Effects Of Rootstocks On Growth And Fruit Development And Physiology And Biochemistry Of Grafted Watermelon

The effects of different rootstocks on the growth, development, physiology and biochemistry of grafted watermelon in soil medium culture were studied in this paper. The mainly planted watermelon Heiwushi(CK) was used in the experiments in Fuzhou. Eleven grafting treatments were selected as Heiwushi / Zhongzhen-1, Heiwushi / Haizhen-l,Heiwushi / Haizhen-2, Heiwushi / Fengzhen, Heiwushi / Bendihulu, Heiwushi / Changlehulu, Heiwushi / ChaofengF, Heiwushi / Huapizhigua, Heiwushi / Heizinangua, Heiwushi / Yeshenxigua and Heiwushi / Zhongzhen-25 compared with the Heiwushi (CK). The results were as follows:1 Effects of rootstocks on the growth and development of grafted watermelonDifferent grafting treatments had different grafting compatibility. Heiwushi / Haizhen-1, Heiwushi / Fengzhen and Heiwushi / Bendihulu had better grafting compatibility, and their survival rates were also higher than others. All grafted plants and their fruits grew better than Heiwushi seedlings.Various rootstock species had significant effects on photosynthesis of grafted watermelon plants. Chlorophyll contents of the leaves of grafted watermelon with different rootstocks varied greatly. The leaves' Chlorophyll contents, the plants' photosynthesis rate and transpiration rate and stomata conductance of granted watermelon were higher than Heiwushi seedlings.Watermelon yields were significantly enhanced by grafting treatments. Heiwushi / Haizhen-l,Heiwushi/Fengzhen and Heiwushi / Heizinangua had higher yields. Watermelon yields of all grafting treatments were higher than Heiwushi.2 Effects of various rootstocks on enzyme activities of grafted watermelon's leavesSuperoxide dismutase(SOD) activities of different grafted watermelon's leaves had the same change during fruit deveolopment. SOD activities of grafted watermelon's leaves were higher than Heiwushi. Heiwushi / Bendihulu, Heiwushi/Haizhen-1, Heiwushi / Fengzhen and Heiwushi/ChaofengF₁'SOD activities varied obviously.Peroxide enzyme(POD) activities of different grafted watermelon's leaves had the same change during fruit deveolopment. POD activities of grafted watermelon's leaf were higher than Heiwushi seedlings. Heiwushi / Bendihulu, Heiwushi / Haizhen-1, Heiwushi / Fengzhen and Heiwushi/ChaofengF₁' POD activities varied significantly.The contents of malonyldialdehyde(MDA) of different grafted watermelon's leaves had the same change during fruit development. The MDA contents of grafted watermelon's leaves were lower than Heiwushi. The MDA contents Heiwushi/Bendihulu, Heiwushi / Haizhen-1, Heiwushi / Fengzhen and Heiwushi / ChaofengF₁ were much different from seedlings.Grafting treaments promoted the resistance of watermelon to watermelon's wilt disease. Wilt disease of watermelon didn't happened in Heiwushi/Zhongzhen-1, Heiwushi /Haizhen-1, Heiwushi / Haizhen-2, Heiwushi / Fengzhen, Heiwushi / Bendihulu, Heiwushi / Changlehulu, Heiwushi / ChaofengF₁ and Heiwushi / Heizinangua.3 Effects of rootstocks on fruit quality of grafted watermelonThe contents of soluble solid in the core and in the edge of the fruits of grafted watermelon were lower than Heiwushi seedlings. The contents of soluble solid in the core and in the edge of the fruits of Heiwushi / Haizhen-1, Heiwushi /Fengzhen and Heiwushi / Heizinangua were close to Heiwushi seedlings.The contents of soluble sugar and vitamin c of grafted watermelon varied from Heiwushi seedlings. The contents of soluble sugar of Heiwushi/Haizhen-1, Heiwushi / Fengzhen , Heiwushi / Heizinangua and Heiwushi / Huapizhigua were lower than Heiwushi seedlings. The contents of vitamin c in Heiwushi / Haizhen-1, Heiwushi / Fengzhen , Heiwushi / Bendihulu and Heiwushi / Huapizhigua differed greatly from Heiwushi seedlings.The contents of soluble protein of grafted watermelon were different from Heiwushi seedlings.The contents of soluble protein of Heiwushi / Huapizhigua and Heiwushi / Yeshenxigua were higher than Heiwushi seedlings. The contents of organic acids of grafted watermelon were lower than Heiwushi. Heiwushi / Zhongzhen-1, Heiwushi / Haizhen-1, Heiwushi / Fengzhen and Heiwushi / Yeshenxigua were close to Heiwushi seedlings in terms of organic acids contents.The water content of grafted watermelon were higher than Heiwushi seedlings.The water content of Heiwushi/Haizhen-1 did not differentiate significantly fromHeiwushi. The fresh colour of grafted watermelon was different to Heiwushi seedlings.The fresh colour Heiwushi / Haizhen-1, Heiwushi / Fengzhen, Heiwushi / Huapizhiguaand Heiwushi / Heizinangua's were redder than Heiwushi. .The fruits of The grafted watermelon using local gourds as rootstocks had rough fresh and yellow rib while thoseusing black seed pumpkin as rootstocks had rough fresh and yellow rib as well aspeculiar smell.Overall analysis of the above indicated that Heiwushi / Haizhen-1 and Heiwushi / Fengzhen were better than other grafted watermelon and Heiwushi in respect of growth, resistance and yield. They were not different to Heiwushi in respect of quality. Haizhen-1 and Fengzhen were good rootstocks.