The Screening And Genetic Analysis Of Polyphonel Oxidase (PPO) Activity In Wheat

The enzyme polyphenol oxidase(PPO)activity of F₃ progenies from wheat crosses Yannong 19×Annong0016 and Yannong 19×Annong98017 were measured with the methods of using whole-meal and DOPA or catechol as substrate.Subsequently,the analysis of genetic models of single segregated generation on PPO activities in the combination Yannong19×Annong0016 and Yannong19×Annong98017(F₃ groups)was carded out. The enzyme polyphenol oxidase(PPO)activity in wheat kernel was measured with the methods of different extraction using catechol as substrate.The results showed as follows:1 Because of the different density and size of single wheat kernel,the correlation coefficient between repetitions of the method of single kernel is small.The determination coefficient(R²)between repetitions of the method of 15 kernels in beaker was 0.9727.The correlation coefficient(r)is 0.89 between this method and the method of using spectrophotometer.The method of 15 kernels in beaker is a good extraction way by microplate reader.2 The mean PPO activity in the progrnies from Yannong19×Annong98017 is 419.1 AU/(min*g).The most PPO avtivity is 260.0-620.0AU/min*g.3 PPO activity tested by catechol method is highly significant correlated with that by DOPA method and the correlation coefficient is as high as 0.907 in the progrnies from Yannong19×Annong0016.Therefore,these PPO activity assays are very useful for screening breeding materials and genetic analysis.4 PPO activity of the two crosses(Yannong19x×Annong0016 and Yannong19×Annong98017)are controlled by two major genes and heritability are very high.The effects of first major genes is higher than second ones in cross of Yannong19×Annong0016,but for Yannong19×Annong98017,the effects of two major genes are high equal.