Effects Of Temperature And Light On Healing Of Tube Grafted Solanaceous Vegetable Seedlings

The environment conditions of the healing period determine the survival rate and the late stage performance of the grafted seedlings of solanaceous vegetables directly, tomato( Lycopersicun esculentun Mill., Zhongza NO.105/Guizhen NO.1), pepper( Capsicum annuum L., Zhongjiao NO.6/Craft)and eggplant(Solanum melongena L., Kuaiyuan eggplant/Qiezhen NO.1)were applied to investigate the effects of different night temperatures and supplemental lighting on healing in tube grafted tomato, pepper and eggplant seedlings by microscope observation and other methods. The appropriate temperature and light management parameters of grafted tomato, pepper and eggplant were obtained.1 Design different night temperatures(16 ℃, 21 ℃, 26 ℃)and three supplemental lighting conditions(LL:Dark in 1-3 days after grafting, light intensity was 100 μmol·m-2·s-1 in 4-5 days after grafting; LM:Light intensity was 100 μmol·m-2·s-1 in 1-3 days after grafting, 200 μmol·m-2·s-1 in 4-5 days after grafting; LH:Light intensity was 200 μmol·m-2·s-1 in 1-5 days after grafting)in this study. The results showed that the layer numbers of callus cells increased in the graft union with the increasing temperature. With the decreasing temperature, the process of healing was speed up. Vasculars of scion and rootstock were connected on 9 days after grafting at 16 ℃ at night, the connection period was reduced by 3 days compared to the treatment with 26 ℃. The isolation layer completely disappeared on 9 days after grafting at 16 ℃, the connection period was reduced by 3 days compared to the treatments with 21 ℃ and 26 ℃. The translocation ability of xylem and connecting force were improved. The grafting survival rate and root development indexs were increased significantly. Secondly, supplemental lighting 100 μmol·m-2·s-1 or 200 μmol·m-2·s-1 in 1-3 days after grafting, callus cell layers of graft union of grafted tomato seedlings were increased significantly, chlorophyll content and dry weight were improved. Compare with light intensity 200 μmol·m-2·s-1, the time of vascular bridge connection in treatment with 100 μmol·m-2·s-1 was shorter in 1-3 days after grafting, the healing rate, leaf area, xylem translocation ability and connecting force were increased. This study demonstrates that in the situation of 26 ℃ day temperature, the best environment for healing and growth of tube grafted tomato seedlings is supplementing light 100 μmol·m-2·s-1 in 1-3 days after grafting, and 200 μmol·m-2·s-1 in 4-5 days at 16 ℃ night temperature.2 Design different night temperatures(18 ℃, 23 ℃, 28 ℃)and three supplemental lighting conditions(LL:Dark in 1-3 days after grafting, light intensity was 100 μmol·m-2·s-1 in 4 days after grafting; LM:Light intensity was 100 μmol·m-2·s-1 in 1-3 days after grafting, 150 μmol·m-2·s-1 in 4 days after grafting; LH:Light intensity was 200 μmol·m-2·s-1 in 1-4 days after grafting)in this study. The results showed that the isolation layer was thin and disappeared quickly at 23 ℃ and 28 ℃, and vascular was connected quickly, grafting survival rate, chlorophyll content and dry weight were high. Compared to the treatment with 28 ℃, translocation ability of xylem and connecting force of 23 ℃ were increased. Supplemental lighting 100 μmol·m-2·s-1 or 200 μmol·m-2·s-1 in 1-3 days after grafting, callus cell layers, chlorophyll content, dry weight and translocation ability of xylem were increased. Compare with light intensity 200 μmol·m-2·s-1 in 1-3 days after grafting, the healing rate of 100 μmol·m-2·s-1 speed up, connecting force, leaf area and root volume were increased. This study demonstrates that in the situation of 28 ℃ day temperature, the best environment for healing and growth of tube grafted pepper seedlings is supplemental lighting 100 μmol·m-2·s-1 in 1-3 days after grafting, 150 μmol·m-2·s-1 in 4 days after grafting at 23 ℃ night temperature.3 Design different night temperatures(19 ℃, 24 ℃, 29 ℃)and three supplemental lighting conditions(LL:Dark in 1-3 days after grafting, light intensity was 100 μmol·m-2·s-1 in 4 days after grafting; LM:Light intensity was 100 μmol·m-2·s-1 in 1-3 days after grafting, 150 μmol·m-2·s-1 in 4 days after grafting; LH:Light intensity was 200 μmol·m-2·s-1 in 1-4 days after grafting)in this study. The results showed that with the increasing temperature, the layer numbers of callus cells increased in the graft eggplant union. The isolation layer completely disappeared and vascular was connected on 13 days after grafting at 19 ℃ at night, translocation ability of xylem was increased. Supplemental lighting 100 μmol·m-2·s-1 or 200 μmol·m-2·s-1 in 1-3 days after grafting, callus cell layers, root volume, dry weight, connecting force and translocation ability of xylem were improved. Grafting survival rate was higher under 100 μmol·m-2·s-1. This study demonstrates that in the situation of 29 ℃ day temperature, the best environment for healing and growth of tube grafted eggplant seedlings is supplementing light 100 μmol·m-2·s-1 in 1-3 days after grafting, 150 μmol·m-2·s-1 in 4 days at 19 ℃ night temperature.