Effects Of Altitude On Growth And Physiological And Biochemical Indexes Of Wild Actinidia Kolomikta

Actinidia kolomikta is a dioecious climbing plant belonging to the genus Actinidia in Actinidia family.It has been paid attention and recognized by people due to its high vitamin C content and anti-cancer and anti-tumor effects.In order to be able to large-scale,industrial planting of Actinidia kolomikta fruit,we must understand its habitat conditions.As the most important factor in habitat conditions,altitude affects the growth and development of Actinidia kolomikta fruit and fruit quality to a great extent.Based on this,we investigated the temperature conditions,phenotypes,nutrients,secondary metabolites and plant protective enzyme activities of wild Actinidia kolomikta from different elevations of the same mountain in Xianfeng Forest Farm of Bajjiazi Forestry Bureau.The experimental results are as follows:(1)With the rise of altitude,the days of frost free period decrease,effective accumulated temperature decreases,and the daily maximum temperature and the lowest temperature decrease significantly.The decrease of frost free period,effective accumulated temperature,daily maximum temperature and minimum temperature of Actinidia kolomikta in different altitude areas is different.(2)With the rise of altitude,the leaf shape index of Actinidia kolomikta fruit has no significant change.The leaves gradually thinned and then significantly thickened,the leaf area showed a downward trend,and the leaf area decreased significantly above the altitude of 800 m.The petiole length is significantly shorter in the altitude section of 1000-1200 m.The leaf serration was changed from large to small,the leaf margin split sharply,the leaf villi was obvious,while the color of the vine was not related to the altitude,and all showed dark brown.(3)With the rise of altitude,the fruit shape index,flatness and stalk length of Actinidia kolomikta fruit did not change significantly;the fruit became smaller and the weight of single fruit in 1200-1400 m altitude section was significantly lower than that of other altitude sections;the fruit point changed from little to none,and the color of peel changed from deep to shallow.(4)With the increase of altitude,the pigment content of Actinidia kolomikta showed a downward trend,and all reached the highest level in the 600-800 m elevation,and then decreased significantly.(5)With the rise of altitude,the content of soluble solid,titratable acid and sugar acid ratio of Actinidia kolomikta decreased first and then increased significantly;the total sugar and reducing sugar content decreased first,and increased significantly in the altitude from 1200 m to 1400 m,and the soluble sugar content increased first,and reached the peak in the 1000-1200 m altitude section,and then decreased significantly.In a word,the quality of Actinidia kolomikta fruit is the best at 1200-1400 m altitude section.(6)With the rise of altitude,the content of vitamin C and polysaccharide of Actinidia kolomikta firstly increased,then decreased and then increased,alkaloid content increased first and then decreased,and total phenol content and flavone content decreased first and then increased.In a word,the secondary metabolites of Actinidia kolomikta fruit are the highest at 1200-1400 m altitude section.(7)With the rise of altitude,SOD and AAO enzyme activities of Actinidia kolomikta increased significantly,POD enzyme,PPO enzyme and CAT enzyme activity increased first and then decreased,and malondialdehyde content decreased significantly.SOD and AAO enzyme activities were the highest at 1200-1400 m altitude section,the content of malondialdehyde was the lowest,POD,PPO and CAT enzyme activities were the highest at 1000-1200 m altitude section,followed by those at 1200-1400 m altitude section.In a comprehensive view,the protective enzyme activity and stress resistance of Actinidia kolomikta fruit plant were the highest at1200-1400 m altitude section.In conclusion,the fruit of Actinidia kolomikta at the altitude of 600-800 m is the largest,the coloration is the best,the maturity stage is the earliest,the photosynthetic pigment content is the strongest,and the fruit quality is second only to the altitude of1200-1400 m.The fruit quality was the best at 1200-1400 m altitude section,the content of secondary metabolic substances and the activities of plant protective enzymes were the highest.In summary,if edible,it should be planted in 600-800 m altitude section;If for medicinal,health care and processing,it should be planted on a large scale at an altitude of 1200-1400 m altitude section.