Inheritance of resistance to Fusarium oxysporum f. sp. lycopersici races 2 and 3 in Lycopersicon pennellii

Abstract

An accession of Lycopersicon pennellii, PI414773, was resistant to race 2 isolate 18947 and race 3 isolate 14844 of Fusarium oxysporum f. sp. lycopersici. Tomato cultivar Contender, which is homozygous for gene 1-2, was resistant to race 2 but susceptible to race 3 of the pathogen. Cultivar Rouge de Marmande was susceptible to both race 2 and race 3. The inheritance of resistances to race 2 and race 3 in PI414773 was investigated in test crosses involving parents Contender, Rouge de Marmande and PI414773. Segregation of the F2 of the crosses Rouge de Marmande x PI414773 and Contender x PI414773 revealed that resistance to race 2 in PI414773 was controlled by two independent dominant genes, one of which is allelic with gene I-2. Segregations in F2, backcrosses and inbred backcrosses derived from Contender x PI414773 indicated that a single dominant gene conferred resistance to race 3. The symbol I-3 was proposed for this gene.