Genetic inheritance analysis of melon aphid (Aphis gossypii Glover) resistance in cucumber (Cucumis sativus L.)

Abstract

AbstractThe melon aphid Aphis gossypii Glover is one of the most serious pests in cucumber production, often causing severe damage in commercial fields. Identifying and deploying resistant germplasm and understanding the inheritance of melon aphid resistance are required for cucumber geneticists to develop an effective breeding strategy. In this study, resistance of 30 cucumber selections to melon aphid was evaluated at the seedling stage. Six generations, P1, P2, F1, BC1, BC2 and F2 derived from the cross of JY30 (susceptible) × EP6392 (resistant), were used as genetic populations to study the inheritance of melon aphid resistance in cucumber with the mixed major gene plus polygene inheritance model with the joint analysis method of multiple generations. Eight of the 30 tested selections displayed resistance to the melon aphid. The resistance of cucumber to melon aphids was controlled by one additive and dominant major gene plus additive and dominant polygenes, and was affected by environment as well. The additive effect and the dominant effect of the major gene were greater than the additive effect and the dominant effect of the polygenes. The heritabilities of the major gene in BC1, BC2 and F2 were 63.62 %, 0 % and 70.39 %, respectively. The polygenic heritabilities were 22.62 %, 37.0 % and 9.32 %, and the ratios of the environmental variance to phenotype variance were 58.54 %, 63.16 % and 30.77 %. We conclude that selections of cucumber with high resistance to melon aphid could be screened in advanced generations.