Preliminary study on species variability and evolutionary status of African walnut (Plukenetia conophora)

Abstract

An analysis of the biochemical composition of African walnut seeds collected from two different geographical areas, Nigeria and Cameroon, was used to conduct the primary assessment of varietal differences and evolutionary status of Plukenetia conophora. The experiment was conducted at the Laboratory of Department of Biochemistry and Technology, Federal University of Technology, Owerri, Nigeria. The experimental design was completely randomized design with five replications. Significant difference (P > 0.05) was not observed with the proximate properties of the seeds of the two lines except for carbohydrate. However, higher values in protein (28.32%), crude fat (5.67%), ash (4.33%), and moisture (38.44%) content were obtained for the line from Nigeria, while the line from Cameroon had higher values for carbohydrate (20.87%) and crude fibre (9.32%). With regard to mineral composition, significant difference (P < 0.05) was observed in some mineral elements such as manganese, sodium, and chromium. Anti-nutritional composition such as proximate properties did not show any significant difference between the two lines. However, the line from Nigeria had higher values of phytate (6.27%) and oxalate (0.11%), while a higher content of tannin (0.36%) and saponin (0.27%) was obtained for the line from Cameroon. Evidently, the result obtained was not substantial to establish varietal differences between the two lines; nevertheless, it showed some level of evolutionary changes in the crop over the years.

Keywords

• african walnut
• biochemical properties
• variability
• evolution