Mechanisms of adaptation to climate variability in West African pearl millet landraces – a preliminary

Haussmann, B I G and Boureima, S S and Kassari, I A and Moumouni, K H and Boubacar, A (2007) Mechanisms of adaptation to climate variability in West African pearl millet landraces – a preliminary. Journal of SAT Agricultural Research, 3 (1). pp. 1-3.

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Abstract

Landraces are generally expected to possess specific mechanisms of adaptation to their growing environments. In West and Central Africa (WCA), growing conditions of pearl millet (Pennisetum glaucum) are characterized, among other hazards, by highly variable beginnings and endings of the rainy season, and unpredictable drought stress at any time during the growing season. Adaptation to such unpredictable variable environment can be due to individual and/or populational buffering (Allard and Bradshaw 1964), two mechanisms initially defined by Lerner (1954) as developmental and genetic homeostasis. Individual buffering may be favored by phenotypic plasticity. Photoperiod-sensitive flowering is an example of phenotypic plasticity that can enhance adaptation to variable planting dates followed due to a scattered beginning of the rainy season in a region, as typical for WCA. It enhances simultaneous flowering of the cultivar in the target region, independent of the individual date of planting in different fields. This has particular advantages in terms of reducing bird damage and insect pressure; prolonging vegetative development in case of early planting but accelerating development in case of late planting; therefore fitting plant development to available rainfall patterns and resulting potentially in increased yielding stability. Populational buffering can be promoted by genetic heterogeneity in plant stand as different genotypes present in the population are specifically adapted to different environmental conditions (Bradshaw 1965). An example is intra-varietal variation for flowering time, which would assure that in case of a dry spell, not all plants in the field will be affected by drought in their most sensitive flowering stage.

Item Type: Article
Divisions: UNSPECIFIED
CRP: UNSPECIFIED
Subjects: Mandate crops > Millets
Depositing User: Library ICRISAT
Date Deposited: 15 Oct 2011 15:22
Last Modified: 14 Sep 2013 12:07
URI: http://oar.icrisat.org/id/eprint/2624
Official URL:
Projects: UNSPECIFIED
Funders: Federal Ministry for Economic Cooperation and Development, Germany, International Fund for Agricultural Development
Acknowledgement: The authors thank A Abarchi, A Amadou, D Lankoande and H Garba for their excellent technical assistance. This study was funded by the Federal Ministry for Economic Cooperation and Development, Germany (photoperiodism trial), the International Fund for Agricultural Development (IFAD) and ICRISAT Core (FSF trials).
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