Effect of Light-Emitting Diodes on the Proliferation of Immature Endosperm-Derived Calli of Coconut (Cocos nucifera L.)

Coconut endosperm has a unique fatty acid profile with a predominance of saturated fatty acids like lauric and myristic acids. Manipulating fatty acid biosynthesis pathways can be possible with the in vitro multiplication of endosperm tissuein this important oil-yielding perennial palm tree. In this study, influence of Light Emitting Diodes (blue, yellow and purple colored) was investigated on in vitro initiation and proliferation of coconut (Cocos nucifera L.) endosperm calli. Biomass accumulation, total soluble sugars, reducing sugars, free amino acids, total polyphenols and fatty acid profile were estimated from endosperm calli of Gangabondam Green Dwarf (GBGD) cultivar. Calli grown under dark conditions served as control. Results indicated that initiation of calli was faster under dark conditions, whereas the mass was significantly high under purple LED. Production of total soluble sugars and reducing sugars were enhanced in cultures under LEDs in comparison to control. Fatty acid profiles generated through gas chromatography (GC) indicated that medium-chain saturated fatty acid content was higher, while long chain saturated and unsaturated fatty acid content was less in cultures grown under LEDs than in cultures under control conditions. It is evident from the results that coconut endosperm calli can be initially initiated under dark conditions and it has the potential to proliferate under LED conditions with a significant impact on fatty acid synthesis.