Isolation,Identification And Control Of Pathogens Of Sweet Cherry Gummosis Disease

The sweet cherry（Prunus avium L.）belongs to the subspecies Cerasus of the Rosaceae family.It has a hard,crisp,full-feeling and unique taste.It is currently one of the "consumption growth fastest fruit".But the gummosis disease,one of the three major diseases of cherries,has become a key factor hindering the sustainable and healthy development of the cherry industry with the increase of sweet cherry planting.at present,scholars at home and abroad have not studied the pathogenic mechanism of sweet cherry gummosis disease deeply,and research on its prevention and control is rare.this paper will study the types of pathogens and biological characteristics of the pathogens causing sweet cherry gummosis disease,and screen out the agent that can effectively inhibit sweet cherry gummosis disease,so that there is a certain scientific basis for in-depth study of the inhibition mechanism and the improvement of prevention and control.This article cuts from the following three aspects:Firstly,the tissue isolation method was used to isolate and purify the pathogens in the branches of sweet cherry with obvious gelling phenomenon,and the biological status of the pathogen in sweet cherry was determined by morphological analysis,pathogenicity detection and molecular biological identification.Inducing pathogens to produce conidia through three stress modes:nutritional deficiencies,near-ultraviolet irradiation,and colony scratch;Secondly,the plate culture method was used to explore the biological characteristics and the lethal temperature range of pathogen by taking temperature,nitrogen source,carbon source,pH and light as factors.Finally,with the pathogen as the research object,the indoor virulence determination of 5 kinds of agents was determined to screen out the agent that can effectively control the gummosis disease of sweet cherry.1.Three predominant strains were obtained by isolating and purifying colloidal branches:strain Ⅰ,strain Ⅱ,and strain Ⅲ.According to Koch’s postulates,the pathogenic strain was identified as strain Ⅲ.On the morphological analysis and the ITS sequence,the EF-la sequence analysis judgment,strain III for Botryosphaeria dothidea;2.The segmental structure of the hyphae of Botryosphaeria dothoidea is prominent,containing the transverse septa and branching like a tree.most of the hyphae can be wound into a network structure.Lack of nutrients,near-ultraviolet irradiation,and colony scratching can induce a large number of conidia.The conidia are ovoid or ellipsoid,with different sizes and aggregation;3.Temperature,nitrogen source,carbon source,pH and light are all important conditions for the growth of Botryosphaeria dothidea:the best temperature is 28℃;The best nitrogen sources are sodium nitrate and potassium nitrate;The best carbon source is glucose;the best pH is 6.0;the best light-dark ratio is 12h:12h alternating illumination;the lethal temperature range of Botryosphaeria dothidea in water bath for 20 min was 50-55℃;4.Among the tested agents,ferulic acid,zinc sulphate and caffeic acid have antibacterial effects on Botryosphaeria dothidea and ferulic acid had the best antibacterial effect with EC₅₀ of 7.16 mM;the bacteriostatic effect of zinc sulfate and caffeic acid was the second,EC₅₀ was 25.57 mM and 91.62 mM,respectively;sodium hydrosulfide and ethyl pyruvate had no inhibitory effect on pathogen;...