No abstract

Sorghum [Sorghum bicolor (L.) Moench] is an important food crop in Burkina Faso. Farmers grow various sorghum landraces, distinguished by their morphological and phenological characteristics. This study aimed addressing how this varietal diversity is managed by farmers, and how their management shape the genetic structures of local sorghum. Diversity levels in ten local sorghum guinea varieties (25 panicles per variety) collected from different farms in three agro-ecological regions across Burkina Faso were assessed using nine agro-morphological traits and twelve SSR markers. The importance of phenotypic intra-varietal diversity in early, intermediate and late maturing varieties varied in relation to the observed trait. The genetic analysis specified that the highest diversity rates were in the late maturing varieties (3.3 for allelic richness and 0.47 for gene diversity). Factorial Discriminant Analysis on quantitative traits and cluster analysis based on SSR markers showed that early maturing varieties were discriminated from late and intermediate ones, confirming farmers' classification of maturity groups (MG). Multivariate Q ST and F ST values revealed two subgroups of quantitative traits that underwent either stabilizing or divergent selection among MG scale. These results underline the role of farmer practices in phenotypic and genetic evolution of sorghum. This concept should be well considered in sorghum breeding programs.

The realization of mechanized zaï with draft animal encounters the weakness of hitch traction capabilities. To overcome this issue, a study was conducted in three villages in the northern Burkina Faso with the aim at evaluating the effect of improved yoke and improved collar respectively with oxen and donkey harnessing on the traction force delivered. The experimental design was a simple randomized bloc comparing improved yoke to classic yoke and improved collar to classic collar. The results showed that the improved yoke allows oxen harness to get 57% more traction force compared with the harness of classic yoke which was 53 daN (P < 0.0001). For the donkey harness there was no statistical difference between the improved collar and the classic one (24 daN and 23 daN). Tillage quality was better with the improved yoke and generates more soil roughness index. This led to increase in sorghum grain yield by 60% (694 kg.ha -1 ) and sorghum straw yield increase by 91% (2688 kg.ha -1 ). The improved yoke increases oxen traction force, dry soil tillage efficiency and sorghum production. These results showed that improved yoke can contribute to an increase in sorghum yield in the northern Burkina Faso.

Local sorghum varieties managed and cultivated by farmers contribute in a large part in crop production of Burkina Faso. The loss of local sorghum varieties were reported, but very few investigations have been made on it. This study was conducted to assess the status of 739 local sorghum varieties collected in four regions of Burkina Faso and to identify the threats factors of sorghum diversity. A sample of 159 varieties identified as "rare" and described by the cycle length, the uses and disadvantageous characteristics has been submitted to a Multiple Correspondence Analysis (MCA) to determine sorghums groups and characterize them. The results showed a higher varietal richness in the North, East and Centre-East regions compared to the SouthWest region, with respectively 13.0; 11.7; 10.9 and 6.1 varieties per village. The MCA underlined four main groups of sorghum: custom sorghums, lain period sorghums and tincture sorghums, pharmacopeia sorghums and sweet-stem sorghums; they are characterized by lateness associated to the low grain productivity, earliness associated to the low grain quality, drought sensitivity. For these sorghums groups it appears that the climatic and socio-cultural changes are the main threats factors of sorghum diversity loss. Farmers' associations at regional level and research structures should in common develop suitable initiatives to follow-up and conserve sorghum diversity.

(1) Background: Sorghum (Sorghum bicolor (L.) Moench) is a staple food cereal for most of the rural populations in sub-Saharan Africa. In Burkina Faso, a great diversity of sorghum cultivar is cultivated, but its nutritional potential still needs to be assessed. This study aims to characterize the physicochemical and nutritional profile of grains from 15 sorghum cultivars grown in Burkina Faso in order to identify the best ones for selection and breeding programs. (2) Methods: The physicochemical, nutritional, and antioxidant-activity characterizations of the grains were performed according to standard methods. (3) Results: The study shows significant differences between cultivars according to the physicochemical traits of the grains, such as 1000-grain weight, moisture, and germination rate. For nutritional parameters, the best contents of carbohydrates (79.36%), proteins (9.21%), and fats (4.40%) were recorded with cultivars V12, V8, and V11, respectively. The heavy grains are flouriest with high contents of carbohydrates with high ABTS antiradical activity. However, these grains have low contents of proteins and flavonoids. Those with high ash contents are the richest in amylose and phenolic compounds. Principal component analysis based on physicochemical and nutritional characteristics of sorghum grains identified four groups of varieties with specific characteristics. Group 1 (G1), which includes cultivars V1, V12, V13, V14, and V15, is characterized by a high weight of 1000 grains and mealy cultivars with relatively high total carbohydrate content and ABTS.+ antiradical activity. Group 2 (G2) includes cultivars V7, V9, and V11 and is characterized by cultivars with low 1000-grain weight, less floury but good germination rate, high protein, flavonoids, and relatively high antioxidant activity. Group 3 (G3) includes cultivars V3, V4, and V8 with relatively high ash, amylose, and polyphenol contents, while group 4 (G4), which includes cultivars V2 and V6, has high antioxidant activity and high fatty acid content. Conclusions: The study recorded a variation of physicochemical and nutritional characteristics of sorghum grain according to cultivars. The cultivars were divided into four groups. Among them, the group 1 cultivars have the best nutritional traits and could therefore be used in breeding and selection programs to improve the nutritional potential of sorghum.