STS标记在扬麦158×淮麦18F_4群体中的应用及其与PPO活性的关系

The Application of STS Marker in Yangmai158 × Huaimai18 F_4 Separating Plant Lines and its Relations with PPO Activity

小麦籽粒中的多酚氧化酶活性是导致酶促褐变的主要因素。选育低多酚氧化酶活性的品种是改良面制食品外观品质的重要途径之一。本研究利用位于小麦2A和2D染色体上PPO基因分子标记PPO18和STS01,对扬麦158×淮麦18组合的300个F4代分离株系进行PCR扩增,说明不同带型与PPO活性的相关性。结果表明用PPO18扩增的300个分离株系中有59个扩增出876bp(2Aaa型)的目标片段,其活性均值为82.01;46个同时扩增出685bp和876bp的目标片段(2Aab型)其活性均值为163.41;其余195个扩增出685bp的目标片段(2Abb型)其活性均值为233.73。方差分析表明三者的PPO活性差异达到极显著水平,其中基因型为2Aaa型的PPO活性值明显低于2Abb型;PPO18在本试验群体中对PPO活性的决定系数为66.61%;用STS01扩增的300个株系中都扩增出了560bp的片段,群体间没有差异。文中说明了两对引物在该群体中的效应及其与PPO活性的关系。

Polyphen ol oxidase （PPO） activity is the major factor of resulting the brown discoloration of wheat-end-products. It is an important way to breed new wheat cultivars with low PPO activity in order to improve their quality in appearance. Two STS markers PPO18 and STS01 were used to screen the 300 F4 separating plant lines derived from a cross Yangmai158 × Huaimai 18 and validate the correlation between the polymorphic fragments of PPO 18, STS01 and grain PPO activity. The results indicated that PPO 18 could amplify 685 bp and 876 bp in different genotypes. 59 plant lines with the genotype 2Aaa showed low PPO activity （mean value： 82.01）; 46 plant lines with the genotype 2Aab showed middle PPO activity （mean value： 163.41）; the rest 195 plant lines with the genotype 2Abb showed high PPO activity （mean value： 233.73）. The R-square of this maker （PPO18） in the separating plant lines is 66.61% of phenotypic variance for PPO activity. PPO18 is an efficient and reliable molecular marker for PPO activity and can be used in wheat breeding programs so as to choose low PPO activity cultivars. All plant lines amplified 560 bp fragments using STS01. The article also evaluated the two markers for their feasibility in breeding programs.