Effects Of Exogenous ABA On Physiological And Biochemical Characteristics In Dichondra Repens Forst.under PEG Stress

Dichondra repens Forst. For bindweed Horseshoe metal perennial creeping rooting herbs, wild distribution in Taiwan and south of the Yangtze River and other places since1980from the United States to China after the introduction of improved varieties, beautiful appearance, easy floor space, extensive management, adaptability, and a wide range of uses, is a very good ground cover and ornamental plants of, followed by the introduction and cultivation in northern China and other places, but due to the northern temperature and moisture factors range of applications, making repens and floor space effect was extremely restricted.Many studies show that plants is an important endogenous hormone abscisic acid (ABA), involved in the regulation of many drought resistance physiological and biochemical processes, such as plant primary root growth and the formation of aquatic plants aerial leaf structure, stomatal opening and closing the plant stress protein and proline synthesis. There are also related studies have shown that by application of exogenous ABA treatment can improve the resistance of plants, such as increased by the administration of exogenous ABA treatment plant cold tolerance and cell suspension cultures of cold hardiness, drought and heat resistance of plants, the seeds of the anti-dehydration. Subsequently, many scholars from the point of view of plant physiology and biochemistry, plant growth regulator of the ABA, GA, MET and allyl Uniconazole bermudagrass, centipedegrass, perennial ryegrass and tall fescue lawn plants and other plants the impact of drought and cold resistance, and achieved some success.To the northern city of the main floor space to the Golden Horseshoe lawn green prolongation, and play the Dichondra repens Forst. and the northern city of common cold season turfgrasses compared to the unique shape, management and low cost characteristics of the fine, to further strengthen its application, this study repens seedlings as materials, different concentrations of PEG (0%,10%,20%,30%, respectively) to simulate different drought conditions its stress treatments, and through the corresponding concentration applied to the corresponding treatment group (0,1,10,100μmol/L) exogenous ABA treatment, using Coomassie brilliant blue G250staining guaiacol the lignans law and tetrazolium (NBT) for four consecutive days, determined Dichondra repens leaf soluble protein content and SOD, POD activity, analysis of exogenous ABA treatment under drought stress the Dichondra repens Forst. soluble protein content and the antioxidant enzymes in. The results showed that:1. Dichondra repens leaf soluble protein content of different concentrations of ABA under PEG stressDichondra repens Forst. seedlings watered with different concentrations of PEG after2days treated foliar spraying different concentrations of exogenous ABA, soluble protein content than normal growth of plants without ABA treatment plants were decreased by ABA treatment, the soluble protein content over time grew faster than normal plants have varying degrees of increase,10%PEG treatment sprayed with1mol/L ABA,20%PEG treatment after spraying10mol/L ABA30%PEG treatment after spraying100mmol/L ABA of D. repens seedlings to PEG stress of drought-resistant performance is strong.2. different concentrations of ABA under PEG stress Dichondra repens leaf SOD activityDichondra repens Forst. seedlings watered with different concentrations of PEG after2days treated foliar spraying different concentrations of exogenous ABA SOD activity than normal growth of plants without ABA treatment plants declined in varying degrees, by ABA treatment, the SOD activity than normal plants grow with time will be increased to varying degrees, in10%PEG treatment sprayed with1mol/L ABA,20%PEG treatment after spraying10mol/L ABA,30%PEG treated spraying100μmol/L ABA, of D. repens seedlings to PEG stress strong drought resistance performance.3. with different concentrations of ABA under PEG stress Dichondra repens leaf POD ActivityDichondra repens Forst. seedlings watered with different concentrations of PEG after2days treated foliar spraying different concentrations of exogenous ABA, POD activity than normal growth of plants without ABA treatment plants declined in varying degrees, by ABA treatment, the POD activity than normal plants grow with time will be increased to varying degrees, in10%PEG treatment sprayed with1mol/L ABA,20%PEG treatment after spraying10mol/L ABA,30%PEG treated spraying100μmol/L ABA, of D. repens seedlings to PEG stress strong drought resistance performance.Overall, PEG stress Dichondra repens Forst. seedling leaves soluble protein content and SOD, POD activity than normal growth were decreased. Effect of ABA, leaf soluble protein content and SOD, POD activity than the spray increased to some extent, indicating that the ABA can enhance their drought resistance.10%PEG stress,1mol/L ABA mitigation works best;20%PEG stress, the best10mol/L ABA mitigation effect;30%PEG stress,100mmol/L ABA mitigation effect good. It can be speculated that the optimum concentration of ABA treatment in certain drought stress, the better not ABA higher the concentration of drought mitigation, which the Golden Horseshoe plants in the practical application of exogenous ABA treatment in order to improve drought resistance of work a reasonable choice of the concentration of ABA certain guiding significance.In order to ascertain the effects of ABA on the content of soluble protein and the activity of antioxidant enzyme in Dichondra repens Forst under PEG stress. First, irrigated PEG solution (the density of0%,10%,20%,30%), after two days, dusted ABA solution (the density of0μmol/L,1μmol/L,10μmol/L,100μmol/L) on the lamina under every different density of PEG. After0th day,1th day,2th day,3th day,4th day, measured the content of soluble protein and the activity of antioxidant enzyme (SOD, POD), respectively. The results showed that the content of soluble protein and the activity of SOD, POD dropped in the PEG treated groups. After dusted ABA solution, the content of soluble protein and the activity of SOD, POD ascended compare to the group of not dusted ABA solution, consequently, strengthened its drought-avoidance.1μmol/L ABA solution was optimum under10%PEG stress;10μmol/L ABA solution was optimum under20%PEG stress;100μmol/L ABA solution was optimum under30%PEG stress. The experiments suggested that there is the optimum density of ABA under the specific density of PEG stress, it is not proper to think that as the density of ABA is higher as the effect is better.