Novel sources of multiple resistance to three races of Fusarium oxysporum f. sp. lycopersici in Lycopersicon germplasm

Abstract

Fusarium wilt, caused by three races of Fusarium oxysporum f. sp. lycopersici, is worldwide one of the most important diseases of tomato (Lycopersicon esculentum Mill.). In Brazil, all races are now present offering a unique opportunity for a simultaneous evaluation of accessions to these pathogen variants. A germplasm collection comprising 94 Lycopersicon accessions was challenged with a race 3 isolate. A range of responses varying from immune-like resistance to high susceptibility was observed. A sub-group of 32 accessions displaying immune-like and highly resistant responses to race 3 was re-evaluated for the reaction to race 1, 2, and 3 isolates. Accessions combining high levels of resistance to all three races were identified in L. hirsutum, L. chilense, L. pennellii and L. peruvianum. The availability of distinct sources of resistance alleles/genes could be an important tool in breeding to anticipate future problems such as the emergence of other pathogen races besides 1, 2 and 3.