Facing the dynamic environment: a systemic perspective on the physiology of leafy cuttings
Leafy shoot tip and nodal cuttings are the starting material for vegetative propagation of many ornamental plant species. Optimization of the propagation process is challenged by highly complex propagation chains, that are continuously changing, and by the great genetic diversity of plants. A better understanding of the crucial physiological principles that underly the vitality and root development in cuttings would provide a roadmap how to reach the ultimate goal, an intensively rooted cutting with intact green leaves with the lowest possible input of resources and time. Majorly based on own research on cuttings of petunia and several other ornamental plant species, a systemic model is presented that integrates physiological functions of distinct cutting parts, which are decisive for successful propagation and respond to diverse environmental factors. Depending on the cutting type, the stem base, differently developed leaves, the shoot apex and axillary buds are considered as important physiological units of a cutting. Homeostasis and signal transduction of distinct plant hormones at whole cutting level are considered as important factors that control leaf vitality and the reprogramming of cells in the stem base toward root regeneration. Reactive oxygen species, the related enzymatic antioxidant system and phenolics act as cofactors during these processes. The carbon-nitrogen source-sink balance, that is further linked to the hormone system, is regarded as important bottleneck for supply of the developing roots with building blocks. Distinct physiological outputs that may be used to evaluate the rooting capacity and performance of cuttings are introduced in this review.
Druege, U. (2023). Facing the dynamic environment: a systemic perspective on the physiology of leafy cuttings. Acta Hortic. 1368, 93-102
propagation, adventitious root, senescence, phytohormones, reactive oxygen species (ROS), phenolics, carbohydrates, nitrogen, light