Assessment of Genetic Variability of Three Types of Sorghum Cultivated in Burkina Faso Using Morphoagronomic Quantitative Traits and Brix

Abstract

In Burkina Faso, tree types of sorghum are mainly grown. Despite their genetic proximity revealed by molecular markers, the identification of distinctive agro-morphological traits between sweet grain sorghum, sweet sorghum and grain sorghum could contribute to better management of their genetic resources. Thus, 42 genotypes consisting of the three sorghum types were evaluated in a three replicate Fisher incomplete block design using 20 quantitative traits. The results showed a high variability of traits within each sorghum type and a greater closeness between sweet grain sorghum and sweet stalk sorghum. In addition, nine traits clearly discriminated sweet grain sorghum from the other sorghum types. Sweet grain sorghum expressed the highest values of the sowing-heading cycle, leaf sheath length, stem diameter, productive tillers, and panicle width and the lowest values of mean heading-flowering difference, 100-grain weight, and Brix. Moreover, the ‘sorghum type’ factor is less preponderant than the ‘genotype factor’ in expressing the variability of all traits. Therefore, the 42 genotypes are organized into three genetic groups independently of the sorghum- type factor, where the group I contains all sweet grain sorghum genotypes and three sweet stalk sorghum genotypes. These results could be exploited in sorghum breeding programs.