Identification and Characterization of Arbuscular Mycorrhizal Strains from the Roots and Rhizospheres of Tomato, Brinjal, Chilli and Onion

Rhizosphere soils and roots of two vegetables (tomato and brinjal) and two spices (chilli and onion) crops were collected from each of four Agro-Ecological Zones (AEZs) of Bangladesh viz. AEZ-9 (RARS, Jamalpur), AEZ-11 (RARS, Jashore), AEZ-25 (ARS, Bogura) and AEZ-28 (BARI, Joydebpur) in 2014-2015. Characterization and identification of arbuscular mycorrhizal strains were studied in the microbiology laboratory of the Bangladesh Agricultural Research Institute (BARI). Different crops showed positive responses in percent root colonization such as 74.11-83.78%, 22.11-24.33%, 7.33-8.89%, and 6.67-9.33% in onion, tomato, chilli, and brinjal, respectively. Rhizosphere soil of individual crops had also variations in the number of spore populations such as 120.11-200.33, 33.44-50.78, 36.11-39.22, and 28.56-41.89 per 100g soil in onion, tomato, chilli, and brinjal, respectively.  Eleven AM strains were identified in tomatoes: Glomus geosporum, G. mosseae, G. fasciculatum, G. spp., Acaulospora dilatata, A. bireticulata, A. mellea, A. morrowiae, Entrophospora infrequens, Sclerocystis coremioides and Gigaspora margarita. Nine each were identified from other three crops. G. spp. and Acaulospora bireticulata were absent in brinjal and chilli. Acaulospora dilatata and A. mellea were absent in onion. The formation of AM structures was found inconsistent and fluctuating from site to site in the present study. Both oval and spherical-shaped vesicles were found among the AM structures.