- Dossou-yovo, Y. Chukwumah and M. Bokanga
Cassava breeding programs selecting for varieties with low amounts of cyanogenic glucosides usually rely on chemical tests, qualitative or quantitative, of cyanogenic compounds in cassava roots at harvest time. A recent approach is however based on an enzyme system that convert L-valine to cyanohydrin (immediate precursor of linamarin). In this current study, the enzyme complex was extracted from the young leaves of 14 cassava varieties. Enzyme activity was compared to the concentration of cyanogenic compounds in the leaves. The results showed that the rates of biosynthesis of cyanogenic compounds in cassava varieties are highly variable. However, no correlation was found between the biosynthesis of the cyanogenic glucosides and the concentration of cyanogenic compounds. Electrophoresis (SDS-PAGE) of the isolates showed a similar band pattern. Further characterization of the linamarin-synthesizing enzyme is in progress to determine the biochemical basis for the differences in biosynthetic activity.