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Gansu Agricultural University (2017)

Effect and Mechanism of Potassium Fertilizer,Phosphate Fertilizer and Rare Earth Fertilizer on Drought Resistance of Potato

杨宏伟;

Titre : Effect and Mechanism of Potassium Fertilizer,Phosphate Fertilizer and Rare Earth Fertilizer on Drought Resistance of Potato

Auteur : 杨宏伟;

Grade : Master’s Theses 2017

Université : Gansu Agricultural University

Résumé partiel
Potassium and phosphorus fertilizer are the most important mineral fertilizers in plant growth and development,they supply nutritions for plants,and they also can improve drought resistance of plants.In northwest of our country,the main cropping lands were arid lands,so water condition become the non-ignorable problem in agricultural production and development.In previous studies,many researchers focused on the effects of multiple fertilizers on qualities and quatities of potatoes,but they did not pay more attention on the regulating mechanisms of potassium or phosphorous fertilizer on drought resistance of potatoes,especially the contents of single fertilizer must be studied deeply.In this study,we used potato variety “Daxiyang” as experimental materials,and controlled the soil water content and different apllying contents of potassium or phosphorous fertilizers,resistant physiological indexes in seedling period and agronomic indexes in maturing period were determined to study the effects of different fertilizer on growth and physiology of potatoes under drought stress,revealed the physiological mechanisms of different fertilizers on improving drought resistance of potatoes,and may give theoretical guidance for potato planting and expanding in arid areas.1.Water deficit is the main reason for latering potato seedlings ? growth and development.In this paper,we set three different contents of soil water,they were Water-CK,Water-1 and Water-2,photosynthetic pigments,osmotic adjustments,antioxidant enzymes and other physiological indexes were determined to study the effects of different fertilizers on potato seedling growth and development under drought stress.The results showed that with the decreasing of soil water content,leaf water content and chlorophyll content decreased,soluble sugar content,soluble protein content,proline content,relative conductance,MDA content and O2-.production rate increased,and the activities of SOD,POD,CAT and APX enhanced,but plant height,stem diameter,root length,the number of stolons and branches reduced,tuber weight,starch content,vitamin C content and reducing sugar content also decreased.Among these treatments,the yield of per plant was changed significantly,it was decreased from 623 g to 423 g.It indicated that drought dtress induced the yields of potatoes decreased.2.The results showed that the damage of potato seedlings caused by drought stress was alleviated significantly by spraying potassium sulphate solutions,and the effects is the best when the spraying amount of potassium sulphate was 3.5g per plant.The plant height,root weight,stem diameter,tuber weight,and overground part weight increased,root,stem and leaf water contents also increased,chlorophyll,carotenoid,soluble sugar,proline improved,MDA contents decreased,the activities of superoxide(SOD),peroxidase(POD),catalase(CAT)enhanced.Our results provide evidence that spray potassium sulphate solution may alleviate the damage caused by drought stress on potato seedlings through improving the activities of antioxidase,decreasing MDA contents,increasing soluble sugar and proline contents,enhancing the accumulation of photosynthate,thus promote seedling growth and tuber yields,improving the nutrition and quality of potato tubers.3.After spraying phosphorus fertilizer on the leaves under drought stress,leaf water content and chlorophyll content increased significantly,the activities of SOD,POD,CAT and APX enhanced relatively,relative conductance,MDA content and O2-.production rate reduced significantly,tuber weight,starch content,vitamin content and reducing sugar content were increased significantly.It is observed that potato seedling growth were inhibited significantly by drought stress,but spraying phosphorus fertilizer could alleviate the oxidative damage through increasing the osmotic adjustment substances contents and anti-oxidative enzymes activities,enhance the drought resistance abilities of potato seedlings.4.Application of exogenous Pr Cl3 significantly alleviated the growth suppression caused by drought stress in potatoes.In parallel with growth,90 mg/L Pr Cl3 application in drought-stressed plants resulted in chlorophyll,soluble sugar and proline contents increased 162.35%,59.59%,154.45%,respectively.MDA contents,O2-.production rate and relative conductance decreased 67.70%,25.29%,37.70%,separately.Furthermore,Pr Cl3 application also markedly increased the activities of antioxidant enzymes under drought stress.

Mots clés : Potato; potassium fertilizer; phosphate fertilizer; rare earth micro fertilizer; drought stress; growth and development; physiological characteristic;

Présentation (CNKI)

Page publiée le 1er février 2018