Monday, 2 March 2026

Phenotypic Variability and Stability of Okra Accessions Using Distinctness, Uniformity and Stability Descriptors |Chapter 5 | Research Perspective on Biological Science Vol. 10

 

Background: 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. Genetic improvement of okra is emerging as a strategic solution. Morphological characterisation based on qualitative traits of crops is a very crucial and essential first step in any crop improvement and breeding programme.

 

Study Aim: 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: Field trials were conducted using a Fisher Block design with five treatments and four replicates. Sowing was carried out on September 12, 2023, and April 19, 2024, for the first and second cycles, respectively. Qualitative and quantitative morphological data were collected from 20 plants per variety following the guidelines of the International Union for the Protection of New Varieties of Plants (UPOV). 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 analysed using generalised linear and linear mixed-effect models, followed by Tukey's post hoc tests for mean comparisons, in R (v4.3.0) with variety and season as fixed factors and block as a random factor.

 

Results: Findings revealed that several qualitative traits were uniform, while significant differences (P < 0.05) were noted in leaf blade colour and fruit shape. Quantitative data indicate significant variability between genotypes across seasons. Total fruit yield (including both commercial and non-commercial fruits) did not show any significant difference between cycles (P = 1). 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. Directed crosses between the best-performing accessions, such as AVOK1502 and AVOK1505, could be considered with the aim of creating new hybrid varieties with improved characteristics.

 

 

Author(s) Details

A. C. G. Mensah
Institut National des Recherches Agricoles du Bénin (INRAB), Centre de Recherches Agricoles en Horticulture (CRA-H), Programme de Recherches sur les Cultures Maraîchères, 01 BP 884, Cotonou 01, Bénin.

 

A. B. B. Kouderin
Unité de Recherche Horticole et Aménagement des Espaces Verts, Laboratoire des Sciences Végétales, Horticoles et Forestières, Ecole d’Horticulture et d’Aménagement des Espaces Verts, Université Nationale d’Agriculture, BP 43 Kétou, Bénin.

 

W. T. Koura
Institut National des Recherches Agricoles du Bénin (INRAB), Centre de Recherches Agricoles en Horticulture (CRA-H), Programme de Recherches sur les Cultures Maraîchères, 01 BP 884, Cotonou 01, Bénin.

 

M. Sikirou
Unité de Recherche Horticole et Aménagement des Espaces Verts, Laboratoire des Sciences Végétales, Horticoles et Forestières, Ecole d’Horticulture et d’Aménagement des Espaces Verts, Université Nationale d’Agriculture, BP 43 Kétou, Bénin.

 

D. A. J. Azagba
Institut National des Recherches Agricoles du Bénin (INRAB), Centre de Recherches Agricoles en Horticulture (CRA-H), Programme de Recherches sur les Cultures Maraîchères, 01 BP 884, Cotonou 01, Bénin.

 

F. Yalinkpon
Laboratoire de Biomathématiques et d’Estimations Forestières, École Doctorale des Sciences Agronomiques et de l'Eau (EDSAE), Université d'Abomey-Calavi (UAC), Bénin.

 

M. Zandjanankou-Tachin
Unité de Recherche Horticole et Aménagement des Espaces Verts, Laboratoire des Sciences Végétales, Horticoles et Forestières, Ecole d’Horticulture et d’Aménagement des Espaces Verts, Université Nationale d’Agriculture, BP 43 Kétou, Bénin.

 

Please see the book here :- https://doi.org/10.9734/bpi/rpbs/v10/7169

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