Thidiazuron induced somatic embryogenesis in Coffea arabica L. and Coffea canephora P ex Fr.

Abstract

The rapid direct and repetitive somatic embryogenesis in Coffea arabica and C. canephora genotypes was tested on Murashige and Skoog medium (MS) containing thidiazuron
\n(TDZ) (1-phenyl-3-(1,2,3,-thiadiazol-5-yl)urea) in concentrations of 2.27–11.35s �M. Segments taken from cotyledon leaf, first leaf and stalk of regenerated plantlets produced clusters of somatic embryos directly from cut portions of explants on TDZ (9.08 �M) containing medium within a period of two months. Subculturing of these embryo clusters produced more secondary embryos on reduced TDZ (0.045–0.91�M) containing medium and these subsequently developed into plantlets (80–85%) on development medium followed by rooting on MS basal medium. This direct somatic embryogenesis from leaf and hypocotyl explants in Coffea sp. is a strong evidence of cell totipotency. The rapid somatic embryo induction protocol would be useful for the mass propagation, direct regeneration and genetic transformation of selected elite lines.