Physiological Response Of Six Watermelon Root-Stocks To Different Temperatures And Evaluation Of Suitability Of Jinxia No.8 Watermelon Grafting

In the grafting cultivation technology of watermelon,the selection of rootstock is an important content,which is of great significance for realizing the high yield and quality of grafted watermelon.In this experiment,6 watermelon rootstocks were used to observe the growth of 6 rootstocks in the early spring,spring and summer three watermelon cutting seasons to screen suitable grafting rootstocks of different cornices.The temperature of early spring,spring and summer seedlings was simulated by setting three temperatures of normal temperature,low temperature and high temperature.The growth and physiological responses of different rootstocks were observed by observing the morphology and physiological indexes of rootstocks.At the same time,the 6 rootstocks and the small fruit watermelon Jinxia No.8 were grafted to evaluate the grafting suitability of the rootstock.The final conclusion is as follows:In three different nursery seasons,the V90 and Morgan rootstocks had a similar seedling index of 0.035 in spring seedlings,and the V90 plant height hypocotyls were 61.89 mm and 47.09 mm,respectively.The rootstock index of Morgan rootstocks in early spring and summer seedlings was 0.125 and 0.062,respectively,which was significantly higher than other rootstocks.The germination rate of 90A in three seasons is lower than that of other rootstock varieties,and it is necessary to improve the germination method or increase the seed amount.The 90A and super gold anvil leaves are shorter and narrower than other rootstocks,which is conducive to ventilation and light transmission.After three different temperature treatments,it is concluded that the low temperature resistance of each rootstock is Morgan,Super Anvil,V90,90A,Steady No.1,and Bright Melon.The high temperature resistance is followed by Morgan,Steady No.1,V90,Super Golden Anvil,Bright Melon,and 90A.Among them,Morgan has good resistance to low temperature and high temperature,and the low temperature resistance of bright melon is relatively poor,and the high temperature resistance of 90A is relatively poor.In addition,at low temperatures,the photosynthesis efficiency of each rootstock decreased.The photosynthesis of V90 was greatly affected by low temperature,and the bright melon was the least affected.Only 90A stomatal conductance and transpiration rate increased in all rootstocks.The stomatal conductance and transpiration rate of the other rootstocks decreased.At high temperature,the photosynthesis rate of V90,Steady No.1 and Morgan rootstock was lower than normal temperature,and the photosynthesis rate of other rootstocks increased.Morgan and 90A stomatal conductance increased.The V90 single fruit weight of the 6 grafted rootstocks was up to 1.41Kg,which was 33.01%higher than ck,and the central sugar content was 11.3%,which was close to 11.8%of ck.90A increased the sugar content of Jinxia No.8,which increased the central sugar from 11.8%to 12.1%.Grafting watermelon with super gold anvil can slightly increase the hardness of watermelon,increasing from 10.24Kg/cm2 of ck to 11.17Kg/cm2.The self-rooting seedling stage is earlier than the grafting combination,and the rootstock grafting of Jinxia No.8 can delay the flowering period by up to 9 days.