Effects Of AM Fungi On Growth And Physiological Characters Of Seriphidium. Under Water Stress

Seriphidium are xerophytic and super dry plants, and most species grow in the grassland, semi-desert or desert grassland. As one of the basis of vegetation in Northwest China, most species of Seriphidium has important forage, medicinal and ecological value. Seriphidium play an important role in the prevention of soil erosion, sand-fixing. In recent years, due to over-grazing and global climate change, grassland vegetation of Seriphidium severely damaged. Its production and ecological function has been seriously weakened, and the ecological balance seriously damaged. Therefore, breeding available plant resources to adapt to arid environment of Northwest and using of mycorrhizal biotechnology for healthy growth of Seriphidium can improve the Northwest desert, semi-desert grassland productivity for our agricultural development and ecological rehabilitation services.In this paper, four species of Serphidium (S. santolinum, S. transiliense, S. sublessingianum and S. minchünense) were for the experimental materials, which grew in the greenhouse with different water conditions. Four species of Serphidium studied on plant growth, physiological and biochemical characteristics and POD isozyme of four species of Serphidium. Through a comprehensively evaluated, S. minchünense was the most drought resistance. Then, the effect of AM fungi was studied on the growth and physiological characteristics of S. minchünense under water stress. The main results were as followed:1. Through a comparative analysis of plant growth and physiological and biochemical characteristics of four species of Serphidium by subordinative function method, drought-resistant capability of four plants was in an ordination of S. minchünense > S. santolinum > S. transiliense > S. sublessingianum.2. Polyacrylamide Gel Electrophoresis (PAGE) was used to analyze the POD isozyme of four species of Serphidium ,the result showed that POD isozyme can be divided two regions (A and B). A region of four species of Serphidium contains two bands, and B region had more isozyme bands, and the bands in this region were higher activity. Under water stress, bands color and numbers all changed, a part of isozymes disappeared activities and bands, other part isozymes activities significantly increased or appeared new bands. Such results would facilitate Serphidium breeding for improving drought resistance and the new bands were relative to the mechanism of drought resistance.3. AM fungi and S. minchünense form a good symbiotic relationship. Variance analysis showed that, infection rate were significantly increased by inoculation AM fungi, but severe stress significantly inhibited the infection rate. Mycorrhizal dependency and contribution rate of S. minchünense increased under water stress.4. Variance analysis showed that the content of leaf relative water, soluble protein, chlorophyll, total N and total P were significantly improved in different stages, and total flavonoids content of leaf was significantly increased just under severe stress, while the proline content was decreased throughout the growth period by colonization AM fungi. The content of soluble sugar in leaves of inoculated plant was significantly lower than that of non-inoculated plants in early stage , and significantly higher than that of non-inoculated plant in middle and latter stages.