Histological Observation on the Healing Process of Grafted Rootstock and Scion of Thin Skinned Cucumis Melo

In order to understand the rootstock-scion compatibility and healing of thin skinned Cucumis melo after grafting, Guangmi No.1, the main local cultivar in Guangxi, was selected as the scion, and the three cultivars, white melon rootstock BX-1, pumpkin rootstock NX-3 and pumpkin rootstock NX-4, which were bred by Horticulture Institute of Guangxi Academy of Agricultural Science, were selected as the rootstocks. Then, the histological observation of the rootstock-scion healing on the 2nd, 4th, 6th, 8th and 10th days after grafting was carried out. The results showed that white melon rootstock BX-1, pumpkin rootstock NX-3 and pumpkin rootstock NX-4 all showed good grafting compatibility, and the histological changes of the rootstock-scion healing site and the healing speed after grafting were basically the same. On the 2nd day after grafting, the rootstock and scion formed an isolation layer respectively, and the graft was in the formation stage of isolation layer. On the 4th day after grafting, the color of the isolation layer became lighter, and the callus formed at the edge of the isolation layer, and the graft was in the formation stage of callus. On the 6th day after grafting, the color of the isolation layer became lighter obviously, and the callus differentiated further, forming callus bridges. On the 8th day after grafting, many discontinuous callus bridges were formed at the junction between the incisions of rootstock and scion, and most of the gap outside the isolation layer was filled with callus. On the 10th day after grafting, the isolation layer at the junction of rootstock-scion incision almost disappeared.