Pathogen Diversity Of Apple Valsa Canker In Shanxi Province

Apple rot decay is a black leather case of pathogenic bacteria cause disease stems,resulting in a decline in yield and quality apple;Known as the apple tree "cancer".Rot disease severely restricts the healthy development of apple industry in Shanxi Province.So far,about the apple tree canker pathogen species diversity structure in Shanxi Province,there is no system study,the serious influence to the prevention of the disease.This study rot of apple’s main areas of Shanxi Province has carried on the systematic research,from the pathogen pathogenicity,pathogen system development,pathogen morphology and biological characteristics of 5 aspects are studied.The results of the study summarized as follows:1,Through the survey found that apple tree canker symptoms in Shanxi Province are mainly local cortical ulcer decay and branches die two types,give priority to with ulcer type.Apple trees rot scar number and the size and the average disease recurrence rate increases with the increase of tree age;Different parts of the same age of orchard rot disease,there is a big difference,is closely related to the management level of the garden,but the incidence of rot is gradually increasing with the increase of tree age.2,2013-2015,in yuncheng,linfen,jinzhong 8 areas,such as,it is mined here,243 specimens,133 strains pathogenic bacteria were isolated from pure.This study phylogenetic study(ITS genes)was used to construct phylogenetic tree method was studied and morphology(colony morphology and microscopic morphology)of apple’s main areas of Shanxi Province with the methods of system identification of decomposing bacteria,clear V.m ali and Valerie plame yri apple rot pathogenic bacteria for Shanxi Province.3,under the condition of temperature 22℃,humidity 45%,V.m ali and Valerie plame yri can infect apple branches,v.Mali disease of apple trees force stronger than v.pyri.Vaccination v.Mali strain of disease spot expanding quickly,after 7 d after disease spot,on average,5.8 cm long,15 d disease spot to produce a large number of black conidium,some branches disease spot appeared yellow conidium Angle,vaccination Valerie plame yri strain of disease spot after extension slower disease spot,on average,2.8 cm long,after 7 d after 10 d disease spot produces gray conidium.4,shanxi apple rot pathogen v.Mali colony color is divided into grey and brown two types,v.pyri colonies with a white,milky white.Compared the two v.pyri hypha growth rate faster,conidium generated earlier and large.5,has been clear about the decomposing bacteria,sensitive to temperature when the temperature is greater than 51.25℃,the bacteria conidium germination rate declined obviously;When the temperature is greater than 47.50℃,the loss of vitality of the hypha.