Enzyme polymorphism of Penizisetum americaieum in the Ivory Coast

Polymorphism in populations of pearl millet from the Northern Ivory Coast was studied t o determine the variability of three enzymatic proteins, alcohol dehydrogenase, phosphoglucomutase and phosphoglucoseisomerase, coded by three loci. The results show significant linear variation of frequencies associated with an eastwest axis for two of the loci. No significant variability for phosphoglucoseisomerase was found. The analysis of isolated populations allowed us t o examine the important effect of genic flow that might explain the appearance of a linear gradient. The adaptation of these enzymes to flooding conditions was also studied, and the environmental variation from east t o west might be sufficient t o cause the appearance of allelic variations and the resultant adaptation. In this paper both hypotheses are discussed.