水稻和狗尾草来源稻梨孢的鉴定及其交互侵染作用分析

Identification and Cross-infectivity Analysis of Pyricularia oryzae from Rice and Green Bristlegrass

稻梨孢除了能侵染水稻,引起稻瘟病造成严重产量损失外,还能侵染多种禾本科作物和杂草。为了探究水稻来源稻梨孢与狗尾草来源稻梨孢之间是否具有交互侵染作用,本研究以水稻和狗尾草叶片病斑上分离得到的101株稻梨孢作为研究对象。经形态学鉴定,101株菌株都为稻梨孢。对15株代表菌株进行肌动蛋白、β微管蛋白和钙调蛋白基因扩增,构建系统发育树,发现基于钙调蛋白和3个基因联合构建的系统发育树中水稻来源菌株聚为1个分支,狗尾草来源菌株聚为1个分支,表明稻梨孢存在种群分化现象。52株水稻来源稻梨孢可以侵染狗尾草,49株狗尾草来源稻梨孢不能侵染水稻。因此,种植水稻时应及时清除稻田周围杂草,以减少稻梨孢野生寄主数量。

Pyricularia oryzae not only infects rice causing blast and leading to heavy yield loss,but also infects many crops and weeds in Gramineae.In order to investigate whether or not cross-infectivity exist between P.oryzae isolates from rice and green bristlegrass,in this study,a total of 101 isolates were isolated from rice and green bristlegrass.These isolates were P.oryzae based on morphological characteristics.Actin,β-tubulin and calmodulin genes of fifteen representative isolates were amplified and sequenced.Phylogenetic trees were constructed.P.oryzae isolates from rice were clustered into a clade,and isolates from green bristlegrass were clustered into a clade in the phylogenetic tree based on calmodulin and the tree based on combined 3 genes sequences.These results demonstrated that population subdivision within P.oryzae.Fifty-two isolates from rice could infect green bristlegrass,and forty-nine isolates from green bristlegrass could not infect rice.Therefore,when planting rice weeds around rice fields should be eliminated timely to reduce the number of alternate hosts.