籼粳杂种后代支链淀粉结构及其与稻米糊化特性相关性分析

The Relationship between Amylopectin Structure and Rice Pasteproperty of Indica/Japonica Cross Progenies

为了探讨利用优质粳稻改良灿稻品质的可行性,以食味品质极佳的粳稻品种越光为母本、食味品质差的籼稻品种桂朝2号为父本构建的重组自交系群体(RIL)为试验材料,研究了籼粳杂种后代的支链淀粉结构变异特征及其与稻米胶稠度、起始成糊温度和RVA谱特征值的相关关系。结果表明,在RIL群体中,所有性状呈现连续分布,且双向超亲分离明显,双亲平均值除最高粘度和崩解值低于低亲值外,其余性状均介于双亲之间。RIL群体中支链淀粉短链(6≤DP≤11)分配比率表现为籼型<偏籼型<偏粳型<粳型,中链(12≤DP≤24)分配比率表现为籼型>偏籼型>偏粳型>粳型,存在极少量短链分配率较高而中链分配率较低的灿型株系,说明利用优质粳稻与籼稻杂交,其后代的籼粳特性对稻米支链淀粉结构有较显著影响,但通过加强后代选择,也可以选到支链淀粉结构象粳型的优良株系。在RIL群体中,支链淀粉短链分配率与起始成糊温度呈极显著负相关,中链分配率与起始成糊温度呈极显著正相关,长链分配率与消减值呈极显著负相关关系,而支链淀粉链长与胶稠度和RVA谱其他特征值的相关性表现因种植地点不同而有差异。研究结果为灿粳亚种间杂交育种的品质改良提供了理论参考。

In order to study the feasibility of improving rice quality of indica by high quality japonica variety. A recombinant inbred line（ RIL） population derived from the cross between Koshihikari,an elite japonica variety with superior grain quality,and Guichao2,an indica variety with poor grain quality,was used to investigate the relationship of amylopectin structure with gel consistency（ GC）,pasting temperature（ PT） and RVA profile. The result showed that the distributions of all traits in RIL population were continuous and transgressive segregations were obviously observed.The means of all traits in the RIL populated fell between two parents except for peak viscosity（ PKV） and breakdown viscosity（ BDV） which had lower mean values than the small value parent. In the RIL population,the short-chain ratio of 6≤DP≤11 in different type lines was in the order of Indica-type Indicaclinous-type Japonicaclinous-type Japonica-type and the intermediate-chain ratio of 12≤DP≤24 was in the order of Indica-type Indicaclinous-type Japonicaclinous-type Japonica-type,very few Indica lines with higher short-chain ratio and lower middle-chain ratio as Koshihikari were observed. This indicated that although the Indica-Japonica characteristics have significant correlation with amylopectin structure in Indica /Japonica cross progenies,elite lines as Japonica type could be bred by intensive screening. Correlation analysis revealed that the short-chain ratio had very significantly negative correlation but the intermediate-chain ratio had very significant positive correlation with PT,the longer chain ratio had very significant negative correlation with setback viscosity（ SBV）. The correlation of chain length of amylopectin with GC and the other RVA profile properties were different in different planting locations. The result could provide theoretical refrence for quality improving in indica-japonica cross breeding.