Seed Germination Characteristics And Responses To Salt Stress Of Cassia Nomame

Cassia nomame(Sieb.) Kitag is a kind of wild plant resounce which have great economic development potencial attribute to its medicinal, hygienical and edible values. Lacking of resource protection consciousness and large-scale production system, wild resources of C. nomame are in a severe situation, therefore the need of its cultivation is urgent. Seeds biological characteristics include morphological characteristics, compositions, hardness and germination characteristics, the relationship between hard degree and vigor of seeds, and salt resistance of seeds and seedlings of C. nomame have been studied for cultivation and utilization. The main results were as follow:1. Seeds of C. Nomame were small and were oily seeds beacause the crude fat content was high; There have various of microelements as Ca, Mg, Fe, Mn, Zn, and Cu in C.nomame seeds especially Ca and Mg.2. The hard seed rate of C.nomame was as high as 95.33%; Although the method of treating the seeds with 98% H2SO4 10 ~ 30 min was the best to break the hard seeds, 80℃ hot water soaking was more secure and easier in comparison with other methods; In addition, the most suitable conditions were at 25℃ and under dark conditions for the seed germination.3. There have differences between hard degree of C.nomame seeds, and it was positive correlation between hard degree and the vigor level of seeds, seeds with higher hard degree have higher vigor level; With the change of seed hard degree,the electrical conductivity and soluble sugar content in extract, respiration intensity,dehydrogenase activity, POD activity, SOD activity and MDA content of C.nomame seeds have specific variation tendency respectively, they can be used as indicators for evaluating the vigor level of seeds.4. C.nomame seeds can resistance particular concentration salt stress and the testa have a protective effect, the seeds of C.nomame can germination under200mmol/L salt stress and grow well when the salt concentration below 25mmol/L,the development of seedlings of C.nomame were obviously inhibited with theincreasing of salt concentration. The morphological indexes including the length,fresh weight and dry weight of roots and seedlings, the number, length, breadth and pairs of leaves showed declining tendency with the increase of salt concentration;Root activity, chlorophyll content, SOD and POD activity of roots and leaves of seedlings under salt stress increased first, then decreased when the salt concentration was high, MDA content variation tendency was contrary, there have significant correlative between SOD, POD activity and MDA content.