Abstract:In order to evaluate graft compatibility of different honey pomelo (Citrus grandis) rootstock-scion combinations at seedling stage, five cultivars of honey pomelo, such as ‘Hongmianmiyou’, ‘Sanhongmiyou’, ‘Hongroumiyou’, ‘Huangjinmiyou’ and ‘Guanximiyou’ were used as scions, and Citrus grandis, C. junos, Poncirus trifoliate as rootstocks, some physiological and biochemical indexes of 15 rootstock-scion combinations at seedling stage were determined. Their graft compatibility was evaluated by using principal component and cluster analysis. The results showed that there were significant differences in seedling growth among different rootstock-scion combinations, which ‘Hongmianmiyou’/Poncirus trifoliata and ‘Huangjinmiyou’/Poncirus trifoliata combinations were imcompatibility. The changes in PPO, POD activities, soluble protein, soluble sugar contents were similar at graft union stage in different rootstock-scion combinations. Four principal components could present 91.33% information of 15 indexes, and the cluster analysis showed that 15 rootstock-scion combinations could be divided into 4 clusters. Therefore, it was suggested that ‘Guanximiyou’, ‘Hongroumiyou’, ‘Sanhongmiyou’ could graft with Citrus grandis and Poncirus trifoliata, ‘Hongmianmiyou’ and ‘Huangjinmiyou’ with Citrus grandis, ‘Hongmianmiyou’ and ‘Huangjinmiyou’ could not graft with Poncirus trifoliata.