Morphological Diversity of Arbuscular Mycorrhizal Fungi and Mycorrhization of Okra (Abelmoschus esculentus L.) Cultivars in the Peri-Urban Area of Abidjan (Côte d’Ivoire)

Abstract

In Côte d’Ivoire, okra (Abelmoschus esculentus L.) plays a key role in market-gardening systems due to its nutritional and economic importance. However, the productivity of this crop remains limited by soil degradation and excessive use of chemical inputs. From a sustainable agriculture perspective, the use of arbuscular mycorrhizal fungi (AMF) represents a promising alternative. This study evaluated the morphological diversity of AMF communities and the mycorrhization abilities of seven okra cultivars to identify those showing the highest affinity for this beneficial symbiosis. The experiment was conducted on an experimental plot in the district of Abidjan. Soil samples were analyzed by wet-sieving and morphological observation to characterize AMF communities, while stained root samples from the different cultivars were examined to determine mycorrhizal colonization frequency and intensity. The results revealed an average density of 4.48 ± 0.24 spores/g of soill, with a predominance of spores measuring 90 µm (52.30%) and 45 µm (40.11%). Ten morphotypes were identified belonging to the genera Glomus, Gigaspora, Acaulospora, and Scutellospora with a clear dominance of Glomus. Analysis of the roots showed high variability in mycorrhization depending on the cultivar. Colonization frequencies reached 100% in Noura F1 and Djonan F1, while the highest intensity (56.12%) was recorded in Noura F1, followed by Kopê F1. Conversely, the Divo cultivar had the lowest values. These results open up prospects for selecting more mycorrhizogenic cultivars and the promotion of AMF as a sustainable biotechnology for okra cultivation.