杨树腐烂病菌与不同寄主互作后致病力分化研究

Study on Pathogenicity Differentiation of Cytospora chiysosperma and Different Hosts After Interaction

将DSYS菌株接种到新疆杨、银白杨、胡杨和灰杨枝条及叶片上进行发病率、显症时间、产孢体出现时间、病斑扩展速度的研究结果表明,DSYS菌株均能使4种不同寄主健康的枝条发病,在胡杨和灰杨枝条上第3 d开始显症,显症时间最早;在新疆杨枝条上第10 d开始显症,显症时间最晚,且产孢体形成需要时间最长达到14 d;在银白杨枝条上病斑扩展速度最快,为1.46 cm/d。DSYS菌株经历不同寄主培养后,继代菌株在病斑扩展速度和发病特征上发生明显分化现象,在新疆杨和灰杨连续培养3代后病斑扩展速度呈增加趋势且达到显著性差异,在胡杨连续培养3代后病斑扩展速度没有达到显著性差异,在银白杨上连续培养后病斑扩展速度在继2代与继1代和继3代表现上有显著性差异。

Inoculation of DSYS strains to Populus bolleana,Populus alba,Populus euphratica and Populus pruinosa.The disease incidence,display time,formation time of sporulation and the lesion extended speed,the DSYS strains was inoculated to Populus bolleana,Populus alba,Populus euphratica and Populus pruinosa for continuous culture and acquired1generation strains,2generation strains and3generation strains,andwas inoculated to populus bolleana for pathogenicity evaluation.The results showed that DSYS strains were able to cause4different hosts healthy branches of disease,in Populus euphratica and Populus pruinosa branches on the beginning of the first3days syndrome,the earliest manifestation of time,in Populus bolleana branches on the first10days began to show the disease,the most late,and the formation of spore-forming need time to reach14days;The1.46cm/d was the fastest in the Populus alba branches.After the DSYS strains underwent different hosts cultures,the apparent differentiation of subculture strains on the rate and characteristics of disease plaque growth.after3generations of continuous culture of Populus bolleana and Populus pruinosa,the rate of plaque expansion showed an increasing trend and significant difference,and the rate of disease plaque expansion did not reach significant difference after3generations after continuous culture.The rate of plaque expansion was significantly different between the2generation strains and1generation strains and3generation strains after continuous culture on the Populus alba.