Physicochemical Response of External Plant Growth Regulator in the Cutting Process of Mulberry

Abstract

Adventitious roots play a crucial role in the nourishment and propagation of arboreal vegetation. In order to shed light on the physiological and biochemical characteristics of the challenging-to-propagate mulberry tree species, an investigation was conducted. This study aimed to compare the responses of various root morphological indicators, endogenous hormones, and oxidase activities in the “Yueshenda 10” fruit mulberry, at different stages of treatment. The ultimate objective was to identify the factors influencing the process of root development. The findings revealed a distinct ”/\“ pattern in the levels of IAA and JA within the cuttings. Conversely, the changes in ABA, ZR, and GA3 exhibited a ”/\/“ pattern. The fluctuation of the IAA/ABA values followed a ”\/\“ mode, whereas the IAA/ZR values initially increased, followed by a subsequent decrease. The correlation between the initial concentrations of these five endogenous hormones and the rooting rate displayed variations. Notably, IAA demonstrated the strongest association with the rooting rate, exhibiting a positive correlation with both IAA and ZR. Regarding the activity of three antioxidant enzymes (IAAO, POD, and PPO), a ”/\“ trend was observed, wherein the enzyme activity increased under ABT1 treatment. However, the peak activity levels of the enzymes appeared during different periods: callus generation, rooting induction, and adventitious root expression, respectively. Overall, the most effective treatment for promoting root development and significantly enhancing the root growth parameters of mulberry was found to be 800 mg/L ABT1. Exogenous hormone treatment expedited the synthesis of antioxidant enzymes, thereby shortening the rooting time and facilitating root formation.