Évaluation de la diversité génétique des sorghos à grains sucrés ( Sorghum bicolor (L.) Moench) du Nord du Burkina Faso

Fruits is a scientific journal for original articles and reviews on fruit crops in temperate, Mediterranean, subtropical and tropical regions

Sweet sorghum is mainly cultivated for the sweetness of its stems and the quality of its fodder. Unfortunately, its cultivation is gradually being abandoned in Burkina Faso due to climatic hazards. In a general context of strong variations in the rainfall regime, it is, therefore, important to determine the effect of the sowing period on the expression of agromorphological traits and Brix content. Thus, 29 sweet sorghum accessions were evaluated using 15 quantitative variables in a three-replicate Fisher block design with two sowing dates spaced 25days apart. The results of the study showed that only stalk length (pr.=0.519) and internode length (pr.=0.367) were not significantly influenced by sowing date. Indeed, delayed sowing resulted in an increase in the number of vegetative (+2.44) and useful (+1.3) tillers, as well as Brix (+1.16). However, a reduction in leaf area (4.35cm×1.43cm), plant height (85.69cm), panicle length (2.63cm), and panicle weight (6.19g), as well as a reduction in the sowing-to-flowering cycle from 3 to 21 days, was obtained at the second sowing date. Thus, all accessions are sensitive to photoperiod with photoperiodic coefficients varying from 0.19 (GB02) to 0.93 (BSA5). These results could be exploited in the sweet sorghum improvement program.

Sweet grain sorghum [Sorghum bicolor (L.) Moench] is an under-harvested crop produced mainly for its sweet grains in the pasty stage. Little is known of its genetic diversity remains. This study aims to determine the level and structure of the genetic diversity of sweet grain sorghum from Burkina Faso. Thus, 93 accessions were evaluated using 15 polymorphic microsatellite markers. The analysis revealed 49 alleles in total, 6 rare alleles, an average of 3 alleles per locus, a moderate Nei diversity of 0.474, a low level of heterozygosity (0.031) in the collection and very high Wright's fixation index (Fis) of 0.934. The accessions were organized into three genetic groups: A, B and C. Groups A and B were the farthest, with an Fst and a genetic distance of 0.37 and 0.22, respectively, whereas Groups B and C were the closest, with an Fst (genetic differentiation) of 0.279 and a genetic distance of 0.142. This diversity could be exploited in Burkina Faso sweet grain sorghum breeding programs. Key words: Burkina Faso, neglected culture, sorghum, simple sequence repeats (SSR) markers, genetic variability.

The eggplant (Solanum aethiopicum) is the species of the Solanum genus, whose geographical distribution is broadest. It is grown throughout tropical Africa, and includes three groups of cultivars commonly called African or indigenous eggplant. Kumba group or “bitter eggplant” is an important Solanaceous vegetable crop in Burkina Faso. The objective of this study was to determine genetic variability, strength of association and level of heritability among agronomic interest traits. Phenotypic and genotypic variations and heritability of 14 traits were estimated in 61 accessions at Institut de Développement Rural (IDR), Gampela in Burkina Faso. High phenotypic and genotypic coefficients of variation were observed for fruit diameter, number of seeds per fruit, fruit weight, leaf blade length and width, and height at flowering. In addition, genetic and phenotypic variances were high for the number of seed, fruit weight, plant height at flowering and days to 50% flowering. High heritability estimates were recorded for all traits. Fruit weight showed a positive association with fruit diameter and thickness. The fifty percent flowering cycle registered positive correlations with plant height and fruit diameter. Fruit number showed a negative association with fruit weight and diameter, and 50% flowering cyle. Key Words: Agromorphological, bitter eggplant, Burkina Faso