卷叶基因Rl_((t))对杂交稻稻米品质性状的影响

Effect of Rolled Leaf Rl_((t)) Gene on Grain Quality in Hybrid Rice (Oryza sativa)

以3对卷叶近等基因系杂交组合为研究对象,设置两种施肥水平处理,研究Rl(t)卷叶基因对杂交稻稻米品质性状的影响。在正常肥力水平下,卷叶组合的精米率显著或极显著高于其对应组合,整精米率高于其对应组合,垩白率和垩白度均低于其对应组合。稻米淀粉RVA谱特征值中,卷叶组合的最高粘度、热浆粘度和崩解值均大于其对应组合,其他性状指标值在对应组合间的差异表现趋势不一致。增施穗肥,除汕优63外,各组合的糙米率、精米率和整精米率都有提高的趋势,各组合最高粘度、热浆粘度和崩解值均降低,消减值均增大,其他性状指标值变化趋势因组合而异。增施穗肥,卷叶组合的精米率和整精米率都高于其对应组合,其中卷叶汕优559与汕优559的整精米率差异达显著水平,其他性状指标值在对应组合间的差异没有明显的规律性,说明Rl(t)基因在一定条件下有利于提高稻米品质。

Grain quality characters of hybrid rice with or without rolled leaf Rl_((t)) gene were analyzed by using three pairs of rolled leaf near-isogenic lines under two fertilization treatments. Under normal fertilization level (e.g. 450 kg urea per ha), milled rice recovery and head rice rates of rolled leaf hybrids were significantly higher than those of corresponding non-rolled crosses, while the chalky rice rate and chalkiness degree were lower. Of the RVA profiles, the peak viscosity, the hot paste viscosity and the breakdown viscosity of the rolled leaf hybrids were all higher than those of the corresponding non-rolled ones at various degrees. Increasing fertilizer application for panicle development promoted the brown, milled and head rice rates except for (Shanyou) 63, while the RNA parameters metioned above all decreased to different levels. Increasing fertilizer application for panicle development, milled rice recovery and head rice rates of rolled leaf combinations were higher than those of corresponding ones. There existed significant difference in head rice rates between Rl_((t)) Shanyou 559 and Shanyou 559; indicating that Rl_((t)) could improve rice quality under a certain condition.