Response of mycorrhizal citrus rootstock plantlets to salt stress

Citrus is highly susceptible to salinity and arbuscular mycorrhizal fungi (AM fungi) inoculation resulted in increase stressed tolerance to the host plants with enhanced water and nutrient absorption. In the present study two citrus rootstocks (Citrus jambhiri and Poncirus trifoliata) under different salinity levels had improved survival and growth due to AM inoculation. The seedlings of Citrus jambhiri and Poncirus trifoliata were inoculated with the soil-based AM inocula (Glomus sp. and Gigaspora sp.). The salinity gradient was developed by frequent irrigation containing NaCl in different concentrations (0, 50, 100, 150 mM). The results revealed that although AM colonization decreased significantly under salt stress, it lead to total sugars and chloride accumulation in tissues irrespective of salinity levels in both the Citrus species. Proline, phosphorus, potassium and sodium accumulation increased significantly with the increasing salinity levels; while total chlorophyll, calcium and magnesium contents declined.