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Feng S, Xi E, Wan W, Ru D. Genomic signals of local adaptation in Picea crassifolia. BMC PLANT BIOLOGY 2023; 23:534. [PMID: 37919677 PMCID: PMC10623705 DOI: 10.1186/s12870-023-04539-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 10/18/2023] [Indexed: 11/04/2023]
Abstract
BACKGROUND Global climate change poses a grave threat to biodiversity and underscores the importance of identifying the genes and corresponding environmental factors involved in the adaptation of tree species for the purposes of conservation and forestry. This holds particularly true for spruce species, given their pivotal role as key constituents of the montane, boreal, and sub-alpine forests in the Northern Hemisphere. RESULTS Here, we used transcriptomes, species occurrence records, and environmental data to investigate the spatial genetic distribution of and the climate-associated genetic variation in Picea crassifolia. Our comprehensive analysis employing ADMIXTURE, principal component analysis (PCA) and phylogenetic methodologies showed that the species has a complex population structure with obvious differentiation among populations in different regions. Concurrently, our investigations into isolation by distance (IBD), isolation by environment (IBE), and niche differentiation among populations collectively suggests that local adaptations are driven by environmental heterogeneity. By integrating population genomics and environmental data using redundancy analysis (RDA), we identified a set of climate-associated single-nucleotide polymorphisms (SNPs) and showed that environmental isolation had a more significant impact than geographic isolation in promoting genetic differentiation. We also found that the candidate genes associated with altitude, temperature seasonality (Bio4) and precipitation in the wettest month (Bio13) may be useful for forest tree breeding. CONCLUSIONS Our findings deepen our understanding of how species respond to climate change and highlight the importance of integrating genomic and environmental data in untangling local adaptations.
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Affiliation(s)
- Shuo Feng
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, 810016, People's Republic of China.
| | - Erning Xi
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, 810016, People's Republic of China
| | - Wei Wan
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, 810016, People's Republic of China
| | - Dafu Ru
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystem, College of Ecology, Lanzhou University, Lanzhou, 730000, People's Republic of China.
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Shen Y, Xia H, Tu Z, Zong Y, Yang L, Li H. Genetic divergence and local adaptation of Liriodendron driven by heterogeneous environments. Mol Ecol 2021; 31:916-933. [PMID: 34773328 DOI: 10.1111/mec.16271] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 10/31/2021] [Accepted: 11/05/2021] [Indexed: 12/13/2022]
Abstract
Ecological adaptive differentiation alters both the species diversity and intraspecific genetic diversity in forests, thus affecting the stability of forest ecosystems. Therefore, knowledge of the genetic underpinnings of the ecological adaptive differentiation of forest species is critical for effective species conservation. In this study, single-nucleotide polymorphisms (SNPs) from population transcriptomes were used to investigate the spatial distribution of genetic variation in Liriodendron to assess whether environmental variables can explain genetic divergence. We examined the contributions of environmental variables to population divergence and explored the genetic underpinnings of local adaptation using a landscape genomic approach. Niche models and statistical analyses showed significant niche divergence between L. chinense and L. tulipifera, suggesting that ecological adaptation may play a crucial role in driving interspecific divergence. We detected a new fine-scale genetic structure in L. chinense, and divergence of the six groups occurred during the late Pliocene to early Pleistocene. Redundancy analysis (RDA) revealed significant associations between genetic variation and multiple environmental variables. Environmental association analyses identified 67 environmental association loci (EALs; nonsynonymous SNPs) that underwent interspecific or intraspecific differentiation, 28 of which were associated with adaptive genes. These 28 candidate adaptive loci provide substantial evidence for local adaptation in Liriodendron. Our findings reveal ecological adaptive divergence pattern between Liriodendron species and provide novel insight into the role of heterogeneous environments in shaping genetic structure and driving local adaptation among populations, informing future L. chinense conservation efforts.
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Affiliation(s)
- Yufang Shen
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Hui Xia
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Zhonghua Tu
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Yaxian Zong
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Lichun Yang
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Huogen Li
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
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Huang R, Wang Y, Li K, Wang YQ. Genetic variation and population structure of clonal Zingiber zerumbet at a fine geographic scale: a comparison with two closely related selfing and outcrossing Zingiber species. BMC Ecol Evol 2021; 21:116. [PMID: 34107885 PMCID: PMC8191059 DOI: 10.1186/s12862-021-01853-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/27/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There has always been controversy over whether clonal plants have lower genetic diversity than plants that reproduce sexually. These conflicts could be attributed to the fact that few studies have taken into account the mating system of sexually reproducing plants and their phylogenetic distance. Moreover, most clonal plants in these previous studies regularly produce sexual progeny. Here, we describe a study examining the levels of genetic diversity and differentiation within and between local populations of fully clonal Zingiber zerumbet at a microgeographical scale and compare the results with data for the closely related selfing Z. corallinum and outcrossing Z. nudicarpum. Such studies could disentangle the phylogenetic and sexually reproducing effect on genetic variation of clonal plants, and thus contribute to an improved understanding in the clonally reproducing effects on genetic diversity and population structure. RESULTS The results revealed that the level of local population genetic diversity of clonal Z. zerumbet was comparable to that of outcrossing Z. nudicarpum and significantly higher than that of selfing Z. corallinum. However, the level of microgeographic genetic diversity of clonal Z. zerumbet is comparable to that of selfing Z. corallinum and even slightly higher than that of outcrossing Z. nudicarpum. The genetic differentiation among local populations of clonal Z. zerumbet was significantly lower than that of selfing Z. corallinum, but higher than that of outcrossing Z. nudicarpum. A stronger spatial genetic structure appeared within local populations of Z. zerumbet compared with selfing Z. corallinum and outcrossing Z. nudicarpum. CONCLUSIONS Our study shows that fully clonal plants are able not only to maintain a high level of within-population genetic diversity like outcrossing plants, but can also maintain a high level of microgeographic genetic diversity like selfing plant species, probably due to the accumulation of somatic mutations and absence of a capacity for sexual reproduction. We suggest that conservation strategies for the genetic diversity of clonal and selfing plant species should be focused on the protection of all habitat types, especially fragments within ecosystems, while maintenance of large populations is a key to enhance the genetic diversity of outcrossing species.
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Affiliation(s)
- Rong Huang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Yu Wang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Kuan Li
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Ying-Qiang Wang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China. .,Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, China.
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Zhang X, Sun Y, Landis JB, Zhang J, Yang L, Lin N, Zhang H, Guo R, Li L, Zhang Y, Deng T, Sun H, Wang H. Genomic insights into adaptation to heterogeneous environments for the ancient relictual Circaeaster agrestis (Circaeasteraceae, Ranunculales). THE NEW PHYTOLOGIST 2020; 228:285-301. [PMID: 32426908 DOI: 10.1111/nph.16669] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/08/2020] [Indexed: 05/25/2023]
Abstract
Investigating the interaction between environmental heterogeneity and local adaptation is critical for understanding the evolutionary history of a species, providing the premise for studying the response of organisms to rapid climate change. However, for most species how exactly the spatial heterogeneity promotes population divergence and how genomic variations contribute to adaptive evolution remain poorly understood. We examine the contributions of geographical and environmental variables to population divergence of the relictual, alpine herb Circaeaster agrestis, as well as the genetic basis of local adaptation using RAD-seq and plastome data. We detected significant genetic structure with an extraordinary disequilibrium of genetic diversity among regions, and signals of isolation-by-distance along with isolation-by-resistance. The populations were estimated to begin diverging in the late Miocene, along with a possible ancestral distribution of the Hengduan Mountains and adjacent regions. Both environmental gradient and redundancy analyses revealed significant association between genetic variation and temperature variables. Genome-environment association analyses identified 16 putatively adaptive loci related mainly to biotic and abiotic stress resistance. Our genome-wide data provide new insights into the important role of environmental heterogeneity in shaping genetic structure, and access the footprints of local adaptation in an ancient relictual species, informing future conservation efforts.
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Affiliation(s)
- Xu Zhang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yanxia Sun
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
| | - Jacob B Landis
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA, 92507, USA
- School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, NY, 14850, USA
| | - Jianwen Zhang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Linsen Yang
- Hubei Key Laboratory of Shennongjia Golden Monkey Conservation Biology, Administration of Shennongjia National Park, Shennongjia, Hubei, 442400, China
| | - Nan Lin
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Huajie Zhang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
| | - Rui Guo
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lijuan Li
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yonghong Zhang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Tao Deng
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Hang Sun
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Hengchang Wang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
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Dering M, Chybicki IJ, Rączka G. Clonality as a driver of spatial genetic structure in populations of clonal tree species. JOURNAL OF PLANT RESEARCH 2015; 128:731-745. [PMID: 26153428 DOI: 10.1007/s10265-015-0742-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/16/2015] [Indexed: 06/04/2023]
Abstract
Random genetic drift, natural selection and restricted gene dispersal are basic factors of the spatial genetic structure (SGS) in plant populations. Clonal reproduction has a profound effect on population dynamics and genetic structure and thus emerges as a potential factor in contributing to and modelling SGS. In order to assess the impact of clonality on SGS we studied clonal structure and SGS in the population of Populus alba. Six hundred and seventy-two individuals were mapped and genotyped with 16 nuclear microsatellite markers. To answer the more general question regarding the relationship between SGS and clonality we used Sp statistics, which allows for comparisons of the extent of SGS among different studies, and the comparison of published data on SGS in clonal and non-clonal tree species. Sp statistic was extracted for 14 clonal and 27 non-clonal species belonging to 7 and 18 botanical families, respectively. Results of genetic investigations conducted in the population of P. alba showed over-domination of clonal reproduction, which resulted in very low clonal diversity (R = 0.12). Significant SGS was found at both ramet (Sp = 0.095) and genet level (Sp = 0.05) and clonal reproduction was indicated as an important but not sole driving factor of SGS. Within-population structure, probably due to family structure also contributed to high SGS. High mean dominance index (D = 0.82) indicated low intermingling among genets. Literature survey revealed that clonal tree species significantly differ from non-clonal species with respect to SGS, having 2.8-fold higher SGS. This led us to conclude that clonality is a life-history trait that can have deep impact on processes acting in populations of clonal tree species leading to significant SGS.
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Affiliation(s)
- Monika Dering
- Laboratory of Systematics and Geography, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035, Kórnik, Poland,
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Maharramova EH, Safarov HM, Kozlowski G, Borsch T, Muller LA. Analysis of nuclear microsatellites reveals limited differentiation between Colchic and Hyrcanian populations of the wind-pollinated relict tree Zelkova carpinifolia (Ulmaceae). AMERICAN JOURNAL OF BOTANY 2015; 102:119-128. [PMID: 25587154 DOI: 10.3732/ajb.1400370] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
UNLABELLED • PREMISE OF THE STUDY The Caucasus represents one of the world's biodiversity hotspots and includes the climatic refugia Hyrcan on the southern coast of the Caspian Sea and Colchis on the eastern coast of the Black Sea, where different species survived during the Quaternary climatic oscillations. We evaluated the genetic diversity of the relict tree Zelkova carpinifolia shared between the two refugia and distributed throughout the Caucasus and adjacent areas.• METHODS Specimens were collected from 30 geographical sites in Azerbaijan, Georgia, Iran, and Turkey and screened for variability at eight nuclear microsatellite loci. The genetic diversity among and within populations was assessed using a set of statistical measures.• KEY RESULTS We detected 379 different genotypes from a total of 495 individuals with varying degrees of clonal reproduction at the different sites. Low to intermediate levels of genetic diversity were observed at all sites, and strong differentiation between sampling sites was absent. In addition, we observed no clear genetic differentiation between the Colchis and Hyrcan. Bayesian clustering of the genotypes revealed three populations with high levels of admixture between the sampling sites.• CONCLUSIONS The lack of strong genetic structure of studied populations of Z. carpinifolia contrasts with a previous study based on chloroplast markers and suggests that long-distance pollen dispersal is an important factor of gene flow among populations of Z. carpinifolia. The present study does not reveal any particular site with particularly isolated genotypes that would deserve more attention for conservation purposes than others, although some sites should be considered for further investigation.
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Affiliation(s)
- Elmira H Maharramova
- Botanischer Garten und Botanisches Museum Berlin-Dahlem, Freie Universität Berlin, 14195 Berlin, Germany Institute of Botany, Azerbaijan National Academy of Sciences, AZ1073 Baku, Azerbaijan
| | | | - Gregor Kozlowski
- Department of Biology and Botanic Garden, University of Fribourg, CH-1700 Fribourg, Switzerland Natural History Museum, CH-1700 Fribourg, Switzerland
| | - Thomas Borsch
- Botanischer Garten und Botanisches Museum Berlin-Dahlem, Freie Universität Berlin, 14195 Berlin, Germany Institut für Biologie-Botanik, Freie Universität Berlin, 14195 Berlin, Germany
| | - Ludo A Muller
- Institut für Biologie-Botanik, Freie Universität Berlin, 14195 Berlin, Germany
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Lasso E. The importance of setting the right genetic distance threshold for identification of clones using amplified fragment length polymorphism: a case study with five species in the tropical plant genus Piper. Mol Ecol Resour 2013; 8:74-82. [PMID: 21585721 DOI: 10.1111/j.1471-8286.2007.01910.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amplified fragment length polymorphism (AFLP) has been widely used for clone identification, but numerous studies have shown that clonemates do not always present identical AFLP fingerprints. Pairwise AFLP distances that distinguish known clones from nonclones have been used to identify a threshold genetic dissimilarity distance below which samples are considered to represent a single clone. Most studies to date have reported threshold values between 2% and 4%. Here, I determine the consistency of the clonal threshold across five species in the tropical plant genus Piper, and evaluate the sensitivity of genetic diversity indices and estimates of frequency of clonal reproduction to the threshold value selected. I sampled multiple ramets per individual from widely distributed plants for each of the five Piper species to set a threshold at the point where the error rate of clonal assignments was lowest. I then sampled all individuals of each shade-tolerant species in a 1-ha plot, and of each light-demanding species in 25 × 35-m plot, to estimate the frequency of asexual recruitment in natural populations using a series of different thresholds including the threshold set with the preliminary sampling. Clonal threshold values for the different species ranged from 0% to 5% AFLP genetic dissimilarity distance. To determine the sensitivity of estimates of clonal reproduction, I calculated several clonal diversity indexes for the natural populations of each of the five species guided by the range in clonal threshold values observed across the five Piper species. I show that small changes in the value of the clonal threshold can lead to very different conclusions regarding the level of clonal reproduction in natural populations.
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Affiliation(s)
- E Lasso
- Smithsonian Tropical Research Institute, Unit 0948 APO AA 34002-0948, Panama, University of Illinois at Urbana-Champaign, 265 Morrill Hall, 505 Goodwin Ave, IL 61801, USA
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Lopez L, Barreiro R. Genetic guidelines for the conservation of the endangered polyploid Centaurea borjae (Asteraceae). JOURNAL OF PLANT RESEARCH 2013; 126:81-93. [PMID: 22678690 DOI: 10.1007/s10265-012-0497-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 04/30/2012] [Indexed: 06/01/2023]
Abstract
Appropriate management of species of conservation concern requires designing strategies that should include genetic information as small population size and restricted geographic range can reduce genetic variation. We used AFLPs to investigate genetic variation within and among populations of the endangered narrow endemic Centaurea borjae, and found no evidence for genetic impoverishment despite its <40 km range and potential for vegetative propagation. Genetic variation was comparable to other plants with similar life history (88 % occurring within populations) and potential clone mates were less frequent than expected. Nonetheless, populations separated by few hundred meters showed signs of significant genetic differentiation suggesting low gene flow between them. Our results suggested that the three geographically closer populations located at the center of the range might be treated as a single management unit, while the remaining ones could be considered independent units. We found evidence of fine-scale spatial genetic structure up to 80 m indicating that the collection of germplasm for ex-situ conservation should focus on individuals separated >80 m to maximize genetic variation.
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Affiliation(s)
- Lua Lopez
- Área de Ecología, Facultad de Ciencias, Universidad da Coruña, Campus A Zapateira s/n, 15071 A Coruña, Spain.
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Lasso E, Dalling JW, Bermingham E. Strong spatial genetic structure in five tropical Piper species: should the Baker-Fedorov hypothesis be revived for tropical shrubs? Ecol Evol 2012; 1:502-16. [PMID: 22393518 PMCID: PMC3287332 DOI: 10.1002/ece3.40] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 08/19/2011] [Accepted: 08/24/2011] [Indexed: 11/10/2022] Open
Abstract
Fifty years ago, Baker and Fedorov proposed that the high species diversity of tropical forests could arise from the combined effects of inbreeding and genetic drift leading to population differentiation and eventually to sympatric speciation. Decades of research, however have failed to support the Baker-Fedorov hypothesis (BFH), and it has now been discarded in favor of a paradigm where most trees are self-incompatible or strongly outcrossing, and where long-distance pollen dispersal prevents population drift. Here, we propose that several hyper-diverse genera of tropical herbs and shrubs, including Piper (>1,000 species), may provide an exception. Species in this genus often have aggregated, high-density populations with self-compatible breeding systems; characteristics which the BFH would predict lead to high local genetic differentiation. We test this prediction for five Piper species on Barro Colorado Island, Panama, using Amplified Fragment Length Polymorphism (AFLP) markers. All species showed strong genetic structure at both fine- and large-spatial scales. Over short distances (200-750 m) populations showed significant genetic differentiation (Fst 0.11-0.46, P < 0.05), with values of spatial genetic structure that exceed those reported for other tropical tree species (Sp = 0.03-0.136). This genetic structure probably results from the combined effects of limited seed and pollen dispersal, clonal spread, and selfing. These processes are likely to have facilitated the diversification of populations in response to local natural selection or genetic drift and may explain the remarkable diversity of this rich genus.
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Chung MY, Nason JD, Chung MG. Effects of population succession on demographic and genetic processes: predictions and tests in the daylily Hemerocallis thunbergii (Liliaceae). Mol Ecol 2007; 16:2816-29. [PMID: 17594450 DOI: 10.1111/j.1365-294x.2007.03361.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Spatial genetic structure within plant populations is influenced by variation in demographic processes through space and time, including a population's successional status. To determine how demographic structure and fine-scale genetic structure (FSGS) change with stages in a population's successional history, we studied Hemerocallis thunbergii (Liliaceae), a nocturnal flowering and hawkmoth-pollinated herbaceous perennial with rapid population turnover dynamics. We examined nine populations assigned to three successive stages of population succession: expansion, maturation, and senescence. We developed stage-specific expectations for within-population demographic and genetic structure, and then for each population quantified the spatial aggregation of individuals and genotypes using spatial autocorrelation methods (nonaccumulative O-ring and kinship statistics, respectively), and at the landscape level measured inbreeding and genetic structure using Wright's F-statistics. Analyses using the O-ring statistic revealed significant aggregation of individuals at short spatial scales in expanding and senescing populations, in particular, which may reflect restricted seed dispersal around maternal individuals combined with relatively low local population densities at these stages. Significant FSGS was found for three of four expanding, no mature, and only one senescing population, a pattern generally consistent with expectations of successional processes. Although allozyme genetic diversity was high within populations (mean %P = 78.9 and H(E) = 0.281), landscape-level differentiation among sites was also high (F(ST) = 0.166) and all populations exhibited a significant deficit of heterozygotes relative to Hardy-Weinberg expectations (range F = 0.201-0.424, mean F(IS) = 0.321). Within populations, F was not correlated with the degree of FSGS, thus suggesting inbreeding due primarily to selfing as opposed to mating among close relatives in spatially structured populations. Our results demonstrate considerable variation in the spatial distribution of individuals and patterns and magnitude of FSGS in H. thunbergii populations across the landscape. This variation is generally consistent with succession-stage-specific differences in ecological processes operating within these populations.
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Affiliation(s)
- Mi Yoon Chung
- Department of Biology and Institute of Basic Science, Gyeongsang National University, Jinju 660-701, South Korea
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Clonal and spatial genetic structure in natural populations of Luohanguo (Siraitia grosvenorii), an economic species endemic to South China, as revealed by RAPD markers. BIOCHEM SYST ECOL 2007. [DOI: 10.1016/j.bse.2007.03.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Variation in demographic and fine-scale genetic structure with population-history stage of Hemerocallis taeanensis (Liliaceae) across the landscape. Ecol Res 2007. [DOI: 10.1007/s11284-007-0341-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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CHUNG JAEMIN, LEE BYEUNGCHEUN, KIM JINSEOK, PARK CHONGWOOK, YOON CHUNG MI, GI CHUNG MYONG. Fine-scale genetic structure among genetic individuals of the clone-forming monotypic genus Echinosophora koreensis (Fabaceae). ANNALS OF BOTANY 2006; 98:165-73. [PMID: 16675603 PMCID: PMC2803556 DOI: 10.1093/aob/mcl083] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 12/22/2005] [Accepted: 02/13/2006] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS For rare endemics or endangered plant species that reproduce both sexually and vegetatively it is critical to understand the extent of clonality because assessment of clonal extent and distribution has important ecological and evolutionary consequences with conservation implications. A survey was undertaken to understand clonal effects on fine-scale genetic structure (FSGS) in two populations (one from a disturbed and the other from an undisturbed locality) of Echinosophora koreensis, an endangered small shrub belonging to a monotypic genus in central Korea that reproduces both sexually and vegetatively via rhizomes. METHODS Using inter-simple sequence repeats (ISSRs) as genetic markers, the spatial distribution of individuals was evaluated using Ripley's L(d)-statistics and quantified the spatial scale of clonal spread and spatial distribution of ISSR genotypes using spatial autocorrelation analysis techniques (join-count statistics and kinship coefficient, F(ij)) for total samples and samples excluding clones. KEY RESULTS A high degree of differentiation between populations was observed (phi(ST(g)) = 0.184, P < 0.001). Ripley's L(d)-statistics revealed a near random distribution of individuals in a disturbed population, whereas significant aggregation of individuals was found in an undisturbed site. The join-count statistics revealed that most clones significantly aggregate at < or = 6-m interplant distance. The Sp statistic reflecting patterns of correlograms revealed a strong pattern of FSGS for all four data sets (Sp = 0.072-0.154), but these patterns were not significantly different from each other. At small interplant distances (< or = 2 m), however, jackknifed 95% CIs revealed that the total samples exhibited significantly higher F(ij) values than the same samples excluding clones. CONCLUSION The strong FSGS from genets is consistent with two biological and ecological traits of E. koreensis: bee-pollination and limited seed dispersal. Furthermore, potential clone mates over repeated generations would contribute to the observed high F(ij) values among genets at short distance. To ensure long-term ex situ genetic variability of the endangered E. koreensis, individuals located at distances of 10-12 m should be collected across entire populations of E. koreensis.
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Affiliation(s)
- JAE MIN CHUNG
- Division of Specimen and Genetic Resources, National Arboretum, Korea Forest Service, Gyeonggi Province, 487-821, Republic of Korea, School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea and Department of Biology and Institute of Basic Science, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - BYEUNG CHEUN LEE
- Division of Specimen and Genetic Resources, National Arboretum, Korea Forest Service, Gyeonggi Province, 487-821, Republic of Korea, School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea and Department of Biology and Institute of Basic Science, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - JIN SEOK KIM
- Division of Specimen and Genetic Resources, National Arboretum, Korea Forest Service, Gyeonggi Province, 487-821, Republic of Korea, School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea and Department of Biology and Institute of Basic Science, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - CHONG-WOOK PARK
- Division of Specimen and Genetic Resources, National Arboretum, Korea Forest Service, Gyeonggi Province, 487-821, Republic of Korea, School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea and Department of Biology and Institute of Basic Science, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - MI YOON CHUNG
- Division of Specimen and Genetic Resources, National Arboretum, Korea Forest Service, Gyeonggi Province, 487-821, Republic of Korea, School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea and Department of Biology and Institute of Basic Science, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - MYONG GI CHUNG
- Division of Specimen and Genetic Resources, National Arboretum, Korea Forest Service, Gyeonggi Province, 487-821, Republic of Korea, School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea and Department of Biology and Institute of Basic Science, Gyeongsang National University, Jinju 660-701, Republic of Korea
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