Identification of genetic variability among isolates of Fusarium oxysporum f. sp. vasinfectum of cotton

Abstract

Fusarium wilt of cotton caused by Fusarium oxysporum f.sp. vasinfectum (FOV) causes yield losses, especially in the States of São Paulo and Paraná. The disease can mainly be controlled by the use of resistant cultivars, and knowledge regarding the genetic diversity among isolates of the pathogen has become essential. Diversity among 15 isolates collected from different Brazilian cotton-producing States was studied along with one isolate of F. solani, using molecular techniques. The results of RAPD, PCR-RFLP of rDNA, ERIC and REP-PCR were comparable with each other and indicated the existence of genetic variability among some of the FOV isolates of different geographic origins. This indicates the necessity of using different FOV isolates that represent the genetic diversity of the population, while screening cultivars for genetic resistance against this disease, so that only cultivars that are resistant to isolates from different geographic origins may be used in breeding programs.

EF-1α gene and IGS rDNA sequencing of Fusarium oxysporum f. sp. vasinfectum and F. oxysporum f. sp. phaseoli reveals polyphyletic origin of strains

“…Race 6 of Fov has been discovered in Brazil (Armstrong & Armstrong, 1978) and since then no further studies were made to characterize the races present in the country. Genetic diversity among Brazilian Fov isolates has been detected through RAPD, PCR-RFLP of rDNA, ERIC and REP PCR but occurrence of races was not investigated (Bibanco et al, 2010).…”