Transportation Pathway Of Potassium Or Phosphorous And Their Effect On Grape Fruit Quality

Grape fruit quality was improved by spraying leaves with 0.5% KH2PO4 at two week intervals during the development of ' Jingyou' ( Vitis vinifera L.x V. labrusca L.) berries. The results showed that the content of reducing sugar and soluble solid content increased, polar diameter and eguatorial diameter and fresh weight of fruit were longer than control, and tartaric acid decreased in berries mature period. The reason of content of reducing sugar increment was that the treatment of 0.5%,1% NaH2PO4 or KCl amplified activities of acid invertase (AI), neutral invertase (NI) in berries, sucrose synthase (SS), sucrose phosphate synthase (SPS) in leaves.32P, 86Rb absorbed from the root system can be transported to fruits through two ways: xylem and phloem. 32P, 86Rb absorbed from leaves were dominantly transported through phloem to fruits. 32P,86Rb transported to fruits from treated leaves were significantly different at every stages of fruit development, measurement of fruits content of 32P showed the order as the first stage of fruit development > the third stage of fruit development > veraision > the second stage of fruit development, and that of 86Rb showed the order as the third stage of fruit development > the first stage of fruit development > the second stage of fruit development > veraision. The first and the third stage of fruit development were main stages for 32P, 86Rb transported to fruit from leaf.Distribution proportion of fruit of 32P in the bearing branch of grape varied with different stages of fruit development. Measurement of fruits content of 32P showed the order as the first stage of fruit development > the third stage of fruit development > veraision > the second stage of fruit development, 86Rb showed the order as the third stage of fruit development > the first stage of fruit development > the second stage of fruit development > veraision. Nutrition level, gibberellin (GA), source-sink ratio influence on absorption of 86Rb from leaves and influx into grape fruits. Treatments of 0.5%, 1% NaH2PO4 or KCl significantly suppressed absorption of32P, 86Rb from leaves to grape fruits. Increment of source leaves amount, transport of 32P,86Rb from the treated leaf to grape fruit decreased. Reduction of fruits amount, transport of 32P, 86Rb from the treated leaf to grape fruit increased. GA treatment of 50 mg.L-1 ,100 mg.L-1 resulted in more 32P,86Rb influx into fruits than control.The proportion of phenol soluble phosphide gradually increased during 32P transported from leaf to fruit, and that of phosphatides gradually decreased. The proportion of DNA-P and RNA-P gradually decreased. The other forms phosphorous that were mainly Protein and amylose increased. The proportion of phenol soluble phosphide gradually decreased during 32P from root transporting to fruit and leaves at first, increased latter and approached the level of root. Proportion of phosphatides varied little except increasing appreciably in the stem. The proportion of DNA-P, RNA-P increased during transporting to up-ground plant and reached to the highest value (13.73%), decreased to 7.06% in fruit and 6.91% in leaves.