Agro-morphological Stability of Five Okra (Abelmoschus esculentus L.) Candidate Varieties for Registration in the Beninese Catalogue of Plant Species and Varieties

Abstract

Aims: Okra is a vegetable of major nutritional and economic importance in tropical and subtropical regions. In Benin, its production remains limited by disease and pest pressure and the lack of high-performing varieties. This study aims to assess agro-morphological traits of five varieties (TZSMN86, AVOK1501, AVOK1505, AVOK1502 and C101), as part of the requirements for their inclusion in the Beninese Catalogue of Plant Species and Varieties (CaBEV). Methodology: The criteria of Distinctness, Uniformity and Stability (DUS) were assessed over two cycles of on-station trials. Agreement between qualitative parameter classifications across production seasons was assessed using Cohen's Kappa coefficient, while phenological and agro-morphological data were analyzed using generalized linear and linear mixed-effect models, followed by Tukey's posthoc tests for mean comparisons, in R (v4.3.0) with variety and season as fixed factors and block as random factor. Results: Findings revealed that several qualitative traits were uniform, while significant differences (P < 0.05) were noted in leaf blade color and fruit shape. Quantitative data indicate significant variability between genotypes across seasons. Ascending hierarchical clustering (AHC) grouped the varieties into three distinct clusters. Accessions AVOK1502 and AVOK1505 also showed good stability across seasons. Conclusion: These results provide a scientific basis for the approval and registration of high-performing okra varieties (TZSMN86, AVOK1501, AVOK1505, AVOK1502 and C101) in the national variety catalogue.