Standardization of Sterilization Techniques and Suitable Explants for Aseptic Establishment in Mulberry (Morus spp.) Tissue Culture

Abstract

Mulberry (Morus spp.) cv. Thar Lohit, a high-yielding and resilient cultivar, is pivotal for sericulture, fruit production and medicinal applications. This study aimed to standardize explant selection and sterilization techniques for efficient micropropagation to support sustainable mulberry cultivation. Using a completely randomized design, explants such as meristem tips, apical buds and nodal segments from field-grown Thar Lohit plants were subjected to various sterilization treatments involving 70% ethanol and 0.1%–0.2% mercuric chloride (HgCl2) at different time durations. Nodal segments, particularly the third node, exhibited the lowest contamination rate (34.67%) and highest survival rate (65.33%), outperforming meristem tips (49.33% contamination, 50.67% survival) and apical buds (42.67% contamination, 57.33% survival). The optimal sterilization protocol, combining 70% ethanol (1 min) with 0.2% HgCl2 (10 min) achieved the lowest contamination (18.33%) and highest survival (81.67%). These findings highlighted the superior regenerative capacity of nodal segments and the efficacy of combined sterilants and consistent with prior research. This standardized protocol ensures reproducible, high-yield production of disease-free mulberry plants, enhancing sericulture, genetic conservation and commercial cultivation.