[Objective]Pear fire blight is a devastating bacterial disease that affects pear trees.It spreads quickly and widely,which is extremely harmful and difficult to control.Understanding the level of resistance to pear fire blight of pear germplasm resources at home and abroad is important for the construction of pear fire blight resistance resources and resistance genes as well as the selection and breeding of disease resistant varieties.[Method]The isolated branches of 90 pear germplasm resources were inoculated with strong pathogenic bacteria of Erwinia amylovora by using the technique of artificial inoculation of isolated the young annual branches for identification.Observe the branch and leaf lesion characteristics after inoculation,and by comparing the branch incidence and disease index of different pear germplasm resources after inoculation with the pathogenic bacteria,the disease resistance evaluation index of pear germplasm resources was formulated to comprehensively evaluate the disease resistance level of pear germplasm resources for testing.[Result]All 90 pear germplasm resources had different degrees of pathogenicity.The resistance level of pear fire blight varied significantly among the 90 pear germplasm resources,with the incidence rate ranging from 20%to 100%,among them,'Yeshan pear'had the lowest incidence(20%).There were 68 pear germplasm resources with 100%incidence of all,accounting for 75.56%of the total measurements.The disease index ranged from 8.89 to 100,among them,'An pear'had the lowest disease index(8.89),'Hanxiang'had the highest disease index(100).The disease resistance level among the 90 pear germplasm resources for testing was generally low.No highly resistant varieties were found,there were 2 resistant varieties,which only accounted for 2.22%of the total number of measurements.There were 8 medium resistant varieties,which accounted for 8.89%of the total number of measurements.The genetic background of the resistant germplasm showed Asian pears＞European pears.[Conclusion]10 pear germplasm resources are identified as having better resistance to pear fire blight,including'An pear''Longyuanxiang''Longyuanyanghong''Ganlizao 6''Bayuehong''Jinmi pear''Zaosu''Fenlao''Hanhong''Shuofeng pear',which can be used as resources for pear fire blight resistance breeding.This study may provide a reference for the breeding of pear fire blight resistance and the mining of related resistance genes.
NETL
NSTL
万方数据
