Bullwhip Rhodiola (rhodiola Fastigiata) The Environmental Stress Response Mechanism

In order to investigate the Rhodiola Fastigiata'response mechanism to mountain environment stress, the paper studied Rhodiola Fastigiata'physiological and biochemical response and adaptive mechanisms to temperature and UV-B radiation from germination rate, germination energy, germination index, seedlings and adult plants'lipid peroxidation level, antioxidant system, organic osmotic substances, photosynthetic pigments and photo-protection substances, the results are as follows:â… ,In addition to its own factors, seed germination also has great relationship with the surrounding environment factors , in this experiment, with the incubation temperature rise (5℃â†'35℃), Rhodiola Fastigiata seeds'germination rate, germination energy, germination index basically showed a "lowâ†'highâ†'low" trend, a peak-type, it is the so-called three-point temperature of plant metabolism, 25℃is the optimum temperature of the Rhodiola Fastigiata seed germination(three seed germination index all reached its maximum, which are all produced by Y mountain), low temperature is more stable than high temperature relatively, it showed that Rhodiola Fastigiata has somewhat adapted low temperature through long-term evolution, Y mountain is a model. According to the statistical analysis, temperature gradient has a very significant impact on Rhodiola Fastigiata seeds'three germination index of three plots, it showed that temperature is one of the important environmental factors of Rhodiola Fastigiata seeds'germination, at the same time, there are some differences among seeds from three plots.With the UV-B radiation enhanced, Rhodiola Fastigiata seeds'germination rate, germination energy and germination index showed a decreasing trend, it showed a certain degree of negative correlation between them, but the negative correlation is not significant, Rhodiola Fastigiata has adapted the strong UV-B radiation factor to some extent through natural evolution, and this generated a certain amount of resistance, particularly the performance of Y outside'performance in the higher UV-B radiation. According to the statistical analysis, UV-B radiation has significant effect on seeds'germination rate from three plots, but not so significant on seed'germination index, effect on seeds from Y mountain and Y outside are significant, but is not significant on Y edge. It showed that UV-B radiation is an important stress factor which affected Rhodiola Fastigiata seeds'germination, at the same time, there are some differences among seeds from three plots.â…¡,When Rhodiola Fastigiata seedlings is in the temperature gradient and UV-B treatment, only proline content showed a positive correlation with the temperature, the rest indicators'activity or content don't have positive or negative correlation with temperature. Treated by two stress factors, plant response are different, it showed that the plants'response mechanism to the temperature and UV-B stress factor are different, after five levels of stress in two factors, response to stress between the various components have a different mode of coordination compensation respectively. According to the statistical analysis, temperature and UV-B gradient have a very significant impact on Rhodiola Fastigiata seedlings'indicators, other indicators reached very significant level in five gradient except for AsA and photosynthetic pigments.â…¢,Through tracing study of Rhodiola Fastigiata growing stage seasonal main related indicators'change in Y mountain, Y outside and Y edge three plots , such as lipid peroxidation level, antioxidant system, organic osmotic substances, photosynthetic pigments and photo-protection substances, the results show that seasonal temperature and UV-B radiation environmental factors have had a very significant impact on all indicators, most indicators reached very significant level in five gradient, in which MDA content showed a strong negative linear relationship with the seasonal temperature, UV-B radiation factor showed inhibition in the pre-growth and promotion in the late-growth. Natural temperature and UV-B radiation combined stress showed antagonism in the prophase and superposition in the later.Plants'response to environmental stress is an active stress process, the stress system has a strong systemic, the experimental results show that Rhodiola Fastigiata live through the adversity through cooperative compensation mechanism between various components, such as SOD, CAT and POD and AsA complement in antioxidant system, Chloroplast Chl and Car complement in photosynthetic pigments, soluble sugar and proline complement each other as osmoregulation substance, there are also complementary relationship between photo-protection substances UV-B radiation absorbing material and anthocyanin.Y mountain plants performed the best growth in extreme harsh environments based on its strongest resistance.