Clonal Propagation of Khaya spp.: Epicormic Shoot Emission in Adult African Mahogany Species

Abstract Research on vegetative propagation in the genus Khaya remains limited and has focused mainly on juvenile trees, which restricts the selection of plus trees previously tested for growth potential and economic value. This study aimed to evaluate the vegetative propagation of three African mahogany species by inducing epicormic shoots in adult trees, and to investigate evidence of rejuvenation/reinvigoration during adventitious rooting, as well as the influence of branch diameter on bud and shoot emission. Plant material was collected from an experimental plantation using basal branches of 10-year-old trees. For each species, 72 leafless branches were standardized and maintained in a climate-controlled greenhouse. The experiment followed a completely randomized design with three diameter classes. After 21 days, the number of buds and shoots emitted per branch was recorded. Biochemical analyses included the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), total proteins, and total carbohydrates to characterize metabolic differences between adult tissues and epicormic shoots. Results indicate that branch diameter had a significant effect on bud and shoot emission in all three African mahogany species, with branches 4.5–6 cm in diameter being the most suitable source material. For assessing tissue rejuvenation and metabolism, SOD and CAT activities in K. senegalensis , SOD activity in K. grandifoliola , and total carbohydrate content in K. ivorensis were the most responsive biochemical variables for distinguishing epicormic shoots from adult tissues. Although adventitious rooting percentages were low, this study indicates that epicormic shoot induction in adult trees is a feasible strategy for obtaining vegetative propagules.