Research On Amsonia Tabernaemontana Seed Breeding And Drought Resistance

High latitude cold area of arid environments lack appropriate ornamental plant resources. Taking perennial herb ornamental plant of Amsonia tabernaemontana as tested materials. Through discuss the optimization of seed propagation technology and evaluate drought resistance, provide a scientific basis for application in garden.Study on constant temperature of15℃、20℃、25℃、30℃and5variable temperature gradient., different light of full exposure、8h light/16h dark、16h light/8h dark、dark, Physical treatment (soaking and hot water). Through different PEG stress of5%、10%、15%、20%、ck (contrast group) to treat the seed,study the correlation of morphological and physiological indexes on seed germination and seedling growth.5%、10%、15%、20%.25%concentration of PEG simulated drought stress combined with water recovery treatment and ot water control treatment of4、8、12、16d、20d on seedling. Comprehensively evaluate on the drought resistance ability. The results are as follows:1.Amsonia tabernaemontana seeds thousand-grain weight for25.41g;30℃is the optimum temperature of seed germination, There was a significant difference on constant temperature and the order of temperature affecting germination rates was30℃(98.33%)>25℃(13.33%)>20℃(5%)>15℃(0%); The germination rate also reaching97.23%when the variable temperature was15～30℃; Seed germination is not sensitive to light. After seed-soaking of70℃、3h.the germination rate reached the highest,respectively increased13.3%and9.2%.2.PEG concentration of5%promotes seed germination,10-25%inhibits. The seeds could not germinate at PEG concentration of20～25%.85.78～91.57%of the seeds failed to germinate at PEG concentration of20～25%regerminate through water recovery experiments. It still has the ability to recover. The stage germination of A. tabomae seed has a certain resistance to drought.3. With the different concentration PEG drought stress on seedling, the trauma of5%and10%is least and ornamental value of Amsonia tabernaemontana vanish on24h、18h、12h after stressed by PEG of15%、20%、25%. Water recovery of25%concentration PEG treatment group can not be restored to the ck level, seedling death.PEG simulated drought stress has significant effect on Amsonia tabernaemontana physiological index. Relative leaf water content has negative correlation to stress time, MP has very significantly negative correlation to SOD,MDA has positive correlation to SOD, so it all can be used as drought resistance of the reference indicators. Chlorophyll a and b decreased to the lowest point and photosynthesis slowly. Osmotic regulation material of soluble sugar and soluble protein loss function in the later period. It partially reflect the plant adaptation, also can be used as reference index.4. When water-control pot experiment in12d, the plants suffered drought stress seriously and losed ornamental. After rewatering it could restore. It can tolerate12d drought stress maximuinly. When the stress for16days, the plants will die. Soil water content, leaf relative water content、chlorophyll a and b content and stress time showed a significant negtive correlation. The relative conductivity, proline, soluble protein and stress time showed a positive correlation. SOD, POD, MDA, soluble protein content increased first and then decreased. It can resist drought stress through self-regulation.These indexes can be used as a measure of drought resistance indexes.