Identification of Physiological Races of Powdery Mildew on Cucumis melo ssp. melo in Xinjiang

【Objective】In order to breed new melon varieties of resistant powdery mildew,the physiological races were identified in Xinjiang.【Method】Twelve strains of powdery mildew were collected from melons under different conditions in different cultivation sites of Xinjiang.Physiological races were identified on the strains by using thirteen internationally differential hosts.【Result】The observation form microstructure Podosphaera xanthii(P.xanthii)indicated that the twelve melon powdery mildew strains were P.xanthii.They were highly susceptible to IranH,Topmark,Vedrantais and Nantais Oblong,immune to PMR5,PMR6 and PMR45,highly resistant to WMR 29 and Edisto 47,resistant to PI 414723,PI 124111,PI 124112 and MR1.It occurred as the same as race 1 of P.Xanthii.【Conclusion】It could be preliminarily confirmed that physiological race of melon powdery mildew was race 1 of P.Xanthii.and no other races were discovered in Xinjiang Region.