Study on the Outside Tube Micrografting Techniques for the Tissue Culture Seedlings ofMomordica charantia Linn.

【Objective】The study was to establish an outside tube micrografting technique for the tissue cultured buds of the broad-shoulder bitter gourd (Momordica charantia Linn.) in order to solve the problem of weak growth of the tissue cultured buds at present. 【Method】Taking 5-7 cm healthy tissue culture seedlings of Dingpei No.1 bitter gourd as the scion and tower gourd (Luffa cylindrica) and pumpkin (Cucurbita moschata D.) seedlings as the rootstocks, the effect of different grafting methods(including time of hardening tissue culture seedling, different moisture methods of graft unions, ages and species of root stocks and scion interfaces dipped with different concentrations of 6-BA and sprayed with different concentrations of sucrose) on the graft survival rate, increment of scions and total stain heights of grafted seedlings were studied.【Result】The optimal time to harden tissue culture seedlings of the broad-shoulder bitter gourd was 6-7 days. It was easy to package the graft unions by using rubber casing and grafting clip and remarkable moisturizing effect could be obtained. The best rootstock was the towel gourd “Yinzhen No.1” seedling with two piece of true leaf. The optimal concentrations of 6-BA and sucrose were 0.5 mol/L and 6%, respectively, and the highest graft survival rate of 65.9% could be obtained.【Conclusion】It was the first time to establish an outside tube micrografting technique for the tissue cultured buds of the broad-shoulder bitter gourd. The application of such technique will improve the weak growth and the survival rate of tissue culture seedling of the broad-shoulder bitter gourd.