无毒基因在不同寄主梨孢菌中的变异研究  

Variability of avirulence genes in Pyricularia isolates from different hosts

作　　者：余欢[1,2] 姜华[2] 王艳丽[2] 孙国昌[2] 

机构地区：[1]杭州师范大学生命与环境科学学院,浙江杭州310036 [2]浙江省农业科学院植物保护与微生物研究所,浙江杭州310021

出　　处：《浙江农业学报》2015年第8期1414-1421,共8页Acta Agriculturae Zhejiangensis

基　　金：公益性行业(农业)科研专项经费资助(201203014);浙江省公益技术研究农业项目(2013C32019);浙江省重大科技专项(2012C12901-1&2)

摘　　要：梨孢菌除侵染水稻外,还可侵染禾本科和莎草科等多种植物,已有研究表明稻区草类寄主的梨孢菌与稻瘟病的发生有关。无毒基因在水稻—稻瘟病菌互作系统中扮演了重要角色,并且无毒基因经常发生变异,可以利用无毒基因变异的特性来研究梨孢菌群体的遗传多样性。对35株草类寄主的梨孢菌进行系统进化分析,这些菌株被分为两类,一类是寄主为马唐的菌株,另一类是寄主为牛筋草和狗尾草的菌株。筛选了27对无毒基因引物,对这些草类寄主梨孢菌进行扩增,结果表明无毒基因在这些菌株中的变异类型有完全缺失、插入、不完全缺失、多位点,其中完全缺失为主要的变异类型。进一步对无毒基因的扩出率进行统计,结果表明,供试菌株中没有菌株同时含有所有已克隆的无毒基因,此外,所有供试菌株均没有AVR-Pik/km/kp,PWL3和PWL4基因,以马唐为寄主的菌株中没有ACE1,AVRPiz-t,AVR-Pita1和PWL1;以牛筋草为寄主的菌株中没有AVR-Pia,AVR-Pita1,AVR-Pita2和PWL2;以狗尾草为寄主的菌株中没有AVR-Pii,AVR-Pia,PWL1和PWL2。Pyricularia fungi could infect not only rice, but also many other gramineous and cyperaceous plants. Many reports indicated that Pyricularia strains from grass around paddy field had relationships with the occurrence of rice blast, and avirulence （AVR） gene played an important role in rice-blast interaction. AVR genes were often variable and could be used to study the diversity of genetic structure of Pyricularia strains. The present study constructed neighbor-joining （NJ） trees to analyze 35 Pyrictdaria strains isolated from grass hosts. The results showed that the isolates were divided into two groups, isolates from Digitaria sanguinalis was a distinct phylogenetic group, and the other isolates from Eleusirve indica and Setaria viridis were another phylogenetic group. Meanwhile, 27 pairs of prim- ers were selected to amplify AVR genes from these isolates. The results indicated that the mutation types of AVR genes in these isolates included complete deletions, insertion, partial deletions and multiple fragments, and the main mutation type was complete deletion. We also carried out the statistics to analyze the amplification rate of AVRgenes, which implied that none of these isolates contains all AVR genes, and AVR-Pik/km/kp, PWI_3 and PWIA cannot be amplified in all strains. Moreover, ACE1, AVRPiz-t, AVR-Pital and PWL1 were not contained in isolates from Digitaria sanguinalis, and there was no AVR-Pia, AVR-Pital, AVR-Pita2 and PWL2 amplification in isolates from Eleusine indica, and no A VR-Pii, A VR-Pia, PWL1 and PWL2 amplifications in isolates from Setaria viridis.

关 键 词：梨孢菌 草类寄主 无毒基因 变异 

分 类 号：S432.44[农业科学—植物病理学]