Conservation genetics of Pitcher’s thistle (Cirsium pitcheri), an endangered Great Lakes endemic

Botany ◽  
2010 ◽  
Vol 88 (3) ◽  
pp. 250-257 ◽  
Author(s):  
Martha Gauthier ◽  
Emily Crowe ◽  
Lindsey Hawke ◽  
Neil Emery ◽  
Paul Wilson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Great Lakes ◽  
Genetic Data ◽  
Nuclear Data ◽  
Population Connectivity ◽  
Chloroplast Microsatellite ◽  
Management Plans ◽  
Low Levels ◽  
Cirsium Pitcheri ◽  
Pitcher's Thistle

Pitcher's thistle ( Cirsium pitcheri Torr. ex Eaton (Torr. & Gray)) is a Great Lakes endemic that in Canada is designated as threatened at both the provincial (Ontario) and national levels. Management plans will benefit from conservation genetic data, which can provide insight into population genetic diversity and differentiation. We obtained genetic data from nuclear and chloroplast microsatellite markers from 17 populations of C. pitcheri around the Great Lakes. The nuclear data revealed overall low levels of diversity, high levels of inbreeding, and low levels of population connectivity. The chloroplast data identified a single haplotype, which is consistent with reduced genetic diversity following postglacial colonization. The high levels of inbreeding within populations will likely pose a serious threat to populations in the short term; these have resulted from a combination of low connectivity between populations, and small and fluctuating population sizes. Future management of C. pitcheri populations should consider human-mediated dispersal of plants or seeds among sites.

The evolutionary history and conservation value of disjunct Bartonia paniculata subsp. paniculata (Branched Bartonia) populations in Canada

Botany ◽  
2013 ◽  
Vol 91 (9) ◽  
pp. 605-613 ◽  
Author(s):  
Claudia Ciotir ◽  
Chris Yesson ◽  
Joanna Freeland
Keyword(s):  
Great Lakes ◽  
Evolutionary History ◽  
Common Ancestor ◽  
Recent Common Ancestor ◽  
Great Lakes Region ◽  
Conservation Value ◽  
Most Recent Common Ancestor ◽  
Disjunct Populations ◽  
Management Plans ◽  
Global Status

Understanding the spatial distribution of genetic diversity and its evolutionary history is an essential part of developing effective biodiversity management plans. This may be particularly true when considering the value of peripheral or disjunct populations. Although conservation decisions are often made with reference to geopolitical boundaries, many policy-makers also consider global distributions, and therefore a species’ global status may temper its regional status. Many disjunct populations can be found in the Great Lakes region of North America, including those of Bartonia paniculata subsp. paniculata, a species that has been designated as threatened in Canada but globally secure. We compared chloroplast sequences between disjunct (Canada) and core (USA) populations of B. paniculata subsp. paniculata separated by 600 km, which is the minimum distance between disjunct and core populations in this subspecies. We found that although lineages within the disjunct populations shared a relatively recent common ancestor, the genetic divergence between plants from Ontario and New Jersey was substantially greater than expected for a consubspecific comparison. A coalescence-based analysis dated the most recent common ancestor of the Canadian and US populations at approximately 534 000 years ago with the lower confidence estimate at 226 000 years ago. This substantially predates the Last Glacial Maximum and suggests that disjunct and core populations have followed independent evolutionary trajectories throughout multiple glacial–interglacial cycles. Our findings provide important insight into the diverse processes that have resulted in numerous disjunct species in the Great Lakes region and highlight a need for additional work on Canadian B. paniculata subsp. paniculata taxonomy prior to a reevaluation of its conservation value.

Analysis of Genetic Diversity of Saccharum Complex Using Chloroplast Microsatellite Markers

Sugar Tech ◽  
2015 ◽  
Vol 18 (2) ◽  
pp. 141-148 ◽  
Author(s):  
Punnya Raj ◽  
A. Selvi ◽  
P. T. Prathima ◽  
N. V. Nair
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Saccharum Complex ◽  
Chloroplast Microsatellite

scholarly journals The genetic legacy of fragmentation and overexploitation in the threatened medicinal African pepper-bark tree, Warburgia salutaris

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Annae M. Senkoro ◽  
Pedro Talhinhas ◽  
Fernanda Simões ◽  
Paula Batista-Santos ◽  
Charlie M. Shackleton ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Habitat Degradation ◽  
Random Mating ◽  
Diversity Management ◽  
Iucn Red List ◽  
Ex Situ ◽  
Management Plans ◽  
Conservation Actions ◽  
Genetic Diversity Management ◽  
High Level

AbstractThe pepper-bark tree (Warburgia salutaris) is one of the most highly valued medicinal plant species worldwide. Native to southern Africa, this species has been extensively harvested for the bark, which is widely used in traditional health practices. Illegal harvesting coupled with habitat degradation has contributed to fragmentation of populations and a severe decline in its distribution. Even though the species is included in the IUCN Red List as Endangered, genetic data that would help conservation efforts and future re-introductions are absent. We therefore developed new molecular markers to understand patterns of genetic diversity, structure, and gene flow of W. salutaris in one of its most important areas of occurrence (Mozambique). In this study, we have shown that, despite fragmentation and overexploitation, this species maintains a relatively high level of genetic diversity supporting the existence of random mating. Two genetic groups were found corresponding to the northern and southern locations. Our study suggests that, if local extinctions occurred in Mozambique, the pepper-bark tree persisted in sufficient numbers to retain a large proportion of genetic diversity. Management plans should concentrate on maintaining this high level of genetic variability through both in and ex-situ conservation actions.

scholarly journals Genetic diversity of rice stem borer (Chilo suppressalis Walker) from Northern Iran and comparison with other countries

2016 ◽  
Vol 48 (3) ◽  
pp. 360 ◽  
Author(s):  
M. Shayanmehr ◽  
E. Yoosefi-Lafooraki
Keyword(s):  
Genetic Diversity ◽  
Stem Borer ◽  
Chilo Suppressalis ◽  
Mazandaran Province ◽  
Northern Iran ◽  
Low Genetic Diversity ◽  
High Gene ◽  
Major Pest ◽  
Different Populations ◽  
Low Levels

Rice striped stem borer, <em>Chilo suppressalis</em> Walker (Lepidoptera: Crambidae) is considered the major pest of rice in Iran. Because of the serious damage on rice in Northern Iran, the present study was conducted to investigate genetic diversity within populations of <em>C. suppressalis</em>, from Mazandaran using a template of cytochrome oxidase I gene, 750 bps, (<em>COI</em>). Later the haplotypes from Iran were compared with those found in other countries. According to the results of this study, there is very low genetic diversity (two haplotypes) among different populations of this pest in populations of Northern Iran. The genetic similarity and low levels of genetic diversity of these populations suggest that the pest colonization occurred relatively recently and there is high gene flow between these populations of the province. In addition, haplotypes of Mazandaran province are different with those found in other countries. The similarity of Iranian population (Simorgh) with one population from China indicated that China might be the origin of <em>C. suppresalis</em>.

scholarly journals Population dynamics of Amazonian floodplain forest species support spatial variation on genetic diversity but not range expansions through time

2021 ◽  
Author(s):  
Gregory Thom ◽  
Camila C. Ribas ◽  
Eduardo Shultz ◽  
Alexandre Aleixo ◽  
Cristina Y. Miyaki
Keyword(s):  
Genetic Diversity ◽  
Spatial Patterns ◽  
Amazon Basin ◽  
Population Connectivity ◽  
Alternative Methods ◽  
Forest Species ◽  
Effective Population ◽  
Habitat Specificity ◽  
Heterogeneous Distribution ◽  
Solimões River

Aim: We tested if historical demographic changes of populations occurring on the floodplains of a major Amazon Basin tributary could be associated with range expansions from upper and middle sections of the river, following the establishment of widespread river-created environments during the Late Pleistocene and Holocene. Location: Solimoes River, Western Amazon, South America Taxon: Myrmoborus lugubris, Thamnophilus cryptoleucus and Myrmotherula assimilis Methods: We analyzed thousands of UltraConserved Elements to explore spatial patterns of genetic diversity and connectivity between individuals. Range expansions were tested with alternative methods. We quantified habitat preference for the analyzed species in order to test if the occupation of dynamic habitats could predict spatial patterns of genetic diversity. Results: Our study did not support shared population range expansions related to historical regionalized changes in habitat availability. We found considerable variation in the spatial distribution of the genetic diversity between studied taxa, and that species with higher levels of specialization to dynamic environments have a more heterogeneous distribution of genetic diversity and reduced levels of gene flow across space. Main conclusions: Our results suggest that demographic expansions along the Solimoes River might be linked to geographic homogeneous oscillation in the distribution of floodplain environments, promoting effective population size changes but not range expansion. We found that habitat specificity might be a good predictor of population connectivity along the Amazonian floodplains.

scholarly journals Population genetic structure and variability in Lindera glauca (Lauraceae) indicates low levels of genetic diversity and skewed sex ratios in natural populations in mainland China

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8304 ◽  
Author(s):  
Biao Xiong ◽  
Limei Zhang ◽  
Shubin Dong ◽  
Zhixiang Zhang
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Isolation By Distance ◽  
Sex Ratios ◽  
Mainland China ◽  
Small Sample ◽  
Chloroplast Microsatellites ◽  
Wild Populations ◽  
Haplotype Networks ◽  
Low Levels

Lindera glauca (Lauraceae) is a tree of economic and ecological significance that reproduces sexually and asexually via apomictic seeds. It is widely distributed in the low-altitude montane forests of East Asia. Despite the potential implications of a mixed reproductive system in terms of genetic diversity, few studies have focused on this aspect. In this study, the genetic structure of wild populations of L. glauca was investigated via genetic analyses. Overall, 13 nuclear microsatellites (nSSRs) and five chloroplast microsatellites (cpSSRs) were used to genotype 300 individual plants, taken from 20 wild populations (a small sample size in some wild populations is due to the limitation of its specific reproduction, leading to certain limitations in the results of this study) and two cultivated populations ranging across nearly the entire natural distribution of mainland China. The populations exhibited low levels of genetic diversity (nSSR: AR = 1.75, Ho = 0.32, He = 0.36; cpSSR: Nb = 2.01, Hrs = 0.40), and no significant effect of isolation by distance between populations existed, regardless of marker type (nSSR: R2 = 0.0401, P = 0.068; cpSSR: R2 = 0.033, P = 0.091). Haplotype networks showed complex relationships among populations, and the H12 haplotype was predominant in most populations. Analyses of molecular variance obtained with nuclear markers (Fsc = 0.293, FST = 0.362) and chloroplast markers (Fsc = 0.299, FST = 0.312) were similar. The migration ratio of pollen flow versus seed flow in this study was negative (r = −1.149). Results suggest that weak barriers of dispersal between populations and/or the similarity of founders shared between neighbors and distant populations are indicative of the gene flow between populations more likely involving seeds. Wild L. glauca in mainland China was inferred to have highly skewed sex ratios with predominant females. In addition, some populations experienced a recent bottleneck effect, especially in Gujianshan, Chongqing, and southwest China (population GJS). It is suggested that few wild male individuals should be conserved in order to maintain overall genetic diversity in the wild populations of this species. These findings provide important information for the sustainable utilization and preservation of the overall genetic diversity of L. glauca.

scholarly journals Evolution of recombination in eutherian mammals: insights into mechanisms that affect recombination rates and crossover interference

2013 ◽  
Vol 280 (1771) ◽  
pp. 20131945 ◽  
Author(s):  
Joana Segura ◽  
Luca Ferretti ◽  
Sebastián Ramos-Onsins ◽  
Laia Capilla ◽  
Marta Farré ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mammalian Species ◽  
Evolutionary Change ◽  
Critical Importance ◽  
Recombination Rates ◽  
Allelic Variants ◽  
Crossover Interference ◽  
Chromosomal Segregation ◽  
Low Levels ◽  
Taxonomic Groups

Recombination allows faithful chromosomal segregation during meiosis and contributes to the production of new heritable allelic variants that are essential for the maintenance of genetic diversity. Therefore, an appreciation of how this variation is created and maintained is of critical importance to our understanding of biodiversity and evolutionary change. Here, we analysed the recombination features from species representing the major eutherian taxonomic groups Afrotheria, Rodentia, Primates and Carnivora to better understand the dynamics of mammalian recombination. Our results suggest a phylogenetic component in recombination rates (RRs), which appears to be directional, strongly punctuated and subject to selection. Species that diversified earlier in the evolutionary tree have lower RRs than those from more derived phylogenetic branches. Furthermore, chromosome-specific recombination maps in distantly related taxa show that crossover interference is especially weak in the species with highest RRs detected thus far, the tiger. This is the first example of a mammalian species exhibiting such low levels of crossover interference, highlighting the uniqueness of this species and its relevance for the study of the mechanisms controlling crossover formation, distribution and resolution.

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