Effect Of Altitude On Phenotypic Characters And Physiological And Biochemical Indexes Of Actinidia Arguta

Actinidia arguta is a perennial deciduous vine fruit tree of Actinidia genus Actinidia.It is favored by consumers because of its strong stress resistance,high economic benefits and unique flavor.In recent years,Actinidia arguta industry has made great progress.However,we know little about the growth environment conditions of Actinidia arguta.In order to explore the habitat conditions of Actinidia arguta,we used wild Actinidia arguta at different altitudes on the same mountain in the Xianfeng Forest Farm of Bajiazi Forestry Bureau as experimental materials to investigate its phenotypic traits,fruit quality,plant protection system indicators and secondary Biometabolite content,the results show:1)As the altitude increases,the frost-free period becomes shorter and the effective accumulated temperature decreases,but the frost-free period and the effective accumulated temperature are not consistent.With the increase in altitude,there is no change in the frost-free period in the low-altitude to mid-altitude section,and the frost-free period in the mid-altitude to high-altitude section is shortened by 9days;while the effective accumulated temperature in different altitude sections changes differently,the effective accumulated temperature in the low-altitude to mid-altitude section and the mid-altitude to high-altitude section decreases by 461℃and 244℃ respectively.2)With the increase in altitude,both the daily maximum temperature and daily minimum temperature during the growth period decreased significantly,but the temperature decrease in different altitude sections was different.In the low-altitude section,the highest temperature decreases by 0.988°C for every 100 m increase in altitude,while in the high-altitude section,the daily maximum temperature decreases by 0.380°C for every 100 m altitude increase;on the contrary,in the low-altitude section,the altitude increases every 100 m The daily minimum temperature drops by0.228°C,while in the high-altitude section,the daily minimum temperature drops by0.367°C for every 100 m increase in altitude.3)With the increase in altitude,the leaves of Actinidia arguta are significantly thicker,the petioles are significantly elongated,the leaves are significantly smaller,the serrations of the leaves become smaller,and the leaf hairs become denser.4)As the altitude increases,the fruit of Actinidia arguta becomes smaller,flattened and tends to be cylindrical,and the soluble solid content and titratable acid content decrease.The fruits of Actinidia arguta in the middle and high altitude areas were significantly smaller,and the soluble solid content and titratable acid content decreased significantly in the high altitude areas.With the increase in altitude,the pigment content of leaves showed a downward trend,but there was no significant change;while the content of total sugar and soluble sugar increased first and then decreased,reducing sugarshow a downward trend,and the content of three sugars decreased significantly in the high-altitude section.5)As the altitude increases,the content of total alkaloids,polysaccharides and flavonoids increases,while the content of total phenols and vitamin C decreases.The content of total alkaloids and flavonoids in the high altitude section is significantly higher than that in the low altitude section;the polysaccharide content increases significantly between each altitude section;the total phenol content in the middle and high altitude section is significantly lower than that in the low altitude section;The vitamin C content is significantly lower than that in the middle and low altitude sections.6)With the increase in altitude,the activities of SOD,CAT and PPO in the plant protection enzyme system continue to increase.The activity of PPO reaches a peak in the middle altitude section and decreases significantly in the high altitude section,while the SOD activity in the middle and high altitude section Significantly higher than the low-altitude section;POD and AAO activities decreased significantly in the middle-high altitude section.As the altitude increases,the MDA content first increases significantly,then decreases significantly,reaching the peak content in the mid-altitude section.In short,as the altitude increases,the frost-free period becomes shorter,the effective accumulated temperature decreases,the leaves become smaller and thicker,the fruit becomes smaller and flattened,and tends to be cylindrical,and the quality deteriorates,the nutrient content decreases,but the secondary metabolites The content increases,the plant protection system is active.Although planting at extreme altitudes increases stress resistance and secondary metabolites content,it is not conducive to the production of high-quality fruits.We weigh the pros and cons.The middle altitude area is the best planting section of Actinidia arguta.