Abstract:

Sapium sebiferum (L.) Roxb. is a unique color-leaf tree species in China. Its leaf has a bright red color in spring and autumn, and it has a high ornamental value. With China’s forestry development, Sapium sebiferum has been gradually valued. In this paper, three different ratios of root pruning were carried out on the container seedlings of Sapium sebiferum, and the morphological and physiological indexes were compared. The results show that root pruning could significantly promote the seedling height, ground diameter, above-ground biomass, underground biomass and fibrous root biomass, but there is no significant difference between the root pruning treatments. The root morphology of Sapium sebiferum container seedlings could be greatly improved by root pruning. The ideal method is to prune 1/3 of the main root, with an average number of first-order lateral roots of 4.56, a total length of 484.26 cm, a root surface area of 210.59 cm² and a root volume of 7.62 cm³, the root length with a diameter less than 0.5 mm is 255.91 cm and the root length with a diameter more than 4.5 mm is 21.05 cm. The nutritional content and root activity of the seedlings’ roots change after root pruning. The content of soluble sugar and starch of the pruning of 1/3 main root are the highest, 53.34 mg/g and 138.80 mg/g respectively. The root vigor increases with the root pruning ratio.

Key words: Sapium sebiferum, container seedling, root pruning, biomass, root activity, soluble sugar and starch