水稻种子蛋白质含量及组分在品种间的变异与分布

Variation and Distribution of Seed Storage Protein Content and Composition among Different Rice Varieties

采用近红外光谱技术测定分析了351份不同类型水稻品种(系)糙米中的蛋白质含量,结果显示粗蛋白含量在9.3%～17.7%之间,平均为12.4%;籼稻平均蛋白质含量为13.2%,比粳稻高约1个百分点。蛋白质含量低的粳稻品种明显偏多,表现出明显的遗传不平衡现象。现有生产上主栽品种稻米蛋白质含量大多处于中等水平,而高蛋白粳稻种质极少。但仍有部分蛋白质含量极高或低的种质,如饲料稻、早籼稻和一些籼粳交后代品系蛋白质含量较高,而部分粳稻和外来籼稻品种中的蛋白质含量较低。因此可以从一些地方品种、外来品种以及籼粳交后代中筛选到极端类型的种质,为遗传育种提供研究的原材料。SDS-PAGE分析结果显示不同类型水稻间各贮藏蛋白组分具一定差异。

The crude protein contents （PC） in 351 varieties were measured by near infrared spectroscopy （NIRS） and their distribution and classification were analyzed. The results showed that the average value of crude protein content in indica and japonica types were 13.2% and 12.2%, respectively, with an average of 12.42%. The ranges of those above were 10.8-16.8%, 9.3-17.7%, and 9.3-17.7%, respectively. It elucidated that PC was higher in indica rice than that in japonica rice. The huge difference in ratios of varieties （lines） based on their PC showed the genetic disequilibrium between subspecies indica and japonica, for example, the ratio of japonica rice with low PC was eight times that of indica rice with low PC. According to the criterion classifying varieties with different protein contents, most of rice genotypes fell into the group with intermediate PC, and there was very small number of varieties with either high or low PC, especially with very high PC in japonica rice. However, we could find some extreme individuals whose PC were very high/low, such as those with high PC： forage rice, early maturity varieties and indica-japonica hybrid progenies close to indica in the subspecies of indica, or close to japonica in the subspecies of japonica; and those with low PC： some japonica rice （but the PC not low enough）, some overseas germplasms in indica. Thus it was not impossible to find out extreme germplasms on PC from landrace, overseas germplasms or indica-japonica hybrid progenies etc., which are fine basic materials in genetic and breeding research. From the results of SDS-PAGE analysis of the total seed storage proteins among some representative varieties, we could know that the seed storage protein composition was different among different types of rice genotypes.