Groenewald Susan, Van Den Berg Noëlani, Marasas Walter F O, Viljoen Altus
Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, South Africa.
Mycol Res. 2006 Mar;110(Pt 3):297-305. doi: 10.1016/j.mycres.2005.10.004. Epub 2006 Feb 14.
Fusarium oxysporum f. sp. cubense (Foc) is responsible for fusarium wilt of bananas. The pathogen consists of several variants that are divided into three races and 21 vegetative compatibility groups (VCGs). Several DNA-based techniques have previously been used to analyse the worldwide population of Foc, sometimes yielding results that were not always consistent. In this study, the high-resolution genotyping method of AFLP is introduced as a potentially effective molecular tool to investigate diversity in Foc at a genome-wide level. The population selected for this study included Foc isolates representing different VCGs and races, isolates of F. oxysporum f. sp. dianthi, a putatively non-pathogenic biological control strain F. oxysporum (Fo47), and F. circinatum. High-throughput AFLP analysis was attained using five different infrared dye-labelled primer combinations using a two-dye model 4200s LI-COR automated DNA analyser. An average of approx. 100 polymorphic loci were scored for each primer pair using the SAGA(MX) automated AFLP analysis software. Data generated from five primer pair combinations were combined and subjected to distance analysis, which included the use of neighbour-joining and a bootstrap of 1000 replicates. A tree inferred from AFLP distance analysis revealed the polyphyletic nature of the Foc isolates, and seven genotypic groups could be identified. The results indicate that AFLP is a powerful tool to perform detailed analysis of genetic diversity in the banana pathogen Foc.
尖孢镰刀菌古巴专化型（Foc）可引发香蕉枯萎病。该病原菌由多个变种组成，这些变种被分为三个生理小种和21个营养体亲和群（VCG）。此前已使用多种基于DNA的技术来分析Foc的全球种群，有时得出的结果并不总是一致。在本研究中，引入了AFLP高分辨率基因分型方法，作为一种潜在有效的分子工具，用于在全基因组水平上研究Foc的多样性。本研究选取的种群包括代表不同VCG和生理小种的Foc分离株、尖孢镰刀菌石竹专化型的分离株、一种假定无致病性的生防菌株尖孢镰刀菌（Fo47）以及轮枝镰刀菌。使用五种不同的红外染料标记引物组合，通过双染料4200s LI-COR自动DNA分析仪实现了高通量AFLP分析。使用SAGA(MX)自动AFLP分析软件，对每个引物对平均约100个多态性位点进行评分。将五种引物对组合产生的数据合并，并进行距离分析，包括使用邻接法和1000次重复的自展检验。从AFLP距离分析推断出的一棵树揭示了Foc分离株的多系性质，并且可以识别出七个基因型组。结果表明，AFLP是对香蕉病原菌Foc的遗传多样性进行详细分析的有力工具。
