The Distribution Of Downy Mildew In Xinjiang And Identification Of Infecting-disease Property On Plasmopara Viticola To The Germplasm Resource Of Grape

Xinjiang grape production regions are divided into serious occurrence region, constantoccurrence one, second-rate permanent occurrence one and no occurring one by conductinginvestigations the occurring of Downy Mildew from2009to2012and historical occurrenceand getting climatic conditions during May and August. Yili river valley represents seriousoccurrence region and is the most serious one in Xinjiang, which causes serious damage toproduction. The main climatic characteristics are abundant rainfall and high relative humidityand popular frequency is higher than other regions in Xinjiang. Constant occurring region ismainly these areas along Tianshan mountains in northern Xinjiang, which includes Changji,Shehezi, Kuitun, Bole etc. The main climatic characteristics in the region are less rainfall andlower relative humidity than these of Yili river valley and Downy Mildew often can occur andpopular frequency is lower. But in the years with more rainfall, infection occurred seriously.The main climatic characteristics in second-rate permanent occurrence region involvingAkesu, Kuerle and Atushen are between those in constant occurring one and no occurring one,and it may resulted in economic lost in some more rainfall years.The results from identification of15different resistance grape cultivars to Plasmoparaviticola by excised leaves inoculation indoor, leaf inoculation in field and natural infection infield were analyzed by correlation analysis with DPS. The results showed that results of threemethods were consistent and the correlation coefficients were above0.95. The feasibilities ofthree identification methods were compared that inoculating leaf tissues indoors was aneffective method for grape cultivars resistance to Plasmopara viticola because it was simple,fast, reliable and easy to control.In order to test the resistance of grape germplasm resources to Plasmopara viticola,excised leaves inoculation indoor and natural infection in field were studied during two years.The results showed that there were apparent difference in resistance of grape germplasmresources to Plasmopara viticola, and most American vines and Franco-american were moreresistant than Eurasian. There was no immune material in the83grape germplasm resources,Catawba was highly resistant (HR),9kinds of Beichun were resistant (R),45kinds of Flameseedless were susceptible (S), and28kinds of Red Globe were highly susceptible (HS).By identification of excised leaves inoculation indoor and natural infection in field andobservation of grape leaves pubescence and stomatal density under scanningelectron-microscope, preliminary clear that pubescence, in a way, block the invasion ofPlasmopara viticola. there was no obvious relationship with contents of Ca and K in grapeleaves in cultivar resistance by determining contents of Ca and K in leaves.