Screening for efficient AM (arbuscular mycorrhizal) fungal bioinoculants for two commercially important ornamental flowering plant species of Asteraceae

The objective of this study was to screen for the most efficient arbuscular mycorrhizal (AM) fungal bioinoculant and to evaluate possible effects of inoculation of different species of AM fungi on growth, yield, and flower fresh weight loss in two ornamental plant species of commercial importance, Chrysanthemum morifolium Ramat. and Tagetes erecta L. The research work was carried out in 2010-2011. The treatments included uninoculated control and plants inoculated with pure cultures of AM species (Acaulospora laevis, A. scrobiculata, Glomus coremioides, G. intraradices G. fasciculatum, G. mannihotis and Gigaspora albida). A complete randomized block design in factorial arrangement with five replicates was employed. Root and shoot length and dry weight, number of lateral branches, number of days required for flowering, and number, diameter, fresh weight of flower and fresh weight loss of flower/day were recorded. Results showed that inoculation of AM species had a significant effect on plant growth and flower quantity and quality. Increased flower number in C. morifolium (11-22%) and T. erecta (13-66%) was observed upon AM inoculation compared with the uninoculated control. Glomus intraradices proved to be the most efficient AM fungal bioinoculant, increasing flower number in both the plant species. This is attributed to its ability to colonize and multiply at a faster rate than the other AM fungal species used in the study.