不同地区香蕉枯萎病菌4号生理小种生物学特性及ITS序列分析

香蕉枯萎病菌4号生理小种的传入给我国香蕉产业带来严重威胁。利用核糖体基因(rDNA)及其内转录间隔区(ITS)序列分析对采自广东省和云南省不同地理环境的香蕉枯萎病菌4号生理小种菌株进行系统发育研究。结果表明,广东和云南两省菌株的遗传距离为0.002,两省菌株的同源性高达99.8%,以NJ法建立系统树分析表明,云南和广东两省菌株的亲缘关系很近,但仍存在一定差异。广东、云南不同地区菌株的生物学基本特性比较研究表明,两地区菌株在生长速率、菌落直径和产孢量等方面差异较大。与采自广东的菌株相比,采自云南的菌株接种香蕉后发病较早、产孢量高。此外,采自广东的菌株略嗜酸性,云南地区的菌株略嗜碱性。

Biological characteristics and ITS sequence analysis of strains Fusarium oxysporum f.sp.cubense race 4 from different regions of Guangdong and Yunnan province

Strains Fusarium oxysporum f.sp.cubense race 4 was introuduced into China and the serious threat was brought for our country’s banana industry.This research analysis recombinant deoxyribonucleic acid(rDNA) and ITS sequence to conduct the phylogenetic study for strains Fusarium oxysporum f.sp.cubense race 4 from different regions of Guangdong and Yunnan province.The results showed that the ITS sequence of Yunnan strains has similarity of 99.8% to Guangdong strains and the genetic distance of strains between two provinces was 0.002.Established the phylogenetic tree by NJ method,we found that strains of Yunnan and Guangdong provinces was close,but there is still some difference.The studies showed that the strains from different regions have great differences in colony growth rate,the diameter and the spores quantity.So the sporulation of earlier onset strains in Yunnan province was high comparing with the strains in Guangdong province after inoculation.In addition,the strains from various regions of Guangdong were different from the strains of Yunnan in terms of the pH.The former preferred slightly acidic and the latter preferred slightly alkaline.