| dc.description.abstract | Coconut (Cocos nucifera L.) has contributed enormous economic and
environmental values to human life on this planet. However, many elite and
commercial coconut species are threatened with extinction, a threat that requires
our immediate actions to conserve their genetic materials. Direct organogenesis
using coconut shoot tips has been identified as a potential tissue culture pathway
to conserve coconut genetic materials. However, key challenges in successfully
introducing shoot tips into in vitro culture include controlling contamination,
maintaining survival, and inducing an initial culture response. In this study, Xiem
Red Dwarf coconut shoot tips were isolated from seednuts and from in vitroembryo cultured plantlets by control and cut protocol, and cultured onto Y3
medium (Eeuwens, 1976) supplemented with TDZ (10 µM), sucrose 5%, phytagel
(2g/L) and activated charcoal (2 g/L). Double sterilization was found to reduce
contamination rates from 86.67% to 26.67% in seednut-derived shoot tips. Intact
shoot tips from both seednuts and in vitro plantlets exhibited higher shoot
induction rates compared to cut protocol cultures. In subsequent experiments, it
was observed that seednut-derived shoot tips cultured on medium supplemented
with 10 μM TDZ had the highest rate of elongation with the earliest signs of
greening compared to 0, 5 and 15 μM TDZ. Meanwhile, in vitro-derived shoot tips
elongated best on 15 μM TDZ 30 days post-inoculation. This study provides a
protocol for successful inoculation of coconut shoot tips taken from either seednuts
or in vitro plantlets, with low contamination rates and sufficient induction, helping
to pave the way for in vitro conservation or future propagation of these plant
materials. | en_US |
