青海小麦籽粒硬度等位变异研究

为了解小麦品种籽粒硬度的遗传多样性,利用单粒谷物硬度测定、PCR扩增和核苷酸测序技术,分析了66份青海小麦品种籽粒硬度主效基因的等位变异。结果表明,青海小麦以硬质类型为主,比例达到47.0%,混合麦比例为19.7%,软质麦比例为33.3%。硬度基因有5种组合类型:野生型、Pina-D1a/PinbD1b、Pina-D1a/Pinb-D1c、Pina-D1a/Pinb-D1x和Pina-D1b/Pinb-D1a。野生型小麦类型比例最高,占59.09%,SKCS硬度指数平均为44.12,变化范围为12.75~84.89。突变类型的品种籽粒均为硬质。因此,在青海硬质小麦可以通过突变类型的分子标记进行选育,软质小麦选育需在利用硬度基因分子标记筛选的基础上进一步考察籽粒硬度性状的表现型。

Genetic Variation of Grain Hardness of Wheat Cultivars in Qinghai Province

Grain hardness is an important trait in wheat, affecting the quality of final products. Research about genetic diversity of grain hardness can provide theoretical guidance for wheat quality improvement. In this study, single kernel characterization system(SKCS), PCR and nucleotide sequencing were employed for evaluating genetic diversity of grain hardness of wheat cultivars in Qinghai province. According to hardness value, 31 hard, 13 semi-hard and 22 soft wheat cultivars were classified in 66 Qinghai wheat cultivars. The hardness values of 8 cultivars were less than 30, which mean they could be used for biscuit. Five types of Puroindoline gene combinations existed in these cultivars. They were wild-type, Pina-D1a/Pinb-D1b, Pina-D1a/Pinb-D1c, Pina-D1a/Pinb-D1x and Pina-D1b/Pinb-D1a. The proportion of wild-type reached 59.09%. The average hardness value of wild type was 44.12, and range was from 12.75 to 84.89. Wheat varieties with wild-type Puroindoline gene were not always soft, but almost all cultivars with mutation Puroindoline were hard. Thus, molecular markers can be used for hard wheat breeding in Qinghai province, while the phenotype should be taken to consideration more seriously in soft wheat cultivar breeding except molecular marker.