四川省小麦条锈菌耐高温性鉴定及其cDNA文库构建

摘要

近年条锈菌越夏调查发现，小麦条锈菌耐高温性增强，越夏海拔下限有所降低。本研究通过在高温（21±0．2）℃条件下接种，评价了119个来自四川省的条锈菌菌株耐高温性，并构建了耐高温菌株 SC-PX143萌发夏孢子的 cDNA 文库。结果发现来自四川的条锈菌群体中耐高温菌株占35．3％，主要分布在成都市、凉山市、简阳市和广元市。夏孢子萌发率统计分析表明，耐高温菌株在高温条件下比温度敏感菌株具有更高的萌发率。采用SMART 技术构建了耐高温菌株萌发夏孢子 cDNA 文库，库容为2．1×106 cfu，插入片段平均多大于1．0 kb。本研究结果初步明确了四川省小麦条锈菌群体中耐高温菌株组成和分布区域，不同菌株在夏孢子萌发阶段对高温的耐受性存在显著差异，为进一步研究条锈菌耐高温机制奠定基础。%In the oversummering surveys of stripe rust pathogen in recent years,it was found that high-tempera-ture tolerance of the pathogen has been enhanced and the lowest elevation of the oversummering areas declined. In this study,we inoculated stripe rust isolates at high temperature (21±0.2)℃ to assay the high-temperature tol-erance of 119 stripe rust isolates from Sichuan Province,and constructed a cDNA library of the germinated uredio-spores of a high-temperature tolerant strain SC-PX1 4 3.The results showed that 35.3% of the 119 isolates were high-temperature tolerant,mainly distributed in Chengdu,Liangshan,Jianyang and Guangyuan.In addi-tion,high-temperature tolerant isolates had a higher germination rate under high temperature (21±0.2)℃ than the temperature sensitive ones.SMART technology was used to construct a cDNA library with the germinated ure-diospores of a high-temperature tolerant isolates.The total capacity of the cDNA library was 2.1×106 cfu,and most insert cDNA fragments were more than 1.0 kb in length.We preliminarily made clear the composition and distribution areas of high-temperature tolerant wheat stripe rust strains from Sichuan,and there was significant difference in high-temperature tolerance of stripe rust strains during urediniospore germination stage.These results will promote the further studies of high-temperature tolerance mechanism of wheat stripe rust pathogen.