不同抗性香蕉品种遗传多样性的ISSR分析

Genetic diversity analysis for different wilt disease resistant bananas by ISSR

利用香蕉枯萎病的病原菌尖孢镰刀菌古巴专化型4号生理小种,对巴西蕉、粤科1号、粤科3号、抗枯1号、粉杂1号、农科1号等香蕉品种进行离体叶片的病原菌接种试验,结果显示,不同香蕉品种对枯萎病的抗性存在明显差异,其中巴西蕉最感病,其他品种都具有不用程度的抗性。对不同香蕉品种(包括抗枯5号)进行ISSR分子标记试验,从100条ISSR引物中筛选出19条扩增效果好、多态性高、重复性好的ISSR引物用于遗传多样性分析,共检测到121个条带,其中98个为多态性条带,多态性比率达81.0%;记录ISSR标记的多态性数据,用NTSYS2.10e软件计算得到Dice相似性系数为0.57～0.94,表明香蕉品种间遗传背景丰富,UPGMA法聚类将7个香蕉品种分为两大类群。综合分析表明,不同香蕉品种对枯萎病的抗性强弱与其遗传相似性之间没有明确的相关性。

Using Fusarium oxysporum f.sp.Cubense race 4 and 6 banana varieties, including Baxi, Yueke No.l, Yueke No.3, Kangku No.I, Fenza No.l, and Nongke No.l, disease test experiments by in vitro leaf inoculation were conducted. The results showed that 6 different banana varieties had different resistance to Fusarium wilt disease, Baxi was the most susceptible, and other varieties had different degree of resistance. ISSR molecular marker experiments were carried out for 7 banana varieties including Kangku No.5, 19 ISSR primers, which had good amplification effect, high polymorphism, and good repeatability, were screened out from i00 ISSR primers for genetic diversity analysis. Totally 121 bands were detected, and 98 bands had polymorphism among 7 banana varieties, the polymorphism ratio was 81.0%. Transferred ISSR polymorpbism into data, using NTSYS2.10e software to compute the Dice similarity coefficient, the similarity coefficient was between 0.57-0.94, it indicated that 7 banana varieties had abundant genetic diversities, and were divided into two groups by UPGMA cluster method. Combining the disease test and genetic diversity analysis results, it showed that disease resistance of banana varieties to Fusarium Oxysporumf.sp.cubense race 4 had no clear relationship with their genetic diversities.