尖角突脐孢菌紫外光诱变及高致病力菌株的筛选  

Screening of Exserohilum monoceras UV-induced mutants for high pathogenicity

作　　者：董朝霞 钟锦 俞雯雯 洪鑫发 陈勇[2] DONG Zhaoxia;ZHONG Jin;YU Wenwen;HONG Xinfa;CHEN Yong(College of Forestry and Landscape Architecture,South China Agricultural University,Guangzhou 510642,China;College of Agriculture,South China Agricultural University,Guangzhou 510642,China;Ruyuan County Branch of Guangdong Tobacco Shaoguan City Co.,Ltd.,Shaoguan 512700,China)

机构地区：[1]华南农业大学林学与风景园林学院,广东广州510642 [2]华南农业大学农学院,广东广州510642 [3]广东烟草韶关市有限公司乳源县局分公司,广东韶关512700

出　　处：《南京农业大学学报》2022年第2期269-279,共11页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(31672039);国家重点研发计划项目(2017YFD0201300)。

摘　　要：[目的]尖角突脐孢菌(Exserohilum monoceras)是生物防治中防治稗草(Echinochloa crusgalli(L.)Beauv)的病原真菌之一。本研究通过紫外光诱变并筛选出对稗草高致病力的尖角突脐孢菌诱变株。[方法]通过紫外光诱变获得诱变菌株并检测诱变株产孢量、离体叶片致病力和稗草植株病情指数,筛选出对稗草高致病力的尖角突脐孢菌诱变株;对筛选出的高致病力菌株进行分子鉴定及生物学特性研究,并对其安全性进行研究。[结果]根据不同紫外光照射时间处理后菌株的死亡率,确定最佳诱变时间为25 min;检测诱变株产孢量、离体叶片致病力和活体稗草植株病情指数,筛选出4株高致病力诱变菌株,提取4株诱变菌株基因组DNA,对其ITS序列比对分析表明,4株诱变得到的菌株与尖角突脐孢菌的序列相似度为98%;出发菌株和诱变株仅对高粱有轻微的侵染,一段时间后,高粱恢复正常;但对其他7种作物安全。[结论]紫外光诱变尖角突脐孢菌的最佳时间为25 min;诱变株X27-UV148、X27-UV48、X27-UV45和X27-UV286为高致病力尖角突脐孢菌,为生物防治提供了优异的新材料;紫外光诱变提高了尖角突脐孢菌耐紫外线、耐高温和耐低温的能力。[Objectives]Exserohilum monoceras is one of the important pathogenic fungi of Echinochloa crusgalli(L.)Beauv in biological control.In this study,we used ultraviolet light to mutagenize and screen out a mutant strain of E.monoceras that was highly pathogenic to barnyardgrass.[Methods]Mutagenic strains by UV mutagenesis were obtained and the spore production,the pathogenicity of the detached leaves and the disease index of the barnyardgrass plants were detected,and the mutagenic strains that were highly pathogenic to barnyardgrass were screened out;molecular identification and biological characteristics of the highly pathogenic strains were screened out,and their safety were investigated.The study on the biological characteristics of mutants was performed,such as,the conidial production and pathogenicity of the mutagenesis strain,colony growth,spore germination rate,anti-ultraviolet ability thermal tolerances,and the indoor safety of the mutagenic strain to main crops by using spore suspension.[Results]The best mutation time was 25 minutes according to the mortality of the strains treated with different UV irradiation time;by detecting the spore yield,pathogenicity of leaves in vitro and disease index of barnyardgrass in vivo,four mutant strains with high virulence were screened;the genomic DNA of four mutant strains were extracted,and sequencing and comparative analysis showed that the sequence similarity of the four strains was 98%with that of Echinochloa crusgalli(L.).The results showed that the original strain and the UV-induced mutants only slightly infected sorghum,and sorghum returned to normal after a period of time.But it was safe for the other seven crops.[Conclusions]The optimum time for UV mutagenesis of Exserohilum monoceras was 25 minutes.The mutants X27-UV148,X27-UV48,X27-UV45 and X27-UV286 were high virulence strains,which provided excellent new materials for biological control.UV mutagenesis also improved the ability of Exserohilum monoceras to resist UV,high temperature and low temperature.

关 键 词：尖角突脐孢菌 稗草 紫外光诱变 致病力 

分 类 号：S435[农业科学—农业昆虫与害虫防治]