新疆小麦品种中多酚氧化酶(PPO)活性基因等位变异的分布

Distribution of Allelic Variations of Polyphenol Oxidase Genes in Xinjiang Wheat Cultivars

为了给新疆选育低PPO活性的小麦品种以及进行面制品色泽的改良提供依据,利用PPO基因的功能标记PPO18、PPO16和PPO29,检测了252份新疆小麦品种(系)(包括农家品种、国内外引进品种和20世纪60年代以来的育成品种)中2A和2D染色体上PPO等位基因Ppo-A1a(高PPO活性)、Ppo-A1b(低PPO活性)、Ppo-D1a(低PPO活性)和Ppo-D1b(高PPO活性)的分布。结果表明,含有Ppo-A1a、Ppo-A1b、Ppo-D1b和Ppo-D1a基因型的频率分别为69.0%、31.0%、13.1%和86.9%,以Ppo-A1a和Ppo-D1a基因型为主;两个PPO基因的等位基因组合Ppo-A1a/Ppo-D1b(高PPO活性)、Ppo-A1a/Ppo-D1a(中等偏高PPO活性)、Ppo-A1b/Ppo-D1b(中等偏高PPO活性)和Ppo-A1b/Ppo-D1a(低PPO活性)的分布频率依次为9.9%、59.1%、3.2%和27.8%。总体来看,新疆小麦品种PPO活性中等偏高的材料最多。农家品种、引进品种和育成品种的PPO活性基因分布频率存在明显差异,其中具有Ppo-A1b/Ppo-D1a等位基因组合类型(低PPO活性)的分布频率依次为21.3%、33.3%和27.1%。共检测出了70个具有Ppo-A1b/Ppo-D1a等位基因组合类型(低PPO活性)的品种(系),并且新疆育成的冬小麦品种(系)携有Ppo-A1b/Ppo-D1a等位基因组合类型(低PPO活性)的数量比春小麦要多,可在培育低PPO活性品种时作为杂交亲本利用。

In order to understand the presence of four allelic variants of Ppo-A1a（with high PPO activity）,Ppo-A1b（with low PPO activity）,Ppo-D1b（with high PPO activity） and Ppo-D1a（with low PPO activity） among Xinjiang common wheat cultivars,a total of 252 wheat lines,including landraces,cultivars and lines bred during 1960s to present in Xinjiang,cultivars and advanced lines introduced from overseas and other provinces of China,were used to investigate the distribution of allelic variations of PPO genes on chromosomes 2A and 2D by functional markers PPO18,PPO16 and PPO29.The results indicated that the frequencies of cultivars with genotypes of Ppo-A1a,Ppo-A1b,Ppo-D1b and Ppo-D1a were 69.0%,31.0%,13.1% and 86.9%,respectively.The genotypes of Ppo-A1a and Ppo-D1a were the major types among all wheat collections.Frequencies of allelic combinations of PPO gene for Ppo-A1a/ Ppo-D1b,Ppo-A1a/ Ppo-D1a,Ppo-A1b/ Ppo-D1b and Ppo-A1b/ Ppo-D1a were 9.9%,59.1%,3.2% and 27.8%,respectively.Wheat cultivars with medium to high PPO activity were dominant in Xinjiang.The frequencies of four PPO genotypes were different dramatically in landraces,cultivars bred in Xinjiang and introduced cultivars,the frequencies of genotypes with Ppo-A1b/Ppo-D1a（with lowest PPO activity） were 21.3%,33.3% and 27.1%,respectively.In total,70 cultivars or lines with genotype of Ppo-A1b/Ppo-D1a were identified,and the quantities of winter wheat cultivars or lines with this genotype were more than that of spring wheat cultivars or lines.Therefore,using the PPO markers to test parents and segregating generations in breeding programs would be helpful to select the individuals with low PPO activity,and accelerate the progress for the improvement of color quality of wheat-based end products.