Diversity of leaf traits related to productivity in 31 Populus deltoides x Populus nigra clones

Abstract

To test if some leaf parameters are predictors of productivity in a range of Populus deltoides (Bartr.) Marsh. x P. nigra L. clones, we assessed leaf traits and productivity in 2-month-old rooted cuttings from 31 clones growing in 4-l pots in a greenhouse, under conditions of controlled temperature and optimal irrigation. We evaluated four groups of variables describing (1) productivity (total biomass), (2) leaf growth (total leaf number increment and total leaf area increment rate), (3) leaf structure (specific leaf area and nitrogen and carbon contents) and (4) carbon isotope discrimination (delta), which is negatively correlated with time-integrated water-use efficiency. High-yielding clones did not necessarily display high leaf growth rates, but they displayed a larger total leaf area, lower specific leaf area and lower leaf nitrogen concentration than clones with low productivity. Total leaf area was mainly controlled by maximal individual leaf area and total leaf area increment rate (r = 0.51 and 0.56, respectively). Carbon isotope discrimination did not correlate with total biomass, but it was associated with total number of leaves and total leaf area increment rate (r = 0.39 and 0.45, respectively). Therefore, leaf area and specific leaf area were better indicators of productivity than leaf growth traits. The observed independence of delta from biomass production provides opportunities for selecting poplar clones combining high productivity and high water-use efficiency.

DNA methylation and histone acetylation: genotypic variations in hybrid poplars, impact of water deficit and relationships with productivity

“…Genotypes differed for morphological traits as already reported in previous studies (Bonhomme et al, 2008;Marron et al, 2005;Monclus et al, 2006). In response to water deficit a general decrease of most of these morphological traits was recorded.…”

“…Indeed, previous results show that in response to longer and stronger droughts poplars (and particularly those of this study) are differentially sensitive to water deficit (Marron et fine physiological differences, not easily revealed in short term experiments. Possibly for similar reasons specific leaf area was not affected, either (Marron et al, 2005;Monclus et al, 2006).…”

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.…”

Variation génétique de la productivité, de caractères foliaires et de la discrimination isotopique vis-à-vis du carbone chez des hybrides de peuplier cultivés sur des sites contrastés

“…SLA displayed a greater variability and higher values in the glasshouse (190 < SLA (cm 2 g −1 DW ) < 235; Marron et al, 2005) than in the nursery (104.4 < SLA (cm 2 g −1 DW ) < 126.3) or in the poplar plantation (90.3 < SLA 2005 (cm 2 g −1 DW ) < 121.3). In all experiments, the productivity index did not correlate with Δ measured from bulk leaf dry matter.…”

“…A detailed study with several commercial poplar genotypes (DN hybrids) grown as young cuttings in glasshouse (3-month-old rooted cuttings; Marron et al, 2005) or in a nursery (1 to 4-year-old rooted cuttings coppiced each year; Monclus et al, 2005; indicated consistent genotypic differences in W i , and a lack of correlation between W i and productivity. The stability of these observations remains to be established under a wider range of environmental conditions and with older trees, as some juvenility effects might interfere with the observed ranking.…”