Effects Of Light Environment On Healing And Seedling Quality Of Grafted Cucumber

Grafting is an important agronomic means to improve the yield and quality of vegetables and widely used in cucumber seedlings in China.Illumination intensity,photoperiod,and light quality have important effects on graft healing and strong seedling formation of cucumber,but there is still no precise management technology for light environment.In this experiment,we used'Jinyou No.35'cucumber as scion and'Huang chenggen No.2'Pumpkin as rootstock to graft.We set different illumination intensity(0?25?50?100?150?mol·m^-2·s^-1),photoperiod?12/12?14/10?CK??18/6?24/0?and light quality?W?CK??R7B3?R7B3W3?R7B3W7?during the healing period and studied the effect of light environment on grafting healing and seedling quality of cucumber.The main results are as follows:1.The healing period of cucumber grafting should be managed by stage gradient illumination intensity,the best illumination intensity gradient is 25?1d?-50?2³d?-100?4⁵d?-150?6⁷d??mol·m^-2·s^-1.Compared with constant illumination intensity management(50?mol·m^-2·s^-1),the stage gradient illumination intensity management promotes the lignin and sugar content of the grafted seedlings significantly,and the activities of CAD,POD and CAT were significantly enhanced.The survival time was 0.3 days earlier,the seedling time?two leaves and one bud?was 1.2 days earlier,and the grafting survival rate was increased by3 percentage points.Root vigor,photosynthetic rate,transpiration rate and chlorophyll content increased,and the seedling index increased by 23.3%.2.The optimal photoperiod of the healing period of grafted cucumber seedlings was18h/6h.Under this threatment,the survival time of treatment at 18h/6h was shortened by 0.6days,the seedling time was shortened by 1.0 days,the survival rate of grafting increased by 1percentage point,stem diameter,leaf area and root growth parameters increased,whole plant dry weight and seedling index increased by 10%and 25.6%;Compared with 14h/10h,the rate of grafting and healing was increased at 24h/0h,but the survival rate was decreased by 5percentage points,and the healing speed,survival rate and seedling quality of the grafted seedlings treated at 12h/1 h were not significantly changed.3.Compared with white light,R7B3W3?red:blue:white:7:3:3?and R7B3W7?red:blue:white:7:3:7?shorten the time of cucumber grafting seedlings to live by 0.5 and 0.3 days respectively,seedling time?two leaves and one heart?shortened by 0.5 days and 0.9 days respectively,the seedling index increased by 12.5%and 16.6%,root vitality increased by8.1%and 5.5%,net photosynthesis rate increased by 25.9%and 29.4%,chlorophyll content increased by 3.1%and 17%,chlorophyll a/b increased by 3.2%and 6.2%,and the content of nutrients and ATP during the healing period increased;The effect of red and blue combined light R7B3 on graft healing and strong seedling formation is not obvious.