Seasonal Physiological And Biochemical Response Of Haloxylon Bunge To Atmosphere Drought

This text proceeds from angle of botanical physiology and biochemistry, combining with the aid of field investigation, the physiological index determination and biostatistics method, adopting continuous sampling, measured the varities of relative conductivity, the content of osmoregulators, activity of antioxidant enzymes, integrating the net volume of growth of assimilative twig and the change of circumstance factors, study physiological and biochemical response in the season of growth of adult plant of two kinds of Haloxylon Bunge in Xinjiangî º Haloxylon ammodendron and H. persicum, and probe into the relation between its growth and circumstance factors, such as air temperature, groundwater level, air relative humidity and so on. The result of research as follow:(1) Soil drought isn't the major factor of affecting growth of Haloxylon Bunge, which belong to deep root system. Air drought is one of main reason of evoking dormancy of growing and coming off the young twig.(2) The dissolvable proline (pro) and the dissolvable sugar is only fit for the weak atmosphere drought-stress in the initial stage of the season of growth of Haloxylon Bunge. Under the severe atmosphere drought-stress, the activity of superoxide dismutase (SOD) and peroxidase (POD) increasing goes on physiologic adjustion, and assimilative twig stopping growth and falling off is in progress growing adjustment.(3) The activity of polphenol oxidase (PPO) of Haloxylon Bunge is positive related to the net volume of growth of them, signitantly. So PPO activity can take for one of indexes of judging growth of Haloxylon Bunge.(4) Under the same ecological environment, the overground volume of growth of H. ammodendron the content of the dissolvable protein of lower than that of, and this difference is extremely significant ; and the penetration of membrane, the content of MDA, dissolvable pro and dissolvable sugar of H. ammodendron is lower than those of H. persicum. Though the activity of POD and SOD of H. ammodendron is also lower than those of H. persicum, the coordination of them is better. So the adaptability of H. ammodendron is stronger than that of H. persicum.