Genetic analysis of downy mildew resistance in Indian slicing cucumber (Cucumis sativus L.)

Abstract

Abstract The genetics and gene action conferring downy mildew resistance was revealed among the populations derived from Indian slicing cucumbers, from the parental source comprised of resistant parent IIHR-438 and moderately resistant parent IIHR-433 and two susceptible parents Swarna Agethi and IIHR-431. The two cross Swarna Agethi × IIHR-438 and IIHR-431 × IIHR-433 combination was made and develop six generations (P1, P2, F1, F2, BC1 and BC2) and parents, filial, backcross populations was deployed for genetics. The Mendelian segregation in F2 and back cross suggested that resistance is governed by two pair of recessive genes i.e. inhibitory recessive epistasis (3 resistant: 13 susceptible) in both the cross. IIHR-438 possess higher degree of resistance and epistatic interaction (additive × dominance) was greater importance than main effect. These genetic finding on downy mildew resistance infers to advance the reciprocal recurrent selection breeding method followed by pedigree selection for breeding of downy mildew resistance cucumbers effectively.