Improving Pineapple (Ananas comosus L.) Micropropagation: Effects of Different Types and Levels of Auxin on Root Development

Pineapple (Ananas comosus L.) is a highly valuable tropical fruit with significant economic importance. However, conventional propagation methods struggle to meet the growing demand for planting materials. Micropropagation offers a viable solution, though its efficiency is often limited by poor rooting. This study investigates the effects of three auxins-naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA)-on pineapple micropropagation, aiming to optimize plant regeneration and enhance rooting efficiency.

Following sterilization, axillary buds measuring approximately 1.0-1.5 cm in length were carefully excised from the crowns and cultured as explants on Murashige and Skoog (MS) medium supplemented with 4 mg/L benzyladenine (BAP) for shoot initiation. For root induction, microshoots were transferred to MS medium containing NAA, IAA, or IBA at concentrations of 0.0, 0.5, 1.0, 1.5 and 2.0 mg/L. After four weeks, shoot length, leaf number, root number and root length were measured.

All auxin treatments significantly improved root and shoot development compared to the control (p<0.05). Indoleacetic acid (IAA) at 0.5 mg/L produced the longest roots (30.82 mm) compared to the control (10.15 mm) and other treatments, indicating its superior efficacy in promoting root development. These findings provide a practical approach to enhancing micropropagation efficiency, contributing to sustainable and scalable pineapple cultivation.