Morpho-physiological traits conferring drought adaptation among cotton genotypes in Cameroon
Jun 16, 2019
Breeding & Genetic improvement Climate change Network coordination Network-MedMiddleEast Climate-WestCentralAfrica Breeding-WestCentralAfrica
CIRAD – France
In Cameroon, water shortage is the major abiotic factor limiting cotton (Gossypiumhirsutum L) yield and lint quality. Understanding cotton physiological responses to water supply and their consequences on growth and development therefore provides insight into the problem of yield stagnation. The underlying strategies for yield maintenance under water deficit in Cameroon have not been well understood. The objective of this paper is to evaluate which ecophysiological traits could confer a good response to drought among a panel of cotton genotypes used in Cameroon. These genotypes were compared in field and greenhouse trials under potential and water-limited conditions (fraction of soil transpirable water range: 0.39 to 0.83). Water deﬁcit had a negative impact on almost all the plant functions, both under field and controlled environments. The recent cultivar L484 bred for the driest production area responded quite differently from the other cultivars in this study. L484 had the fastest development, thickest leaves with the most chlorophyll and thus maintained the highest level of photosynthesis and transpiration per unit of leaf area in water-limited conditions. In these conditions, L484 had the highest radiation use eﬃciency and water use efficiency maintenances. However, despite the advances in cotton breeding in Cameroon, no significant improvement between old cultivars and recently released ones were found on biomass, harvest index and cotton yield across water conditions. The lint percentage was the only yield component significantly enhanced, irrespective of water status.
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