Abstract

Accessions of Cola acuminata and Cola anomala were analysed based on the variation of free amino acids during germination and seedling growth. These compounds were determined by high performance liquid chromatography (HPLC) methods. In the non-germinated seeds of C. acuminata, arginine (Arg) was the major amino acid found in all six accessions and valine (Val) was the least present, while in C. anomala, gamma (γ)-aminobutyric acid (GABA) was predominant and isoleucine (Ile) was less abundant. During germination, the seeds of the two species accumulated large amount of GABA and very little tryptophan. Principal component and cluster analyses of Cola sp. categorized the accessions into two groups distinguishing the two Cola species. The differences between the groups were related not only to the absence/presence of histidine (His) and phenylalanine(Phe), but also to amide amino acids asparagine (Asn), glutamine (Gln) and Arg contents. In Cola sp., free amino acids varied significantly during these two processes indicating their high utilization. These metabolites can be considered as crucial in the control of germination.

Key words: Cola sp., amino acids, germination, seedling growth.

Abbreviation

HPLC, High performance liquid chromatography; GABA, γ-amino-butyric acid; BSA, bovine serum albumin; PVP, polyvinylpyrrolidone; PVPP,polyvinyl-polypyrrolidon; OPA, O-phthalaldehyde; NEAA, non essential amino acids;EAA, essential amino acids; PC, principal component.