Authors : Noushin Shafagh , Mahrokh Falahati Rastegar and Behrouz Jafarpour
Abstract: Fusarium wilt of melon, caused by Fusarium oxysporum f.sp. melonis is one of the most important diseases of this crop, which annually causes tremendous losses. Because of the importance of this disease in Northern and Razavi Khorasan provinces, race identification and genetic diversity of the pathogen was investigated by using the differential standard hosts cultivars and molecular marker RAPD. Total 15 from 20 isolates which obtained from 52 fields located at different geographical regions were identified as pathogenic in pathogenicity test. In formae speciales test, seedling of melon, cucumber, watermelon and pea were used and typical symptoms of disease observed on melon plants only, therefore F. oxysporum f.sp. melonis was identified as the cause of wilting disease in melon. At race determination test, differential hosts were used and the existence of race 1 in the regions was proved. The result of RAPD-PCR bands showed a polymorphism among population of this fungus. Cluster analysis showed that there are 7 genotypic groups in Fusarium oxysporum f.sp. melonis population which designated as A to G.
Noushin Shafagh , Mahrokh Falahati Rastegar and Behrouz Jafarpour , 2008. Physiological Race and Genetic Diversity Determination of Fusarium oxysporum f.sp. melonis by Differential Hosts and Molecular Marker Rapd in Northern and Razavi Khorasan Provinces . Research Journal of Biological Sciences, 3: 790-793.