Research On Nutrients Change Rule Of Vitis Davidii Fo(?)x. And Influence Of Potassium To Fruit Sugar Accumulation

Vitis davidii Fo???x is an important wild resource for wine grapes and table grapes in South China.They are widely planted in Hunan Province,but the unbalanced fertilization and low fruit quality exist and affect the normal growth of plant and the improvement of fruit quality due to extensive cultivation.Based on the analysis of the dynamic change of nutrients in vineyard soil,this study explored the absorption of nutrients uptake of major organs in different phenological phases combined with pot experiment,and discussed the influence of the potassium on sugar accumulation with different potassium treatments.The results are as follow:1.The soil pH distributed between 5.5⁶.5 in this vineyard,belonging to slightly acid;The organic matter was in inadequate range;available N,P and K contents were abundant;exchangeable Ca,exchangeable Mg and available B contents were in lower range;available Fe,available Mn,available Cu and available Zn contents were in normal range.On the basis of the current fertilizing mode,the nutrient contents of the vineyard soil were mainly in the suitable range.It indicated that this fertilization pattern can meet the needs for the normal growth of Vitis davidii Fo???x,and it was feasible to be applied in other regions.2.Pot experiment results showed that:?1?N and P contents in the leaves,fruits and shoots were generally reduced in the growth cycle,but N contents in the shoots slightly recovered after harvest;K contents in the leaves were gradually declined,while K contents in the shoots and fruits reached the peak during mature period;Ga,Mg,Mn and Zn contents in each organ expressed similar anniversary change trend,and the contents kept stable during different periods;Fe contents in the leaves increased during growth cycle,while there were little change in the shoots;the Fe contents in the fruits were relatively high in expanding period and then decreased;Cu contents showed large variation in organs,with higher content in verasion period;B contents in the leaves and shoots changed greatly,and the contents in fruits decreased.?2?the rules for nutritional elements allocated in different grape organs were:?N,Ca,Fe,Mn and Cu?:leaf>shoot>fruit;?P,Mg and Zn?:shoot>leaf>fruit;?K?B?:fruit>shoot>leaf.?3?The nutrients requirements in different phenological period were:there were more requiremnts for N,Ca,Mg,Fe and B before fruit setting;and more requirements for P and Mn between fruit setting and verasion period;more requirements for K during veraison to harvest;requirements for Cu and Zn were distributed equally in every stage.Scientific fertilization can be carried out according to the above-mentioned rules.3?When potassium rates is 270 g/plant,higher net photosynthetic rates and transpiration rate were achieved.Maximum respectively appeared in veraison and expanding period,and intercellular CO₂ concentrations were in lower range;When potassium rates is540 g/plant,stomatal conductances of the leaves were higher in every period;there were extremely significant positive correlations between potassium and net photosynthetic rate,transpiration rate and stomatal conductance;Bimodal curve presented in photosynthetic diurnal variation in different periods,with peaks at 10:00 and 16:00,and with the former higher.Maximum net photosynthetic rates in expanding,veraison and defoliation period were achieved with potassium rates of 540 g/plant at 10:00,respectively 6.05,7.63 and 4.75?mol/?m²·s?;net photosynthetic rates came second with potassium rates of 270 g/plant;maximum net photosynthetic rates in flowering and harvest period were achieved respectively with potassium rates of 135g/plant and 270 g/plant;At 16:00,maximum net photosynthetic rates in four periods were achieved with potassium rates of 270 g/plant except in flowering period with 540 g/plant,with 4.26,3.61,2.87,2.30?mol/?m²·s?in order.4?The rational application of K?270 g/plant?could increase sugar contents of the Vitis davidii Fo???x,reduce organic acid,and improve the TSS.In the case of 270 g/plant,the contents of glucose,fructose and sucrase were 6.01%,6.24%and 0.53%,tartaric acid and malic acid were 0.47%and 0.21%,and TSS was 16.0%.K nutrition affected the activities of metabolic enzymes,and the suitable K application promoted AI,NI,SS and SPS.There were significant positive correlation between K application rates and AI activity.5?K fertilizers increased the expression of AI,SS and SPS gene.There were no obvious regulation between potassium and the NI gene.There were different effects on gene expression in different periods.As a whole,the higher K concentration?270 g/plant,540g/plant?up-regulated the genes mentioned above.There were significant positive correlation between K application rates and AI,SS and SPS gene.