稻瘟病菌在中国鉴别品种及CO39近等基因系上的致病型分析

稻瘟病是影响水稻高产、稳产的主要病害之一,在中国的大多数稻区都有发生.崇阳、远安是湖北省稻瘟病常发区,在两地采集稻瘟病穗颈瘟标本,从中分离得到60个稻瘟病菌单孢菌株(崇阳、远安两地的菌株各30个),分别在中国鉴别品种和CO39近等基因系上进行致病型鏊定,发现60个单孢菌株接种于CO39近等基因系6个品种上,在可能的26个致病类型中出现了20种,小种丰富度为2.54,优势类型为I 37.1.相同的60个单孢菌株在中国鉴别品种上出现4群13个小种,小种丰富度1.22,优势种群与前几年的一致,均为ZA群.

Pathotype Structure of Pyricularia grisea in Chinese Host Differentials and CO39 NILs

In this study,single spore of blast was isolated from the rice-growning fields of Chongyang and Yuan'an in Hubei province where rice blast occurred frequently.60 isolates were pathotyped against two sets of host differentials:Chinese host differentials and CO39 NILs.20 of the 60 pathotypes that were possible with the six indica host differentials (CO39 NILs) were observed,while 4 race groups 13 pathotypes were observed out of the same single spore isolates with Chinese host differentials which consists of three indica cultivars and four japonica cultivars.The diversity of the pathotypes of Pyricularia grisea populations tested by CO39 NILs was 2.54 and the pathotype I 37.1 occurred at predominantly high frequency (21.67%).The diversity of physiological races of pyrieularia grisea populations tested by Chinese host differentials was 1.22 and the race group ZA occurred at predominantly high frequency (73.33%).Compared with other results obtained in the similar study in other years,this result did not show obvious difference in the structure of pathotypes of Pyricularia grisea.The diversity of physiological races of pyrieularia grisea in Chongyang and Yuan'an were also caleulated.Overall,the diversity of pathotypes of Pyricularia grisea in Yuan'an was higher than that in Chongyang's with the two sets of the host diffrentials.