珠海香蕉枯萎病菌遗传多样性的AFLP分析

为了解广东省珠海地区香蕉枯萎病菌(Fusarium oxysporumf.sp.cubense)的种群分化和遗传变异规律,采用AFLP技术对来自珠海、湛江、台山的20株尖孢镰刀菌(Fusarium oxysporum)进行DNA指纹分析,以1株分离自粉蕉的木贼镰刀菌(F.equiseti)为外参。20株尖孢镰刀菌中17株来自珠海,包括3株非致菌、2株香蕉枯萎病1号生理小种、12株香蕉枯萎病4号生理小种,2株来自湛江的为香蕉枯萎病4号生理小种,1株来自台山的为香蕉枯萎病1号生理小种。8对AFLP引物对供试菌株扩增出253条带,其中多态性带97条,占总带数的38.34%,供试菌株的遗传距离变化在0.21~0.99,平均为0.85。利用NTSYSpc软件中的UPGMA算法构建了21株镰刀菌的AFLP亲缘树状图,聚类结果表明:供试菌株被聚为3个大的类群,分别为1号生理小种、4号生理小种以及非致病性尖孢镰刀菌。亲缘关系分析结果表明:1号生理小种内菌株间的遗传分化大于4号生理小种,其聚类结果与菌株的地理来源有一定的相关性。总体而言,珠海地区香蕉枯萎病菌的遗传多样性较为丰富。

Genetic Diversity of Zhuhai Isolates of Fusarium oxysporum f. sp. cubense Revealed by AFLP Analysis

In order to study the population subdivision and genetic variation of Fusarium oxysporum f. sp. cubense in Zhuhai of Guangdong Province, amplified fragment length polymorphism （AFLP） was used to analyze the DNA fingerprint of 20 different isolates of Fusarium oxysporum from Zhuhai, Zhanjiang and Taishan. One isolate of F. equiseti （FOC017） from tissues of Musa ABB was chose to be biological control. 17 isolates of Fusarium oxysporum were from Zhuhai, including 12 Foc race 4 isolates, 2 Foc race 1 isolates and 3 non-pathogenic isolates. Two Foc race 4 isolates from Zhanjiang and one Foc race 1 isolates from Taishan. The results showed that a total of 253 AFLP bands were obtained using 8 primer combinations, and 97 of them, covering 38.34% , showed polymorphism. Genetic distance of 21 isolates ranged from 0.41 to 0.95, averaged 0.85. Results of UPGMA analysis divided 21 tested isolates into three major groups, which was race 1, race 4 and non-pathogenic Fusarium oxysporum. AFLP analysis revealed that the diversity level of race 1 was greater than that of race 4 and there was a correlation between AFLP groups and geographic origin of tested isolates.The results indicated that the genetic diversity of F. oxysporum f. sp. cubense was high among tested isolates from Zhuhai.