Abstract

The present study was carried out with the aim of highlighting the diversity of arbuscular mycorrhizal fungi (AMF) associated with the rhizosphere of cotton grown in the Far-North region of Cameroon. To achieve this, composite soil and root samples were taken in six fields, chosen according to edapho-climatic conditions and types of cultural practices. After entrapping the glomales in the greenhouse, the roots of the trap plants were thinned and stained to assess colonization. The spores were isolated by wet sieving and their identification was made after analysis of their morpho-anatomical structures; then the diversity was evaluated through the calculated index. The results obtained have revealed the presence of AMF in all sites surveyed with a maximum abundance of 432 spores per 100 g of soil. Despite the low diversity of AMF that exist, four genera have been identified: Acaulospora, Gigaspora, Glomus and Scutellospora. A significant dominance of Glomus spp. (42%) was found. A strong correlation was found between soil physico-chemical parameters and abundance, as well as between species richness. This study confirms the presence of AMF strains in the cotton rhizosphere cultivated in this zone. The exploitation of this AMF could lead to a controlled production of local fungal inoculum, adapted to the edaphic and climatic conditions of the region, for a sustainable agriculture in Cameroon.

Key words: Cotton, rhizosphere, arbuscular mycorrhizal fungi (AMF), diversity, Far-North, Cameroun.