Study On Seeds Germination Characteristics And Seedlings Drought Resistance Of Four Kinds’of Clematis L

Clematis L. is known as "Queen of climbing plants". C.brevicaudata, C. serratifolia, C. hexapetala, C.fusca all belong to Clematis L.Florescence almost concentrate in summer and fall that can make up the lack of flower plants in late summer and early autumn of north east. In this paper, taking the four kinds of seeds of Clematis L. and seedlings of C.brevica udata, C. serratifolia as materials, the influence of hormones,temperature, light treatment on seeds germination,the changes of physiological and biochemical characteristics in the process of seeds germination, the physiological and biochemical changes of C.brevicaudata and C. serratifolia under PEG stress and natural water loss were studied. At last, the comprehensive evaluation of drought resistance of C.brevicaudata and C. serratifolia were evaluated with subordinate function.Provide the reference basis for Clematis L.’s cultivation in Harbin.The results are as follows:(1)C.brevicaudata’s suitable temperature is20℃-25℃, C. serratifolia’’s suitable temperature is25℃.Variable temperature conditions of25℃/20℃, significantly promoted the seed germination of C.brevicaudata, C. serratifolia, C. hexapetala, temperature treatment cannot improve C.fusca’s seed germination rate.(2)Four kinds of seeds’germination all need light.(3)20mg.L-1IAA is the best concentration to C.brevicaudata,20mg·L-1IAA、5mg·L-1GA3is the best concentration to C.serratifolia.500mg·L-1GA3can significantly promote the C. hexapetala and C.fusca’s seed germination rate.(4)In the process of seeds’ germination, the enzyme activities of SOD and POD show the trend of gradually increase and the soluble sugar content, soluble protein content show the trend of rise firstly and then decline, MDA content show the trend of decline.(5) Effect of PEG stress on physiological and biochemical of C.brevicaudata and C. serratifolia is as follows:The unilateral analysis of their various physiological indexes and comprehensive analysis of subordinate function value method show that the drought resistant ability of C.brevicaudata is better than C. serratifolia.(6)With the extension of soil drought stress, the drought resistance of C.brevicaudata and C. serratifolia’s seedlings decreased.After rewater treatment, two seedlings’ physiological and biochemical indexes have various degree of recoveries. When the stress is relatively small, various physiological index of C.brevicaudata can recover to normal level within a short time, and the various physiological index of C. serratifolia can recover to normal levels. With the deepening of soil drought stress, the various physiological index of two kinds of Clematis.L cann’t recover to normal level within a short time. The result of comprehensive analysis of the subordinate fuction value method shows that C.brevicaudata’s drought resistance surpass C. serratifolid’s.(7)The results of the PEG stress and soil drought stress all show that C. brevicaudatd’s drought resistance surpass C. serratifolia’s.