| The study was preliminary on techniques of soft-wood cutting of Umlus pumila. Four 2a Umlus pumila seedlings were selected which were superior on salt-tolerant of the coastal for soft-wood cutting, used 2a seedlings of Bao-ding Umlus pumila to check. Did salt stress to the cuttings with saline soil of 0.6% salinity. After 35 days stress, measured photosynthetic, physiological indicators of the cuttings'leaf and compared ion content in various parts of the cuttings. The main results are as follows:(1) Chose Umlus pumila as study object, using IAA, IBA, NAA, ABT1, ABT3 and mixed (IAA, IBA, NAA of the same concentration) six hormone types, 250 ppm, 500ppm, 1000 ppm and 2000 ppm four concentrations tested. The results showed that the type of hormone is the main factor. The Umlus pumila dealt with ABT3 has the highest survival rate, rooting the best, significantly better than the other hormone treatments. Integrated all the various indicators to deal with, the test finally adopted ABT3 of 500 ppm of good salt-tolerant Umlus pumila clones for soft-wood cutting.(2) Salt stress on the different clones of Umlus pumila had varies degrees of salt injury, the salt injury to the minimum on the clone 2 and clone 4 and to the maximum on the clone 5.(3) Salt stress also restrained photosynthesis of Umlus pumila clones. The net photosynthetic rate, transpiration rate, stomatal conductance, intercellular carbon dioxide concentration and chlorophyll content of Umlus pumila clones were reduced in different degrees. The clone 2 reduced least and clone 5 reduced most of the five clones, clone 2 had the lightest salt stress and clone 5 had the heavest.(4) Under salt stress, the content of Na+ and K + in different parts of different Umlus pumila clones increased. The Na+ / K+ was higher of the clones in the salinity soil than in nursery soil. The Na+ / K+ of clone 2 increased the minimum. It's showed that under the high-salt stress, the clone 2 had resistance on salt-tolerant. Clone 2 did not absorb the Na+ in the soil completely, so Na+ / K+ was not high.(5) The soluble protein and cell protective enzyme activities in all clones had been changed under salt stress. Soluble protein content had declined, SOD, POD and CAT activity increased in different degrees. The clone 5 had the lowest change rate of cell protective enzyme activity and soluble sugar.(6)Under salt stress, the content of MDA changed significantly between the clones. MDA increased 79.11% and 76.88% in clone 1and clone 5. The soluble sugar content changed most in clone 2, was 23.55%; clone 5 increased the least, was 5.01%. (7) As can be seen through the various indicators, in addition to clone 5, other clones all had high salt resistance and clone 2 was the most stable on the various indicators. We could use vegetative propagation techniques for ecological restoration to the coastal saline areas to provide the preferred eco-reference. |
