Heterosis studies in okra (Abelmoschus Esculentus (L.) Moench) through line x tester analysis

Abstract

Okra is a commercially and nutritionally vital vegetable crop, yet its average productivity remains constrained by reliance on low-yielding varieties and extreme vulnerability to biotic stresses such as Yellow Vein Mosaic Virus and the fruit and shoot borer. This investigation was undertaken to study heterosis and combining ability to identify high-yielding and disease-resistant F1 hybrids. The experiment was conducted during the Kharif 2025 and Summer 2026 seasons. Seven exotic female lines and four male testers were crossed utilizing a Line × Tester mating design to generate 28 F1 hybrids. The 41 treatments, comprising the parents, hybrids, and two standard commercial checks, were evaluated in a Randomized Block Design with two replications. Data were recorded for fourteen quantitative characters, including growth parameters, yield attributes, and disease or pest incidence. Analysis of variance revealed highly significant genetic variability among the genotypes for all evaluated traits. The cross combination EC305689 × Parbhani Kranti emerged as the most superior hybrid, exhibiting the highest fruit yield per plant (275.00 g), yield per plot (3.02 kg), and yield per hectare (8.06 tonnes). Furthermore, this specific hybrid demonstrated highly significant standard heterosis for yield traits and recorded the lowest incidence of Yellow Vein Mosaic Virus (5.46%) and fruit and shoot borer (18.75%). The combining ability analysis indicated a predominance of non-additive gene action governing most yield-contributing traits. Among the parents, the female line EC305689 and the male tester Pusa Sawani were identified as the best general combiners for overall fruit yield. The exploitation of these superior parental lines and the specific elite hybrid EC305689 × Parbhani Kranti holds significant promise for commercial cultivation and future heterosis breeding programs aimed at simultaneously improving okra productivity and biotic stress resistance.