尖孢镰刀菌致病性菌株遗传多样性的ISSR分析

肖荣凤　陈燕萍　朱育菁　詹洪　刘波　葛慈斌

摘 要 致病性尖孢镰刀菌（Fusarium oxysporum）是一种世界性分布的作物土传病原真菌，为明确其不同寄主及专化型菌株遗传差异性和亲缘关系，利用ISSR分子标记技术对来源于不同寄主（专化型）及地理分布的43个菌株进行了遗传多样性分析。结果表明，供试的15条引物通过ISSR-PCR 扩增，共扩增出147条条带，其中多态性条带为144条，平均多态性条带达98.0%。43个菌株的聚类结果表明，各菌株间的遗传相似系数为0.67～0.97，且遗传多样性与其寄主和地理来源没有明显的相关性。进一步将供试菌株中葫芦科与茄科作物尖孢镰刀菌分别进行聚类分析，当遗传相似系数为0.84时，16个葫芦科的菌株可分为6个ISSR类群；当遗传相似系数为0.77时，16个茄科的菌株亦可分为6个ISSR类群；且均表现为相同寄主或专化型菌株因地理来源不同，被归属于不同的ISSR类群，说明寄主或专化型相同的菌株与地理来源存在一定的相关性。

关键词 尖孢镰刀菌；专化型；ISSR-PCR；遗传多样性

中图分类号 S43；Q78 文献标识码 A

Abstract Pathogenic Fusarium oxysporum is one of the most common soil-borne fungal pathogens all over the world. To specify genetic difference and phylogenetic relationship of F. oxysporum strains，the genetic diversity of 43 strains with different host and geographic origin or formae speciales strains was analyzed using the ISSR-PCR molecular marker technique. The results showed that 147 fragments were amplified from 43 strains by 15 tested primers. Among them， the polymorphic band was 144，which accounted for 98.0% in the total amplified fragments. The ISSR analysis showed that genetic similarity coefficient was 0.67-0.97， suggesting a high genetic variability within 43 strains. However， the results did not reveal a clear relationship between variability and the host/geographic origin. The isolates from cucurbitaceae and solanaceae crops were further performed the cluster analyses of genetic variability， respectively. At the level of 0.84，16 isolates from cucurbitaceae crops could be obviously divided into six ISSR groups. At the level of 0.77， 16 isolates from solanaceae crops could be also obviously divided into six ISSR groups. Moreover， these F. oxysporum isolates from the same host or formae speciales strains could be divided into different ISSR groups due to their different geographic origin. The results indicated that there was a relationship in a certain degree between variability and geographic origin within the isolates from the same hosts or the same formae speciales strains.

Key words Fusarium oxysporum；Formae speciales；ISSR-PCR；Genetic diversity

doi 10.3969/j.issn.1000-2561.2015.11.014

由尖孢镰刀菌（Fusarium oxysporum）引起的作物枯萎病是一种世界性分布的土传病害，也是造成作物连作障碍的主要原因之一。该病菌可危害各种作物，一般造成20%～30%产量损失，严重者可导致绝收[1-4]。该病原菌在遗传上十分复杂，且极易发生变异，导致菌株间的差异较大，仅靠传统的形态学分类和致病性检测进行种间及种内鉴定，难以准确揭示物种的进化关系。目前，ISSR分子遗传标记技术由于其稳定性和重复性较好、操作简单快速、所需DNA量少、不需要活体材料、也没有组织特异性等特点[5-6]，在多种植物病原菌的遗传多样性研究中得到应用[7-10]。……