Efficient Micropropagation System for Tuberose (Polianthes tuberosa L.) from Cormel-derived Explants Using Optimized Cytokinins and Auxins

Abstract

Background: Tuberose (Polianthes tuberosa L.) is a commercially important ornamental and aromatic bulbous plant whose large-scale production is constrained by conventional propagation methods, necessitating the development of an efficient in vitro micropropagation system for rapid multiplication of disease-free planting materials. Aims: Tuberose is an economically important ornamental and aromatic plant, but its conventional propagation through cormels is slow and often associated with disease transmission. Thus, the present study was conducted to develop an efficient in vitro propagation system for tuberose through optimization of plant growth regulators and acclimatization media. Study Design: Completely Randomized Design (CRD) with factorial treatment combinations. Place and Duration of Study: Plant Breeding and Biotechnology Laboratory and net house, Khulna University, Bangladesh, from January to December 2025. Methodology: Healthy cormels were surface sterilized, and cultured on Murashige and Skoog (MS) medium supplemented with varying concentrations of 6-benzylaminopurine (BAP) for in vitro sprouting. Sprouted shoots were used as explants for shoot multiplication using BAP and kinetin, alone and in combination. Rooting was carried out on MS medium containing indole-3-butyric acid (IBA) and α-naphthalene acetic acid (NAA), individually and in combination. Rooted plantlets were acclimatized in different potting media under net house conditions. Results: The highest cormel sprouting (89.2%) was achieved with 2.0 mg L-1 BAP. Maximum shoot multiplication (7.5 shoots culture-1) was recorded at 1.5 + 2.0 mg L-1 BAP and kinetin, while the highest plant height (9.2 cm) and leaf number (11.4 plantlet-1) were obtained at 1.5 + 1.0 mg L-1. For rooting, 1.5 mg L-1 IBA produced the highest root number (5.5 plantlet-1) and root length (4.9 cm), while combined application of 1.5 + 0.2 mg L-1 IBA and NAA further improved root development (6.3 roots plantlet-1 and 5.4 cm). The highest survival rate (93.5%) during acclimatization was observed in cocopeat + vermicompost (1:1). Conclusion: A simple and effective micropropagation system was established for tuberose with optimized cytokinins and auxins combinations. The technique can be used for rapid large-scale production of healthy and uniform planting materials for commercial cultivation.