Title : Genetic diversity of Hibiscus sabdariffa collected in some countries of the Central African sub-region
Roselle (Hibiscus sabdariffa) is a Malvaceae with multiple economic and pharmacological potential, little or poorly known and under-exploited in Cameroon. The aim of this study was to assess the genetic diversity of 36 collections from several countries in the Central African sub-region, in a two-repeat Alpha lattice (6x6) set-up at the University of Yaoundé I. Results obtained from the analysis of 20 traits, including 13 qualitative and 7 quantitative, showed significant differences (P<0.0001) between collections at 60 days after sowing. Mean heights to the first branch ranged from 2.62 to 14.70 cm, with plant heights ranging from 10.5 to 86 cm. Mean collar diameter values ranged from 0.40 to 1.36 cm. Hierarchical ascending classification was used to classify the different collections into groups of 10, 12 and 14 collections each. However, no differences were observed between origins for any of the parameters studied. Diameter at collar was strongly and positively correlated with number of branches (r= 0.8). The same is true of the 50% flowering date and the date of flower bud initiation (r= 0.6) and flowering (r= 0.8). On the other hand, thanks to their high heritability, growth parameters such as collar diameter (0.6143), number of branches (0.6363), plant height (0.7240) and height of first branch (0.7653) revealed great potential for selection and genetic improvement.
Keywords: Agromorphological characterization, Genetic variability, Collections, Hibiscus sabdariffa, Central Africa.