Evaluation of N Fertilizers Effects on Grape Based on the Expression of N Metabolic Genes

In order to study the influence of different types of N fertilizers on grapevine(Vitis labruscana ‘Black Summer') trees were used as experiment materials and fertilizers foliar application trails were conducted in the flowering and veraison stages. The expression levels of five grapevine N metabolic genes, including Vv GHD, Vv Ni R, Vv NR, Vv GS and Vv AS, were analyzed, some physiological traits including the flower and fruit dropping rate, leaves and shoots growth rate, chlorophyll content and the fruit size of grape berry were also investigated. The results showed that,in general, the expression levels of the five N metabolic genes were increased after foliar applied different types of N fertilizers in the two periods.N metabolic genes showed similar expression patterns toward the same type of fertilizer in the two periods, whereas foliar applied different types of N fertilizers, their expression patterns changed. Moreover, the N fertilizer which had stronger and longer influence on the N metabolic genes could enhance the physiology traits more dramatically. Given the gene expression levels and the changes of physiology traits, we conclude that urea and ammonium nitrate have the best effect on grapevine; calcium nitrate can help to reduce the flower and berry dropping rate; ammonium sulphate and sodium nitrate have relatively poor effects on grapevine.