Vegetative compatibility and rep-PCR DNA fingerprinting groups of Fusarium solani isolates obtained from different hosts and their pathogenicity

Fusarium solain is the most important pathogen of huge range of plant hosts, especially potato in the word, which causes tuber rot in storage and root rot of potato plants in fields. Fifty four isolates from potato, bean, chickpea and cucurbit (melon, watermelon and cucumber) was subjected in a study through analysis of vegetative compatibility groups (VCGs) and rep-PCR DNA fingerprinting. Nit mutants were used to force heterokaryon formation to determine VCGs and Twenty three groups were determined which designated as VCG A to VCG W. VCG A, was the largest group with 18 members and VCG B, VCG C and VCG D were composed of 8, 6 and 3, respectively. Other groups were identified as two or single-member VCGs. Presence of high single-member VCGs indicates that there is a high level of genetic diversity among isolates and isolates of each host classify in different VCGs. Dendrogram generated using data of rep-PCR, suggests high level of genetic diversity among the isolates and no correlation between DNA fingerprinting groups and host and geographical origin of the isolates. Pathogenicity of twenty three F. solani isolates as VCGs representatives originated from mentioned hosts was examined on plants and tubers of Agria cultivar of potato. Except four and two isolates, other isolates were pathogenic on potato plants and tubers. Pathogenicity tests distinguished that F. solani isolates do not have host specific behavior and isolates obtained from non-potato hosts are able to cause disease on potato plants and tubers.