Selection of efficient ectomycorrhizal fungi for improved growth, biomass and nutrient uptake of Shorea robusta seedlings

Abstract

Shorea robusta Gaertn. (sal) forests are rapidly decreasing across India owing to the low survival rate and establishment of their seedlings. Because of this, the present study identified ectomycorrhizal (ECM) associates of S. robusta and the role they play in increasing the growth and efficiency of nutrient uptake by the mycorrhizal roots of this plant. During the field survey we identified, collected, cultured and systematically investigated three dominant ECM associates of S. robusta: Russula kanadii Dutta & Acharya, R. cyanoxantha (Schaeff.) Fr. and Lactarius shiwalikensis Kumar and Atri, organically connected to the host plant roots. Pure cultures of each of these mycorrhizal fungal associates were grown using tissue culture techniques. We prepared spawn via purified mycelium using boiled wheat grains for mass inoculation and used the prepared inoculums for inoculating the germinating sal seeds for establishing the mycorrhizal association. To evaluate the effects of mycorrhizal colonization on various growth parameters, we observed the inoculated and control plants every three months for one year. The growth parameters in the sal seedlings grown in ECM‐inoculated soil exhibited significantly higher values over the un‐inoculated control soil owing to the increased uptake of both macro‐ and micronutrients. The overall results indicate that S. robusta seedlings inoculated with ECM fungal partners exhibited better establishment and enhanced growth and development, essential for the regeneration and survival of this plant. This technique will accelerate and assure successful reforestation programs and contribute toward appropriate functioning of sal forest ecosystems.