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Title: Growth and physiological responses of isohydric and anisohydric poplars to drought

Understanding how different plants prioritize carbon gain and drought vulnerability under a variable water supply is important for predicting which trees will maximize woody biomass production under different environmental conditions. Here, Populus balsamifera (BS, isohydric genotype), P. simonii (SI, previously uncharacterized stomatal behaviour), and their cross, P. balsamifera x simonii (BSxSI, anisohydric genotype) were studied to assess the physiological basis for biomass accumulation and water-use efficiency across a range of water availabilities. Under ample water, whole plant stomatal conductance (g s), transpiration (E), and growth rates were higher in anisohydric genotypes (SI and BSxSI) than in isohydric poplars (BS). Under drought, all genotypes regulated the leaf to stem water potential gradient via changes in gs, synchronizing leaf hydraulic conductance (K leaf) and E: isohydric plants reduced K leaf, g s, and E, whereas anisohydric genotypes maintained high K leaf and E, which reduced both leaf and stem water potentials. Nevertheless, SI poplars reduced their plant hydraulic conductance (K plant) during water stress and, unlike, BSxSI plants, recovered rapidly from drought. Low gs of the isohydric BS under drought reduced CO 2 assimilation rates and biomass potential under moderate water stress. While anisohydric genotypes had the fastest growth under ample watermore » and higher photosynthetic rates under increasing water stress, isohydric poplars had higher water-use efficiency. Overall, the results indicate three strategies for how closely related biomass species deal with water stress: survival-isohydric (BS), sensitive-anisohydric (BSxSI), and resilience-anisohydric (SI). Lastly, we discuss implications for woody biomass growth, water-use efficiency, and survival under variable environmental conditions.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Hebrew Univ. of Jerusalem (Israel). Inst. of Plant Sciences and Genetics in Agriculture
  2. Bordeaux Sciences Agro UMR INRA-ISPA, Gradignan (France); North Carolina State Univ., Raleigh, NC (United States); Duke Univ., Durham, NC (United States)
  3. Duke Univ., Durham, NC (United States); Swedish University of Agricultural Sciences (SLU), Umea (Sweden)
  4. Duke Univ., Durham, NC (United States); Univ. of Western Ontario, London, ON (Canada)
  5. Hebrew Univ. of Jerusalem (Israel). Inst. of Plant Sciences and Genetics in Agricultur
Publication Date:
Grant/Contract Number:
SC0006967
Type:
Accepted Manuscript
Journal Name:
Journal of Experimental Botany
Additional Journal Information:
Journal Volume: 66; Journal Issue: 14; Journal ID: ISSN 0022-0957
Publisher:
Oxford University Press
Research Org:
Duke Univ., Durham, NC (United States)
Sponsoring Org:
USDOE; US–Israeli Bi-national Science Foundation; National Science Foundation (NSF); Natural Sciences and Engineering Research Council of Canada (NSERC); USDA
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 59 BASIC BIOLOGICAL SCIENCES; Bioenergy; biomass; carbon; hydraulic conductance; stomata; transpiration
OSTI Identifier:
1343100