PHYSIOLOGICAL CHARACTERISTICS OF SALT TOLERANCE IN FENUGREEK (Trigonella foenum graecum L.)
Fenugreek (Trigonella foenum graecum L.) is an important medicinal crops cultivated throughout the world. To quantify its salinity tolerance during germination and vegetative growth, a Tunisian cultivated accession of fenugreek was exposed to 200 mM NaCl. Physiological traits such as germination percentage, percent mortality, fresh and dry weights, water status and mineral contents (Na, K and Ca) were measured. Results showed that germination was delayed at higher salinity level and that the high NaCl treatment does not affect the mortality percentage. Salinity caused a reduction in growth parameters such as relative growth rate (RGR), fresh and dry weights of leaves and stems. Whereas, roots growth was not affected by salinity. These changes were associated with a decrease in water content, K+ and Ca2+ concentrations and a highly increased in Na+ contents in all organs. Thus, the K+/Na+ and Ca2+/Na+ ratios decreased with the applied of NaCl 200 mM. Relationship between leaf water content and its Na+ content, suggest that fenugreek developed a sodium inclusion mechanism to maintain its growth and consequently its survival under high salinity conditions (200 mM NaCl). These results suggest that fenugreek is a salt tolerant crop.