TY - JOUR
T1 - Differences in heat tolerance, water use efficiency and growth among Douglas-fir families and varieties evidenced by GWAS and common garden studies
AU - Compton, Samuel
AU - Stackpole, Charles
AU - Dixit, Aalap
AU - Sekhwal, Manoj K.
AU - Kolb, Thomas
AU - De la Torre, Amanda R.
N1 - Funding Information:
This project was supported by the U.S. Department of Agriculture/National Institute of Food and Agriculture [McIntire Stennis project 1020440], by the National Science Foundation [CAREER project 2145834], and by new faculty start-up funds awarded to A.R.D.L.T. at NAU. The authors would like to thank Brad St.Clair (USFS) for providing the seeds for planting; Matthew Weiss and Valeria Ugarte for planting seeds; Adair Patterson for taking care of seedlings at the greenhouse; Amanda Fitzhugh for helping prepare samples for electrolytic leakage; and Amy Whipple and David Auty for allowing students to use some of the equipment in their research labs.
Publisher Copyright:
© The Author(s) 2023. Published by Oxford University Press on behalf of the Annals of Botany Company.
PY - 2023/2/1
Y1 - 2023/2/1
N2 - Severe and frequent heat and drought events challenge the survival and development of long-generation trees. In this study, we investigated the genomic basis of heat tolerance, water use efficiency and growth by performing genome-wide association studies in coastal Douglas-fir (Pseudotsuga menziesii) and intervarietal (menziesii × glauca) hybrid seedlings. GWAS results identified 32 candidate genes involved in primary and secondary metabolism, abiotic stress and signaling, among other functions. Water use efficiency (inferred from carbon isotope discrimination), photosynthetic capacity (inferred from %N), height and heat tolerance (inferred from electrolyte leakage in a heat stress experiment) were significantly different among Douglas-fir families and varieties. High-elevation seed sources had increased water use efficiency, which could be a result of higher photosynthetic capacity. Similarly, families with greater heat tolerance also had higher water use efficiency and slower growth, suggesting a conservative growth strategy. Intervarietal hybrids showed increased heat tolerance (lower electrolyte leakage at 50 and 55 °C) and higher water use efficiency compared with coastal families, suggesting that hybridization might be a source of pre-adapted alleles to warming climates and should be considered for large-scale reforestation projects under increasingly arid conditions.
AB - Severe and frequent heat and drought events challenge the survival and development of long-generation trees. In this study, we investigated the genomic basis of heat tolerance, water use efficiency and growth by performing genome-wide association studies in coastal Douglas-fir (Pseudotsuga menziesii) and intervarietal (menziesii × glauca) hybrid seedlings. GWAS results identified 32 candidate genes involved in primary and secondary metabolism, abiotic stress and signaling, among other functions. Water use efficiency (inferred from carbon isotope discrimination), photosynthetic capacity (inferred from %N), height and heat tolerance (inferred from electrolyte leakage in a heat stress experiment) were significantly different among Douglas-fir families and varieties. High-elevation seed sources had increased water use efficiency, which could be a result of higher photosynthetic capacity. Similarly, families with greater heat tolerance also had higher water use efficiency and slower growth, suggesting a conservative growth strategy. Intervarietal hybrids showed increased heat tolerance (lower electrolyte leakage at 50 and 55 °C) and higher water use efficiency compared with coastal families, suggesting that hybridization might be a source of pre-adapted alleles to warming climates and should be considered for large-scale reforestation projects under increasingly arid conditions.
KW - carbon isotope discrimination
KW - Douglas-fir
KW - electrolytic leakage
KW - GWAS
KW - heat tolerance
KW - hybridization
KW - Water use efficiency
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U2 - 10.1093/aobpla/plad008
DO - 10.1093/aobpla/plad008
M3 - Article
AN - SCOPUS:85160323490
SN - 2041-2851
VL - 15
JO - AoB PLANTS
JF - AoB PLANTS
IS - 2
M1 - plad008
ER -