Journal of Farm Sciences

Abstract

Cotton (Gossypium hirsutum L.) is a globally important fiber crop whose productivity is increasingly threatenedby sucking pests, with leafhopper (Amrasca biguttula biguttula) infestation emerging as a major concern. The present studyaimed to elucidate the inheritance of leafhopper resistance in cotton using F2 populations derived from four crosses betweenexotic susceptible and indigenous resistant genotypes. Field evaluations were conducted under unprotected conditionsduring kharif 2023-24 at the Agricultural Research Station, Dharwad. Inheritance analysis revealed variable genetic controlof resistance across the crosses. The F2 population of 0774-3-3 × 1-2-1 exhibited a 13:3 ratio, indicating inhibitoryepistasis, whereas the populations of Raider 276 × 8-1-2 and 0774-3-3 × MCU-12 followed a 9:7 ratio, consistent withcomplementary gene action. In contrast, the F2 population of Raider 276 × MCU-13 segregated in a 3:1 ratio, confirmingcontrol by a single dominant gene. These results demonstrate that leafhopper resistance in cotton is governed by eithermonogenic or digenic interactions, depending on the parental genetic background. These findings provide valuable insightsfor cotton breeding programs focused on developing high-yielding, leafhopper-resistant cultivars with improved agronomicperformance and fibre quality under unprotected conditions.