Combining Ability Analysis for Earliness and Growth Parameters in Sudanese Okra Collection [Abelmoschus esculentus (L.) Moench]

Abstract

Aims: This study aimed to evaluate the combining ability and heterotic potential of elite Sudanese okra [Abelmoschus esculentus (L.) Moench] lines to identify superior hybrids for breeding programs. The primary objective was to assess key growth parameters and determine the genetic effects contributing to the development of high-yielding, early-maturing, and well-adapted okra varieties. Study Design: A line x tester mating design was employed using ten parental lines, including seven female lines and three testers. Twenty-one F1 hybrids were generated and evaluated in a complete randomized block design with three replications. Methodology: The study was conducted at the demonstration farm of the Faculty of Agriculture, University of Al Zaeim Al Azhari, Khartoum North. Data were collected on key growth parameters: days to flowering, plant height, pod length, length of pod pedicle, number of nodes per plant, and number of lateral branches. Analysis of variance was performed, and general combining ability and specific combining ability effects were estimated using the line x tester analysis method. Genetic variance components were calculated, and the contributions of lines, testers, and their interactions were evaluated. Results: Significant genetic variability among the genotypes was observed for most traits. The high SCA variance for plant height, pod length, and number of nodes per plant indicated a predominance of non-additive gene action. The hybrid HSD2550 x Hjerat exhibited the most favorable SCA effect for early flowering (-2.41**), while HSD2482 x Sinnar demonstrated significant positive effects on plant height (5.10*). Notably, the number of nodes per plant and lateral branching were significantly influenced by specific parental combinations, emphasizing the importance of hybrid breeding strategies. Conclusion: The study highlighted the critical role of non-additive gene action in the expression of key agronomic traits in Sudanese okra. The identification of promising hybrids like HSD2550 x Hjerat and HSD2482 x Sinnar underscores the potential for developing high-yielding and early-maturing okra varieties. These findings provide valuable insights into the genetic improvement of Sudanese okra germplasm, supporting the development of superior hybrids with enhanced agronomic performance and adaptability.