高抗性淀粉粳稻新品系稻米淀粉链长分布与主要品质特征差异

 【目的】通过对水稻抗性淀粉性状的遗传研究,为高抗性淀粉水稻资源创新与育种提供理论和实践依据。【方法】以抗性淀粉含量有显著差异的粳稻品系为材料,比较分析高低抗性淀粉粳稻品系类型间的支链淀粉链长分布、稻米RVA谱特性值、膳食纤维和直链淀粉含量等主要品质特性的差异及其相关性。【结果】高低抗性淀粉水稻品系间支链淀粉链长分布差异显著,高抗性淀粉水稻品系的支链淀粉中短链部分即聚合度为5～12所占的相对百分比率显著低于低抗性淀粉类型品系,而长链尤其是聚合度为13以上的长链比率明显高于低抗性淀粉类型品系。膳食纤维和直链淀粉含量,高抗性淀粉品系显著高于低抗性淀粉品系,最高黏度值、最终黏度值、热浆黏度值和崩解值等,高抗性淀粉品系均显著或极显著低于低抗性淀粉类型品系。抗性淀粉含量与支链淀粉短链聚合度（DP≤12）呈极显著负相关,但与支链淀粉的中长链聚合度（12＜DP≤36）呈极显著正相关,与直链淀粉含量和膳食纤维含量呈极显著正相关。【结论】水稻中支链淀粉的链长分布、直链淀粉含量和稻米RVA谱特性值与稻米抗性淀粉含量关系密切,在育种实践中可作为育种选择指标之一。

The Difference Between Starch Chain Length Distribution and Main Quality Characteristics of High Resistant Starch Lines of Japonica Rice

【Objective】 Providing a theoretical and practical basis for breeding and germplasm enhancement by means of genetic analysis on resistant starch content in japonica rice. 【Method】 Using japonica rice lines with significant differences in resistant starch content , this paper analyses differences and correlation of amylopectin chain length distribution, RVA spectral properties value, dietary fiber and amylose content and other quality characteristics between them. 【Result】 The chain length distribution of amylopectin shows significant differences between high and low resistant starch content strains . For the high resistant starch content strains, the relative percentage of the degree of short chain polymerization 5 to 12 about amylopectin content, which is obviously lower than low resistant starch content strains. However, the degree of polymerization in long chain (particularly above 13 proportions) is obviously higher than the low ones. Dietary fiber and amylose content of high resistant starch content is higher than that of low ones. And the peak viscosity, cool paste value, hot paste viscosity and breakdown value of high resistant starch content is significantly or very significantly lower than that of the low ones. The polymerization degree (DP≤12) of short chain amylopectin shows very significantly negative correlation to resistant starch content. On the contrary, the very significantly positive correlation between resistant starch content and the proportion of polymerization degree (12＜DP≤36) of long chain amylopectin, and the amylose content and the dietary fiber content was observed. 【Conclusion】 The resistant starch content is closely related to amylopectin chain length distribution, amylose content, RVA spectral properties value. Therefore, it could be used as a breeding index.