On Pathogenicity Differentiation Of Botrytis Cinerea And Relationship Between Pathogenicity And Cell-wall-degrading Enzyme Activities

In this paper,the isolates of Botrytis cinerea Pers from different hosts were used as the tested microorganism.The pathogenicity of the tested isolates to different hosts and the activities of cellulase and pectinase of the isolates were investigated respectively, and the relationship between the pathogenicity and the cell wall degrading enzyme activities was analsed.The results showed that there were significant differentiation in pathogenicity among the tested isolates of Botrytis cinerea from different districts of Anhui Province.And there was a very significant linear correlation between the pathogenicity and the two cell wall degrading enzyme activity produced by Botrytis cinerea Pers.The results were as follows:1 Pathogenicity differentiation of Botrytis cinerea from different hosts1.1 Pathogenicity differentiation of B.cinerea from different hosts to tomatoEighteen isolates of Botrytis cinerea were obtained from the diseased plant tissue collected in Hefei,Bengbu,Changfeng and Hexian in Anhui province,by means of tissue isolating method.The pathogenicity of the isolates of B.cinerea from different hosts to the fruits and leaves of tomato were investigated by applying wound inoculation with mycelial blocks.The results showed that all of the tested isolates caused grey mould on tomato fruits,but there was significant difference in the average diameters of the lesions caused by different isolates,suggesting that there was significant differentiation in pathogenicity of B.cinerea strains to tomato fruits among isolates.According to the average diameters of the lesions on tomato fruits,the pathogenicity of the all isolates was classified into three categories:strong,intermediate and weak.In general,the isolates from tomato were more strongly pathogenic to tomato fruits than the isolates from strawberry,grape and capsicum.However,there was difference in pathogenicity among the different isolates from the same host,and the pathogenicity difference was not obviously related to the localities of isolates.After inoculation of tomato leaves,all of the tested isolates except CF3 caused grey mould on tomato leaves,but there was significant difference in the average diameters of the lesions caused by different isolates;and the difference in pathogenicity to tomato leaves was not obviously related to the host and locality of isolates.1.2 Pathogenicity differentiation of B.cinerea from different hosts to capsicum, strawberry and grapeThe pathogenicity of the isolates of B.cinerea from different hosts were investigated on capsicum,strawberry and grape by applying mycelial block wound inoculation,respectivily.The results of test showed that there were significant differences in pathogenicity to the same host among the different isolates from different hosts,and in the pathogenicity of the same isolate to different hosts.There was also difference in pathogenicity among the different isolates from the same host to the same hosts or the different hosts.However,there was difference in pathogenicity of the isolates from the same or different district.These all proved that there was significant differentiation in pathogenicity of B.cinerea isolates from different hosts of different localities in Anhui,and the pathogenicity of the isolates was not obviously related to the locality source of isolates.Moreover,the results of test showed that there was no obvious host speciality in B. cinerea isolates.which could infect the different host plants.2 Cell wall degradating enzyme activities of Botrytis cinerea and their relationship to the pathogenicityThe cellulase and pectinase of B.cinerea isolates were extracted from their culture filtrate.The activities of cellulase and pectinase of the isolates were investigated respectively,and the relationship between the pathogenicity and the cell wall degrading enzyme activities was analsed.The results indicated that there was significant difference in two enzyme activities of different B.cinerea isolates.There was some correlation between the expansion rate of the lessions caused by B.cinerea and the activities of pectinase and cellulase.The tests indicated that the relationship of pathogenicity of B. cinerea and the activities of pectinase and cellulase was of positive correlation. Therefore,testing of the activities of pectinase and cellulase could be a rapid valid method for measuring the pathogenicity of the pathogen.It was suggested that both cellulose and pectinase were the pathogenic enzymes of B.cinerea.