The Optimization For The Rootstock’s Varieties And Key Technology Of The Watermelon Grafted Seedlings

With the reduction of city’s arable land and the tightening of soil rotation cycle, the factory cultivation of watermelon grafting has become the trend of our world. In the watermelon grafting culti vation techniques, one of the most important content is rootstock sel ection and handling, which is of great significance for realizing the high producion and good quality of grafted watermelon. The goals o f this test are to guarantee the producion and the quality of grafted watermelon fruit and to improve the efficiency of grafting seedling p roduction management. We select the introduced cultivation variety“Zaojia8424” in the Shanghai area for experimental materials and res earch the effect of hole tray seedling varieties stocks pumpkin, rootst ock different diameter hole tray and different modes of cutting blade rootstock on the watermelon grafting survival rate, seedling growth traits and fruit quality. The main research contents are as follows:1.1 Research on the effect of pumpkin rootstocks on graftin g watermelon growth, production and quality.The research results sh ow that the survival rate of all the grafting treatment combinations have significant difference and the survival rate of Jingxin stock 3 is as high as 97%. In terms of growth potential, grafting is beneficial t o promote the growth of plants. For the nutritional quality, the perfo rmance of Jingxin stock 3、Jingxin stock 8、Naire and Qingyanxiuzh en are better. The taste flavor evaluation result shows that the series of Jingxin, which have good performance on the nutritional quality,also have the same outstanding performance. Fruit production statisti cs shows that grafting can significantly increase fruit weight and frui t yield and compared with the seedling production, grafted watermelo n producions up to 1.8t / 666.7m2. In summary, the grafting Jingxin stock 3、Qingyanxiuzhen are the ideal pumpkin rootstock varieties b ecause of the high survival rate, the strong growth potential and less impact on the nutritional flavor quality.1.2 Research on the effect of root stocks’ different plug ap erture handling on grafted watermelon seedling growth.After handling the plug apertures of root stocks differently, the results show that t he survival rates of all the combinations have significant difference,and the survival rate of grafted 128 plate hole is significantly lower than 50 and 72 plate hole’s. The height of 50 and 128 plate hole is significantly higher than 72 plate hole’s and the 128 plate hole’s ab normality may be due to the closing distance between plants which cause the excessive growth of plants. There is no difference between50 and 72 plate hole in terms of stem diameter\and they are signifi cantly stronger than the 128 plate hole. The evaluation of seedling p lants robustness show that the plants of 72 plate hole are the most robust and the plants of 128 plate hole are less robust. The different plug apertures of rootstocks have a significant impact on the root act ivities. After grafting, the 72 and 50 plate hole before 20 d are not s ignificantly different and are significantly higher than 128 plate hole’s. In the entire measurement cycle, there is no difference between th e 72 and 50 plate hole about chlorophyll and they are significantly higher than the 128 plate hole. According to the analysis above, the72 plate hole can form a more robust plant and it has no adverse ef fect on the root activity, chlorophyll and other aspects.1.3 Research on the effect of rootstocks cotyledons’ differen t resection on the grafted watermelon seedling growth.After handling the cotyledons of rootstocks differently, the results show that the su rvival rates of all the combinations have significant difference and th e resection of cotyledons can be helpful to improve the survival rate of grafting. The heights of combinations that didn’t remove the cot yledons or remove the monolithic cotyledon are significantly stronger than those removed each half of two cotyledons. The resection of r ootstocks’ cotyledons is good for promoting the thickening of plant s talks. The evaluation of seedling plants robustness show that removin g each half of two cotyledons is helpful for the robust growth of gr afting plants. The result of root activity shows that the resection of rootstocks cotyledons will reduce its root activity. Removing each hal f of two cotyledons and removing the monolithic cotyledon has no s ignificant difference in the root activity, which indicates that there m ay be a relationship between resection area of rootstocks pumpkin cotyledons and root activity. In terms of chlorophyll, the measurement results before 14 d show no significant difference in all the combinati ons. In a word, removing each half of two rootstocks pumpkin cotyl edons can cultivate a more robust plant.Above all, based on the research of the selection of grafted rootstocks pumpkin, the handling of rootstocks nursery plug and the resection of rootstocks, this study selects the suitable rootstock varie ties of pumpkin, the matching plug aperture and the treatment way o f rootstock cotyledons. In the premise of ensuring the seed quality, t he above conclusion play a positive role in improving the production efficiency of grafted seedlings and in promoting the application of grafted seedlings.