Abstract: [Objective] Chinese bayberry (Myrica rubar Sieb. et Zucc.) is an evergreen tree species and suitable for growing in weak acid soil, and it has been cultivated mainly in southern China. Bayberry fruit is ripe in early summer and delicious with attractive color, flavor, and high economic and medicinal value. M. cerifera is suitable for growing in poor alkaline soil, and different from M. rubar. It is of practical significance to study the grafting compatibility and genetic relationship between M. rubar and M. cerifera for expanding M. rubar cultivation.[Method] For three consecutive years, M. rubra and M. cerifera were used as rootstocks, and four cultivated varieties (‘Biqizhong’, ‘Dongkui’, ‘Xiazhihong’ and ‘Shuijingzhong’) as scions, and the interspecific grafting was carried out on the beach of Yuyao, Zhejiang Province (soil pH8.01). The genetic relationship between M. rubar and M. cerifera was identified and clustered based on SSR. After three years of grafting experiments, survival rate of grafting and related indexes of rootstock-scion combinations were investigated.[Results] The grafting survival rate of rootstock-scion combinations of M. rubra was 70.08-83.47%, among which the grafting survival rate of scion of ‘Xiazhihong’ was highest (81.98%), and the grafting survival rate of ‘Biqizhong’ was the second (80.43%). The grafting survival rate of rootstock-scion combinations of M. cerifera were 27.51%-38.29%, among which the grafting survival rate of scion ‘Dongkui’ was highest (34.88%). The grafting survival rate of M. cerifera rootstock-scion combinations was significantly lower than that of M. rubar rootstock-scion combinations. T-test showed that BQ4-6, DK4-6 and SJ4-6 of M. cerifera rootstock-scion combinations had significantly higher crown diameter, dry rootstock perimeter and plant height than those of M. rubra combinations, respectively. The correlation analysis of six indexes showed that there was a significant positive correlation between grafting survival rate and plant height and crown diameter, and a negative correlation between plant height and rootstock height in both rootstock populations over three consecutive years experiment. A total of 127 SSR markers were used to detect DNA polymorphisms of 2 rootstocks and 4 scions, these materials were clustered into 3 groups, and the genetic similarity between M. cerifera and M. rubra was 0.31. The relationship between rootstock of M. rubra and ‘Xiazhihong’ was the closest, followed by ‘Biqizhong’. The rootstock of M. cerifera had the highest relationship coefficients with ‘Dongkui’; it was demonstrated that the closer genetic relationship the higher grafting survival rate.[Conclusion] This study proved that M. cerifera used as rootstocks had to a certain degree grafting affinity with M. rubra scion, which was more suitable than M. rubra rootstocks for growing in alkali soil.

Key words: Myrica cerifera, Myrica rubar, rootstock, interspecific grafting, correlation analysis, cluster analysis