The Research Of Potato Drought Damage And Improve Its Drought Resistance Methods

The potato is the typical temperate crops, and very sensitive to water deficit, Drought will affect the normal growth and late potato yield formation, and becoming the limiting factor of potato industry development. For the exact research of the effects of drought stress on potato growth and physiological and the role of different methodes to improve its drought resistance, this experiment with different potato varieties for materials, research the effects of drought on potato seedlings, such as, membrane permeability, antioxidant enzyme activities and antioxidants contents, and studied the guidance of drought resistance of potatoes to potassium and exogenous chitosan, meanwhile,discuss the physiological responses of potatoes to drought stress and different inductions for improving droughtresistance, it provides theoretical basis for planting and breeding variety of potato. The main results are as follows:1. Effects of different drought treatments on potato growth and physiological charactersThis experiment with potato varieties of "meikangl" for materials, by potted plant methods simulating soil drought conditions, set up the soil relative water content was80%,60%,40%and20%four water treatment gradient, research for different degrees of drought stress on seedling growth and physiological characteristics of potato. In dry processing of6days and12days, potatoes the plant height, stem diameter, fresh weight per plant and leaf area were the biggest in the seedling of80%(relative water content (RSWC)(CK), and theys lightly declined in60%RSWC, but were greatly reduced in40%-20%RSWC. The malondialdehyde (MDA), soluble sugar (SS), superoxide dismutase (SOD) and peroxidase (POD) change is smooth with stress time in80%RSWC; SS, SOD, POD rise with the increase of stress time in60%RSWC; MDA, SS also rise with time in40%and20%RSWC and increase quickly, SOD and POD, in a short time, jumpping to peak and then falling-apidly. The results show, the potato is not able to bear or endure long time high strength drought,50%RSWC is seedling growth, biomass accumulation and physiological characteristics significantly inhibited by the drought stress intensity threshold,20%RSWC stress to the young processing produces serious harm.2. Effects of potassium on physiological characters of potatoes under drought stressThis research with the "Netherlands15" species generation potato for material set to seedling ind tuber initiation of two drought stress period, every period set four levels potassium and four lifferent gradient drought stress, by means of measuring the the physiological indexes of drought esistance to study the the relationship of potassium and plant drought resistance. In mild drought tress conditions, potassium nitrogen application improving activity of SOD, POD and content of oluble sugar (SS), soluble protein (SP), free prolin (Pro), thus reduce content of MDA.and mproving photosynthetic pigment. In aggravating drought stress conditions, porassium decling seed of activity of SOD, POD and content of SS, SP, Pro is decreased, lower MDA content rising and reduced relatively content of MDA content. From these physiological changes, we can find suitable potassium nitrogen can improve the physiological and biochemical reaction of the plants, thus improve the drought resistance.3. Effects of exogenous chitosan on physiological characteristics of potatoes under drought stressTaking the potato seedlings of "Netherlands15" as test materials, this paper studied the effects of exogenous chitosan (CTS) on their physiological characteristics under drought stress and rehydration Applying50,100and200mg L-1of exogenous chitosan (CTS)sodium could cause the leaves of potato seedlings under drought stress to increase their proline contents and soluble protein contents whereas decrease their MDA contents and membrane relative permeability, and accelerate differentially the activities of superoxide dismutase (SOD), and peroxidase (POD). At the same time, it ensured the rapid Undo physiological characteristics after rehydration. It confirms that Appropriate concentration exogenous chitosan (CTS) may enhance resistance against drought stress through raising anti-oxidative capability in potato seedling under drought stress, and100mg L-1of CTS had the most satisfactory effect.