Physiological Mechanisms For Plant Growth Nutrient Solution On Drought Resistance And Yield Of Potato

China is the largest country in potato acreage, but per unit area yield is lower than theworld average of19.18%, currently China’s potato production need to solve the problemwhich increasing the per unit area yield,Inner Mongolia is one of the main potatoproducing provinces in China, more than80%of the area is dry farming, Drought hasbecome the important factors limiting the growth and yield increase of potato.Plant growthnutrient solution is a new type of foliar fertilizer containing humic acid substances, it hasplay a positive role in drought resistance and increasing yield for potato In view of thedrought and low production, through combining the pot and field, and through sprayingwith different concentrations of plant growth nutrient solution.at different with differentconcentrations of plant growth nutrient solution.at different period. Under different waterconditions and drought stress after re-watering conditions, this paper studies the impact ofpotato growth, physiological reaction in different organs of potato and yield,anddiscussion on the mechanism of plant growth and yield, then screening the appropriateconcentration; Explore the nutrient solution on plant growth regulatory mechanisms,potatoyield and drought, provide a theoretical basis and technical support for improving droughtresistance, increasing the yield of potato and achieving stable production of potato.1. Spraying plant growth nutrient solution with different concentrations all canincrease the potato plant height, stem diameter, leaf area index, dry matter, diluted500times had the largest increase, Per unit area yield increases29.45%, Under differentirrigation methods, Spraying plant growth nutrient solution all can increase the potato plantheight, stem diameter and plant fresh weight, and improve the root activity.2. Spraying plant growth nutrient solution at different period all can reduce REC andMDA content of leaves at each growth period,and increase free proline content andactivities of protective enzymes; the REC, MDA content and freeproline are significantdifference influence by spraying plant growth nutrient solution at Potato tuber expansionperiod; spraying plant growth nutrient solution at different period all can significantlyincrease SOD and CAT activity, and have a small effect in POD activity. 3. Plant growth nutrient solution can improving the SPAD value of leaves, andslowing SPAD value decreased under severe water stress. The water stress reducedphotosynthetic rate, transpiration rate and stomatal conductance. Spraying Plant growthnutrient solution can enhance photosynthetic rate, reducing transpiration rate and stomatalconductance. Plant growth nutrient solution can reduce the REC, reducing theaccumulation of MDA, and severe water stress is the largest. Plant growth nutrient solutioncan increasing the osmotic adjustment substance, and has a greater impact on content offree-proline, the maximum increase is25.25%. Plant growth nutrient solution can improvethe activity of protection enzyme, and increase scale in tuber bulking stage is the mostsignificant.4. In seedling stage, Spraying Plant growth nutrient solution has no significant effecton physiological characteristics of normal supply water in potato, but has the largerinfluence on the drought treatments. Under persistent drought, SPAD value increasedsignificantly at the seventh days after spraying plant growth nutrient solution, the REC ofleaves reduce significantly at5,7d, and MDAcontent（P<0.05）reduce significantly at7d,free-proline and soluble protein content increase significantly at7d of persistent drought,soluble sugar content improve significantly at the fifth day (P<0.05), plant growth andnutrient solution treatment significantly increase protective enzyme activity and rootactivity in the later period of drought.5.Under water stress, Spraying plant growth nutrient solution improve significantlythe photosynthetic characteristics of potato, reduce significantly the REC and MDAcontent of roots and leaves (P<0.05), inhibited significantly the synthesis of MDA（P<0.05）; Osmoregulation Substances Content in leaves more than in root, the effect ishigher on Osmoregulation Substances of leaves; there are a larger increase scale inSOD,POD,CAT activity, and the protective enzyme activities of the leaves is greater thanthe roots, improve significantly the root activity. After re-watering, there is no significantdifference between the plant growth nutrient solution under moderate water stress andnormal water treatment, plant growth nutrient solution under severe water stress treatmenthave the significant different with normal water supply. The impacts of plant growthnutrient solution on potato are greater than after re-watering under water stress treatment.Under Severe water stress, the plant growth nutrient solution treatments get the biggestincrease in yield, up to7.55%.6.Under different irrigation methods, plant growth nutrient solution treatment increasephotosynthetic rate, reduce the transpiration rate and stomatal conductance compared with the control, there are significantly different under the drought farming condition (P<0.05);plant growth nutrient solution treatments reduce the REC of different organs is3.62%to25.08%, and the MDA content is4.56%to20.11%, drought farming treatments get thelargest decline; plant growth nutrient solution treatments increase free-proline, solublesugar and soluble protein content, there are larger effect in the leaves than stems and roots;different organ protective enzyme activity show that: leaves> roots> stems, plant growthand nutrient solution increase significantly protective enzyme activity of leaves, have lesseffect on the roots and stems, and under the condition of low irrigation, spraying plantgrowth nutrient solution is benefit to enhance the activity of the protection enzyme. Plantgrowth nutrient solution increase the yield by9.70%-24.36%, and drought farming> dripirrigation> sprinkler irrigation; plant growth nutrient solution improve dry matter andstarch content.7.The correlation analysis showed that plant height, plant fresh weight, root activity,SPAD of leaves, photosynthetic rate of the potato have an extremely significant correlationwith yield; the REC, MDA and free-proline content of different organs have an extremelysignificant negative correlation with yield; the POD and CAT activity of roots and stemssignificantly or extremely significant negative correlation with yield, the POD of leaveshas a significantly negative correlation with yield. Above all, those indicators could be aneffective index to judge drought resistance and yield of potato under different waterconditions.