Toward improved drought tolerance in bioenergy crops: QTL for carbon isotope composition and stomatal conductance in Populus

Food and Energy Security

Maud Viger¹  Maricela Rodriguez-Acosta¹  Anne M. Rae¹  James I. L. Morison² 

[1] Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton, United Kingdom;Centre for Forestry and Climate Change, Forest Research, Farnham, Surrey, United Kingdom

关键词: Carbon isotope composition;    Populus;    QTL;    stomatal conductance;    WUE;   

DOI  :  10.1002/fes3.39

来源: Wiley

【 摘 要 】

Abstract

Dedicated non-food bioenergy crops like poplar are needed as sustainable, low-input feedstocks for renewable energy in a future drier climate, where they can be grown on marginal soils. Such plants should have a low water, carbon, and chemical footprint. Capturing natural variation in traits associated with water use efficiency (WUE) is the first step to developing trees that require less water and may be adapted to drier environments. We have assessed stomatal conductance (g_s) and leaf carbon isotope composition (δ¹³C, an indirect indicator of leaf WUE) in two Populus species, P. deltoides and P. trichocarpa and their F₂ progeny, grown in the United Kingdom and in Italy. Populus deltoides leaves showed lower δ¹³C than P. trichocarpa, suggesting a higher WUE in P. trichocarpa, although without drought preconditioning, g_s of P. trichocarpa was less responsive to dehydration and abscisic acid treatment than P. deltoides, suggesting that leaf anatomy may also contribute to δ¹³C in Populus. Quantitative trait loci (QTL) were identified for δ¹³C on eight linkage groups (LG) and two QTL for g_s. From these. QTL and differential gene expression in response to drought from microarray data, we focused on three hotspots and identified 23 novel candidate genes on LG VI, X, and XVI. We have begun to unravel the genetic basis of WUE in bioenergy Populus revealing important underpinning data for breeding and improvement in poplar genotypes for a future drier climate.

【 授权许可】

CC BY   
© 2013 The Authors. Food and Energy Security published by John Wiley & Sons Ltd. and the Association of Applied Biologists.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.