Productivity, water-use efficiency and tolerance to moderate water deficit correlate in 33 poplar genotypes from a Populus deltoides x Populus trichocarpa F1 progeny

Abstract

Genotypic variability for productivity, water-use efficiency and leaf traits in 33 genotypes selected from an F1 progeny of Populus deltoides Bartr. ex Marsh x Populus trichocarpa L. was explored under optimal and moderate water-deficit conditions. Saplings of the 33 genotypes were grown in a two-plot open field at INRA Orléans (France) and coppiced every year. A moderate water deficit was induced during two successive years on one plot by withholding irrigation, while the second one remained irrigated (control). Stem biomass and leaf structure (e.g., specific leaf area and leaf area) were measured in 2004 and 2005 and functional leaf traits (e.g., carbon isotope discrimination, Delta) were measured only in 2004. Tolerance to water deficit was estimated at genotype level as the ability to limit losses in biomass production in water deficit versus control trees. Stem biomass, leaf structure and Delta displayed a significant genotypic variability whatever the irrigation regime. For all traits, genotype ranks remained stable across years for similar irrigation conditions. Carbon isotope discrimination scaled negatively with productivity and leaf nitrogen content in controls. The most productive genotypes were the least tolerant to moderate water deficit. No relationship was evidenced between Delta and the level of tolerance to water deficit. The relationships between traits evidenced in this collection of P. deltoides x P. trichocarpa F1 genotypes contrast with the ones that were previously detected in a collection of P. deltoides x Populus nigra L. cultivars tested in the same field trial.

Performance of hybrid poplar clones in short rotation coppice in Mediterranean environments: analysis of genotypic stability

“…The average difference in biomass between extreme clones was substantial (about 2.5-fold). Such large variability is documented elsewhere, both at interspecific and intraspecific levels (Monclus et al, 2009), hence reflecting the wide genetic base of the genus (Stettler et al, 1996). Previous results also agree with the observed superiority of 'AF2' over 'Monviso', both clones being specifically bred for biomass although belonging to different taxonomic groups (Mareschi et al, 2005).…”

Genotypic variation in transpiration of coppiced poplar during the third rotation of a short‐rotation bio‐energy culture

“…Differences in WUE can be identified by differences in carbon isotope ratios in trees, and genotypes with high carbon isotope discrimination (Δ 13 C) have been usually related with higher biomass production and lower WUE (Farquhar, Ehleringer, & Hubick, 1989). However, the occurrence of a significant genotypic variability for productivity and for Δ 13 C (used as a proxy of WUE) in poplars and other tree species has been demonstrated, including a negative relationship between biomass and Δ 13 C (Cassasoli et al., 2004; Guehl, Nguyen‐Queyrens, Loustau, & Ferhi, 1994; Monclus et al., 2009; Zhang, Zang, & Li, 2004) or an opposite pattern (Marron et al., 2005; Rae, Robinson, Street, & Taylor, 2004). WUE in poplars is highly heritable (Monclus et al., 2005, 2006) and there is generally no trade‐off between WUE and productivity.…”

Scientific Basis for Sustainable Management of Eucalyptus and Populus as Short-Rotation Woody Crops in the U.S.

“…Investigators in Germany concluded that establishing Populus plantations on a large scale would reduce groundwater recharge [11]. Water use, water use efficiency, and drought resistance vary substantially among hybrid poplar clones [90][91][92], making clone selection an important strategy for minimizing impacts in areas where water is limiting.…”