Diversity of arbuscular mycorrhizal fungi in Populus deltoides agroforestry systems at Kurukshetra in Northern India

摘要

This study was carried out in Populus deltoides agroforestry systems located at Gulabgarh, Kurukshetra (29-58-N, 76-57-E, 250 m above mean sea level), northern India. The aim was to analyze arbuscular mycorrhizal (AM) fungal diversity, the spatial distribution of AM fungal spore density in the soil and AM root colonization in sugarcane and wheat crops integrated with trees in Populus deltoides agroforestry systems. A total of 47 species of AM fungi belonging to five genera, i.e., Acaulospora, Entrophospora, Glomus, Gigaspora and Sclerocystis were isolated from the rhizosphere soils of wheat and sugarcane in the studied agro forestry systems. There was significant effect of soil depth and crop growth stage on the AM fungal spore density and AM fungal root colonization. The AM fungal spore density was greatest in the Populus + sugarcane system as compared to that of the Populus + wheat systems. The density of AM spores was found to attain its peak at crop maturity of the wheat crop; a significant decrease in AM spore density occurred with increase in soil depth. The colonization of sugarcane roots by AM fungi was greatest at 15 to 30 cm soil depth under 1 to 2 yr old Populus + sugarcane agro forestry systems. In the case of wheat roots (5-7 yr old Populus + wheat agroforestry systems), the AMF root colonization was greatest at 7.5 to 15 cm soil depth as wheat roots were concentrated up to 15 cm soil depth.