High genetic diversity but limited gene flow among remnant and fragmented natural populations of Liriodendron chinense Sarg

2014 ◽  
Vol 54 ◽  
pp. 230-236 ◽  
Author(s):  
Kangqin Li ◽  
Long Chen ◽  
Yuanheng Feng ◽  
Junxiu Yao ◽  
Bo Li ◽  
...  
2021 ◽  
Author(s):  
Tao Zhang ◽  
Xue Li ◽  
Shuilian He

Abstract Magnolia odoratissima is a highly threatened species with small populations and scattered distribution due to habitat fragmentation and human activity. The species is recognized as a Plant Species with Extremely Small Populations (PSESP) and is endemic to China. In the current study, the population structure and levels of genetic diversity of M. odoratissima in the five remaining natural populations and three cultivated populations were evaluated using single nucleotide polymorphisms (SNPs) derived from Specific-Locus Amplified Fragment Sequencing (SLAF-seq). A total of 180,650 SNP loci were found in seventy M. odoratissima individuals. The genome-wide Nei’s and Shannon’s nucleotide diversity indexes of the total M. odoratissima population were 0.3035 and 0.4695, respectively. The observed heterozygosity (Ho) and expected heterozygosity (He) were 0.1122 and 0.3011. Our results suggest that M. odoratissima has relatively high genetic diversity at the genomic level. FST and AMOVA indicated that high genetic differentiation existed among populations. A phylogenetic neighbor-joining tree, Bayesian model–based clustering and principal components analysis (PCA) all divided the studied M. odoratissima individuals into three distinct clusters. The Treemix analysis showed that there was low gene flow among the natural populations and a certain gene flow from the wild populations to the cultivated population (LS to KIB, and GN to JD). In addition, a total of 36 unique SNPs were detected as being significantly associated with environmental parameters (altitude, temperature and precipitation). These candidate SNPs were found to be involved in multiple pathways including several molecular functions and biological process, suggesting they may play key roles in environmental adaptation. Our results suggested that three distinct evolutionary significant units (ESUs) should be set up to conserve this critically endangered species.


2020 ◽  
Vol 12 (2) ◽  
pp. 177
Author(s):  
Bárbara Rayane Ramos Muniz Nassau ◽  
Lorena Ramos da Mata ◽  
Márcio de Carvalho Moretzsohn ◽  
Vânia Cristina Rennó Azevedo ◽  
Marcelo Mattos Cavallari ◽  
...  

The Babassu (Attalea sp.) is a native palm tree, belonging to the family Arecaceae, with a wide distribution in Brazil. The species Attalea vitrivir Zona occurs in the Northwest of Minas Gerais State and Southwest of Bahia State, where the Cerrado is the predominant biome. Babassu is an important native oil resource and one of the main extractive products in Brazil, besides contributing significantly to the economy of some Brazilian States. The results of an ongoing study of the conservation status and genetic diversity of populations of the palm A.vitrivir are presented. The distribution of A. vitrivir has been reduced by habitat fragmentation, resulting in two main regions of occurrence (northern and southern), with a large gap between them, being only one of them protected by a conservation unit. A total of 84 microsatellite primer pairs designed for Attalea speciosa were screened for polymorphism and transferability in A. vitrivir individuals and 21 transferable primer pairs were used to better understand the distribution of genetic variability, gene flow and conservation status of A. vitrivir populations.The genetic diversity estimates using these primers indicated high levels of genetic variation and showed that a higher variation was located within than among populations, probably due to reproductive isolation. The five populations evaluated were grouped into two distinct groups, coinciding with northern and southern regions. High genetic diversity within populations and high differentiation among both regions indicate limited gene flow. The northern unprotected populations presented high genetic variability and should also be considered for protection for the long term conservation of the species.


2019 ◽  
Vol 48 (4) ◽  
pp. 1237-1241
Author(s):  
Qikui Wu ◽  
Limin Sun ◽  
Xiaojing Liu ◽  
Xuan Wang ◽  
Xia Sun ◽  
...  

The present studies were conducted to assess the genetic diversity and to infer population structure of 220 individuals of Indigofera kirilowii from 8 natural populations of Shandong province, north China, using amplified fragment length polymorphism (AFLP) markers. A total of 1589 AFLP bands were produced, of which 99.87% were polymorphic. High genetic diversity was considered (H = 0.1401; I = 0.2346), with high genetic differentiation (GST = 0.1058), while estimates of gene flow (Nm) were high in all analysis. No correlations were observed between geographic location and genetic diversity (r = –0.0901; p = 0.3293). Based on the results, here a strategy for the conservation of I. kirilowii germplasm was proposed.


2014 ◽  
Vol 16 (2) ◽  
pp. 459-476 ◽  
Author(s):  
Guilherme Dias ◽  
Juan Francisco Beltrán ◽  
Miguel Tejedo ◽  
Maribel Benítez ◽  
Emilio González Miras ◽  
...  

2021 ◽  
Vol 51 (4) ◽  
Author(s):  
Dominique N. Gallery ◽  
Michelle L. Green ◽  
Ilsa B. Kuffner ◽  
Elizabeth A. Lenz ◽  
Lauren T. Toth

AbstractIncreases in local and global stressors have led to major declines in coral populations throughout the western Atlantic. While abundances of other species have declined, however, the relative abundance of the mustard hill coral, Porites astreoides, has increased. Porites astreoides is relatively resilient to some stressors, and because of its mixed reproductive strategies, its populations often recover quickly following disturbances. The ability for P. astreoides to continue as a potential “winner” in western Atlantic reefs relies on maintaining sufficient genetic variation within populations to support acclimatization and adaptation to current and future environmental change. Without high genetic diversity and gene flow within the population, it would have limited capacity for adaptation and the species’ competitive advantages could be short-lived. In this study, we determined the genetic relatedness of 37 P. astreoides colonies at four shallow reefs along the offshore Florida Keys Reef Tract (FKRT), a region particularly hard-hit by recent disturbances. Using previously designed microsatellite markers, we determined the genetic diversity and connectivity of individuals among and between sites. Our results suggest that the FKRT likely contains a single, well-mixed genetic population of P. astreoides, with high levels of gene flow and evidence for larval migration throughout the region. This suggests that regional populations of P. astreoides likely have a higher chance of maintaining resilience than many other western Atlantic species as they face current and future disturbances.


2020 ◽  
Author(s):  
Aaliyah D. Wright ◽  
Nicole L. Garrison ◽  
Ashantye’ S. Williams ◽  
Paul D. Johnson ◽  
Nathan V. Whelan

AbstractMany freshwater gastropod species face extinction, including 79% of species in the family Pleuroceridae. The Oblong Rocksnail, Leptoxis compacta, is a narrow range endemic pleurocerid from the Cahaba River basin in central Alabama that has seen rapid range contraction in the last 100 years. Such a decline is expected to negatively affect genetic diversity in the species. However, precise patterns of genetic variation and gene flow across the restricted range of L. compacta are unknown. This lack of information limits our understanding of human impacts on the Cahaba River system and Pleuroceridae. Here, we show that L. compacta has likely seen a species-wide decline in genetic diversity, but remaining populations have relatively high genetic diversity. We also report a contemporary range extension compared to the last published survey. Leptoxis compacta does not display an isolation by distance pattern, contrasting patterns seen in many riverine taxa. Our findings also indicate that historical range contraction has resulted in the absence of common genetic patterns seen in many riverine taxa like isolation by distance as the small distribution of L. compacta allows for relatively unrestricted gene flow across its remaining range despite limited dispersal abilities. Two collection sites had higher genetic diversity than others, and broodstock sites for future captive propagation and reintroduction efforts should utilize sites identified here as having the highest genetic diversity. Broadly, our results support the hypothesis that range contraction will result in the reduction of species-wide genetic diversity, and common riverscape genetic patterns cannot be assumed to be present in species facing extinction risk.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9789
Author(s):  
Aaliyah D. Wright ◽  
Nicole L. Garrison ◽  
Ashantye’ S. Williams ◽  
Paul D. Johnson ◽  
Nathan V. Whelan

Many freshwater gastropod species face extinction, including 79% of species in the family Pleuroceridae. The Oblong Rocksnail, Leptoxis compacta, is a narrow range endemic pleurocerid from the Cahaba River basin in central Alabama that has seen rapid range contraction in the last 100 years. Such a decline is expected to negatively affect genetic diversity in the species. However, precise patterns of genetic variation and gene flow across the restricted range of L. compacta are unknown. This lack of information limits our understanding of human impacts on the Cahaba River system and Pleuroceridae. Here, we show that L. compacta has likely seen a species-wide decline in genetic diversity, but remaining populations have relatively high genetic diversity. We also report a contemporary range extension compared to the last published survey. Our findings indicate that historical range contraction has resulted in the absence of common genetic patterns seen in many riverine taxa like isolation by distance as the small distribution of L. compacta allows for relatively unrestricted gene flow across its remaining range despite limited dispersal abilities. Two collection sites had higher genetic diversity than others, and broodstock sites for future captive propagation and reintroduction efforts should utilize sites identified here as having the highest genetic diversity. Broadly, our results support the hypothesis that range contraction will result in the reduction of species-wide genetic diversity, and common riverscape genetic patterns cannot be assumed to be present in species facing extinction risk.


Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 409-420 ◽  
Author(s):  
Lauren A. Dennhardt ◽  
Edward S. DeKeyser ◽  
Sarah A. Tennefos ◽  
Steven E. Travers

The study of colonizing and of dominant grass species is essential for prairie conservation efforts. We sought to answer how naturalized Kentucky bluegrass in the northern Great Plains has become successful in the last 20 yr despite its long history in the northern Great Plains. We tested for evidence of geographical differentiation using flow cytometry and microsatellite markers to ascertain the population genetics of Kentucky bluegrass. Across all tested wild populations, high levels of genetic diversity were detected along with moderate levels of structure. Mantel tests of geographical patterns were not significant. Using clonal assignment, we found two major clones that made up the majority of the tested wild populations. When we compared the wild individuals to pedigree cultivars, we found virtually no genetic overlap across all tests, which did not support our hypothesis of developed cultivars contributing to high genetic diversity in natural populations. Furthermore, DNA content tests indicated a narrow range in ploidy in wild populations compared with lawn cultivars, further supporting a hypothesis of divergence between wild and pedigree cultivars. These results indicate the recent invasion of Kentucky bluegrass in the northern Great Plains is not because of adaptation or propagule pressure, but rather likely an environmental or land use shift.


Ibis ◽  
2018 ◽  
Vol 160 (4) ◽  
pp. 855-869 ◽  
Author(s):  
Luzhang Ruan ◽  
Wei Xu ◽  
Yuqing Han ◽  
Chaoying Zhu ◽  
Bicai Guan ◽  
...  

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Perla Farhat ◽  
Sonja Siljak-Yakovlev ◽  
Nicolas Valentin ◽  
Carlos Fabregat ◽  
Silvia Lopez-Udias ◽  
...  

Abstract Background Gene flow and polyploidy have been found to be important in Juniperus evolution. However, little evidence has been published elucidating the association of both phenomena in juniper taxa in the wild. Two main areas were studied in Spain (Eastern Iberian Range and Sierra de Baza) with both diploid and tetraploid taxa present in sympatry. Gene flow and ploidy level were assessed for these taxa and the resulted offspring. Results Twenty-two allo-triploid hybrids between J. sabina var. sabina and J. thurifera were found in the Eastern Iberian Range population. However, in the Sierra de Baza population no triploids were found. Instead, 18 allo-tetraploid hybrids between two tetraploid taxa: J. sabina var. balkanensis and J. thurifera were discovered. High genetic diversity was exhibited among the tetraploid hybrids at Sierra de Baza, in contrast to the genetically identical triploid hybrids at the Eastern Iberian Range; this suggests meiotic difficulties within the triploid hybrids. In addition, unidirectional gene flow was observed in both studied areas. Conclusion Polyploidy and hybridization can be complementary partners in the evolution of Juniperus taxa in sympatric occurrences. Juniperus was shown to be an ideal coniferous model to study these two phenomena, independently or in concert.


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