Germination of Cola anomala (K. Shum.) Shott and Endl seeds: effects of provenance, substrate and dehydration

As a step in the process of Cola anomala domestication, investigations were undertaken on germination requirements and desiccation tolerance of its seeds. Three seed provenances (Bamenda, Bayangam and Dschang), three substrates (forest top soil, river sand and a mixture of forest top soil and river sand) and two photoperiods (12 hours/day and, continuous darkness) were investigated for their effects on seed germination. To evaluate their desiccation tolerance, fresh seeds were dried at room temperature for 16 days during which seed moisture content, seed germination percentage and electrical conductivity of seed leachate were monitored at two-day intervals. Results showed that germination percentages were significantly (P < 0.05) higher both on forest top soil alone (86.04 ± 4.8%), and on a mixture of forest top soil and river sand (83.56 ± 4.5%), than on river sand alone (69.96 ± 4.7%). Seeds from Bamenda showed a higher germination percentage (91.4 ± 4.7%) than those from either Bayangam (77.36 ± 4.7%) or Dschang (70.8 ± 4.8%). The desiccation tolerance test revealed that as response to drying, the mean germination percentage was first slightly reduced as moisture was lost, then declined considerably at moisture content below 50.28%. Total germination failure was observed when seed moisture reached 32.24%. Electrical conductivity of seed leachate exhibited a strong correlation with loss of viability as well as with desiccation. It is concluded that there is a provenance-related variation in C. anomala seed germination. The best substrate for germination is forest top soil supplemented or not with river sand in a 1/1 (v/v) ratio. C. anomala seeds are desiccation-sensitive and their storage behaviour is recalcitrant.Keywords: Desiccation tolerance, critical moisture, lethal moisture, electrical conductivity, electrolyte leakage, storage behaviour

Effects of hormones applications on the germination of six populations of Garcinia kola Heckel (Guttiferae) seeds

The present study was carried out to investigate laboratory germination responses of six collections of Garcinia kola seeds to six different hormonal pre-germination treatments. This consisted of soaking seeds for three days in cool distilled water (control), in cool distilled water supplemented with 10-4 M of either naphthaleneacetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), benzylaminopurin (BAP), kinetin (Kin) or gibberellic aicid 3 (GA3). The results showed that the pre-germination treatments had profound effects on the phenology of Garcinia kola seeds germination. Multiple shoots, multiple roots and callus formation were induced from seeds soaked in benzylaminopurin, naphthaleneacetic acid and 2,4-dichlorophenoxyacetic acid solutions, respectively. Analysis of variance showed a significant (p < 0.01) effect of seed collection on the germination velocity, indicating the variability in seed dormancy among collections. Although the rate of germination was higher in seeds treated with NAA, none of the seed treatments significantly enhanced germination when compared with the control. Keywords: Bitter kola, auxins, cytokinins, gibberellic acid, phenology, variable dormancy. International Journal of Biological and Chemical Sciences Vol. 1 (3) 2007: pp. 255-26

In vitro

The in vitro antimicrobial and in vivo heavy metal abatement properties of aqueous extracts of Garcinia kola Heckel (bitter cola) were investigated using opportunistic pathogens and Wistar rats as experimental models. A marked inhibitory activity against Aspergillus niger, Aspergillus flavus and Candida albicans was recorded at 100 mg/ml of the crude relative to ketoconozole and fluconazole drugs. Similarly, different concentrations (25 mg/ml, 50 mg/ml and 100 mg/ml) of the crude extracts of bitter cola inhibited species of Escherichia coli and Pseudomonas aeruginosa almost as effectively as the control drug of streptomycine used. Chronic lead acetate poisoned wistar rats in groups B, C, D, E exposed to G. kola supplemented feed and water ad libitum showed variable decrease in the serum alkaline phosphatase level while aspartate and alanine aminotransferases level reduces in C and D groups compared to the negative control group. The kidney biomarkers; serum creatinine and urea concentrations were not significantly different at P â¤Â 0.05 for rat groups C, D, E when compared with the positive and negative control groups respectively. Mild infiltration and cell distortion were observed in the liver and kidney sections of the rats exposed to uncoated bitter cola supplemented feed while suggesting an overriding effect from the nut coats. The study reaffirms the medicinal potential of coated and uncoated bitter cola to act as abatement of lead toxicity and alternative antimicrobial. Furthermore, G. kola could be a double-edged drug for the spontaneous amelioration of lead toxicity and secondary infections due to lead poisoning. Keywords: Garcinia kola, Antimicrobial, Lead abatement, Histopathology, Opportunistic pathogen