Assessment of Rhizospheric Arbuscular Mycorrhizae Spores in Relation to Soil Characters in the Rice Fields of Malda District, India

Abstract

Arbuscular mycorrhizal fungi (AMF) show symbiotic associations with the roots of plants and facilitates nutrients uptake through the hyphae-plant root-soil interface. Many edaphic and anthropogenic activities greatly influence this mutualistic association. Among which soil parameters are of great importance. The major objective of this study is to assess the soil colonization of AM fungi in different textural and nutritional conditions in agricultural rice fields of different locations of Malda district, West Bengal, India. Fifty rhizospheric soil samples of rice fields were collected from Jadupur (25.080° N, 88.1255° S) and Mohadipur (24.8525° N, 88.1255° E) areas of Malda district, India and the mycorrhizal spores were isolated and quantified according to adhesion and floatation techniques and identified morphometrically through the INVAM database. Soil texture was determined by conventional pipette method and soil pH, conductivity, nitrogen, potassium, phosphorus, and organic carbon contents were quantified according to standard methods. It was observed that the soil samples had a wide diversity of genera of mycorrhizal spores such as Aculospora sp., Entrophospora sp., Gigaspora sp., Glomus sp., and Scutellospora sp. The texture of the sample sites are mostly sandy loamy to loamy and have variations in soil chemical properties. The clay and phosphorous contents are inversely proportional to mycorrhizal spore content whereas it was directly proportional to the organic carbon and nitrogen content in the soil. The AM fungal diversity was more in Jadupur soil while it was less in Mohadipur. The study concludes that low nutrient content soil had more spore numbers than high nutrient content, reflecting their role in mineral acquisition for better plant nutrient supply.