Arbuscular Mycorrhizal Technology for the Growth Enhancement of Micropropagated Spilanthes acmella Murr.

Spilanthes acmella (Asteraceae) is an endangered ornamental cum medicinal annual herb. This study reports on the effect of two arbuscular mycorrhizal fungi (Glomus mosseae and Acaulospora laevis) applied either alone or in combination on post-transplanting performance of micropropagated S. acmella. Complete plantlets of S. acmella were raised by direct organogenesis from nodal explants on Murashige and Skoog medium supplemented with various cytokinins. S. acmella plantlets responded to all three mycorrhizal treatments in a significantly different way. G. mosseae enhanced the survival rate of S. acmella plantlets to 100%. Plant height, plant spread, number of branches per plant, number of leaves per plant, leaf area, biomass production, and chlorophyll content were significantly higher in AM inoculated plantlets as compared to the uninoculated ones. This clearly demonstrates that AM inoculation not only improved the survival rate of micropropagated plantlets but also their growth and biomass yield.