Inheritance of Resistance in Muskmelon to Fusarium Wilt

Abstract

The mode of inheritance of resistance to Fusarium wilt ( Fusarium oxysporum f. sp. melonis ) races 0 and 2 in muskmelon ( Cucumis melo L.) cv Perlita FR and race 2 in ‘Doublon’ was determined by analyzing segregation of F 1 , F 2 , F 3 , and BC 1 populations of crosses with susceptible ‘PMR 45’. The ratios obtained indicate that resistance to both races 0 and 2 in ‘Perlita FR’ is conferred by a dominant gene. The segregation data indicate that resistance to race 2 in ‘Doublon’ also is conferred by a dominant gene. Allelism tests indicated that gene Fom-1 , which controls resistance to race 0 in ‘Doublon’, is different from the gene controlling resistance to race 0 in ‘Perlita FR’ and that 2 different genes confer resistance to race 2 in ‘Doublon’ and ‘Perlita FR’. The reaction of ‘Perlita FR’ and ‘Doublon’ backcross progenies of (resistant × susceptible) × susceptible, inoculated simultaneously or sequentially with race 0 and race 2, suggest that gene Fom-1 confers resistance to races 0 and 2 in ‘Doublon’ and that a single gene confers resistance to both races 0 and 2 in ‘Perlita FR’. The resistant dominant gene in ‘Perlita FR’ is designated F. oxysporum f. sp. melonis 3 ( Fom-3 ). The source of Fusarium wilt resistance in ‘Perlita FR’ is discussed. ‘Perlita FR’ was found susceptible to race 1 and race 1, 2.