Sodium Chloride Effects on Seed Germination, Growth and Ion Concentration in Chamomile (Matricaria Chamomilla)

Matricaria chamomilla is a medicinal plant that is widely cultivated in salt affected soils. This investigation was undertaken to study the effect of NaCl concentration on germination, and the physiological, biochemical and growth characteristics of chamomile. Seed germination and growth were studied at five NaCl concentration levels (0, 40, 80, 120 and 190 mM NaCl concentration). Increasing the level caused significant reduction in seed germination. Salt concentration up to 40 mM led to higher growth, but more than 40mM of NaCl caused significant growth limitation. Chloride and sodium ions increased significantly in various parts of the plant with salinity. Specifically, chloride ions were predominantly concentrated in the shoots whereas sodium ions were concentrated mostly in the roots. With increasing salinity rate, K and Ca concentrations significantly decreased in the shoot and root of M. chamomilla as compared to the control. There was a consistent decrease in K+/Na+ and Ca2+/Na+ ratios in the shoots and roots of M. chamomilla. Plants maintained considerably higher K+/Na+ and Ca2+/Na+ ratios in the shoots than the roots, and the former ratio was significantly higher than 1 in a 40mM salinity level. No change in leaf proline concentration was observed up to 80 mM, but a sharp rise at higher salt levels occurred. Overall, based on the results, M. Chamomilla is a tolerant to moderately salt tolerant crop during its growth, and its response to salinity is associated with the maintenance of high K+/Na+ and Ca2+/Na+ ratios in shoots, the accumulation of Na+ in roots, and proline accumulation in shoots