Analyses multivariées de descendances de rétrocroisements et mise en évidence de distorsions de ségrégation de caractères quantitatifs chez le mil (Pennisetum typhoides (Burm.) Stapf et Hubb.)
Evidence for self-pollination predominance and pollen competition was derived from certain genotypes of pearl millet (Pennisetum typhoides). In the present study, the impact of such phenomena was analyzed, using F2 and backcross lineages resulting from crosses between two millet lines, namely Ligui and Massue. Four backcross families were involved: BC1a (Ligui ♂ × F1), BC1b (F1 ♂ × Ligui), BC2a (Massue ♂ × F1), BC2b (F1 ♂ × Massue). Concatenating the multivariate analysis methods allowed the division of each family into subgroups of affinities. This procedure resulted in disclosing a distortion of the global segregation in favor of the Ligui parent. To explain such distortions, a model including gametic and gametophytic selections is proposed. Besides the utilized statistical methodology, which might prove very effective in sorting out backcross lineages early in selection programs, implications of character differential transmission at the level of population genetic structure are discussed.Key words: Pennisetum typhoides, intergametophytic competitions, segregation distortion.