Genetic Analysis of Locally Development Okra Single Hybrids by the Method of Line × Tester

Abstract

The field experiment was carried out over the 2021 and 2022 growing seasons with the aim of locally developing a single hybrid from grown okra cultivars, and known general and specific combining abilities in one of the private fields in the Mahmoudiya district of Baghdad. In this experiment, ten okra cultivars (denoted as O1 to O10) were introduced into a hybridization program using a 7-line × 3-tester arrangement. Subsequently, in the second season, an experiment was conducted to evaluate the hybrids, their parental lines, and commercial hybrids, totaling [10 Parents + 21 Hybrids + Commercial Hybrid]. The experimental design employed a Randomized Complete Block Design (RCBD) with three replicates across randomized sectors. Growth Traits were studied. Hybrid vigor and stander+ heterosis were calculated, and genetic analysis was carried out. The results indicated that certain parents, specifically O1, O3, O4, O7, and O10, exhibited a positive and significant general combining ability effect in the measured traits, particularly. Notably, the hybrids O4×O2 and O10×O3 displayed a distinct positive and significant specific combining ability effect on pod weight and overall plant yield. Additionally, the dominance variance (σ2D) exceeded the additive variance (σ2A) across in traits (no. of nodes, no. of. leaves, percentage of pods, plant yield). The average degree of dominance (ā) was most pronounced in traits related to the number of pod sets on the main stem and the percentage of nodes set, as well as plant yield. The heritability broad sense was particularly high for phalanx length (92.75%), and plant yield (84.11%), while it was moderate for the number of nodes on the main stem and the percentage of pods. The hybrid O4×O2 also recorded the highest pod weight at 5.31 g and exhibited exceptional hybrid vigor and heterosis in pod weight traits (59.96% and 53.17%, respectively), as well as in plant yield (54% and 22.73%).