Effect of NaCl-induced Salt Stress on Germination and Initial Seedling Growth of Lotus corniculatus L. cv. 'Leo'

Lotus corniculatus L. is one of the agronomically and economically important perennial legume forage species with moderately salt-tolerant. It is well known that even the cultivars of the same species in plants have different responses in salinity. However, studies on the salt response of L. corniculatus and its cultivars, which are more advantageous than other forage crops such as white clover (Trifolium repens) and alfalfa (Medicago sativa L.), in the use of marginal agricultural lands affected by abiotic stress factors such as salinity, are limited. Under salt stress, the most crucial phases of the plant life cycle that are directly related to the survival of the plant are seed germination, growth, and vigour. Therefore, this study was carried out to determine the germination and growth responses of L. corniculatus cultivar 'Leo', which is known to have higher tannin content than other cultivars, under NaCl-derived salt stress in vitro. For this purpose, L. corniculatus seeds were cultured in MS (Murashige and Skoog/Gamborg) medium containing 0, 40, and 80 mM NaCl for 14 days. Seed germination percentage, mean germination time, germination rate index, shoot-root length, root to shoot length ratio, shoot-root fresh dry weight, shoot-root dry matter, the ratio of root to shoot dry matter, shoot-root water content and seedling vigour index parameters were measured. According to the results of the research, the germination percentage did not change in the applied NaCl treatments, but the germination rate decreased. However, shoot length decreased and root length increased. Although there was no statistically significant change in shoot and root fresh-dry weight, both decreased in 80 mM NaCl treatment. The shoot and root dry matter increased and the water content decreased. Also, the seedling viability index decreased. In 40 mM NaCl treatment, on the other hand, there was an increase in shoot fresh-dry weight, dry matter ratio and seedling viability index with the positive effect of low dose. Within the scope of this study, comprehensive information was presented for L. corniculatus (cultivar 'Leo'), an important forage plant, in terms of germination and seedling growth under salt stress.