Seasonal Diversity of Arbuscular Mycorrhizal Fungi in Forest Tree Species of Chittagong University Campus in Bangladesh

Status of Arbuscular mycorrhizal (AM) colonization in seven tree species ( Albizia saman, Acacia auriculiformis A. Cunn. ex Benth., Albizia lebbeck, Chickrassia tabularis A. Juss., Eucalyptus camaldulensis Dehnn., Gmelina arborea (Roxb) DC and Swietenia macrophylla King.) collected from the hilly areas of Chittagong University (CU) was investigated. Roots and rhizosphere soil samples were collected in different seasons (pre-monsoon, monsoon and post monsoon). Percentage of AM colonization in root and number of spores/100gm dry soil were assessed. The result of the investigation reveals that the intensity and percentage of AM colonization varied in different forest tree species in different seasons. Maximum AM colonization and spore population were found in pre-monsoon and minimum were in monsoon season. The intensity of colonization was maximum in C. tabularis (74.43%) in pre-monsoon, A. lebbeck (69.45%) in monsoon and S. macrophylla (67.8%) in post monsoon seasons and minimum in A. auriculiformis (53.75%) during pre-monsoon, A. saman (24.4%) in monsoon and A. saman (19.36%) in post monsoon seasons. The number of AM fungal spores found per 100g dry soil ranged from 164 to 376 during pre-monsoon, 27 to 310 during monsoon and 194 to 299 in post monsoon seasons. Out of six recognized genera of AM fungi, Glomus, Sclerocystis, Entrophospora, Scutellospora, Acaulospora and other unidentified spores were observed.