Chloroplast DNA polymorphisms in eastern hemlock: range-wide genogeographic analyses and implications for gene conservation

Michée Joseph Lemieux; Jean Beaulieu; Jean Bousquet

doi:10.1139/x11-005

Chloroplast DNA polymorphisms in eastern hemlock: range-wide genogeographic analyses and implications for gene conservation

Canadian Journal of Forest Research ◽

10.1139/x11-005 ◽

2011 ◽

Vol 41 (5) ◽

pp. 1047-1059 ◽

Cited By ~ 10

Author(s):

Michée Joseph Lemieux ◽

Jean Beaulieu ◽

Jean Bousquet

Keyword(s):

Chloroplast Dna ◽

Population Differentiation ◽

Genetic Distances ◽

Adelges Tsugae ◽

Eastern Hemlock ◽

Dna Polymorphisms ◽

Ex Situ ◽

Glacial Refugium ◽

Geographical Pattern ◽

Genetic Patterns

The objective of this study was to determine if the genetic diversity of eastern hemlock ( Tsuga canadensis (L.) Carrière) is uniformly distributed or structured. Such information is relevant to help guide conservation efforts. Individuals were sampled in 60 range-wide populations of T. canadensis and genotyped at seven polymorphic chloroplast DNA loci. All 16 chlorotypes identified in T. canadensis were highly divergent from the unique chlorotype detected in Carolina hemlock ( Tsuga caroliniana Engelm.). Among-population differentiation in T. canadensis was low (GST = 0.020) and the distribution of chlorotypes did not show any strong geographical pattern, which is likely due to the homogenizing effect of pollen gene flow during the Holocene. Nevertheless, a spatial Bayesian approach revealed two distinct groups of populations. Furthermore, an analysis of relative genetic distances indicated that southeastern Appalachian populations harboured greater population differentiation while conserving relatively high allelic richness, which might represent the imprint of an ancient glacial refugium in the region. Thus, these distinctive genetic patterns and the risk of Tsuga decline following climate warming combined with the introduction of the insect Adelges tsugae (Annand) indicate that the southern part of the range should be considered of high priority for ex situ conservation.

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A Comparison of Population Differentiation Across Four Classes of Gene Marker in Limber Pine (Pinus flexilis James)

Genetics ◽

10.1093/genetics/146.3.1153 ◽

1997 ◽

Vol 146 (3) ◽

pp. 1153-1163 ◽

Cited By ~ 1

Author(s):

Robert G Latta ◽

Jeffry B Mitton

Keyword(s):

Gene Flow ◽

Chloroplast Dna ◽

Population Differentiation ◽

Paternity Analysis ◽

Allelic Frequency ◽

Dna Polymorphisms ◽

Gene Marker ◽

Pinus Flexilis ◽

Limber Pine ◽

Allozyme Loci

We examined genetic differentiation among seven populations of limber pine using four classes of gene marker. Among-population differentiation was much higher for maternally inherited mitochondrial DNA polymorphisms than for paternally inherited chloroplast DNA, indicating that wind-dispersed pollen is the main agent of gene flow. Chloroplast DNA differentiation is consistent with gene flow estimated in a prior paternity analysis. Using the estimates of seed and pollen flow derived from mtDNA and cpDNA differentiation, we predicted the value of Fst expected at nuclear loci. Allelic frequency differentiation at seven allozyme loci was relatively homogeneous across loci and consistent with the level of differentiation predicted from the organellar haplotypes. By contrast four of the nine randomly applied polymorphic DNA (RAPD) markers we examined were more strongly differentiated than this prediction, suggesting the action of diversifying selection. However, the differentiated RAPDs and mtDNA were concordant in dividing the populations into two groups, suggesting some historical division. Simulations show that such historical division can increase the interlocus variance in Fst but neither a historical nor an equilibrium model could account for the joint distribution of Fst estimates across both allozyme and RAPD loci. Thus at least one group of loci appears to be experiencing natural selection.

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Abundant Mitochondrial Genome Diversity, Population Differentiation and Convergent Evolution in Pines

Genetics ◽

10.1093/genetics/150.4.1605 ◽

1998 ◽

Vol 150 (4) ◽

pp. 1605-1614

Author(s):

Junyuan Wu ◽

Konstantin V Krutovskii ◽

Steven H Strauss

Keyword(s):

Mitochondrial Dna ◽

Population Differentiation ◽

Mitochondrial Gene ◽

Dna Polymorphisms ◽

Neighbor Joining ◽

Closely Related Species ◽

Breeding Programs ◽

Length Polymorphisms ◽

Polymerase Chain ◽

Mitochondrial Genome Diversity

Abstract We examined mitochondrial DNA polymorphisms via the analysis of restriction fragment length polymorphisms in three closely related species of pines from western North America: knobcone (Pinus attenuata Lemm.), Monterey (P. radiata D. Don), and bishop (P. muricata D. Don). A total of 343 trees derived from 13 populations were analyzed using 13 homologous mitochondrial gene probes amplified from three species by polymerase chain reaction. Twenty-eight distinct mitochondrial DNA haplotypes were detected and no common haplotypes were found among the species. All three species showed limited variability within populations, but strong differentiation among populations. Based on haplotype frequencies, genetic diversity within populations (HS) averaged 0.22, and population differentiation (GST and θ) exceeded 0.78. Analysis of molecular variance also revealed that >90% of the variation resided among populations. For the purposes of genetic conservation and breeding programs, species and populations could be readily distinguished by unique haplotypes, often using the combination of only a few probes. Neighbor-joining phenograms, however, strongly disagreed with those based on allozymes, chloroplast DNA, and morphological traits. Thus, despite its diagnostic haplotypes, the genome appears to evolve via the rearrangement of multiple, convergent subgenomic domains.

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Phylogeography of Prunus armeniaca L. revealed by chloroplast DNA and nuclear ribosomal sequences

Scientific Reports ◽

10.1038/s41598-021-93050-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Wen-Wen Li ◽

Li-Qiang Liu ◽

Qiu-Ping Zhang ◽

Wei-Quan Zhou ◽

Guo-Quan Fan ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Variation ◽

Chloroplast Dna ◽

Population Expansion ◽

Prunus Armeniaca ◽

River Valley ◽

Nuclear Ribosomal Dna ◽

Glacial Refugium ◽

Ili River Valley ◽

Wild Apricot

AbstractTo clarify the phytogeography of Prunus armeniaca L., two chloroplast DNA fragments (trnL-trnF and ycf1) and the nuclear ribosomal DNA internal transcribed spacer (ITS) were employed to assess genetic variation across 12 P. armeniaca populations. The results of cpDNA and ITS sequence data analysis showed a high the level of genetic diversity (cpDNA: HT = 0.499; ITS: HT = 0.876) and a low level of genetic differentiation (cpDNA: FST = 0.1628; ITS: FST = 0.0297) in P. armeniaca. Analysis of molecular variance (AMOVA) revealed that most of the genetic variation in P. armeniaca occurred among individuals within populations. The value of interpopulation differentiation (NST) was significantly higher than the number of substitution types (GST), indicating genealogical structure in P. armeniaca. P. armeniaca shared genotypes with related species and may be associated with them through continuous and extensive gene flow. The haplotypes/genotypes of cultivated apricot populations in Xinjiang, North China, and foreign apricot populations were mixed with large numbers of haplotypes/genotypes of wild apricot populations from the Ili River Valley. The wild apricot populations in the Ili River Valley contained the ancestral haplotypes/genotypes with the highest genetic diversity and were located in an area considered a potential glacial refugium for P. armeniaca. Since population expansion occurred 16.53 kyr ago, the area has provided a suitable climate for the population and protected the genetic diversity of P. armeniaca.

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Vegetation dynamics in declining eastern hemlock stands: 9 years of forest response to hemlock woolly adelgid infestation

Canadian Journal of Forest Research ◽

10.1139/x06-050 ◽

2006 ◽

Vol 36 (6) ◽

pp. 1435-1450 ◽

Cited By ~ 112

Author(s):

Anne K Eschtruth ◽

Natalie L Cleavitt ◽

John J Battles ◽

Richard A Evans ◽

Timothy J Fahey

Keyword(s):

Invasive Plants ◽

Light Availability ◽

Hemlock Woolly Adelgid ◽

Adelges Tsugae ◽

Eastern Hemlock ◽

Percent Cover ◽

Eastern United States ◽

Transmitted Radiation ◽

Exotic Invasive ◽

Exotic Invasive Plants

Hemlock woolly adelgid (HWA; Adelges tsugae Annand) infestations have resulted in the continuing decline of eastern hemlock (Tsuga canadensis (L.) Carrière) throughout much of the eastern United States. In 1994 and 2003, we quantified the vegetation composition and structure of two hemlock ravines in the Delaware Water Gap National Recreation Area. This is the first study to use pre-adelgid disturbance data, annual monitoring of infestation severity, and annual records of hemlock health to assess forest response to HWA infestation. In 2003, 25% of monitored hemlock trees were either dead or in severe decline. Measures of hemlock decline (crown vigor, transparency, density, and dieback) were correlated with HWA infestation severity and changes in light availability over the study period. Average percent total transmitted radiation more than doubled at these sites from 5.0% in 1994 to 11.7% in 2003. The total percent cover of vascular plants increased from 3.1% in 1994 to 11.3% in 2003. Species richness increased significantly, and more species were gained (53) than lost (19) from both ravine floras over the 9-year study period. Though exotic invasive plants were absent from these ravines in 1994, our 2003 resurvey found invasive plants in 35% of the permanent vegetation plots.

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The Past, Present, and Future of the Hemlock Woolly Adelgid (Adelges tsugae) and Its Ecological Interactions with Eastern Hemlock (Tsuga canadensis) Forests

Insects ◽

10.3390/insects9040172 ◽

2018 ◽

Vol 9 (4) ◽

pp. 172 ◽

Cited By ~ 5

Author(s):

Aaron Ellison ◽

David Orwig ◽

Matthew Fitzpatrick ◽

Evan Preisser

Keyword(s):

Biological Diversity ◽

Carbon Sources ◽

Hemlock Woolly Adelgid ◽

Adelges Tsugae ◽

Ecosystem Dynamics ◽

Eastern Hemlock ◽

Carbon Sinks ◽

The North ◽

Spread Dynamics ◽

Landscape Scales

The nonnative hemlock woolly adelgid is steadily killing eastern hemlock trees in many parts of eastern North America. We summarize impacts of the adelgid on these forest foundation species; review previous models and analyses of adelgid spread dynamics; and examine how previous forecasts of adelgid spread and ecosystem dynamics compare with current conditions. The adelgid has reset successional sequences, homogenized biological diversity at landscape scales, altered hydrological dynamics, and changed forest stands from carbon sinks into carbon sources. A new model better predicts spread of the adelgid in the south and west of the range of hemlock, but still under-predicts its spread in the north and east. Whether these underpredictions result from inadequately modeling accelerating climate change or accounting for people inadvertently moving the adelgid into new locales needs further study. Ecosystem models of adelgid-driven hemlock dynamics have consistently forecast that forest carbon stocks will be little affected by the shift from hemlock to early-successional mixed hardwood stands, but these forecasts have assumed that the intermediate stages will remain carbon sinks. New forecasting models of adelgid-driven hemlock decline should account for observed abrupt changes in carbon flux and ongoing and accelerating human-driven land-use and climatic changes.

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Assessing the Effect of Eastern Hemlock (Tsuga canadensis) Decline from Hemlock Woolly Adelgid (Adelges tsugae) Infestation on Ectomycorrhizal Colonization and Growth of Red Oak (Quercus rubra) Seedlings

The American Midland Naturalist ◽

10.1674/0003-0031-186.1.16 ◽

2021 ◽

Vol 186 (1) ◽

Author(s):

Kathryn E. Caruso ◽

Jonathan L. Horton ◽

Alisa A. Hove

Keyword(s):

Quercus Rubra ◽

Tsuga Canadensis ◽

Hemlock Woolly Adelgid ◽

Adelges Tsugae ◽

Eastern Hemlock ◽

Red Oak ◽

Ectomycorrhizal Colonization

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Genetic diversity among and within populations of Raphanus raphanistrum and Brassica tournefortii (Brassicaceae) in Israel: a case study for planning ex situ conservation program of crop wild relatives

Israel Journal of Plant Sciences ◽

10.1163/22238980-00001027 ◽

2018 ◽

Vol 65 (3-4) ◽

pp. 153-160

Author(s):

Oz Barazani ◽

Nir Hanin ◽

Prabodh Kumar Bajpai ◽

Yoni Waitz ◽

Michal Barzilai ◽

...

Keyword(s):

Genetic Diversity ◽

Reproductive Biology ◽

Ex Situ Conservation ◽

Diversity Indices ◽

Crop Wild Relatives ◽

Genetic Distances ◽

Habitat Characteristics ◽

Ex Situ ◽

Raphanus Raphanistrum ◽

Brassica Tournefortii

The winter annuals Brassica tournefortii and Raphanus raphanistrum (Brassicaceae) share similar habitats and life-history traits, but differ in their reproduction system (self-compatibility vs. self-incompatibility, respectively). The two phylogenetically close species offer means to assess the effect of reproductive biology on genetic diversity between and within populations. In general, genetic diversity between populations of B. tournefortii was higher than that found between populations of R. raphanistrum, while higher genetic diversity indices were evident within populations of R. raphanistrum. In addition, the results of pairwise genetic distances indicated that the genetic distances between populations can be associated to the species’ reproductive biology and not to the population’s distribution pattern. We discuss whether knowledge of reproductive and habitat characteristics can be used to predict genetic diversity when planning sampling scheme for ex situ conservation.

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Combined Effects of Hemlock Woolly Adelgid (Adelges tsugae) Infestation and Treatment with Imidacloprid on Eastern Hemlock (Tsuga canadensis) Leaf Radiometry

Journal of Forestry ◽

10.1093/jofore/fvz021 ◽

2019 ◽

Vol 117 (4) ◽

pp. 340-350 ◽

Cited By ~ 1

Author(s):

Heath W Garris ◽

Thomas H Settle ◽

Jonathan E Crossman ◽

Stephen J Grider ◽

Shawnté L Michaels

Keyword(s):

Optical Properties ◽

Tsuga Canadensis ◽

Hemlock Woolly Adelgid ◽

Adelges Tsugae ◽

Eastern Hemlock ◽

Abiotic Stressors ◽

Leaf Optical Properties ◽

Photosynthetic Potential ◽

And Control ◽

Potential Efficiency

Abstract The neonicotinoid systemic insecticide imidacloprid has proven to be an effective treatment for the prevention and control of hemlock woolly adelgid (Adelges tsugae Annand) in southeastern populations of eastern hemlock (Tsuga canadensis L.). Recent studies have demonstrated that imidacloprid and A. tsugae both stimulate salicylic acid-dependent physiological responses in plant tissues responsible for plant defenses against pathogens, timing of developmental outcomes including flowering and leaf senescence, and resilience to abiotic stressors. We evaluated the interacting effects of A. tsugae presence/absence and treatment with imidacloprid on leaf optical properties indicative of photosynthetic potential, photosynthetic efficiency, and tissue senescence. Our results indicated that A. tsugae changes lower canopy leaf optical properties indicative of reduced photosynthetic potential/efficiency and accelerated senescence in mature leaves. Imidacloprid was associated with declines in photosynthetic potential and showed a largely similar, though less pronounced, effect on leaf spectral properties to that of A. tsugae.

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