Screening for salt tolerance via assessment of ion levels and nutrient contents in Iranian alfalfa ecotypes

An experiment was conducted in order to screening salt tolerance in alfalfa (Medicago sativa) ecotypes on the ion levels (Na, Cl-) and nutrient contents (N, P, K) in University Putra Malaysia during 2008-2010. Five Iranian alfalfa ecotypes including Rehnani, Gharghologh, Shorkut, Bami and Nik-Shahri were evaluated for their response to salt stress in a split plot trial, where five ecotypes were as main plots and levels of salinity including 2, 6, 12, and 18 dS/m were as subplots. To assess of ion levels and nutrient contents the samples from shoots were obtained at each stage of salinity including 6, 12 and 18 dS/m. The results showed that the nutrients content and ion levels were affected by salt concentration and there were varying responses between ecotypes. Salt stress affected the concentration of Na, Cl-, N, K but the concentration of P was not significantly affected by salinity levels. In terms of Na, Cl-, N and K concentrations in shoot the ecotypes were significantly different, vice versa phosphorus concentration in shoot among the ecotypes was not significantly different. It is concluded that ecotype number 2 (Gharghologh) identified as the most tolerant ecotype because of minimum accumulation of Na and Cl- and maximum absorption of nutrients in its shoots.