Impact of Drought on Productivity and Water Use Efficiency in 29 Genotypes of Populus deltoides x Populus nigra

• Published in: The New phytologist Vol. 169; no. 4; pp. 765 - 777
• Main Authors: Monclus, Romain, Dreyer, Erwin, Villar, Marc, Delmotte, Francis M., Delay, Didier, Petit, Jean-Michel, Barbaroux, Cécile, Le Thiec, Didier, Bréchet, Claude, Brignolas, Franck
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Science 01.01.2006; Blackwell; Wiley
• Subjects: Adaptation to environment and cultivation conditions; Agronomy. Soil science and plant productions; Biological and medical sciences; Biomass; Biomass production; Carbon - metabolism; Carbon dioxide; Carbon isotopes; Crosses, Genetic; Deficit irrigation; Dehydration; Drought; Drought tolerance; Fundamental and applied biological sciences. Psychology; Genetic Variation; Genetics and breeding of economic plants; Genotype; Genotypes; Leaf area; Life Sciences; Nitrogen - metabolism; Photosynthesis; Phytopathology and phytopharmacy; Plant Leaves - anatomy & histology; Plant Leaves - growth & development; Plant Leaves - metabolism; Populus; Populus - genetics; Populus - growth & development; Populus - metabolism; Populus deltoides; Populus nigra; Productivity; Stomatal conductance; Varietal selection. Specialized plant breeding, plant breeding aims; Vegetal Biology; Water - metabolism; Centre Region; France; Europe; Loiret; Productivity; hybrid poplars; Tolerance; Isotopic composition; Genetic diversity; Biomass; Water use efficiency; genotypic diversity; Carbon; Salicaceae; leaf traits; water use efficiency (WUE); carbon isotope discrimination (A); open field; Drought resistance; Dicotyledones; Angiospermae; drought tolerance; Hardwood forest tree; Spermatophyta; Populus canadensis; Drought; WATER USE EFFICIENCY; PEUPLIER NOIR; DIVERSITE GENOTYPIQUE; POPULUS DELTOIDE; CARACTERISTIQUE DE LA FEUILLE
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2005.01630.x

$\bullet$ We examined the relationships among productivity, water use efficiency (WUE) and drought tolerance in 29 genotypes of Populus x euramericana (Populus deltoides x Populus nigra), and investigated whether some leaf traits could be used as predictors for productivity, WUE and drought tolerance. $\bullet$ At $Orl\acute{e}ans$, France, drought was induced on one field plot by withholding water, while a second plot remained irrigated and was used as a control. Recorded variables included stem traits (e.g. biomass) and leaf structural (e.g. leaf area) and functional traits [e.g. intrinsic water use efficiency (Wi) and carbon isotope discrimination (Δ)]. $\bullet$ Productivity and Δ displayed large genotypic variability and were not correlated. Δ scaled negatively with Wi and positively with stomatal conductance under moderate drought, suggesting that the diversity for Δ was mainly driven by stomatal conductance. $\bullet$ Most of the productive genotypes displayed a low level of drought tolerance (i.e. a large reduction of biomass), while the less productive genotypes presented a large range of drought tolerance. The ability to increase WUE in response to water deficit was necessary but not sufficient to explain the genotypic diversity of drought tolerance.