Evolutionary dynamics of cycle length in pearl millet: the role of farmer's practices and gene flow.
In the Sahel of Africa, farmers often modify their cultivation practices to adapt to environmental changes. How these changes shape the agro-biodiversity is a question of primary interest for the conservation of plant genetic resources. We addressed this question in a case study on pearl millet in south western Niger where farmers used to cultivate landraces with different cycle length in order to cope with rain uncertainty. Early and late landraces were previously grown on distant fields. Nowadays, mostly because of human population pressure and soil impoverishment, it happens that the two types of landraces are grown on adjacent fields, opening the question whether gene flow between them may occur. This question was tackled through a comparative study among contrasting situations pertaining to the spatial distribution of early and late landraces. Observations of flowering periods showed that pollen flow between the two landraces is possible and has a preferential direction from early to late populations.
Laboratoire Systématique et Evolution, UMR 8079, Université Paris-Sud, Orsay cedex, France. ghayas.lakis@u-psud.fr
Ghayas
G
Lakis
Athman Maï
AM
Ousmane
Douka
D
Sanoussi
Abdoulaye
A
Habibou
Mahamane
M
Badamassi
Françoise
F
Lamy
Naino
N
Jika
Ramatou
R
Sidikou
Toudou
T
Adam
Aboubakry
A
Sarr
Anne
A
Luxereau
Thierry
T
Robert
D000383:Agriculture; D019143:Evolution, Molecular; D051456:Gene Flow; D018895:Microsatellite Repeats; D031782:Pennisetum / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D011157:Population Dynamics