Evaluating the relationship between diploid and tetraploid Vaccinium oxycoccos (Ericaceae) in eastern Canada

Botany ◽  
2015 ◽  
Vol 93 (10) ◽  
pp. 623-636 ◽  
Author(s):  
Tyler W. Smith ◽  
Charlotte Walinga ◽  
Song Wang ◽  
Paul Kron ◽  
Jan Suda ◽  
...  

Vaccinium oxycoccos s.l. is a complex of diploid and polyploid plants. The taxonomic relationship between the cytotypes is uncertain, with conflicting treatments in recent revisions. To clarify this situation, we investigated the relationships among ploidy, morphology, and genetic diversity in this group. We collected samples from a 1000 km transect in eastern Canada. We used flow cytometry to determine DNA ploidy, completed a morphometric analysis of flowering stems, and assessed genetic diversity using AFLPs. Diploids only occurred growing in mixed populations with tetraploids. There were statistically significant morphological differences between ploidies; however, tetraploid variation encompasses the diploid range for most characters. AFLP data demonstrate that the tetraploids have undergone genetic divergence since their formation, obscuring whether they are auto- or allo-polyploids. Our results agree with previous work using isozymes, which revealed genetic divergence of diploids and tetraploids in North America; and morphometry, which demonstrated clear distinctions between diploids and tetraploids in Europe. We found that diploids and tetraploids co-occur much more frequently than previously recognized, which may explain the conflicting treatment of this group by North American taxonomists. We recommend recognizing diploids and tetraploids as distinct species. The distribution of the two species in North America suggests two hypotheses regarding the successful establishment of the tetraploid: the tetraploids’ success is due to their capacity to exploit novel habitats outside the range of the diploid; or the tetraploid has in fact already out-competed the diploid in large areas of its former range, limiting the diploid to the far north. While we cannot rule out ongoing gene flow between diploids and tetraploids, it is likely a rare phenomenon in this group.

2009 ◽  
Vol 45 (No. 4) ◽  
pp. 155-159 ◽  
Author(s):  
X.Z. Liu ◽  
C.S. He ◽  
Y.M. Yang ◽  
H.Y. Zhang

AFLP analyses were used to assess the genetic similarity among selected accessions at the South China Tobacco Breeding Research Centre (Yunnan province, Southwest China). 154 AFLP polymorphic fragments out of 561 fragments were used to assess the genetic diversity among 28 tobacco accessions. The average number of polymorphic bands per AFLP primer pair was 15.4. AFLPs seemed to be an effective classification tools for germplasm conservation and breeding. Limited genetic variation was detected within this group of accessions. The relationship of cultivars was estimated by cluster analysis based on AFLP data.


2015 ◽  
Vol 61 (1) ◽  
pp. 155-180 ◽  
Author(s):  
Jitka Jančúchová-Lásková ◽  
Eva Landová ◽  
Daniel Frynta

Abstract Animal species are delimited by reproductive isolation mechanisms (RIMs). Postzygotic RIMs are mainly products of genetic differences and thus their strength increases with elapsed divergence time. The relationship between postzygotic reproductive isolation and genetic divergence, however, differs considerably among major clades of vertebrates. We reviewed the available literature providing empirical evidence of natural and/or experimental hybridization between distinct species of lizards (squamates except snakes). We found that hybridization events are widely distributed among nearly all major lizard clades. The majority of research focuses on parthenogenetic species and/or polyploid hybrids in families Lacertidae, Teiidae and Gekkonidae. Homoploid bisexual hybrids are mainly reported within Lacertidae and Iguania groups. As a proxy of genetic divergence of the hybridizing taxa we adopted nucleotide sequence distance (HKY85) of mitochondrial cyt b gene. The upper limit of genetic divergence was similar with regard to both parthenogenetic and bisexual hybrids. Maximum values of these distances between hybridizing species of lizards approached 18%?21%, which is comparable to or even exceeds the corresponding values reported for other principal clades of vertebrates. In spite of this, F1 hybrids are typically at least partially fertile in lizards and thus genetic in-trogression between highly divergent species is possible. The relationship between the genetic distance and hybrid fertility was not found.


2012 ◽  
Vol 40 (1) ◽  
pp. 261 ◽  
Author(s):  
Zahra NEMATI ◽  
Ali TEHRANIFAR ◽  
Mohammad FARSI ◽  
Amin MIRSHAMSI KAKHKI ◽  
Hossein NEMATI ◽  
...  

The present research evaluated the diversity of a number of Iranian pomegranate cultivars using fruit morphological characteristics and AFLP markers. Thirty-one pomegranate cultivars were collected from Yazd Pomegranate Collection in Iran to study their diversity. Seven AFLP primer combinations were used to amplify a total of 112 polymorphic fragments (47.26%). By use of AFLPs, a low genetic diversity level was detected among cultivars. The relationship between fruit characteristics was analyzed using the principal component analysis (PCA). The cluster analysis based on both fruit characteristics and AFLP data indicated that cultivars were not grouped according to their geographic origins. Moreover, the correlation between the diversity matrix based on fruit characteristics and Dice’s genetic similarity coefficient was insignificant (r=0.06). The results obtained from this study can improve the conservation and management of pomegranate germplasm resources and could be helpful in optimizing breeding programs.


2020 ◽  
Vol 57 (4) ◽  
pp. 1324-1327
Author(s):  
Phillip Shults ◽  
Alphina Ho ◽  
Estelle M Martin ◽  
Bethany L McGregor ◽  
Edward L Vargo

Abstract Much of the bluetongue (BT) and epizootic hemorrhagic disease (EHD) research in North America focuses on white-tail deer and Culicoides sonorensis (Wirth & Jones) (Diptera: Ceratopogonidae), though several other biting midge species have been suggested as vectors. Culicoides stellifer (Coquillett) has been associated with hosts susceptible to hemorrhagic disease (HD), and more recently, specimens from Florida have tested positive for EHD and BT viral RNA. If C. stellifer is acting as a vector, this could have an impact on the distribution of HD in North America. To determine if gene flow is occurring across the range of C. stellifer within the southeast United States, a mitochondrial haplotype analysis was performed using the COI gene. Our haplotype network showed no population structure in C. stellifer from Florida, Texas, and South Carolina, as the overall genetic divergence between these sites was equal to the genetic divergence within each. We also compared these haplotypes to published sequences of C. stellifer collected in Ontario, Canada. Surprisingly, the genetic diversity of the flies from Ontario was two times greater than what was observed between the southeast U.S. collection sites. This considerable divergence could be evidence of a cryptic species. A better understanding of the connectivity between C. stellifer populations across all of North America will give insight into the distribution of HD. Our results show that gene flow is occurring between sites in the southeastern United States and potentially throughout the eastern distribution of the species.


Phytotaxa ◽  
2019 ◽  
Vol 413 (3) ◽  
pp. 231-243 ◽  
Author(s):  
KENJI SUETSUGU ◽  
AKIHIKO KINOSHITA ◽  
TIAN-CHUAN HSU

This paper presents a re-evaluation of the taxonomic status of Sciaphila tosaensis and S. megastyla (Triuridaceae) distributed in Japan and Taiwan. Based on the detailed morphological data, we concluded that these two species should both be treated as distinct species rather than synonyms of S. secundiflora. Sciaphila tosaensis differs from S. secundiflora and S. megastyla in having very narrow male perianth segments and female perianth segments distinctly shorter than male perianth segments. Sciaphila megastyla differs from the other two species in having very conspicuous style and stigma that is ca. 1.5 times as long as ovary in the flowering stage. Furthermore, a lectotype is designated of S. megastyla because its holotype has been lost. Molecular data also showed that there is considerable genetic divergence between S. tosaensis and S. megastyla, supporting that the morphological differences are mirrored by their genetic distances.


Botany ◽  
2012 ◽  
Vol 90 (8) ◽  
pp. 743-754 ◽  
Author(s):  
Tuula Niskanen ◽  
Kare Liimatainen ◽  
Ilkka Kytövuori ◽  
Joseph F. Ammirati

Five new Cortinarius species with medium to large basidiomata are described based on morphological and molecular data. Three of them, Cortinarius aavae , Cortinarius brunneocalcarius , and Cortinarius grosmorneënsis , belong to subgenus Telamonia and one, Cortinarius subfloccopus , to clade /Fulvescentes. The relationship of the fifth species, Cortinarius brunneotinctus , was not solved but it resembles species of clade /Anomali. Cortinarius brunneocalcarius and C. aavae do not have close relatives within the subgenus Telamonia; whereas, C. grosmorneënsis belongs to section Brunnei. Cortinarius grosmorneënsis is only known from eastern Canada, but the other four species have a wide distribution: C. brunneocalcarius and C. subfloccopus occur in North America and Europe, and C. brunneotinctus and C. aavae in western and eastern North America. The descriptions of the novel species are presented and comparison to similar species provided.


Author(s):  
R. A. Nunamaker ◽  
C. E. Nunamaker ◽  
B. C. Wick

Culicoides variipennis (Coquillett) is probably the most economically important species of biting midge in the U.S. due to its involvement in the transmission of bluetongue (BT) disease of sheep, cattle and ruminant wildlife, and epizootic hemorrhagic disease (EHD) of deer. Proposals have been made to recognize the eastern and western populations of this insect vector as distinct species. Others recommend use of the term “variipennis complex” until such time that the necessary biosystematic studies have been made to determine the genetic nature and/or minute morphological differences within the population structure over the entire geographic range of the species. Increasingly, students of ootaxonomy are relying on scanning electron microscopy (SEM) to assess chorionic features. This study was undertaken to provide comparative chorionic data for the C. variipennis complex.Culicoides variipennis eggs were collected from a laboratory colony maintained in Laramie, Wyoming.


2000 ◽  
Vol 23 (3) ◽  
pp. 541-544 ◽  
Author(s):  
José Alexandre Felizola Diniz-Filho ◽  
Mariana Pires de Campos Telles

In the present study, we used both simulations and real data set analyses to show that, under stochastic processes of population differentiation, the concepts of spatial heterogeneity and spatial pattern overlap. In these processes, the proportion of variation among and within a population (measured by G ST and 1 - G ST, respectively) is correlated with the slope and intercept of a Mantel's test relating genetic and geographic distances. Beyond the conceptual interest, the inspection of the relationship between population heterogeneity and spatial pattern can be used to test departures from stochasticity in the study of population differentiation.


2017 ◽  
Vol 26 (12) ◽  
pp. 1009 ◽  
Author(s):  
Piyush Jain ◽  
Xianli Wang ◽  
Mike D. Flannigan

We have constructed a fire weather climatology over North America from 1979 to 2015 using the North American Regional Reanalysis dataset and the Canadian Fire Weather Index (FWI) System. We tested for the presence of trends in potential fire season length, based on a meteorological definition, and extreme fire weather using the non-parametric Theil–Sen slope estimator and Mann–Kendall test. Applying field significance testing (i.e. joint significance of multiple tests) allowed the identification of the locations of significant trends, taking into account spatial correlations. Fire season length was found to be increasing over large areas of North America, especially in eastern Canada and the south-western US, which is consistent with a later fire season end and an earlier fire season start. Both positive and negative trends in potential fire spread days and the 99th percentile of FWI occurred in Canada and the contiguous United States, although the trends of largest magnitude and statistical significance were mostly positive. In contrast, the proportion of trends with significant decreases in these variables were much lower, indicating an overall increase in extreme fire weather. The smaller proportion of significant positive trends found over Canada reflects the truncation of the time series, necessary because assimilation of precipitation observations over Canada ceased in the reanalysis post-2002.


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