Role of seed flow on the pattern and dynamics of pearl millet (Pennisetum glaucum [L.] R. Br.) genetic diversity assessed by AFLP markers: a study in south-western Niger.
We studied the regional genetic diversity and seed exchange dynamics of pearl millet landraces in south-western Niger. The genetic study was based on AFLP markers. We found significant genetic differentiation between landraces in different geographical areas of south-western Niger. However, the degree of differentiation was low insofar as only 1.9% of the total molecular diversity was due to regional differentiation, suggesting a relatively high gene flow. Anthropologic studies on farming practices have suggested that seed exchanges between farmers on a large geographical scale probably make a considerable contribution to this result. In order to test this hypothesis, the effects of seed exchange on the genetic diversity of landraces was analyzed on seed samples from two distant villages in contrasting areas of south-western Niger. Seeds imported by farmers into the southern village of Sina Koara did not differ significantly from locally grown landraces. By contrast, in the northern village of Alzou, several samples were genetically different from locally grown landraces and closer to southern accessions. These data suggest that the seed flow is preferentially from south to north, i.e. from an area with more favorable rainfall conditions. The potential consequences for the genetic diversity and adaptation of northern pearl millet landraces are discussed.
Allinne
Clementine
C
Laboratoire Evolution et Systématique, UPRESA 8079, bat. 362, Université Paris-Sud, Orsay Cedex, 91405, France. cedric.mariac@mpl.ird.fr
Mariac
Cédric
C
Vigouroux
Yves
Y
Bezançon
Gilles
G
Couturon
Emmanuel
E
Moussa
Djibo
D
Tidjani
Moussa
M
Pham
Jean-Louis
JL
Robert
Thierry
T
D000383:Agriculture / Q000379:methods; D003132:Commerce; D051456:Gene Flow / Q000502:physiology*; D005819:Genetic Markers; D014644:Genetic Variation; D005828:Genetics, Population; D009548:Niger; D021141:Nucleic Acid Amplification Techniques; D031782:Pennisetum / Q000235:genetics* / Q000502:physiology; D010802:Phylogeny; D012639:Seeds / Q000235:genetics / Q000502:physiology*