Vegetative propagation of Polygonatum cirrhifolium (Wall.) Royle through rhizome cuttings

Abstract

Plants are often subjected to various stressors, such as changes in gravity, heavy rainfall, pathogens, wind, herbivory, and human activities, which can result in wounding. This study investigates the effect of various mechanical wounding methods and growth regulators on the survival and vegetative growth of Polygonatum cirrhifolium (Wall.) Royle over two years (2021–2022). In the first year (2021), we evaluated the effect of different wounding techniques, including cut, scrapes, punctures, and abrasions on rhizome to understand their impact on growth and survival. Non-wounded rhizomes (NWR) served as controls. Among different wounding methods, apical section from the whole rhizome (cut) showed superior growth performance (shoot length, increase in rhizome length and survival), when used for propagation. Hence, this was selected as a suitable method of propagation for further experiments. In the second year (2022), apical rhizome sections were treated with different auxins (IAA, IBA, NAA, and Rootex PD.01) and organic fertilizers derived from Quercus, Cedrus and Salix species. Notably, treatment with Rootex PD.01 (a commercial formulation of indole-3-butyric acid at 1000 mg kg⁻¹) by powder application method and soil mixed with organic fertilizer (prepared from Salix alba) in ratio of 2:1, induced the maximum survival and vegetative growth of P. cirrhifolium. This study provides valuable insights into previously underexplored strategies, highlighting the effects of mechanical wounding and growth regulators on enhancing the vegetative propagation of P. cirrhifolium through rhizomes. The propagation method developed through this research can be applied for the mass multiplication and conservation of this endangered species.