Growth Response and Microbulb Formation of True Shallot Seed (Allium cepa L.) with the Addition of Sucrose in Compound Fertilizer Medium in vitro

Abstract

The limited availability of high-quality shallot planting material has encouraged the development of alternative propagation techniques that are disease-free through in vitro culture. The use of alternative culture media is required to improve efficiency and reduce production costs. This study aimed to evaluate the effects of various concentrations of NPK compound fertilizer and sucrose on the growth and microbulb formation of shallots from True Shallot Seed (TSS). The research was conducted at the Plant Tissue Culture Laboratory, Department of Agronomy, Faculty of Agriculture, University of Bengkulu, from August to November 2025. The experiment employed using a complete randomized design (CRD) factorial with two factors, namely the concentration of NPK compound fertilizer (2 g/L, 4 g/L, and Murashige and Skoog as control) and the second factor, namely the concentration of sucrose (30, 60, 90, and 120 g/L). Each treatment was repeated three times, with each repetition consisting of three bottles and each bottle planted with three TSS seeds. The main materials used were Lokananta variety TSS seeds and 32-10-10 NPK compound fertilizer. The data were analyzed using 5% analysis of variance with DMRT follow-up test, while data with a coefficient of variation (CV) >30% were transformed using the formula √((x+0.5)) to reduce the CV value. The results showed an interaction between the concentration of NPK compound fertilizer and the concentration of sucrose. The combination of MS medium with a sucrose concentration of 60 g/L was the best treatment, as it produced the highest number of leaves and roots. MS medium produced the highest average values for the variables of germination time, germination percentage, plant height, number of shoots, root length, and tuber diameter. However, NPK compound fertilizer medium at 2 g/L was only able to match MS medium for the variables of percentage and germination time.