Variabilité phénotypique des sorghos locaux de deux régions du Burkina Faso: La Boucle du Mouhoun et le Centre-Ouest

Abstract

The racial classification of 190 sorghum landraces collected in two regions of Burkina Faso and characterized for 27 agro-morphological traits shows the preponderance of Guinea varieties (96.8%). Durra and Caudatum varieties are rare, respectively 1.6% and 0.5%, whereas 1.1% of the varieties were not classified. Among the Guinea sorghums, the gambicum are more frequent than the margaritiferum which present an important variability in cycle duration. The phenotypic diversity of the landraces is high and poorly explained by geographic factors (villages or climatic zones). The differences between varieties are mainly based on vegetative duration and red-grained sorghums are generally earlier than white-grained sorghums. An initial multivariate analysis of data shows stratification based on racial aspects. In a second analysis, plant cycle and grain type characteristics discriminate two clusters: a group of early and medium cycle sorghum varieties with rather big and floury grain and a group of late cycle sorghum varieties with lower grain weight and vitreous grains. The red sorghums other than the margaritiferum form a specific cluster. In contrast, white sorghums show less homogeneity.