Effects of grafting on the growth and quality of cucumber fruits

Cucumber grafting was known to increase root disease resistance, however, little was known about the grafting on the fruit development and fruit quality. Cucumber cultivars 'Jinyu No.1' and 'Jinchun No.4' (scion) were grafted onto rootstock figleaf gourd (C. ficifolia Bouche), and fruit development and quality were investigated. The experiment was conducted in plastic greenhouse from Aug. to Nov. in 2004, using substrate culture (peat:vermiculite:perlite=1:1:1). The results showed that grafting significantly increased the growth of cucumber fruits. Eight days after pollination, fruit fresh weight of 'Jinyu No.1' and 'Jinchun No.4' grafted plants increased by 38.4% and 36.1% compared with non-grafted cucumber plants, respectively, whereas fruit length increased by 23.7% and 30.2%, respectively. With the development of cucumber fruit, fruit ascorbic acid, soluble protein and free amino acid content gradually decreased, whereas fruit soluble sugar content increased, and there was no significant difference in fruit quality between grafted and non-grafted plants. Fruit quality varied with different fruit set node. Ascorbic acid and soluble sugar contents of fruits at higher fruit set node (node 25-30) were significantly higher than those of at lower (node 8-13) and medium (node 17-22) fruit set nodes, whereas the highest free amino acid content was obtained in fruit at lower fruit set node. Fruit K and Mg concentrations of 'Jinyu No.1' and 'Jinchun No.4' grafted plants were significantly higher than those of non-grafted controls.