Genetic analysis of resistance to tomato leaf curl New Delhi virus in muskmelon (Cucumis melo L.)

Abstract

The genetics and mode of gene action for resistance to tomato leaf curl New Delhi virus (ToLCNDV) in muskmelon (Cucumis melo L.) are elucidated in the current work for the first time under conditions of natural epiphytotic and whitefly-mediated challenge inoculation. In order to accomplish this investigation, susceptible parent (DOM 115) and resistant parent (DSM 132) were utilized to produce the F1, F2, BC1P1 and BC1P2 populations. According to generation mean analysis, genetic dominance may be more significant for the manifestation of ToLCNDV resistance in the cross between DOM 115 and DSM 132 in both screening techniques. The F1 mean was skewed toward the resistant parent and considerably lower than the midparent value. The significance of scaling test proved the existence of epistatic interaction. Estimates of six parametersm, d, h, i, j, and l from generation mean analysis in the cross between DOM 115 and DSM 132 revealed that non-allelic interactions predominated, mostly of additive ×dominance (j) type with negative sign in natural epiphytotic screening and dominance × dominance [l] type with negative signs in challenge inoculation screening methods respectively. Under natural epiphytotic and whitefly mediated challenge inoculation screening procedures, complementary types of epistasis have been found because both components, dominance [h] and dominant × dominance [l], were oriented in the same direction. Above results indicated that the recombination breeding, and hybridization followed by selection at later generations could be used to improve resistance to ToLCNDV.