In vitro culture of coconut endosperm: callus induction and its fatty acids.

Successful induction of callus from coconut endosperm was achieved by using the tissue situated near the micropylar end of a young fruit. For initiation of callus, a high concentration of auxin (20 to 100 ppm) was added to the basal medium containing activated charcoal. Subcultured callus showed a 40-fold increase during culture of three months. Based on the analysis of fatty acid composition, the maturation of endosperm was characterized by an increase in short chain fatty acids (C8, C10, C12, C14)and a decrease in long chain fatty acids (C16, C18: 1, C18: 2). In developing endosperms, proportion of short chain fatty acids was higher in lipids of the antipodal than those of other regions. In the final stage of maturation, around 82% of total fatty acids was short chain fatty acids, while the proportion of long chain fatty acids decreased up to 16%. The fatty acid composition of callus subcultured for six months was comparable to that of the immature endosperm. Lipids were accumulated in callus as globular bodies.