Effects On Physiological Characteristics Of Dendrathema Indicum L. Under Drought Stress

An experiment was conducted to study the physiological characteristics changes in the seeds and seedlings of Dendrathema indicum L. under drought stress.Make sure the law of dry adaptability. Accumulate data to study the Drought-resistant mechanism of Dendrathema indicum L. and to provide a theoretical basis for Dendrathema indicum L. Garden. The seeds were stressed by the different concentrations of polyethylene glycol (PEG-6000)With the increasing concentration of PEG-6000, the Seed Germination and Seedling Growth can tolerate the drought stress environment which the concentration of peg was 20%,but the phenomenon will disappeared under the high concentrations of PEG (25%) stress.From the concentrations of PEG (10%),the seed germination and buds were beginning to be inhibited growth. All indicators reflect the seed of Dendrathema indicum L. sensitive to drought stress, can not adapt the moderate and severe drought in the external environmentAn experiment was conducted to simulated drought environment by PEG to treat Dendrathema indicum L. seedlings. The physiological data Measured in the stress show that the plants produce appropriate protection mechanisms in the early and late of PEG treatment.After the treatment of concentration in PEG 5%,The plant morphology remained intact which shows that mild stress are more conducive to the growth. SOD and POD isozymes of leaves in different concentrations treatment of PEG were changed greatly, compared with SOD and POD, the expression of CAT was stable. This phenomenon may be related to plants treat and regulate related substances. This shows that Gene expression of seedlings to the osmotic stress response was a short-term, reversible regulation way.After the 10 days to drought stress to the seedlings. The content of soluble sugar and soluble protein began to rise from the lower. In this time to rehydrate for seedlings, the indicators be measured was no significant regression. The content of MDA and soluble sugar decreased under the control.May be the Dendrathema indicum L. is in the recovery period, and they did not produce the appropriate conditions for resilience outside, therefore, some indicators was low Instead. But the plant can self-repair. The activity and isozyme of SOD, POD and CAT changed with the same trend. The first 10 days, three enzyme activities and isozyme expression has decreased. Drought stress may have exceeded the capacity of the Dendrathema indicum L. seedlings, and regulatory function of plant protection activity started to decline.But when the 10 days, after rewatering, three enzyme activities and isozyme expression began to rise. Maybe the plants began to adapt to the external environment. To 20 days, the plant morphology appeared severe wilting, however, the expression of its activity and isoenzymes above the control. This shows that Dendrathema indicum L. has a stronger ability to survive for the arid environment.