Chiang Mai Journal of Science

Aquilaria sinensis, a key agarwood source, faces population decline from overharvesting, necessitating urgent development of efficient breeding methods for conservation and economic purpose. Cutting propagation is viable, but A. sinensis’ difficult-to-root characteristic limits efficiency. Therefore, we systematically evaluated the effects of growth regulator concentration, substrate, and trimming techniques on the rooting of semi woody cuttings through orthogonal experiments combined with physiological trait detection and transcriptome analysis. The optimal treatment involved treating flat trimmed cuttings with 200 ppm ABT-6 and inserting them into a loess:peat soil (1:2) substrate. This combination achieved a maximum rooting rate of 71.25%. The rooting of cuttings involves three stages: induction (0-30 days), expression (30-40 days), and extension (40-60 days). During root induction, ABT treatment increased endogenous IAA, ZR, and GA3 levels while suppressing ABA, establishing a hormone balance beneficial for adventitious root initiation. Besides, it also changed the activities of key enzymes (POD, IAAO, and PPO) and content of nutrients, but the changing trends were different. The transcriptome analysis showed that 93 DEGs identified in phytohormone signal transduction pathway. Our results significantly improve the rooting efficiency of A. sinensis cuttings and provide an insight into the hormonal molecular network during root formation in A. sinensis cuttings.