中国大麦种质资源Wx蛋白分析及糯大麦分子标记验证

利用1D-SDS-PAGE分析了中国167份不同直链淀粉含量类型的大麦种质资源Waxy 蛋白类型，发现在低直糯大麦和无直糯大麦两种类型中，可能存在四种生化遗传变异类型。其中有两种与无直糯大麦有关，一种是Wx基因可以正常转录，但转录产生的Wx蛋白无活性，不能催化直链淀粉合成；另一种是Wx基因不能正常转录，既无Wx蛋白产生，也无直链淀粉合成。另外两种与低直糯大麦有关，一种是Wx基因可以正常转录，但转录产生的Wx蛋白活性有限，催化直链淀粉合成的功能降低；另一种是Wx基因不完全正常转录，产生的Wx蛋白数量有限，影响直链淀粉合成。利用4个大麦与小麦的STS标记和2个大麦与小麦的SSR标记对不同Wx蛋白类型进行糯性鉴定，结果表明，迄今利用的Wx基因的STS引物P1可能只适合用于CDC Candle遗传类型相同的糯大麦品种或基因型的鉴定。其它标记均不能用于鉴定大麦糯性胚乳表型，因此当前对于糯大麦育种及Wx分子鉴定研究而言，还有待于开发新的分子标记。

Analysis of Wx Protein in Chinese Barley Germplasm Resources and Validation of Molecular Markers on Waxy Barley

The different Wx protein types for different amylose content in Chinese barley germplasm resources were analyzed by 1D-SDS-PAGE. The results indicated there could be four types of biochemical genetics in the low and no amylose barley. Among them two types were related to no amylose content barley, in one of which waxy gene could transcribe normally, but the enzyme waxy protein produced has no catalytic activity of amylose synthesis. In another of which waxy gene could not transcribe normally and no waxy protein produced. In the third type, waxy gene could transcribe normally, but catalytic activity of waxy protein was low. In the fourth type waxy gene could only partly transcribe and produce insufficient waxy protein. Four STS and two SSR markers in Wx gene of wheat and barley were used to validate waxy barley accessions with different types of Waxy proteins. The results showed that the primer P1, the STS primer of Wx gene used so far, could only identify waxy barley cultivars which were as same genetic type as CDC Candle. The other markers could not identify waxy endosperm phenotype in barley. Therefor new molecular markers should be tapped for breeding and Wx molecular validation of waxy barley.