Powdery Mildew Identification Of Physiological Races In Some Areas Of Xinjiang And Genetic Analysis Of Resistant In Edible Seed Watermelon

Powdery mildew is widespread occurred disease throught the world on the Cucurbitaceaesuch as melon, cucumber and pumpkin. Cucurbitaceae powdery mildew mainly induced bythe pathogenic fungus, which includes6different kinds of species.It is reported thatS.fuliginea has been found11races and E.cichoracearum has2races. According to relativestudies recently, various pathogens physiological races could cause melon powdery mildewdifferent from countries and regions.In this research the identification test for powdery mildew physiological races strictlyapplied international standard system. We chose ten samples of powdery mildew pathogenswhich was collected from7sites in6regions of Xinjiang. In inheritance resistance analysistwo sets of “D18”、“S216”, each of six generation plantets was infected in the greenhouseinoculation or field natural incidence, counting the later generation resistance or susceptibleseparation ratio within Parents、F1、F2andBC1、BC2, analysised by chi-square test. Theconclusion as following:1、 Identification test initially showed that8samples from Aletai, Changji, Yili andTacheng belong to race1. As the basis survey results in asmall range afew years agodetermined that the race1is the powdery mildew dominant race in north Xinjiang.2、 Two samples of powdery mildew, which is from Bazhou,Kashi in south ofXinjiang are physiological race5,but no relative reports before,so it could not be confirmedthe dominant physiological race at present.3、 Greenhouse inoculated with powdery mildew genetic resistance analysis suggestedthat resistant material“D18”、“S216”resistance to powdery mildew is controlled by a singledominant gene.4、 Field powdery mildew genetic resistance analysis suggested that powdery mildew iscontrolled by a single dominant gene. The resistant material ’D18’ F2generation separationdoes not comply with the chi-square test, to infer the occurrence of powdery mildewinfluenced by the environment, when the field environment does not meet the conditions ofonset, significantly reduced the incidence.