Inheritance of Resistance to Downy Mildew [Pseudoperono sporacubensis (Berk. and Curt.) Rostovzev.] in Ridge Gourd [Luff a acutangula (Roxb.) L.]

Abstract

Ridge gourd [Luff a acutangula (Roxb.) L.] is one of the important cucurbit vegetable cultivated widely in India
and other Asian countries. Downy mildew caused by Pseudoperono sporacubensis (Berk. and Curt.) Rostovzev
severely aff ects the ridge gourd production during rainy season. Therefore, in the current study 12 genotypes
including some promising inbred lines were screened for downy mildew resistance which resulted in the selection
of three moderately resistant advanced selections viz., IIHR-17-2-1 (PDI -16.25), IIHR-7-5-1 (PDI -21.40) and
IIHR-17-1-7-3 (PDI -21.60) with low AUDPC values (467.59-634.26).Genetics of downy mildew resistance
in two diff erent F2 populations derived from IIHR-52-1-30 × IIHR-17-1-7-3 and IIHR-23-8-10 × IIHR-7-5-1
respectively revealed that two major genes are interactive in dominant suppression epistasis and complementary
epistasis. These results will aid ridge gourd breeder to develop a strategic downy mildew disease resistant
breeding program.