我国主要梨产区梨腐烂病菌培养表型与致病力差异的研究

[目的] 旨在研究我国主要梨产区不同培养表型的梨腐烂病菌的致病力差异。[方法] 从全国13个省、市、自治区采集梨腐烂病样品,通过组织分离法共分离鉴定出465株梨腐烂病菌,在PDA培养基上观察其培养表型并进行分类;挑选出128株菌株,采用打孔法接种菌丝块测定各菌株在’库尔勒香梨’上的致病力。[结果] 根据所分离的菌株在PDA培养基上的菌落颜色及形态不同粗分为5类,各类菌株均能产生多种类型的子座,菌株的不同培养性状与其地理来源并无关联;在梨果上,不同分离菌株的致病力存在明显分化,但是菌株的致病力差异与其地理来源及培养性状并无关联,且将菌株致病力进行强、中、弱划分后,发现中等致病力的菌株占64%,为优势菌株。[结论] 我国的梨腐烂病菌存在多样的培养性状,且菌株的致病力分化明显,中等致病力的菌株占多数,但是菌株的培养性状、致病力及其地理来源这三者之间并无关联,因此要深入了解梨腐烂病菌,还需从菌株的致病基因入手,采用分子生物学手段对其进行研究。
[Objectives] We carried out this study to analyze different culturing phenotypes and pathogenicity of pear Valsa canker pathogens isolated from China’s main pear production areas. [Methods] Samples from 13 provinces,municipalities and autonomous regions were collected. Using tissue isolation,we identified 465 pear Valsa canker pathogens,observing and classifying their culturing phenotypes on PDA plate. Then we selected 128 strains,inoculating their mycelium block in’Korla Pear’by punching method to measure pathogenicity. [Results] Depending on the different colors of the colonies and their morphology on PDA plate,we roughly divided them into five categories,each type of strains producing different kinds of conidium devices. The different characters among these strains weren’t related to their origins. In pears,the pathogenicity of strains were obviously different unrelated to origins or culturing phenotypes,dividing the pathogenicity into strong,middle and weak types,and the strains with middle pathogenicity were the dominant group,about 64%. [Conclusions] There are diverse culturing phenotypes of pear Valsa canker pathogens in our country,and the strains are obviously different in pathogenicity,the strains with middle pathogenicity were in the majority,but there’re no correlation among culturing phenotypes,pathogenicity and origins. Therefore,we should use molecular biology method to study the disease genes and make a further study of pear Valsa canker pathogens