Influence of gibberellic acid (GA3) on in vitro seed germination of Dendrocalamus strictus (Roxb.) Nees: Exploring its effect under varied storage periods and micropropagation potential

Abstract

Dendrocalamus strictus, or 'male bamboo,' native to the Indian subcontinent, is a fast-growing perennial with a unique once-in-a-lifetime flowering cycle (every 25–40 years), making its propagation a challenge, primarily relying on seed germination and vegetative methods. Bamboo seeds display a tendency of high germination rates during their initial days, followed by a subsequent decline. Therefore, controlled environmental conditions are important for seed storage to maintain seed viability. This study investigates the impact of various storage periods (at 5 °C) and the application of GA₃ on the in vitro germination of Dendrocalamus strictus seeds. Initial storage resulted in 100 % germination across all samples, but as storage time increased, germination rates and seedling growth declined. After 18 months of storage, germination was observed to be 95.2 % in Murashige and Skoog medium enhanced with 0.5 mgL⁻¹ GA₃._, in contrast to the non-treated samples, which achieved only 61.9 % germination. In addition, the GA₃-treated samples exhibited higher germination rates and seed vigour index. The germinated seedlings were subsequently employed for micropropagation. The highest level of multiple shoots was achieved with combinations of BAP (6-Benzylaminopurine) and IAA (Indole-3-acetic acid). IBA (Indole-3-butyric acid) was effective in promoting intense root formation in the micropropagated shoots. The resulting plantlets were acclimatized and effectively established in the ground, exhibiting normal growth.