Effect Of Drought Stress On Physiological Indexes And Structure In Leaves Of Potato(Solanum Tuberosum L.)

Water stress is one of the main limiting factor in crop yields, the yield reduction of crop dueto water stress is the sum of the other disasters. So increasing the crop yield under water stress isone of the important research topic of agricultural. Potatoes are the fourth largest grain crops nextto the wheat, rice, corn. and is more sensitive to water demand in the whole growth. The availablewater deficit slightly to change plant physiological activity in growth of potatoes.Dongnong308、Dongnong309、Dongnong310、Dongnong311、Kexin13and Yanshu4were usedas experiment material in this study, they were grown in the pot culture in the canopy to controlwater at5different stages, to study the effect of physiological and biochemical index、leafstructure and photosynthetic characteristics in potato at different stages under water stress and toexplore the physiological performance of varieties under water stress. The main results are asfollows:1. The relative water content and rate of excised leaf water loss showed downtrend; proline、soluble sugar、bound water/free water and malondialdehyde showed an increasing tendency.Atdifferent stages, the change of physiological index were different. There were significantdifferences in physiological stages and varieties.2. At the same time the data of Fuzzy Funtion of physiological indices was used to comparedrought resistance of6varieties: The Dongnong308was sensitive to water in the squaring periodand starch accumulation period, the seedling stage and fourth stage were high resistance to drought;The Dongnong309was sensitive to water in the seedling stage, other stages were moderateresistance to drought; The Dongnong310was high resistance to drought in the seedling stage andsquaring period, other stages were moderate resistance to drought; The Dongnong311wassensitive to water in the tuber swelling stage and starch accumulation period, other stages weremoderate resistance to drought; The Kexin13was sensitive to water in the seedling stage andinitial bloom stage. According to the characteristics of variety applied to agricultural production.3. Water stress affects leaf structure of potato, making leaf structure thicker and palisade andspongy tissue cell becomes confusion, there has differences between varieties.4. The chlorophyll fluorescence parameters of potato leaves showed that: There was asignificant correlation between the variation of Fo, Fv/Fm, Y(II), Y(NPQ), NPQ and ETR and thevariation of soil moisture. There is no correlation between the variation of Fm, Y(NO) and qP andthe variation of soil moisture. There was a difference among chlorophyll fluorescence parameters of different varieties, the adaptability of drought was Dongnong311> Kexin13> Yanshu4,chlorophyll fluorescence could be used as a diagnostic indicator of drought resistance for thepotato breeding and research.