The Mutual Influence of Oleoresin Between Rootstock and Scion in Grafted Pine

Grafting constitutes a crucial approach for the preservation of pine clones. Slash pine is commonly used as the rootstock for grafting Masson pine scions in Guangxi. In this context, the fresh oleoresin samples of Masson pine, slash pine, and grafted pine (with Masson pine as scion and slash pine as rootstock) were analyzed by gas chromatography–mass spectrometry and gas chromatography, and the key chemical components (α-pinene, β-pinene, longifolene, and isopimaric acid) that can quickly and accurately distinguish the oleoresin of Masson pine and slash pine were found and identified. According to the changes in the relative content of key compounds of oleoresin in scion and rootstock, it was found that the oleoresin of rootstock and scion could interact. Further research showed that the mutual influence of oleoresin between rootstock and scion was persistent, and the influence of rootstock on oleoresin at the scion was affected by height. However, the height effect included a large individual differences, which were not significantly related to the grafting height, tree height, diameter at breast height, etc., but may have been related to the differences in synthesis speed of oleoresin between rootstocks and scions. This work reveals the possible mechanism of mutual influence and secretion of oleoresin in grafted pine trees, laying a foundation for the study of the characteristics of oleoresin from pines grafted by different types, with great significance for the breeding of pine with high yield of oleoresin, and the production and application of special compounds containing oleoresin.