Use of SSR and AFLP techniques for race characterization of Fusarium oxysporum f.sp. lycopersici

Abstract

For race and genetic differentiation, fifteen isolates of Fusarium oxysporum f. sp. lycopersici (Fol):four reference races [Fol1 (race 1), Fol2 (race 2), Fol3A (race 3), Fol3N (race 3)] and eleven isolates collected fromtomato cultivated field in Thailand, were investigated by using the Simple Sequence Repeat (SSR) and Amplified Fragment Length Polymorphism (AFLP). The results demonstrated that the differentiation of Fol was obtainedusing SSR technique with 6 pairs of fluorescent labeling primers was carried out with automated DNA sequencer(ABI PRISMTM 377 DNA Sequencer). A dendrogram constructed by using a similarity matrix derived from 18polymorphic SSR fragments could be classified 15 isolates into two main groups as the pathogenic and non -pathogenic groups, except 2 isolates of CM3 (non - pathogen) and Fol3N (pathogen), which were in opposite group.The isolates of KK1, KK2, KK3 and KK4 could be identified when the addition primers were used. DNA fingerprintsof these fungi using AFLP technique and 11 combination primers (E-AAG/M-CAA, E-AAG/M-CTC, E-AAG/M-CAG, E-AAG/M-CAC, E-AAC/M-CAA, E-ACT/M-CTA, E-ACT/M-CTT, E-ACT/M-CAA, E-ACT/M-CAT,E-ACG/M-CAA and E-ACG/M-CAC) showed an obvious difference of each isolate. The Fol1 (race1) wasdiscriminated from Fol2 (race2), Fol3A (race3) and Fol3N (race3) Nevertheless, the result from cluster analysiscould not discriminate pathogenic from non - pathogenic isolates.