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Li YR, Fritsch PW, Zhao GG, Cheng XJ, Ding ZL, Lu L. Population differentiation and dynamics of five pioneer species of Gaultheria from the secondary forests in subtropical China. BMC PLANT BIOLOGY 2024; 24:516. [PMID: 38851686 PMCID: PMC11161945 DOI: 10.1186/s12870-024-05189-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Accepted: 05/23/2024] [Indexed: 06/10/2024]
Abstract
BACKGROUND The influence of native secondary succession associated with anthropogenic disturbance on the biodiversity of the forests in subtropical China remains uncertain. In particular, the evolutionary response of small understory shrubs, particularly pioneer species inhabiting continuously disturbed habitats, to topographic heterogeneity and climate change is poorly understood. This study aimed to address this knowledge gap by focusing on the Gaultheria crenulata group, a clade of small pioneer shrubs in subtropical China. RESULTS We examined the genetic structure and demographic history of all five species of the G. crenulata group with two maternally inherited chloroplast DNA (cpDNA) fragments and two biparentally inherited low-copy nuclear genes (LCG) over 89 natural populations. We found that the genetic differentiation of this group was influenced by the geomorphological boundary between different regions of China in association with Quaternary climatic events. Despite low overall genetic diversity, we observed an isolation-by-distance (IBD) pattern at a regional scale, rather than isolation-by-environment (IBE), which was attributed to ongoing human disturbance in the region. CONCLUSION Our findings suggest that the genetic structure of the G. crenulata group reflects the interplay of geological topography, historical climates, and anthropogenic disturbance during the Pliocene-Pleistocene-Holocene periods in subtropical China. The observed IBD pattern, particularly prominent in western China, highlights the role of limited dispersal and gene flow, possibly influenced by physical barriers or decreased connectivity over geographic distance. Furthermore, the east-to-west trend of gene flow, potentially facilitated by the East Asian monsoon system, underscores the complex interplay of biotic and abiotic factors shaping the genetic dynamics of pioneer species in subtropical China's secondary forests. These findings can be used to assess the impact of environmental changes on the adaptation and persistence of biodiversity in subtropical forest ecosystems.
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Affiliation(s)
- Yi-Rong Li
- School of Pharmaceutical Sciences, Yunnan Key Laboratory of Pharmacology for Natural Products, Yunnan College of Modern Biomedical Industry, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Peter W Fritsch
- Botanical Research Institute of Texas, 1700 University Drive, Fort Worth, TX, 76017, USA
| | - Gui-Gang Zhao
- Genome Center of Biodiversity, Kunming Institute of Zoology, Chinese Academy of Science, Kunming, 650223, China
| | - Xiao-Juan Cheng
- School of Pharmaceutical Sciences, Yunnan Key Laboratory of Pharmacology for Natural Products, Yunnan College of Modern Biomedical Industry, Kunming Medical University, Kunming, 650500, Yunnan, China
| | - Zhao-Li Ding
- Genome Center of Biodiversity, Kunming Institute of Zoology, Chinese Academy of Science, Kunming, 650223, China.
- Yunnan Key Laboratory of Biodiversity Information, Kunming Institute of Zoology, Chinese Academy of Science, Kunming, 650223, China.
| | - Lu Lu
- School of Pharmaceutical Sciences, Yunnan Key Laboratory of Pharmacology for Natural Products, Yunnan College of Modern Biomedical Industry, Kunming Medical University, Kunming, 650500, Yunnan, China.
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Xu Y, Hu J, Shi Z, Chen W, Zhou J, Zhang B, Yong F, Khanal L, Jiang X, Chen Z. Integrative systematics and evolutionary history of Berylmys bowersi (Mammalia, Rodentia, Muridae). Ecol Evol 2023; 13:e10234. [PMID: 37408634 PMCID: PMC10318578 DOI: 10.1002/ece3.10234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 07/07/2023] Open
Abstract
The Bower's Berylmys (Berylmys bowersi) is one of the largest rodent species with a wide distribution range in southern China and the Indochinese Peninsula. The taxonomy and evolutionary history of the B. bowersi is still controversial and confusing. In this study, we used two mitochondrial (Cyt b and COI) and three nuclear (GHR, IRBP, and RAG1) genes to estimate the phylogeny, divergence times, and biogeographic history of B. bowersi. We also explored morphological variations among the specimens collected across China. Our phylogenetic analyses indicated that the traditional B. bowersi contains at least two species: B. bowersi and B. latouchei. Berylmys latouchei was considered a junior synonym of B. bowersi distributed in eastern China, which is confirmed to be distinguishable at specific level because of its larger size, relatively larger and whiter hind feet, and several cranial traits. The estimated split of B. bowersi and B. latouchei was at the early Pleistocene (ca. 2.00 Mya), which might be the outcome of the combined effects of climate change in the early Pleistocene and isolation by the Minjiang River. Our results highlight the Wuyi Mountains in northern Fujian, China, as a glacial refugia during the Pleistocene and call for more intensive surveys and systematic revisions of small mammals in eastern China.
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Affiliation(s)
- Yifan Xu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co‐founded by Anhui Province and Ministry of Education, School of Ecology and EnvironmentAnhui Normal UniversityWuhuChina
- State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of ZoologyChinese Academy of SciencesKunmingChina
| | - Jiangxiao Hu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co‐founded by Anhui Province and Ministry of Education, School of Ecology and EnvironmentAnhui Normal UniversityWuhuChina
| | - Zifan Shi
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co‐founded by Anhui Province and Ministry of Education, School of Ecology and EnvironmentAnhui Normal UniversityWuhuChina
| | - Wenwen Chen
- School of Resources and Environmental EngineeringAnhui UniversityHefeiChina
| | - Jiajun Zhou
- Zhejiang Forest Resources Monitoring CenterHangzhouChina
| | - Baowei Zhang
- School of Life SciencesAnhui UniversityHefeiChina
| | - Fan Yong
- Nanjing Institute of Environmental SciencesMinistry of Ecology and EnvironmentNanjingChina
| | - Laxman Khanal
- Central Department of Zoology, Institute of Science and TechnologyTribhuvan UniversityKathmanduNepal
| | - Xuelong Jiang
- State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of ZoologyChinese Academy of SciencesKunmingChina
| | - Zhongzheng Chen
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co‐founded by Anhui Province and Ministry of Education, School of Ecology and EnvironmentAnhui Normal UniversityWuhuChina
- State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of ZoologyChinese Academy of SciencesKunmingChina
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Shen Y, Tu Z, Zhang Y, Zhong W, Xia H, Hao Z, Zhang C, Li H. Predicting the impact of climate change on the distribution of two relict Liriodendron species by coupling the MaxEnt model and actual physiological indicators in relation to stress tolerance. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 322:116024. [PMID: 36055092 DOI: 10.1016/j.jenvman.2022.116024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/19/2022] [Accepted: 08/13/2022] [Indexed: 06/15/2023]
Abstract
Climate change has a crucial impact on the distributions of plants, especially relict species. Hence, predicting the potential impact of climate change on the distributions of relict plants is critical for their future conservation. Liriodendron plants are relict trees, and only two natural species have survived: L. chinense and L. tulipifera. However, the extent of the impact of future climate change on the distributions of these two Liriodendron species remains unclear. Therefore, we predicted the suitable habitat distributions of two Liriodendron species under present and future climate scenarios using MaxEnt modeling. The results showed that the area of suitable habitats for two Liriodendron species would significantly decrease. However, the two relict species presented different habitat shift patterns, with a local contraction of suitable habitat for L. chinense and a northward shift in suitable habitat for L. tulipifera, indicating that changes in environmental factors will affect the distributions of these species. Among the environmental factors assessed, May precipitation induced the largest impact on the L. chinense distribution, while L. tulipifera was significantly affected by precipitation in the driest quarter. Furthermore, to explore the relationship between habitat suitability and Liriodendron stress tolerance, we analyzed six physiological indicators of stress tolerance by sampling twelve provenances of L. chinense and five provenances of L. tulipifera. The composite index of six physiological indicators was significantly negatively correlated with the habitat suitability of the species. The stress tolerance of Liriodendron plants in highly suitable areas was lower than that in areas with moderate or low suitability. Overall, these findings improve our understanding of the ecological impacts of climate change, informing future conservation efforts for Liriodendron species.
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Affiliation(s)
- Yufang Shen
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
| | - Zhonghua Tu
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
| | - Yali Zhang
- College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
| | - Weiping Zhong
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
| | - Hui Xia
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
| | - Ziyuan Hao
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
| | - Chengge Zhang
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
| | - Huogen Li
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, 210037, 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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Liu W, Xie J, Zhou H, Kong H, Hao G, Fritsch PW, Gong W. Population dynamics linked to glacial cycles in Cercis chuniana F. P. Metcalf (Fabaceae) endemic to the montane regions of subtropical China. Evol Appl 2021; 14:2647-2663. [PMID: 34815745 PMCID: PMC8591333 DOI: 10.1111/eva.13301] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 08/19/2021] [Accepted: 09/01/2021] [Indexed: 01/03/2023] Open
Abstract
The mountains of subtropical China are an excellent system for investigating the processes driving the geographical distribution of biodiversity and radiation of plant populations in response to Pleistocene climate fluctuations. How the major mountain ranges in subtropical China have affected the evolution of plant species in the subtropical evergreen broadleaved forest is an issue with long-term concern. Here, we focused on Cercis chuniana, a woody species endemic to the southern mountain ranges in subtropical China, to elucidate its population dynamics. We used genotyping by sequencing (GBS) to investigate the spatial pattern of genetic variation among 11 populations. Geographical isolation was detected between the populations located in adjacent mountain ranges, thought to function as geographical barriers due to their complex physiography. Bayesian time estimation revealed that population divergence occurred in the middle Pleistocene, when populations in the Nanling Mts. separated from those to the east. The orientation and physiography of the mountain ranges of subtropical China appear to have contributed to the geographical pattern of genetic variation between the eastern and western populations of C. chuniana. Complex physiography plus long-term stable ecological conditions across glacial cycles facilitated the demographic expansion in the Nanling Mts., from which contemporary migration began. The Nanling Mts. are thus considered as a suitable area for preserving population diversity and large population sizes of C. chuniana compared with other regions. As inferred by ecological niche modeling and coalescent simulations, secondary contact occurred during the warm Lushan-Tali Interglacial period, with intensified East Asia summer monsoon and continuous habitat available for occupation. Our data support the strong influence of both climatic history and topographic characteristics on the high regional phytodiversity of the subtropical evergreen broadleaved forest in subtropical China.
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Affiliation(s)
- Wanzhen Liu
- Guangdong Laboratory for Lingnan Modern Agriculture, & College of Life SciencesSouth China Agricultural UniversityGuangzhouChina
| | - Jianguang Xie
- Guangdong Laboratory for Lingnan Modern Agriculture, & College of Life SciencesSouth China Agricultural UniversityGuangzhouChina
| | - Hui Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, & College of Life SciencesSouth China Agricultural UniversityGuangzhouChina
| | - Hanghui Kong
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical GardenChinese Academy of SciencesGuangzhouChina
- Center of Conservation BiologyCore Botanical GardensChinese Academy of SciencesGuangzhouChina
| | - Gang Hao
- Guangdong Laboratory for Lingnan Modern Agriculture, & College of Life SciencesSouth China Agricultural UniversityGuangzhouChina
| | | | - Wei Gong
- Guangdong Laboratory for Lingnan Modern Agriculture, & College of Life SciencesSouth China Agricultural UniversityGuangzhouChina
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Zhu S, Chen J, Zhao J, Comes HP, Li P, Fu C, Xie X, Lu R, Xu W, Feng Y, Ye W, Sakaguchi S, Isagi Y, Li L, Lascoux M, Qiu Y. Genomic insights on the contribution of balancing selection and local adaptation to the long-term survival of a widespread living fossil tree, Cercidiphyllum japonicum. THE NEW PHYTOLOGIST 2020; 228:1674-1689. [PMID: 32643803 DOI: 10.1111/nph.16798] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 06/27/2020] [Indexed: 05/25/2023]
Abstract
'Living fossils' are testimonies of long-term sustained ecological success, but how demographic history and natural selection contributed to their survival, resilience, and persistence in the face of Quaternary climate fluctuations remains unclear. To better understand the interplay between demographic history and selection in shaping genomic diversity and evolution of such organisms, we assembled the whole genome of Cercidiphyllum japonicum, a widespread East Asian Tertiary relict tree, and resequenced 99 individuals of C. japonicum and its sister species, Cercidiphyllum magnificum (Central Japan). We dated this speciation event to the mid-Miocene, and the intraspecific lineage divergence of C. japonicum (China vs Japan) to the Early Pliocene. Throughout climatic upheavals of the late Tertiary/Quaternary, population bottlenecks greatly reduced the genetic diversity of C. japonicum. However, this polymorphism loss was likely counteracted by, first, long-term balancing selection at multiple chromosomal and heterozygous gene regions, potentially reflecting overdominance, and, second, selective sweeps at stress response and growth-related genes likely involved in local adaptation. Our findings contribute to a better understanding of how living fossils have survived climatic upheaval and maintained an extensive geographic range; that is, both types of selection could be major factors contributing to the species' survival, resilience, and persistence.
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Affiliation(s)
- Shanshan Zhu
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Jun Chen
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Jing Zhao
- Novogene Bioinformatics Institute, Beijing, 100083, China
| | - Hans Peter Comes
- Department of Biosciences, Salzburg University, Salzburg, A-5020, Austria
| | - Pan Li
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Chengxin Fu
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Xiao Xie
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang, 315211, China
| | - Ruisen Lu
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Wuqin Xu
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Yu Feng
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Wenqing Ye
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Shota Sakaguchi
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Yuji Isagi
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Linfeng Li
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200433, China
| | - Martin Lascoux
- Plant Ecology and Evolution, Department of Ecology and Genetics and Science for Life Laboratory, Uppsala University, Norbyvägen 18D, Uppsala, 75236, Sweden
| | - Yingxiong Qiu
- Systematic & Evolutionary Botany and Biodiversity Group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
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Population Genetic Diversity and Structure of Ancient Tree Populations of Cryptomeria japonica var. sinensis Based on RAD-seq Data. FORESTS 2020. [DOI: 10.3390/f11111192] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Research highlights: Our study is the first to explore the genetic composition of ancient Cryptomeria trees across a distribution range in China. Background and objectives: Cryptomeria japonica var. sinensis is a native forest species of China; it is widely planted in the south of the country to create forests and for wood production. Unlike Cryptomeria in Japan, genetic Chinese Cryptomeria has seldom been studied, although there is ample evidence of its great ecological and economic value. Materials and methods: Because of overcutting, natural populations are rare in the wild. In this study, we investigated seven ancient tree populations to explore the genetic composition of Chinese Cryptomeria through ddRAD-seq technology. Results: The results reveal a lower genetic variation but higher genetic differentiation (Ho = 0.143, FST = 0.1204) than Japanese Cryptomeria (Ho = 0.245, FST = 0.0455). The 86% within-population variation is based on an analysis of molecular variance (AMOVA). Significant excess heterozygosity was detected in three populations and some outlier loci were found; these were considered to be the consequence of selection or chance. Structure analysis and dendrogram construction divided the seven ancient tree populations into four groups corresponding to the geographical provinces in which the populations are located, but there was no obvious correlation between genetic distance and geographic distance. A demographic history analysis conducted by a Stairway Plot showed that the effective population size of Chinese Cryptomeria had experienced a continuing decline from the mid-Pleistocene to the present. Our findings suggest that the strong genetic drift caused by climate fluctuation and intense anthropogenic disturbance together contributed to the current low diversity and structure. Considering the species’ unfavorable conservation status, strategies are urgently required to preserve the remaining genetic resources.
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Genetic Diversity and Population Genetic Structure of Cinnamomum camphora in South China Revealed by EST-SSR Markers. FORESTS 2019. [DOI: 10.3390/f10111019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cinnamomum camphora is a valuable broad-leaf tree indigenous to South China and East Asia and has been widely cultivated and utilized by humans since ancient times. However, owing to its overutilization for essential oil extraction, the Transplanting Big Trees into Cities Program, and over deforestation to make furniture, its wild populations have been detrimentally affected and are declining rapidly. In the present study, the genetic diversity and population structure of 180 trees sampled from 41 populations in South China were investigated with 22 expressed sequence tag-simple sequence repeat (EST-SSR) markers. In total, 61 alleles were harbored across 180 individuals, and medium genetic diversity level was inferred from the observed heterozygosity (Ho), expected heterozygosity (He), and Nei’ gene diversity (GD), which were 0.45, 0.44, and 0.44, respectively. Among the 41 wild populations, C. camphora had an average of 44 alleles, 2.02 effective alleles, and He ranging from 0.30 (SC) to 0.61 (HK). Analysis of molecular variance (AMOVA) showed that 17% of the variation among populations and the average pairwise genetic differentiation coefficient (FST) between populations was 0.162, indicating relatively low genetic population differentiations. Structure analysis suggested two groups for the 180 individuals, which was consistent with the principal coordinate analysis (PCoA) and unweighted pair-group method with arithmetic means (UPGMA). Populations grouped to cluster I were nearly all distributed in Jiangxi Province (except population XS in Zhejiang Province), and cluster II mainly comprised populations from other regions, indicating a significant geographical distribution. Moreover, the Mantel test showed that this geographical distance was significantly correlated with genetic distance. The findings of this research will assist in future C. camphora conservation management and breeding programs.
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