杧果畸形病病原菌的营养体亲和性研究

Vegetative compatibility of Fusarium mangiferae strains from mango malformation disease

【目的】为了解我国杧果畸形病病原菌Fusarium mangiferae的营养亲和性及营养亲和群类型,【方法】以采自四川攀枝花市和云南华坪县等不同地区和不同杧果品种的38个畸形病病原菌为材料,在含KClO3培养基上诱导筛选。【结果】共获得抗氯酸盐、不能还原利用硝酸盐营养突变体(nit)455株,通过MM、NM、HM等3种不同氮源培养基划分出nit A、nit B、nit C、nit D 4种突变类型,其中nitA出现频率最高,占总体的78.02%;nit B和nit C其次,分别占7.91%和13.63%;nitD最少,仅占0.44%。采用nit突变体互补型配对技术,将获得的突变菌株进行配对培养,测得不同的营养体亲合群(VCGs)数为5个,其中VCG1内包含30个菌株,3个菌株分布在VCG2内,VCG3和VCG4内各含有2个菌株,菌株MG33单独形成VCG5。【结论】我国杧果畸形病病原菌存在丰富的营养亲和群类型,分析发现F.mangiferae的营养亲和群种类和杧果品种、地理来源间无明显相关性。

【Objective】In order to explicit the vegetative compatibility groups（VGC） of Fusarium mangiferae,【Method】the nitrate-nonutilizing（nit） mutant complementation technique was used to explore the population structure of the fungus.【Result】The 38 strains of F.mangiferae were isolated from different mango cultivars from Panzhihua,Sichuan and Huaping,Yunan Providence in China.The tested single-conidium strains were then transplanted on KClO3-containing potato sucrose agar（KPS） plates to mutagenize nit mutants and 455 nit mutants were recovered from the isolates by transferring chlorate-resistant sectors from KPS plates to minimal medium（MM）.The four mutant types were identified as nit A,nit B,nit C and nit D based on the growing situation of the mutants on three kinds of different nitrogen media,MM,nitrite medium（NM） and hypoxanthine medium（HM）.Among the four types,nit A was the most common one,with the frequency of 78.02%.Next were nit B and nit C,with the frequency of 7.91% and 13.63% respectively.The least one was nit D,0.44%.The nit mutants then were paired on MM plates to test the vegetative compatibility of all isolates,and totally five different VCGs were identified.38 strains were assigned to 5 VCG,30 strains in VCG1,3 strains in VCG2,VCG3 and VCG4 contains 2 strains,respectively,strain MG33 formed separate VCG5.【Conclusion】The correlation between vegetative compatibility of F.mangiferae and mango cultivars or geographical origin was insignificant.