Arbuscular Mycorrhizal (AM) fungi are among the most common fungi in different Agro Ecological Zones of Bangladesh, but they often go unnoticed because they do not grow on standard media. They form partnership with many plant species by colonizing their roots and produce hyphae in the rhizosphere to facilitate uptake of nutrients (mainly immobile phosphorus) and to provide other benefits, either directly or indirectly.
AM fungi colonizes the root cortex of the majority of field crops in a mutualistic association and provide the plant with with nutrients, thus increasing growth and yield, and confer resistance against biotic and abiotic stresses. This particular mycorrhizal association began more than 400 million years ago with the first land plants and both partners have coevolved to the present day. As obligate symbionts, the fungi have evolved exclusively in their associations with host plants and so it is not surprising that they comprise a unique and separate evolutionary lineage now classified as the phylum Glomeromycota. The symbiosis provides sustainable net benefits to both partners; otherwise they would have been “divorced” long before now. This benefit can be physiological, nutritional, ecological or any combination of these processes.
An in vitro system using Agrobacterium-transformed roots and indigenous AM fungi has been developed at ABL to produce viable and aseptic AM fungal spores. The in vitro hairy root-organ culture (ROC) system opens a new era for bio-fertilizer research in Bangladesh and an ideal system for mass-cultivation of AM fungi.
We have developed successful monoxenic culture of several indigenous Glomus sp. with transformed carrot (Daucus carota) roots for the first time in Bangladesh. The strains completed their life cycles under monoxenic conditions over several generations while maintaining their viability. These monoxenic materials could facilitate mass-production of in vitro inoculum in bioreactors. Exploiting and managing mycorrhizas has important and sustainable consequences for both agricultural and natural ecosystems.
