Physiological studies on grafted plants of fruit vegetables

嫁接已被广泛接受在种植水果蔬菜，以避免土传病害或提高抗寒性。然而，在商业种植中，嫁接植物过去生长得如此旺盛，是因为砧木植物吸收水分和矿物质养分的能力更高。本研究旨在阐明嫁接植物在不同环境条件下的生理特性。在较弱光照条件下，黄瓜植株的干重积累明显滞后于嫁接在金花上的植株（C.moschata x c.m ax）。在弱光条件下，嫁接植株叶片组织含氮量高于未嫁接植株。新土沙黄瓜叶片中NH_4-N和Mg浓度较高。嫁接在扶桑上的植株在低温条件下生长较好，在高温条件下生长较差。在较强光照条件下，嫁接在新土上的黄瓜植株生长更为旺盛，叶片中NH_4-N和Mg浓度显著高于植根植株，在较低光照条件下，植根植株的光合速率、同化物转运速率和蒸腾速率显著高于植根植株，嫁接黄瓜对环境条件的响应很大程度上取决于砧木植株的生理特性。不仅在水分和矿质养分的吸收上，而且在光合作用、转运和蒸腾作用上。

Grafting has been widely accepted in growing fruit vegetables in order to avoid the soil-born diseases or to encourage the chilling resistance. In the commercial growing, grafted plants, however, used to grow so vigorously as a result of higher ability of water and mineral nutrient uptakes of rootstock plant. The present studies were undertaken to elucidate the physiological characteristics of grafted plants when exposed to some different environmental conditions.Under lower light condition, cucumber plants grafted on C.ficifolia showed significant retardation in dry weight accumulation as compared with the plants on Shintosa( C.moschata x C.maxima ). Grafted plants contained more nitrogen in leaf tissue than in non-grafted plants when grown under low light. Cucumber plants on Shintosa had higher NH_4-N and Mg concentration in the leaf. Plants grafted on C.ficifolia showed superior growth under low temperature, and inferior growth under high temperature to the plants on Shintosa.Under higher light condition, cucumber plants grafted on Shintosa grew more vigorous, NH_4-N and Mg concentration in the leaf being considerably higher than the plants on C.ficifolia.Under lower temperatures, photosynthetic rate, translocation rate of assimilates and transpiration rate were higher in the plants on C.ficifolia.Grafted cucumber responded markedly to the environmental conditions exposed depending greatly on the physiological characteristics of rootstock plant, not only in water and mineral nutrient uptakes, but also in photosynthesis, translocation and transpiration.