Change in ^(14)C-soluble Sugar Involved in the Photosynthate Translocation Pathway of Tomato  

作　　者：QI Hong-yan LI Tian-lai LIU Hai-tao ZHANG Jie 

机构地区：[1]Key Laboratory of Protected Horticulture of Liaoning Province, Horticultural College, Shenyang Agricultural University, Shenyang 110161, P.R.China

出　　处：《Agricultural Sciences in China》2006年第3期209-215,共7页中国农业科学（英文版）

基　　金：The study was supported by the National Natural Science Foundation of China （30170640）.

摘　　要：Liaoyuanduoli tomato was planted in pots in a solar greenhouse. The first leaf below the second cluster was labeled by ^14CO2 with a dose of 0.555 MBq 30 days after the second cluster anthesis. Mesophyll, midrib, petiole vascular of the fed leaf, internode vascular below the fed leaf （adjacent to the fed leaf）, peduncle vascular of the second cluster, sepal, fruit pedicle, pulp, pectinic, and dissepiment were taken 2, 4, 8, 12, 20, 24, 48, and 72 h, respectively, after ^14CO2 feed to determinate the composition and specific activity of carbohydrate at different sites and different time after the labeling. The results indicated that almost all of the photosynthates resulting from 1 h of photosynthesis could be transported out of the leaf within 72 h and more than 85% of them were exported within 24 h. The greatest amount of sucrose transport occurred in the internode pedicel vascular bundle 8 h after the start of photosynthesis. Assimilates entering the fruit through the internode and pedicel vascular bundles were detectable but in small quantities 2 h after photosynthesis. Only the radio activity of sucrose but not that of glucose and fructose was detected, suggesting that some of the sucrose in the fruit came directly through the phloem at an early stage of fruit development, not through the synthesis of glucose and fructose. Fruit vascular may be the part where sucrose first metabolized after it entered the fruit.Liaoyuanduoli tomato was planted in pots in a solar greenhouse. The first leaf below the second cluster was labeled by ^14CO2 with a dose of 0.555 MBq 30 days after the second cluster anthesis. Mesophyll, midrib, petiole vascular of the fed leaf, internode vascular below the fed leaf （adjacent to the fed leaf）, peduncle vascular of the second cluster, sepal, fruit pedicle, pulp, pectinic, and dissepiment were taken 2, 4, 8, 12, 20, 24, 48, and 72 h, respectively, after ^14CO2 feed to determinate the composition and specific activity of carbohydrate at different sites and different time after the labeling. The results indicated that almost all of the photosynthates resulting from 1 h of photosynthesis could be transported out of the leaf within 72 h and more than 85% of them were exported within 24 h. The greatest amount of sucrose transport occurred in the internode pedicel vascular bundle 8 h after the start of photosynthesis. Assimilates entering the fruit through the internode and pedicel vascular bundles were detectable but in small quantities 2 h after photosynthesis. Only the radio activity of sucrose but not that of glucose and fructose was detected, suggesting that some of the sucrose in the fruit came directly through the phloem at an early stage of fruit development, not through the synthesis of glucose and fructose. Fruit vascular may be the part where sucrose first metabolized after it entered the fruit.

关 键 词：tomato （L. esculentum Mill.）  ^14C-Soluble sugar translocation time metabolism part 

分 类 号：S[农业科学]