云南省昆明市玉米白斑病病原菌鉴定及致病性测定

Identification and Pathogenicity of the Pathogens of Maize White Spot in Kunming City of Yunnan Province

采用组织分离、活体接种、形态学和分子生物学鉴定方法,对云南省昆明市玉米白斑病病叶进行病原菌分离、致病性测定及种类鉴定。结果分离得到15株菌株,其中,9株为致病菌,菌株SL-56-2、JX-E466-15和JXE600-1的致病性最强,发病最快,使玉米叶片产生典型白斑症状;JX-E466-13、JX-E466-12和SL-547-3使玉米叶片产生黄白色小病斑;JX-E102-1、SL-24-8和SL-24-3产生稍大黄白色病斑。形态学及系统发育树结果显示,SL-56-2、JX-E466-15和JX-E600-1为Epicoccum sorghinum,JX-E102-1、SL-24-8和SL-24-3为E.dendrobii,JX-E466-13、JX-E466-12和SL-547-3为附球菌属未定种。研究表明,E.sorghinum为昆明市玉米白斑病的优势致病种,由E.dendrobii引起的玉米白斑病属首次报道。

Using tissue separation,inoculation in vivo,morphological and molecular study methods,the pathogens of maize white spot in Kunming city of Yunnan province were isolated,the pathogenicity of the isolates were tested and the pathogens were identified,respectively.The results showed that,15 strains were isolated,wherein 9 strains were pathogens.In addition,SL-56-2,JX-E466-15 and JX-E600-1 showed the strongest pathogenicity,with the fastest onset,which could produce typical white spot symptoms on maize leaves.Except that,JX-E466-13,JX-E466-12 and SL-547-3 could produce small yellowish white and JX-E102-1,SL-24-8 and SL-24-3 could produce slightly large yellowish white spots on maize leaves.Based on morphological characteristics and a phylogenetic tree analyzed,the results showed that,SL-56-2,JX-E466-15 and JX-E600-1 were identified to be Epicoccum sorghinum,JX-E102-1,SL-24-8 and SL-24-3 were identified to be E.dendrobii,JX-E466-13,JX-E466-12 and SL-547-3 were identified to be undetermined specie of Epicoccum Link.These results indicated that E.sorghinum to be the dominant one and E.dendrobii to be a new pathogen reported firstly.