Molecular diversity of arbuscular mycorrhizal fungi (AMF) in Lake Victoria Basin of Kenya

Abstract

Arbuscular mycorrhizal fungi (AMF) play a key role in land reclamation, sustaining soil fertility and cycling of nutrients, which in turn increases plant vigour and productivity. AMF differ in both structural characteristics and global distribution, which is strongly correlated with the respective functional role. This study investigated the molecular diversity of arbuscular mycorrhizal fungi (AMF) in selected representative farmlands across Lake Victoria Basin and wheat farms in Njoro District of Kenya. Native AMF genera were identified by morphological techniques and their molecular diversity assessed by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) techniques and genetic distance analysis. In all five field sites, three AMF genera were identified with varying relative abundances, namely, Glomus (50%), Scutellospora (30%) and Gigaspora (16%). Lambwe fields had the highest spore densities (13 spores per gram dry weight) and evenness (0.84) while Kibos and Njoro had least spore count (4 - ditto) and evenness (0.32), respectively. The AMF population from Njoro wheat farms had highest heterozygosity (He = 0.257) and hence was the most genetically diverse compared to other populations. Key words: Glomus spp., Gigaspora spp., Scutellospora spp., molecular diversity.