Erica Lombardi1,2, Tatiana A Shestakova3, Filippo Santini1,2, Víctor Resco de Dios1,2, Jordi Voltas1,2. 1. Joint Research Unit CTFC - AGROTECNIO - CERCA, Av. Alcalde Rovira Roure 191, Lleida E-25198, Spain. 2. Departament of Crop and Forest Sciences, University of Lleida, Av. Alcalde Rovira Roure 191, Lleida E-25198, Spain. 3. Woodwell Climate Research Center, 149 Woods Hole Road, Falmouth, MA 02540, USA.
Abstract
BACKGROUND AND AIMS: Understanding the genetic basis of adaptation and plasticity in trees constitutes a knowledge gap. We linked dendrochronology and genomics [single nucleotide polymorphisms (SNPs)] for a widespread conifer (Pinus halepensis Mill.) to characterize intraspecific growth differences elicited by climate. METHODS: The analysis comprised 20-year tree-ring series of 130 trees structured in 23 populations evaluated in a common garden. We tested for genotype by environment interactions (G × E) of indexed ring width (RWI) and early- to latewood ratios (ELI) using factorial regression, which describes G × E as differential gene sensitivity to climate. KEY RESULTS: The species' annual growth was positively influenced by winter temperature and spring moisture and negatively influenced by previous autumn precipitation and warm springs. Four and five climate factors explained 10 % (RWI) and 16 % (ELI) of population-specific interannual variability, respectively, with populations from drought-prone areas and with uneven precipitation experiencing larger growth reductions during dry vegetative periods. Furthermore, four and two SNPs explained 14 % (RWI) and 10 % (ELI) of interannual variability among trees, respectively. Two SNPs played a putative role in adaptation to climate: one identified from transcriptome sequencing of P. halepensis and another involved in response regulation to environmental stressors. CONCLUSIONS: We highlight how tree-ring phenotypes, obtained from a common garden experiment, combined with a candidate-gene approach allow the quantification of genetic and environmental effects determining adaptation for a conifer with a large and complex genome.
BACKGROUND AND AIMS: Understanding the genetic basis of adaptation and plasticity in trees constitutes a knowledge gap. We linked dendrochronology and genomics [single nucleotide polymorphisms (SNPs)] for a widespread conifer (Pinus halepensis Mill.) to characterize intraspecific growth differences elicited by climate. METHODS: The analysis comprised 20-year tree-ring series of 130 trees structured in 23 populations evaluated in a common garden. We tested for genotype by environment interactions (G × E) of indexed ring width (RWI) and early- to latewood ratios (ELI) using factorial regression, which describes G × E as differential gene sensitivity to climate. KEY RESULTS: The species' annual growth was positively influenced by winter temperature and spring moisture and negatively influenced by previous autumn precipitation and warm springs. Four and five climate factors explained 10 % (RWI) and 16 % (ELI) of population-specific interannual variability, respectively, with populations from drought-prone areas and with uneven precipitation experiencing larger growth reductions during dry vegetative periods. Furthermore, four and two SNPs explained 14 % (RWI) and 10 % (ELI) of interannual variability among trees, respectively. Two SNPs played a putative role in adaptation to climate: one identified from transcriptome sequencing of P. halepensis and another involved in response regulation to environmental stressors. CONCLUSIONS: We highlight how tree-ring phenotypes, obtained from a common garden experiment, combined with a candidate-gene approach allow the quantification of genetic and environmental effects determining adaptation for a conifer with a large and complex genome.
Authors: Yue Rui; Chaowen Xiao; Hojae Yi; Baris Kandemir; James Z Wang; Virendra M Puri; Charles T Anderson Journal: Plant Cell Date: 2017-10-03 Impact factor: 11.277