Incidence of Arbuscular Mycorrhizal and Dark Septate Fungal association in Dioscorea species

Dioscorea (Yam) is a tuber crop belonging to the family Dioscoreaceae. It is among the oldest food crop and valuable source of carbohydrate in the diet. A number of Dioscorea species are also cultivated to provide a source of diosgenin, some sapogenins, alkaloids, steroid derivatives and phenolic compounds used in the pharmaceutical industry. As soil microorganisms are crucial for natural soil fertility, two species of Dioscorea from three different sites were investigated for the presence of mycorrhizal and dark septate endophytic (DSE) association. Dioscorea hispida (Dennst.) and D.bulbifera (L.) were collected from June-Nov 2011 along with their fibrous roots and rhizosphere soils. Soil physico-chemical analyses of collected samples were carried out with standard methods. All the samples were found to be colonized with arbuscular mycorrhizal and Dark Septate Endopytic fungi. The percent root colonization was in between 75 to 90.32%. AM fungal spore density was in between 185 to 296 / 100g and spores belonging to Glomus species and Acaulospora sporocarpa were identified. By inoculating the proper indigenous AMF and DSE with Dioscorea species, can produce high yield of crops in future.