This study aimed to explore the effects of different concentrations of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and indene-naphthaleneacetic acid (ABT-1) on the rooting and dynamic changes of the endogenous hormone content of Australian Mulberry (vegetable Mulberry) and Kirin mulberry (Fruit Mulberry) hardwood cuttings. As exhibited by the results, the rooting process of both vegetable mulberry and fruit mulberry could be divided into three stages, namely the initiation stage (1–18 days), the callus formation stage (18–28 days), and the adventitious root formation and elongation stage (28–48 days). The two treatments with 1000 mg·L⁻¹ ABT-1 and 500 mg·L⁻¹ ABT-1 achieved the highest rooting efficiencies of vegetable mulberry and fruit mulberry, significantly higher than those of other treatments (p < 0.01), with average rooting rates of 63.3% and 68.7%, and rooting efficiency indices of 25.3 and 34.3, respectively. During the rooting process, the contents of endogenous IAA and zeatin riboside (ZR) and the ratios of IAA/ABA and IAA/ZR presented a trend of decreasing before increasing, while the abscisic acid (ABA) and jasmonic acid (JA) contents exhibited a trend of increasing before decreasing, and the gibberellin (GA₃), strigolactone (SL), and IBA contents showed a continuous decreasing trend. Hence, ABT-1 was effective in inducing the synthesis of IAA, IBA, JA, and SL, reducing the contents of ABA, ZR, and GA₃, and promoting the rooting of vegetable mulberry and fruit mulberry cuttings. For fruit mulberry and vegetable mulberry cuttings, the optimal concentrations of ABT-1 were 500 mg·L⁻¹ and 1000 mg·L⁻¹, respectively, demonstrating applicability for the efficient propagation of Morus alba L. cuttings.

(1) Background: To further improve the rapid reproduction and large-scale application of Catalpa bignonioides. (2) Methods: With young softwood cuttings from a 3-year-old C. bignonioides mother plant used as materials, the effects of indole-3-acetic acid(IAA), indolebutyric acid(IBA) and rhizogenic powder-1(ABT-1) growth regulators at different concentrations on cutting indexes and the dynamic changes in endogenous hormone contents during the rooting of the C. bignonioides cuttings were studied. (3) Results: The rooting of C. bignonioides cuttings could be divided into five stages. There were three types of rooting of adventitious roots. IBA treatment resulted in a high rooting rate and beneficial root morphology. The morphological indexes of the cutting roots after treatment with 1000 mg·L⁻¹ IBA had the best overall quality, which was significantly higher than that of the roots in the control (CK) group (p < 0.05). Although the average longest root length (20.51 cm) under ABT-1 was the longest, its overall average rooting rate was slightly lower than that under IBA. The rooting effect under IAA was generally lower than that under IBA and ABT-1. The endogenous hormone content of the cuttings was found to be closely related to rooting; the IAA and zeatin nucleoside (ZR) content was high, and the ratios of IAA/ABA and IAA/ZR were high. The contents of gibberellin₃ (GA₃) and abscisic acid (ABA) were low, which had a promoting effect on the rooting of the cuttings. (5) Conclusions: All three kinds of auxin can promote rooting and, of the three treatment groups, the rooting effect of cuttings in the IBA treatment group was the strongest, with 1000 mg·L⁻¹ being the optimum concentration.

Enhancing the capacity of fruit trees to propagate via cuttings is an important endeavor for the high-quality development of the fruit industry. Optimizing the conditions for the cutting propagation of mulberry seedlings is an important factor that influences the industrial production of this plant; however, the currently used mulberry breeding technology system is not mature. In this experiment, an orthogonal design was used to intercept semi-woody shoots of Yueshenda 10 as cuttings and set different hormone concentrations (200, 500, 800, and 1000 mg/L), different hormone types (NAA, IBA, IAA, and ABT-1), and different soaking times (10, 30, 60, and 120 min) for cuttings. The effects of the three factors on the rooting of mulberry cuttings were investigated by soaking the cuttings in clean water for 10 min as a control. The results showed that the primary and secondary order of the three factors affecting the rooting rate of cuttings was hormone concentration > hormone type > soaking time, and the concentration of exogenous hormones had a significant impact on all rooting indicators (p < 0.05). In addition, the rooting rate (66.24%), average number of roots (7.54 roots/plant), and rooting effect index (4.23) of Yueshenda 10 cuttings reached the optimal level when soaked with 800 mg/L ABT-1 for 30 min. The longest root length (10.20 cm) and average root length (4.44 cm) of cuttings achieved the best results when soaked with 800 mg/L NAA for 60 min and 500 mg/L NAA for 30 min, respectively. On balance, it is considered that the preferred solution is to soak the cuttings of Yueshenda 10 with 800 mg/L ABT1 solution for 0.5 h.

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.

Adventitious roots play a crucial role inr 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 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: germination, induction, and expression, respectively. Overall, the most effective treatment for promoting root development and significantly enhancing the root growth parameters of mulberry was found to be 800mg/L ABT1. Exogenous hormone treatment expedited the synthesis of antioxidant enzymes, thereby shortening the rooting time and facilitating root formation.

Quercus variabilis (Q. variabilis), a significant broadleaf species used in afforestation across high, sandy, and mountainous regions, presents unique challenges for transplantation. This species is characterized by its slow above-ground growth and rapid taproot development, which suppresses the proliferation of lateral and fibrous roots, negatively impacting post-transplant survival. Research indicates that targeted root pruning—specifically, the removal of one-third of the roots—promotes the development of lateral roots in these seedlings. This study involved pruning the root systems of Q. variabilis and assessing the subsequent root development in comparison to an unpruned control group. Our analysis, which included transcriptome sequencing and plant hormone metabolism assays conducted at 2, 12, and 25 days post-pruning, yielded 126.02 Gb of clean data and identified 7662 differentially expressed genes (DEGs). These genes were primarily enriched in the plant hormone signal transduction pathway. Further investigation of this pathway, along with hormone content measurements, elucidated the mechanisms that contribute to enhanced root growth following pruning. Additionally, through a weighted correlation network analysis (WGCNA), we identified 20 key genes that are instrumental in promoting root development in Q. variabilis saplings. This research advances the theoretical framework for forestry seedling production and afforestation, laying the groundwork for scientifically informed vegetation restoration techniques.