Abstract
Inoculation with strains of arbuscular mycorrhizal fungi increased weight of fresh root, fresh shoot, dry root and dry shoot of soybean from 78.9 to 133.2 %, 71.6 to 125.4 %, 55.9 to 136.0 % and 111.5 to 169.2 % over the uninoculated control, respectively. The percent increase in plant height varied from 25.4 to 87.6 over the control. The root colonization, AM fungal spore population and mycorrhizal dependency of soybean at 60 days after sowing (DAS) as influenced by different AM strains ranged from 45.0 to 65.0 % , 336.0 to 426.0 spores 100 g-1 soil 163.13 to 232.53 % per cent in maize , respectively. Phenotypic and genotypic variations in response to AMF colonization is found between plant cultivars, genotypes, ecotypes, with respect to nutrient acquisition and growth. In general Glomus ACP-1 strain caused maximum value of all the parameters. The strains Glomus ACP-1 and Glomus ACP-2 were statistically superior in increasing the root dry weight, shoot dry weight ( along with Scutellospora ACP-2 ) and spore population. As far as the efficacy of strains is concerned, the strain Glomus ACP-1 alone caused maximum and significantly higher values of plant height and root colonization over other strains. The maximum mycorrhizal dependency was also observed with the strain Glomus ACP-1, but it was statistically at par to all the other strains, except Acaulospora ACP-1 which was least effective in increasing the mycorrhizal dependency.