Advances in Researches on the Drought Resistance of Walnuts

The walnut was one of the world's famous dried fruits.also a hardwood species with high quality.It was mainly distributed in arid,semi-arid,humid and semi-humid areas,and affected by different degrees of drought.Drought,as a water stress,impacted on plants mainly in the growth,development and physiological metabolic process.Native and foreign researches were systematically reviewed in the changes of walnut morphology,tissue water status,plasma membrane system,osmotic adjustment substances and protective enzyme system under drought conditions.In order to provide a theoretical basis for screening and breeding of drought-resistant and high-yield varieties of walnuts,and the sustainable development of walnut industry.Drought was an adversity that plants often suffered,the world's arid and semi-arid regions accounted for 43% of the world's total area,and sometimes there would be a certain degree of summer drought in the humid and semi humid areas.The impact of drought on economic forests was very large,especially on the growth,yield and quality of nuts.In order to acquaint the different varieties of walnut drought resistance,it was necessary to understand the physiological and biochemical response of the walnuts in drought conditions,and to explore the mechanism.It could provide a theoretical basis for sustainable development of walnut industry to screen and breed drought-resistant high-yield varieties of the walnut.