Nitrogen Requirement Regularity Of Kyoho Grapevines And Absorption, Utilization Features Of The Different Rootstocks

Kyoho grapevines (4,5and18years old), Chardonnay grafted on5rootstocks (1yearold) and seven kinds of rootstocks were used as materials to investigate the fertilizerrequirement regularity, the effects of different fertilizer and load on the growth anddevelopment of grape, the absorption and utilization of nitrogen in different scions/rootstocks,and to screen the rootstocks of nitrogen high efficient absorption gene types, in order to directadequate nitrogen fertilization, and to provide theory for high yield and high quality of tablegrapes. The main results were as follows:1. The absorbed ratios of the15N from the fertilizer to total N (Ndff) in different organswere different under the15N fertilizing treatments at different stages. The Ndffs in the greenshoots and fruits were significantly higher than those of the perennial organs and roots at thebudding stage, and the Ndffs in all the tested organs were increased at the swollen stage.Comparatively, The Ndff of the ripened fruits was only37.6%of the Ndff in fruits at theswollen stage, while the Ndffs of the mature perennial organs and roots were twice-higherthan those at swollen stage.54.8%of15N absorbed in the plants was distributed to the leaves, while only3.6%wasassigned to the fruits at the budding stage. The distribution rate of15N in the fruits was26%while it was38%in leaves at the swollen stage. In general, the15N utilization and distributionin different organs showed the same trends at different stages. The utilization of15N-urea ingrapes was increased from the budding to leaf senescence, and reached the maximum inripened fruits.2. Kyoho grape trees absorbed3.76kg N to produce1000kg fruits. In descending order,the nitrogen distribution in the organs was: fruits> leaves> roots> shoots> stems> branches.Besides, plants demand the least nitrogen before shoots prosperous stage and was also littlebefore fruit stage, and the highest demand and the most efficiency utilization stage was fromfruit swollen to fruit mature.3. The fruit weight per cluster of Kyoho grape decreased with the load amount increasing,and increased with the increasing of fertilizer amount. Yield per hm2was significantlyincreased with the load amount increasing. Under150g compound fertilizer amount，the fruitquality was significantly reduced by the increasing of load amount. Compared with the150gper plant treatment, the fruit quality improved obviously under200g per plant treatment; thetotal sugar contents of low, medium and high load were respectively increased by19.27%,39.20%and12.80%, and the anthocyanins contents increased by85.52%,98.81%and 79.45%, respectively. Large amount of fertilization affected the fruit quality and the branchesnutrition storage, the total sugar content of250g per plant fertilizer was less than200g perplant fertilizer treatments. Besides, the branches nutrition storage of200g per plant fertilizertreatment was more than150g per plant fertilizer treatment, and increasing amount of starch,soluble sugar, free amino acids and soluble protein content were respectively7.45%~57.34%,8.75%~28.13%,16.82%~35.04%and9.82%~30.16%. However the starch content of250g per plant fertilizer treatment was less than200g with different loading.4. All the Chardonnays grafted with different rootstocks absorped more NH4+-N thanNO3--N. Different scions/rootstocks showed different sensitivity to nitrogen forms, in SO4,5BB,1103P,3309C and101-14M grafted Chardonnays, the average Ndff of all plant organswith NH4+-N treatments were3.62,2.31,2.48,1.84and1.84times of NO3--N treatmentsrespectively.Different scions/rootstocks also showed different abosorbtion and utilization to the twoforms of nitrogen. In SO4、5BB、1103P、3309C and101-14M grafted Chardonnays, the totalutilizations with NH4+-N were3.82,2.41,1.66,1.94and1.92times of NO3--N respectively.Chardonnay grafted on101-14M and3309C had the most utilization of NH4+-N and NO3--N,while Chardonnay grafted on SO4absorbed more NH4+-N but the least NO3--N. The15Ndistribution rate of NH4+-N and NO3--N in different scions/rootstocks organs showed the sametrend, characterized by leaves> roots> shoots> rootstock stems> variety stems, the15Ndistribution rate in most scions/rootstocks leaves were above50%.5. Through the nitrogen uptake dynamics experiments of different time gradient anddifferent concentration gradient, we concluded that the rootstocks140Ru and Beta were thenitrogen efficient absorption genotypes. The sequences of absorption efficiency were Beta>140Ru>110R>5BB> SO4>3309C>101-14M, and the results were in agreement with thegrowth potential of rootstocks.