d的幼苗中矮秆的活力反而比高秆的强。经GA₃处理4 d和8 d后，对GA₃敏感的品系过氧化物酶活力较低， 过氧化物酶同工酶带8和酯酶同工酶带7与株高对GA₃的敏感性有关。

关键词: 水稻, 株高基因, 敏感性, 酶, 赤霉素