Effect of IBA and ABT on Endogenous Hormones in Rooted Cuttings of Common Camptotheca Fruit (Camptotheca acuminata Decne)

Cuttings of young branches from common camptotheca fruit(Camptotheca acuminata Decne)plants were treated by ABT and IBA to study their effect on the endogenous hormones in the cuttings. Responding changes on abscisic acid (ABA), indole-acetic acid (IAA), zeatin riboside (ZR), and gibberellins (GA₃) in the leaves and stems of the plantlets by the treatmentswere determined using the enzyme-linked immunosorbent assay (ELISA). The results showed that soaking the cuttings in ABT and IBA solutions in varied concentrationsimproved the rooting over control. The contents of IAA and ZR, as well as the ratios of IAA/ABA and ZR/ABA, in the leaves and stems increased significantly after the pre-treatment.But, those of GA₃, ABA, reduced. Among all treatments, by dipping the cuttings in a 1, 000 mg ABT/L+1, 000 mgIBA/L solution for 20s, the highest survival rate was obtained. IAA in the leaves and the stems peaked on the 40^th day, i.e., an increase by 57.5% and 77.4%, respectively, as compared to that of control. At the same time, GA₃ in the leaves decreased by 24.8% over control. Onthe 30^th day, GA₃ in the stems declined 35.0%, ABA in the leaves and the stems decreased by 19.2% and 32.2%, respectively, over control. The maximal IAA/ABA ratio appeared on the 20^th day in the leaves and 30^th day in the stems, representing the increases of 114.0% and 150.0%, respectively, in comparison to control; and, similarly, the peak ZR/ABA in the leaves and the stems. It appeared that the ratios ofIAA/ABA and ZR/ABA could be used as an index for the survival quality of camptotheca cuttings.