Studies On Drougt Resisitance Of Rocky-grasses Eriophorum Comosum Nees

Eriophorum comosum Nees were used as research materials.Five materials were collected from Ya'an,Nanchong,Mianyang,Chendu-Longquanyi,and Neijiang, Sichuan province.Adopting modeling.drought and rewatering means,by controlling soil moisture(sustainable drought),the growth condition and physiology indexes in the different stages were analyzed,the differences in drought resistance among the five materials was studied,moreover,the mechanism of drought-resistant physiology and restoration capacity were discussed.In order to understand and try to select the materials with strong drought resistance.Meanwhile,the theoretical and practical basis in using well Erioophorum comosum Nees and bio-diversity and community stability in slope re-vegetation were put forward.The main results showed as fallows:(1) All materials showed drought resistance.Eriophorum comosum Nees is ideal plant in slope re-vegetation and it adapt to the special habitat.In the initial stage under drought-stress(0～8days),plants grow well.With the process of drought-stress, growth of the research materials was inhibited.The leaves turned yellow,wilting and even death under water stress for a long time.S0705(Collected from Neijiang) began to die in 26—day water controlling,but S0701(Collected from Ya'an) S0704 (Collected from Chendu-Longquanyi) happened to die in 42-day water contolling.(2) Eriophorum comosum Nees showed obviously physiological adaptation mechanism.The detailed results showed as follows:①the water content of plant body was continuously decreased(leaf relative water content,the leaf water content in vitro,transpiration rate were decreased in different degree),but the water saturation deficit was increased in different degree.②Photosynthesis of research materials was inhibited,which led to the decreased change of chlorophyll content,net photosynthetic rate,stomata conductance and water use efficiency.③Membrane permeability of the leaf changed.Malondialdehyle content and cytomembrane permeability increased.④Free proline gradually accumulated,the result was caused by the leaf injured,not regulatory action as a osmotic substance.⑤root activity weakened continually.(3) After rewatering,research materials showed good restoration capacity. Results showed as follows,the water content of plant body was increased and leaf relative water content reached above 90%;Photosynthesis ability enhanced and chlorophyll increased obviously;membrane nature relative penetrability improved, MDA and the proline content decreased,and the root activity greatly enhanced. Restoration process about different materials was obviously different.(4) According to the experimental result and the difficulty level in the experimental,leaf relative water contents,relative electric conductivity,net photosynthetic rate,chlorophyll contents,MDA contents and the root activity were as physiology indexes of drought resistance.Quantification of the plant growth was advantageous to the data analysis and the comparison.(5) Adopting the subjection function way of fuzzy mathematics,comprehensive appraisal of drought resistance of five research materials came from different geographical regions were categorized.The primary result was followed as:S0704) S0701) S0703) S0702) S0705.Based on the test results,S0704 and S0701 were recommended as good plants used on the re-vegetation on rocky slopes.The two materials grew well and mortality rate was low where the soil is in the seriously drought situation.