转反义 Wx基因糯稻的显性遗传及对稻米粒重的效应分析

Effect of Dominant Waxy Character on Kernel Weight of Transgenic Rice with Antisense Wx Gene

利用直链淀粉含量下降至 2 %左右的 3个转反义Wx基因糯稻为研究材料 ,较为系统地分析了转基因糯稻的遗传及其直链淀粉含量下降后对于稻米粒重的影响。结果表明由转基因技术获得的糯性性状与其它转基因性状一样 ,表现为显性遗传 ,这与一般的糯性变异不同。导入反义Wx基因使直链淀粉含量从 17%下降至糯稻水平时 ,其稻米粒重相应降低 6 %～ 8% ,且下降幅度与直链淀粉含量的下降幅度呈显著正相关。小区试验结果表明 ,由此获得的转基因糯稻仍具有原受体亲本的高产潜力 ,利用转基因技术培育既高产又优质的水稻品种 。

The amylose content in rice endosperm is related to both rice quality and yielding. In previous study, some transgenic rice plants with the antisense Waxy (Wx) gene and very low amylose content, which was similar to the level of the waxy (glutinous) mutant, had been delivered. Genetic analysis of our experiments showed that this waxy character was dominant, which differed from the recessive of the natural waxy mutant. The effect of this dominant waxy character on kernel weight of transgenic rice was carefully investigated. It is found that the weight of waxy kernels is lighter than non waxy ones in all the three transgenic lines, in which the amylose content has been reduced from 17% to 2.6%, 1.9% and 0.6%. The relative difference of weight between waxy and non waxy kernels is 6%～8%, which is significantly correlated to the degree of reduction in amylose content, and this difference was relatively stable in successive generations. The results of field testing showed that the level of reduction of yielding was less than that of the kernel weight, the high yielding potential of original variety could be kept in these transgenic waxy rice lines. These results show that it is an effective way to breeding high yielding waxy rice varieties by transgenic approach.