Research On The Adaptability Of Miscanthus Sinensis And Miscanthus Sacchariflora Under The Treatments Of Mixed Salt Alkali

In recent years, Miscanthus sinensis and Miscanthus sacchariflora, which not only obtained good economic efficiency and a certain ecological benefit, but also widely cultivated in urban landscape, had been a sort of emerging energy plant. Taking Miscanthus sinensis introduced from Ajialing of Benxi, Liaoning province, and Miscanthus sacchariflora, introduced from Sun Island of Harbin, as materials, and simulating the saline-alkali soil environment of Daqing in northeast of China which include low (treatment 1、2)、middle (treatment 3) and high concentration (treatment4、5),we studied those seed germination and each physiological index of seedling when they were in the salt and alkali mixed stress treatment.This main experiment results are as follows:1. In the salt and alkali mixed stress treatment, the germination percentage of Miscanthus sinensis was decline with the mixed alkali-saline concentration increase, the other indexes were increase at first and then decrease, like germinability, germination index and vigor index. The all indexes that have mentioned above of Miscanthus sacchariflora seed were decline with the mixed alkali-saline concentration increase. The two plants’ seeds can resist salt and alkali mixed stress treatment that in middle and low concentration, when they were in high concentration, the all indexes were decline obviously ,but the each index of Miscanthus sinensis seed was superior to Miscanthus sacchariflora seed, it can indicate that Miscanthus sinensis seed is more saline-resistant than Miscanthus sacchariflora seed.2.When Miscanthus sinensis and Miscanthus sacchariflora seedlings were inlow concentration of mixed alkali-saline treatment, all seedlings were alive and grew well; when they were in middle concentration treatment, Miscanthus-sinensis and Miscanthus sacchariflora seedlings survival rate were 92% and 87%, and the Miscanthus sacchariflora seedlings growth vigor was obvious weaker than Miscanthus sinensis seedlings; when they were in high concentration treatment, the survival rate both descend evidently, however, the survival rate of Miscanthus sinensis seedlings were significantly higher than Miscanthus sacchariflora seedlings, indicating the former is more saline-resistant than the latter.3.When Miscanthus sinensis seedlings were in salt and alkali mixed stress treatment, each index of CK group had a little change over time; the chlorophyll content in low concentration treatment increase at first and then decrease; while in middle and high concentration treatment, the chlorophyll content was rising; the relative electrical conductivity and MDA content were also rising over time; while the SOD, POD, CAT, APX, GR activity, ASA, GSH content and root activity were rising slowly in low concentration; but in the treatment of high concentration, these indexes presented increase at first and then decrease with time passing by.4. When Miscanthus sacchariflora seedlings were in salt and alkali mixed stress treatment, CK group indexes were little changed over time; The chlorophyll content under the treatments of various concentration was constantly drop with the stress time prolonged; The root activity was rising under the treatments of low concentrations and middle concentrations over time. While it showed decreased first and then increased and decreased in the end under the treatments of high concentrations; And all the other indexes change was similar to Miscanthus sinensis. The change tendency of each index was more obvious than Miscanthus sinensis when Miscanthus sacchariflora seedlings were under the stress of high concentrations and the time of peak would advance. So the saline alkaline tolerance of Miscanthus sinensis seedlings is better than Miscanthus sacchariflora seedlings.This study basically defined the mixed salt alkali tolerance range of Miscanthus sinensis and Miscanthus sacchariflora in order to provide a theoretical basis for the screening of aline alkaline tolerance and applications in landscape of energy plants like Miscanthus sinensis and Miscanthus sacchariflora in the future.