糜子GBSSI基因的遗传多样性及其对籽粒蒸煮品质的影响

Proso millet (Panicum miliaceum L.) was domesticated in China some time around 10,000 BP. There are abundant grenplasm resources in Northwest, Central China and Inner Mongolia. The Waxy gene encodes glucose bound starch synthase (GBSS) in cereals, and the recessive allele (wx) has loss of function of the enzyme. Since proso millet is a tetraploid, the Waxy gene has two loci, derived from its diploid ancestors. In this study, the GBSSI gene from proso millet will be cloned and genetic diversity of the gene will be analyzed and identified in 120 landraces from different locations. Further, the grain quality traits of each landrace will be phenotyped by the method of viscosity measurement (RVA), and association analysis will be conducted to find the relationships between the GBSSI polymorphisms and the phenotypic appearances of grain quality. Some associated molecular markers with grain quality will be identified. The findings from this study will shed further light on proso millet genetics research and breeding for grain quality improvement.

糜子起源于我国，具有丰富的资源。其糯性胚乳性状由分别来自两个不同二倍体祖先种的隐性位点 (wx) 控制。由Waxy编码的颗粒结合淀粉合成酶I（GBSSI）基因的突变会影响直链淀粉的合成，引起胚乳粳糯性质的变化。本项目以前期收集的120份来自不同生态区的我国糜子资源为材料，参考谷子基因组序列，克隆糜子GBSSI基因，分析我国糜子资源GBSSI基因遗传多样性；同时运用粘度速测仪（RVA）法，评价不同生态区糜子品质性状；进一步将GBSSI多态性变异与糜子蒸煮品质性状进行关联性分析，分析不同的基因型对品质性状的影响，开发与品质性状关联的分子标记。研究结果理论上明确我国糜子GBSSI基因的多态性及与品质的关系，实践上为优异糜子资源筛选和糜子育种奠定基础。