稻米出饭特性QTL分析及遗传研究

Mapping and Genetic Analysis of Quantitative Trait Loci for Related Traits of Cooked Rice

米粒长、饭粒长和饭粒延伸系数等性状与米饭品质密切相关。以籼稻台中本地1号(TN1)与粳稻春江06为亲本构建的加倍单倍体群体为材料,利用全基因饱和分子标记连锁遗传图谱对多个稻米出饭特性相关的性状进行QTL定位,共检测到14个QTL。其中,米粒长和米粒浸长QTL各1个,均位于第2染色体上,分别可以解释性状变异的15.20%和18.50%;1个米粒浸泡膨胀率QTL,位于第6染色体上,可解释性状变异的13.39%;1个煮饭粒长QTL,位于第9染色体上,可解释性状变异的13.60%;3个蒸饭粒长QTL,分别位于第1、3和12染色体上,共解释性状变异45.00%;4个煮饭延伸率QTL,分别位于第3、6、9和10染色体上,共解释性状变异61.30%;3个蒸饭延伸率QTL分别位于第1、3和6染色体上,共解释性状变异49.10%。在已知的Wx和ALK基因所在区域都检测到了米饭延伸性相关的QTL。相比较而言,覆盖ALK基因的QTL对出饭特性的影响更大,LOD值达到了6.35。该研究结果可为稻米出饭特性相关调控基因的克隆奠定基础,同时对稻米品质的改良及高产优质稻品种的分子标记辅助选育提供理论参考。

The milled rice length, cooked rice length and elongation traits are very important in the quality of cooked rice. Map ping of quantitative trait locus （QTL） for cooked rice related traits was conducted using a doubled haploid population from a cross between a typical indica rice cultivar ‘TN1’ and a typical japonica rice cultivar ‘Chunjiang 06’. Using a linkage map based on 177 SSR molecular marker loci covering the distance of 1670. 92 cM, a total of 14 QTLs were identified for the cooked rice related traits. One putative QTL for milled rice length and one for soaked rice length were mapped on chromosome 2, with the explained variance of 15.20% and 18. 50%, respectively. One putative QTL for soaked rice expansion was mapped on chromosome 6, with the explained variance of 13.39%. One putative QTL for boiled rice length was mapped on chromosome 9, with the explained variance of 13.60%. Three QTLs for steamed rice length were detected on chromosomes 1, 3 and 12, totally explaining variance of 45.00%. Four QTLs for boiled rice elongation were detected on chromosomes 3, 6, 9 and 10, totally explaining variance of 61.30%. Three QTLs for steamed rice elongation were detected on chromosomes 1, 3, and 6, totally explaining variance of 49.10%. Two QTLs for elongation related traits of cooked rice were detected on the Wx gene cluster and ALK gene cluster, respectively. Comparing to the Woe gene cluster, the QTL. in the ALK gene cluster played a much more important role in regulation of related traits of cooked rice with the LOD score of 6.35. These results provide a foundation for further cloning of genes that regulate cooked rice related traits and a theoretical basis for the improvement of rice cooking quality and marker-assisted breeding of high yielding and high quality rice varieties.