Comprehensive Evaluation of Relationship Between Rootstocks and Yield and Quality in Grafting Tomato
[Objective]Grafting has been used in protected tomato to limit successive obstacle, a lot of studies have been done on resistance against environmental stress, disease and yield increase by grafting, however, the effects of grafting on vegetable quality were yet not systematical and far from being completed. Therefore, in order to further make clear biological effect of tomato grafting, comprehensive evaluation of the effects of grafting on yield and quality in greenhouse tomato was studied to provide a theoretical basis for application of grafting.[Method]The change characteristics of the seedling quality, plant growth vigor, yield and fruit quality were measured by the same scion grafted on ten different rootstocks and the self-root grafting scion‘Jinpeng No.1’ as control, and effects of grafting on seedling quality and fruit quality were evaluated on the basis of membership values of seedling quality and fruit quality calculated by the method of membership function.[Result]There was a significant difference in seedling growth of grafting plants among different rootstocks, whose coefficient of variation of leaf area and dry matter of root were 18.24%and 15.21%respectively. These grafting seedlings with rootstock of‘MIKADO’ and‘Kagemusha’ had higher seedlings quality with method of membership function, but the grafting survival rates on all rootstocks were higher than 90%. Plant growth vigor and yield of grafting tomato were significantly different among different rootstocks. Although the average rate of increasing yield was 34.87%, the coefficient of variation of yield was 17.16%. Except for yield on‘Vespa’, other grafted plant yields were significantly higher than that of CK, which the increasing yield rate of grafting on ‘MIKADO’ and ‘Magnet’ were 66.82%and 57.56%, respectively. Fruit rigidity was significantly improved and fruit index was changed with grafting, and fresh mass of single fruit of grafting tomatoes were higher than that of CK except for those on‘Vespa’,‘Anka-T’ and‘Support’. Grafting has a significant effect on fruit nutrient quality of tomato, higher effect on Vitamine C, lower effect on soluble solid, whose coefficients of variation were 69.16%and 8.87%, respectively. Fruit dry matter and the contents of soluble solid, soluble protein and titratable acid in all grafting treatments were improved, whereas the change value and direction of other indexes, such as fruit index, Vc, lycopene, soluble sugar and ratio of sugar to acid were dissimilar. The fruit quality was evaluated synthetically by calculating membership values of fruit nutrient quality indexes with membership function, which showed that the membership values of all grafting fruits were higher than the values of CK, and thus confirmed that fruit quality was improved by grafting.[Conclusion]The grafting seedling quality, plant growth vigor, fruit characteristics, yield and quality were significantly different with different rootstocks. Among the ten rootstocks determined, grafted plant yields were significantly higher than that of CK except for that of ‘Vespa’, higher increasing yield rate of ‘MIKADO’ and‘Magnet’ rootstocks. Although the effects of grafting on fruit quality indexes showed differences in connect with different rootstocks, fruit quality of all grafting unions was improved synthetically, especially higher fruit quality was observed on rootstocks of‘Anka-T’,‘Vespa’ and‘Rootstock 001’.