Status of Arbuscular Mycorrhizal Fungi in Tree Species from Eastern Ghats of Tamil Nadu, India

The Arbuscular Mycorrhizal (AM) status of 10 tree species in Pachaimalai Hill, Eastern Ghats of Tamil Nadu was surveyed. All the tree species were observed as colonizer of AM fungi. The root segments were found to contain any of the AM fungal structures i. e. coenocytic hyphae, hyphal coils, vesicles and arbuscules. The extent of AM colonization varied among the tree species. The average percentage of AM fungal colonization ranged from 12 (Cleistanthus collinus) to 89 (Bauhinia purpurea). Roots of all tree species formed hyphae, vesicles and hyphal coils however all tree species lacked arbuscules except Melia azedarach. A total of 25 morphotypes of AM fungi corresponding to 7 genera and 3 families were recorded. Of the 25 morphotyes, 11 belonged to the genus Acaulospora, 6 to the genus Glomus, 2 each to the genera Gigaspora, Scutellospora, Sclerocystis, one each to Entrophosphora and Rhizophagus. Species richness was highest in B. purpurea (20 species) and lowest in M. azedarach (4 species).