Effects of water stress on the texture of cooked rice and the grain quality of transgenic rice plants carrying antisense Wx gene during grain filling

中国人. 以反义Wx基因的转化系及其受体亲本武运粳7号（9522）为材料，研究了结实期水分胁迫对主要品质性状及米饭质地的影响。结果表明，与水层灌溉处理相比，结实期水分胁迫使整精米率和垩白粒率提高；崩解值明显降低，而最终黏度和消减值却明显提高；米饭的硬性增加，黏附性减小，稻米的蒸煮食味品质有着变劣的趋势。

英语. It is well known that environments have significant effects on the yield and rice quality. In previous study, the indices of quality, such as chalkiness, gel consistency and RVA profile were ahered by soil water moisture. Amylose content is always used to evaluate the rice eating and cooking quality. And now the characteristics of RVA profile are preferred for the prediction of the texture of cooked rice. Our earlier work showed that RVA profile of rice flour was affected by water stress, but there was no obvious difference in amylose content between well water and water stress. The objective of the study was to research the effects of water stress on the texture of cooked rice and grain quality for rice with the same genetic background. Three transgenic rice lines CA1, CA2, CA3 carrying antisense Wx gene and wild type （cultivar Wuyunjing 7） were grown in pots and were subjected to water stress from flowering stage to filling stage. The results showed that the grain qualities of transgenic rice plants and Wuyunjing 7 were affected by water stress at the grain-filling stage, head milled rice and the percentage of chalky grains increased obviously （Table 3）. Changes of RVA profile of rice flour were noticed, breakdown was lower under water stress than under well water, and final viscosity and setback under water stress were higher than those under well water （Table 4）. Effect of water stress on the texture of cooked rice presented on the hardness and adhesiveness, the former was increased and the latter was reduced （Table 5）, and there was a tendency of low eating and cooking quality.