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Hu Y, Guy RD, Soolanayakanahally RY. Genotypic variation in C and N isotope discrimination suggests local adaptation of heart-leaved willow. TREE PHYSIOLOGY 2022; 42:32-43. [PMID: 33517390 DOI: 10.1093/treephys/tpab010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 01/18/2021] [Indexed: 06/12/2023]
Abstract
Plants acquire multiple resources from the environment and may need to adjust and/or balance their respective resource-use efficiencies to maximize grow and survival, in a locally adaptive manner. In this study, tissue and whole-plant carbon (C) isotopic composition (δ13C) and carbon/nitrogen (C/N) ratios provided long-term measures of use efficiencies for water (WUE) and nitrogen (NUE), and a nitrogen (N) isotopic composition (δ15N)-based mass balance model was used to estimate traits related to N uptake and assimilation in heart-leaved willow (Salix eriocephala Michx.). In an initial common garden experiment consisting of 34 populations, we found population-level variation in δ13C, C/N ratio and δ15N, indicating different patterns in WUE, NUE and N uptake and assimilation. Although there was no relationship between foliar δ13C and C/N ratios among populations, there was a significant negative correlation between these measures across all individuals, implying a genetic and/or plastic trade-off between WUE and NUE not associated with local adaptation. To eliminate any environmental effect, we grew a subset of 21 genotypes hydroponically with nitrate as the sole N source and detected significant variation in δ13C, δ15N and C/N ratios. Variation in δ15N was mainly due to genotypic differences in the nitrate efflux/influx ratio (E/I) at the root. Both experiments suggested clinal variation in δ15N (and thus N uptake efficiency) with latitude of origin, which may relate to water availability and could contribute to global patterns in ecosystem δ15N. There was a tendency for genotypes with higher WUE to come from more water-replete sites with shorter and cooler growing seasons. We found that δ13C, C/N ratio and E/I were not inter-correlated, suggesting that the selection of growth, WUE, NUE and N uptake efficiency can occur without trade-off.
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Affiliation(s)
- Yi Hu
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Forest Sciences Centre, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
| | - Robert D Guy
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Forest Sciences Centre, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
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Paril JF, Balding DJ, Fournier-Level A. Optimizing sampling design and sequencing strategy for the genomic analysis of quantitative traits in natural populations. Mol Ecol Resour 2021; 22:137-152. [PMID: 34192415 DOI: 10.1111/1755-0998.13458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 05/02/2021] [Accepted: 06/25/2021] [Indexed: 11/27/2022]
Abstract
Mapping the genes underlying ecologically relevant traits in natural populations is fundamental to develop a molecular understanding of species adaptation. Current sequencing technologies enable the characterization of a species' genetic diversity across the landscape or even over its whole range. The relevant capture of the genetic diversity across the landscape is critical for a successful genetic mapping of traits and there are no clear guidelines on how to achieve an optimal sampling and which sequencing strategy to implement. Here we determine, through simulation, the sampling scheme that maximizes the power to map the genetic basis of a complex trait in an outbreeding species across an idealized landscape and draw genomic predictions for the trait, comparing individual and pool sequencing strategies. Our results show that quantitative trait locus detection power and prediction accuracy are higher when more populations over the landscape are sampled and this is more cost-effectively done with pool sequencing than with individual sequencing. Additionally, we recommend sampling populations from areas of high genetic diversity. As progress in sequencing enables the integration of trait-based functional ecology into landscape genomics studies, these findings will guide study designs allowing direct measures of genetic effects in natural populations across the environment.
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Affiliation(s)
- Jefferson F Paril
- School of Biosciences, The University of Melbourne, Parkville, Victoria, Australia
| | - David J Balding
- School of Biosciences, The University of Melbourne, Parkville, Victoria, Australia.,Melbourne Integrative Genomics, The University of Melbourne, Parkville, Victoria, Australia.,School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria, Australia
| | - Alexandre Fournier-Level
- School of Biosciences, The University of Melbourne, Parkville, Victoria, Australia.,Melbourne Integrative Genomics, The University of Melbourne, Parkville, Victoria, Australia
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Abstract
Phylogeography and landscape genetics have arisen within the past 30 y. Phylogeography is said to be the bridge between population genetics and systematics, and landscape genetics the bridge between landscape ecology and population genetics. Both fields can be considered as simply the amalgamation of classic biogeography with genetics and genomics; however, they differ in the temporal, spatial, and organismal scales addressed and the methodology used. I begin by briefly summarizing the history and purview of each field and suggest that, even though landscape genetics is a younger field (coined in 2003) than phylogeography (coined in 1987), early studies by Dobzhansky on the "microgeographic races" of Linanthus parryae in the Mojave Desert of California and Drosophila pseudoobscura across the western United States presaged the fields by over 40 y. Recent advances in theory, models, and methods have allowed researchers to better synthesize ecological and evolutionary processes in their quest to answer some of the most basic questions in biology. I highlight a few of these novel studies and emphasize three major areas ripe for investigation using spatially explicit genomic-scale data: the biogeography of speciation, lineage divergence and species delimitation, and understanding adaptation through time and space. Examples of areas in need of study are highlighted, and I end by advocating a union of phylogeography and landscape genetics under the more general field: biogeography.
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Du YP, Bi Y, Zhang MF, Yang FP, Jia GX, Zhang XH. Genome Size Diversity in Lilium (Liliaceae) Is Correlated with Karyotype and Environmental Traits. FRONTIERS IN PLANT SCIENCE 2017; 8:1303. [PMID: 28798759 PMCID: PMC5526928 DOI: 10.3389/fpls.2017.01303] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 07/11/2017] [Indexed: 05/25/2023]
Abstract
Genome size (GS) diversity is of fundamental biological importance. The occurrence of giant genomes in angiosperms is restricted to just a few lineages in the analyzed genome size of plant species so far. It is still an open question whether GS diversity is shaped by neutral or natural selection. The genus Lilium, with giant genomes, is phylogenetically and horticulturally important and is distributed throughout the northern hemisphere. GS diversity in Lilium and the underlying evolutionary mechanisms are poorly understood. We performed a comprehensive study involving phylogenetically independent analysis on 71 species to explore the diversity and evolution of GS and its correlation with karyological and environmental traits within Lilium (including Nomocharis). The strong phylogenetic signal detected for GS in the genus provides evidence consistent with that the repetitive DNA may be the primary contributors to the GS diversity, while the significant positive relationships detected between GS and the haploid chromosome length (HCL) provide insights into patterns of genome evolution. The relationships between GS and karyotypes indicate that ancestral karyotypes of Lilium are likely to have exhibited small genomes, low diversity in centromeric index (CVCI) values and relatively high relative variation in chromosome length (CVCL) values. Significant relationships identified between GS and annual temperature and between GS and annual precipitation suggest that adaptation to habitat strongly influences GS diversity. We conclude that GS in Lilium is shaped by both neutral (genetic drift) and adaptive evolution. These findings will have important consequences for understanding the evolution of giant plant genomes, and exploring the role of repetitive DNA fraction and chromosome changes in a plant group with large genomes and conservation of chromosome number.
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Affiliation(s)
- Yun-peng Du
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry SciencesBeijing, China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Engineering Technology Research Center of Functional FloricultureBeijing, China
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture and College of Landscape Architecture, Beijing Forestry UniversityBeijing, China
| | - Yu Bi
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry SciencesBeijing, China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Engineering Technology Research Center of Functional FloricultureBeijing, China
| | - Ming-fang Zhang
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry SciencesBeijing, China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Engineering Technology Research Center of Functional FloricultureBeijing, China
| | - Feng-ping Yang
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry SciencesBeijing, China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Engineering Technology Research Center of Functional FloricultureBeijing, China
| | - Gui-xia Jia
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture and College of Landscape Architecture, Beijing Forestry UniversityBeijing, China
| | - Xiu-hai Zhang
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry SciencesBeijing, China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Engineering Technology Research Center of Functional FloricultureBeijing, China
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Limborg MT, Seeb LW, Seeb JE. Sorting duplicated loci disentangles complexities of polyploid genomes masked by genotyping by sequencing. Mol Ecol 2016; 25:2117-29. [PMID: 26939067 DOI: 10.1111/mec.13601] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 02/19/2016] [Accepted: 02/24/2016] [Indexed: 01/04/2023]
Abstract
Many plants and animals of polyploid origin are currently enjoying a genomics explosion enabled by modern sequencing and genotyping technologies. However, routine filtering of duplicated loci in most studies using genotyping by sequencing introduces an unacceptable, but often overlooked, bias when detecting selection. Retained duplicates from ancient whole-genome duplications (WGDs) may be found throughout genomes, whereas retained duplicates from recent WGDs are concentrated at distal ends of some chromosome arms. Additionally, segmental duplicates can be found at distal ends or nearly anywhere in a genome. Evidence shows that these duplications facilitate adaptation through one of two pathways: neo-functionalization or increased gene expression. Filtering duplicates removes distal ends of some chromosomes, and distal ends are especially known to harbour adaptively important genes. Thus, filtering of duplicated loci impoverishes the interpretation of genomic data as signals from contiguous duplicated genes are ignored. We review existing strategies to genotype and map duplicated loci; we focus in detail on an overlooked strategy of using gynogenetic haploids (1N) as a part of new genotyping by sequencing studies. We provide guidelines on how to use this haploid strategy for studies on polyploid-origin vertebrates including how it can be used to screen duplicated loci in natural populations. We conclude by discussing areas of research that will benefit from better inclusion of polyploid loci; we particularly stress the sometimes overlooked fact that basing genomic studies on dense maps provides value added in the form of locating and annotating outlier loci or colocating outliers into islands of divergence.
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Affiliation(s)
- Morten T Limborg
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Box 355020, Seattle, WA, 98195, USA.,National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600 Silkeborg, Denmark
| | - Lisa W Seeb
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Box 355020, Seattle, WA, 98195, USA
| | - James E Seeb
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Box 355020, Seattle, WA, 98195, USA
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McKown AD, Guy RD, Klápště J, Geraldes A, Friedmann M, Cronk QCB, El-Kassaby YA, Mansfield SD, Douglas CJ. Geographical and environmental gradients shape phenotypic trait variation and genetic structure in Populus trichocarpa. THE NEW PHYTOLOGIST 2014; 201:1263-1276. [PMID: 24491114 DOI: 10.1111/nph.12601] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 10/09/2013] [Indexed: 05/18/2023]
Abstract
• Populus trichocarpa is widespread across western North America spanning extensive variation in photoperiod, growing season and climate. We investigated trait variation in P. trichocarpa using over 2000 trees from a common garden at Vancouver, Canada, representing replicate plantings of 461 genotypes originating from 136 provenance localities. • We measured 40 traits encompassing phenological events, biomass accumulation, growth rates, and leaf, isotope and gas exchange-based ecophysiology traits. With replicated plantings and 29,354 single nucleotide polymorphisms (SNPs) from 3518 genes, we estimated both broad-sense trait heritability (H(2)) and overall population genetic structure from principal component analysis. • Populus trichocarpa had high phenotypic variation and moderate/high H(2) for many traits. H(2) ranged from 0.3 to 0.9 in phenology, 0.3 to 0.8 in biomass and 0.1 to 0.8 in ecophysiology traits. Most traits correlated strongly with latitude, maximum daylength and temperature of tree origin, but not necessarily with elevation, precipitation or heat : moisture indices. Trait H(2) values reflected trait correlation strength with geoclimate variables. The population genetic structure had one significant principal component (PC1) which correlated with daylength and showed enrichment for genes relating to circadian rhythm and photoperiod. • Robust relationships between traits, population structure and geoclimate in P. trichocarpa reflect patterns which suggest that range-wide geographical and environment gradients have shaped its genotypic and phenotypic variability.
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Affiliation(s)
- Athena D McKown
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Forest Sciences Centre, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Robert D Guy
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Forest Sciences Centre, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Jaroslav Klápště
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Forest Sciences Centre, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
- Department of Dendrology and Forest Tree Breeding, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, 165 21, Czech Republic
| | - Armando Geraldes
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Michael Friedmann
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Quentin C B Cronk
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Yousry A El-Kassaby
- Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Forest Sciences Centre, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Shawn D Mansfield
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Forest Sciences Centre, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Carl J Douglas
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
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