Hybridization between the threatened herb Boltonia decurrens (Asteraceae) and its widespread congener, B. asteroides

Botany ◽  
2011 ◽  
Vol 89 (3) ◽  
pp. 191-201
Author(s):  
Jennifer DeWoody ◽  
John D. Nason ◽  
Marian Smith
Keyword(s):  
Parental Species ◽  
Backcross Progeny ◽  
Illinois River ◽  
Morphological Data ◽  
Hybrid Origin ◽  
Sympatric Population ◽  
Closely Related Species ◽  
Low Frequencies ◽  
Marker Data ◽  
Boltonia Decurrens

Boltonia decurrens (Torr. & A. Gray) A. Wood is a federally threatened herb endemic to the Illinois River floodplain, and currently restricted to fewer than 25 populations. We tested for hybridization between this species and a widespread congener, Boltonia asteroides (L.) L’Hér., at two sites where they are known to occur in sympatry, by comparing morphological and genetic diversity with an allopatric population of each species. Morphological analyses identified significant differentiation between species. Discriminant classification analysis of the morphological data assigned most individuals to one or the other of the two parental species with high probability (>0.95), with only four plants having an intermediate probability of assignment (<0.90) indicative of hybrid origin. Similarly, likelihood-based methods based on genetic marker data (allozymes) failed to detect the presence of F1 hybrids in either sympatric population and revealed only low frequencies of F2 and backcross progeny. These findings demonstrate that combining morphological and genetic data increases the likelihood of detecting low-scale introgression between closely related species. Even with this combined approach, the low rate of recombination between these species together with their limited sympatry indicate that hybridization does not pose an immediate threat to the genetic integrity of B. decurrens.

Evidence for the hybrid origin of Carex knieskernii with comments on hybridization in the genus Carex (Cyperaceae)

1994 ◽  
Vol 72 (6) ◽  
pp. 860-871 ◽  
Author(s):  
Marcia J. Waterway
Keyword(s):  
Chromosome Numbers ◽  
Parental Species ◽  
Distinct Species ◽  
Allozyme Variation ◽  
Morphological Data ◽  
Hybrid Origin ◽  
Meiotic Pairing ◽  
Species Overlap ◽  
Different Populations ◽  
The One

Carex knieskernii, originally described as a distinct species, is shown to be a sterile hybrid between Carex arctata and Carex castanea based on evidence from allozyme variation, chromosome numbers, morphology, and geographical distribution. The two parental species differed at eight enzyme-coding loci; C. knieskernii showed the expected heterozygous pattern at each of these loci. Individuals of C. knieskernii were highly sterile and the enzyme patterns suggested that they were F1 hybrids formed independently at each location. Chromosome numbers determined for 27 individuals of C. arctata (n = 27, rarely 26) agreed with previously published counts. The eight counts of C. castanea (n = 22) differed from the one previous count of 2n = 64. Individuals of C. knieskernii from five different populations all had disturbed meiosis with irregular pairing and ca. 49 chromosomes. A canonical discriminant analysis of morphological data from population samples of the three taxa clearly separated C. arctata and C. castanea, with the individuals of C. knieskernii having intermediate scores on the first canonical axis. Carex knieskernii is a widespread but rarely occurring hybrid that is found where the ranges of the parental species overlap and the blooming times are synchronous. The sterility of this hybrid, the obvious disruptions of normal meiotic pairing, and the large genetic distance between the parental species based on allozyme variation suggest that although the two species hybridize, they may not be closely related. Key words: Carex knieskernii, Cyperaceae, hybridization, allozyme variation, chromosome numbers.

Hybridization as a biodiversity driver: The case of Veronica × gundisalvi

2021 ◽  
Vol 42 ◽  
pp. e67901
Author(s):  
Noemí López-González ◽  
Javier Bobo-Pinilla ◽  
David Gutiérrez-Larruscain ◽  
Maria Montserrat Martínez-Ortega ◽  
Blanca María Rojas-Andrés
Keyword(s):  
Biological Diversity ◽  
Parental Species ◽  
Biodiversity Loss ◽  
Chromosome Count ◽  
Plant Evolution ◽  
Morphological Data ◽  
Hybrid Origin ◽  
Distribution Models ◽  
New Localities ◽  
Endemic Taxon

Hybridization is an important mechanism in plant evolution, which contributes to the adaptability and biological diversity of species in fundamental ways. Based on morphological data, Veronica × gundisalvi Sennen (Veronica orsiniana × V. tenuifolia subsp. tenuifolia) is an Iberian endemic taxon of presumably polytopic hybrid origin restricted to five localities in Catalonia, where the putative parental species grow in sympatry. In this study, species distribution models were developed for the putative parental species to seek potential new localities where active hybridization could be taking place. As a result, a new location of this nothotaxon in Zaragoza is provided, along with a chromosome count and ploidy level estimations. The data presented here further support Veronica × gundisalvi as a homoploid hybrid taxon that occurs in non-altered habitats. In contrast to the traditional view of hybridization as deleterious for the conservation of biodiversity, it does not always represent a problem in this regard. Hybridization is a complex evolutionary force that requires case-specific evaluation. Given that biodiversity loss is one of the main contemporary challenges, it is important to consider the creative nature of hybridization, a widespread evolutionary mechanism able to produce novel diversity.

scholarly journals Hepatica transsilvanica Fuss (Ranunculaceae) is an Allotetraploid Relict of the Tertiary Flora in Europe – Molecular Phylogenetic Evidence

2020 ◽  
Vol 89 (3) ◽  
Author(s):  
Levente Laczkó ◽  
Gábor Sramkó
Keyword(s):  
Parental Species ◽  
Gene Tree ◽  
Diploid Species ◽  
Nuclear Gene ◽  
Hybrid Origin ◽  
Distribution Area ◽  
Recent Common Ancestor ◽  
Term Survival ◽  
Quaternary Glaciation ◽  
Eastern Carpathians

The <em>Hepatica </em>section <em>Angulosa </em>consists of mainly tetraploid (2<em>n </em>= 28) species that are distributed disjunctly throughout Eurasia. Karyological evidence proves the hybrid origin of the polyploid species of this section. <em>Hepatica transsilvanica </em>is a member of this species group with a conspicuous distribution restricted to the Eastern Carpathians. Based on genome size and cytotypes, the paternal parent of <em>H. transsilvanica </em>is described to be the only diploid species in section <em>Angulosa</em>, <em>H. falconeri</em>. The maternal species is hypothesized to be <em>H. nobilis</em>, a European species with entirely lobed leaves and a wider distribution area. Although the hybrid origin of <em>H. transsilvanica </em>is well documented by karyological evidence, the time of hybridization has never been studied. By using sequences of both the nuclear and plastid genome, we reconstructed the phylogenetic relationships and divergence times of <em>H. transsilvanica </em>and its parental species. The identity of the parental species is corroborated by discordant gene tree topologies of the nrITS and plastid sequences. Moreover, both gene copies of the parental species could be identified with the low-copy nuclear gene, <em>MLH1</em>. Divergence dating analysis using Bayesian phylogenetic methods strongly supported the long-term survival of <em>H. transsilvanica </em>in the Southeastern Carpathians, as the most recent common ancestor of the hybrid and parent species existed not later than the beginning of the Pleistocene, ca. 3 million years ago. These results not only highlight the biogeographic importance of the Southeastern Carpathians in the Quaternary glaciation periods, but also emphasize that Tertiary lineages could have survived in a Central European cryptic refugium.

scholarly journals A Unique Conjunction: Evidence for Gynogenesis Accompanying Haplodiploid Sex Determination in the Australian Ant Myrmecia impaternata Taylor

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Robert W. Taylor ◽  
Hirotami T. Imai ◽  
Eisuke Hasegawa ◽  
Colin D. Beaton
Keyword(s):  
Host Species ◽  
Related Species ◽  
Parental Species ◽  
Female Offspring ◽  
Hybrid Origin ◽  
Sperm Cells ◽  
Reproductive Systems ◽  
Free Living ◽  
Sperm Donor ◽  
Diploid Female

Myrmecia impaternata is an allodiploid all-female species of hybrid origin. Its parental taxa are confirmed here to be M. banksi and M. pilosula. We suggest that its queens produce diploid female offspring by gynogenetic parthenogenesis, a process which requires interaction between unreduced maternal oocytes and allospecific sperm cells obtained by copulation with another related species. We propose that impaternata queens almost certainly mate for this purpose with males reared in impaternata nests from eggs laid by impaternata females. Because sex in ants is determined by haplodiploidy (males haploid, females diploid), we posit that these males would in fact not be technically conspecific with the females in whose reproductive systems they developed, since they would each carry the haploid genome of one or other of the hybridic parental species. They would therefore be individually identical karyologically to males of either M. banksi or M. pilosula and appropriately allospecific to M. impaternata. We postulate that, unlike all other known gynogens, M. impaternata would have no need to maintain parasitic affiliation or sympatry with free-living sperm-donor host species. Its queens are arguably able to produce the required allospecific males by accessing their own genomes. M. impaternata apparently originated by instantaneous speciation when individuals of its parental species first successfully hybridized.

scholarly journals Living a dog’s life: a putative gray wolf in a feral dog group

Mammalia ◽  
2020 ◽  
Vol 84 (2) ◽  
pp. 115-120
Author(s):  
Elitsa Popova ◽  
Diana Zlatanova
Keyword(s):  
Related Species ◽  
Ecological Impact ◽  
Complex Interaction ◽  
Domestic Dog ◽  
Hybrid Origin ◽  
Mountainous Area ◽  
Gray Wolf ◽  
Closely Related Species ◽  
Feral Dogs ◽  
In The Wild

AbstractThe gray wolf and the domestic dog are closely related species that can interbreed and produce fertile offspring. In settings where unrestrained dogs are present in the wild, hybridization can happen naturally. However, the behavior of the resulting hybrids and their ecological impact is largely understudied. In September–November 2018, a putative gray wolf was repeatedly camera-trapped in a group of 10 presumably feral dogs in a remote mountainous area (the Osogovo Mountain) along the border between Bulgaria and North Macedonia. The most feasible explanation for this individual’s atypical behavior is that it is of hybrid origin (assumption based on phenotype). To the best of our knowledge, this is the first documented observation of such a kind. A discussion of its recruitment and position in the group is presented, setting the basis for further investigation of the complex interaction between wolves, dogs and hybrids in the wild.

Morphological reassessment and new locality records for Galea comes Thomas, 1919 (Rodentia, Caviidae)

Mammalia ◽  
2019 ◽  
Vol 83 (6) ◽  
pp. 601-609
Author(s):  
Pablo Teta ◽  
María Carolina Madozzo-Jaén ◽  
Alexandra M.R. Bezerra ◽  
Pablo E. Ortiz ◽  
Sergio O. Lucero ◽  
...  
Keyword(s):  
South America ◽  
Related Species ◽  
Morphological Traits ◽  
Morphological Data ◽  
Closely Related Species ◽  
Northwestern Argentina ◽  
Qualitative And Quantitative ◽  
Distributional Range ◽  
Emended Diagnosis

Abstract The genus Galea Meyen, 1833 includes at least five species of terrestrial, diurnal and herbivorous cavies that occupy grasslands and rocky scrub areas at both high and low elevations in South America. According to the available molecular and morphological data, Galea comes Thomas, 1919 is restricted to highland areas above 2000 m in southern Bolivia and northwestern Argentina. Its distributional range as well as its morphological distinctiveness from other closely related species (Galea leucoblephara and Galea musteloides) is poorly documented. Using both qualitative and quantitative morphological traits, we provided an emended diagnosis for G. comes. In addition, we added six new locality records to its known distribution.

scholarly journals Limited intrinsic postzygotic reproductive isolation despite chromosomal rearrangements between closely related sympatric species of small ermine moths (Lepidoptera: Yponomeutidae)

2019 ◽  
Vol 128 (1) ◽  
pp. 44-58 ◽  
Author(s):  
Katerina H Hora ◽  
František Marec ◽  
Peter Roessingh ◽  
Steph B J Menken
Keyword(s):  
Reproductive Isolation ◽  
Parental Species ◽  
Meiotic Chromosome ◽  
Chromosomal Rearrangements ◽  
Sympatric Species ◽  
Hybrid Fitness ◽  
New Host ◽  
Closely Related Species ◽  
Postzygotic Reproductive Isolation

Abstract In evolutionarily young species and sympatric host races of phytophagous insects, postzygotic incompatibility is often not yet fully developed, but reduced fitness of hybrids is thought to facilitate further divergence. However, empirical evidence supporting this hypothesis is limited. To assess the role of reduced hybrid fitness, we studied meiosis and fertility in hybrids of two closely related small ermine moths, Yponomeuta padella and Yponomeuta cagnagella, and determined the extent of intrinsic postzygotic reproductive isolation. We found extensive rearrangements between the karyotypes of the two species and irregularities in meiotic chromosome pairing in their hybrids. The fertility of reciprocal F1 and, surprisingly, also of backcrosses with both parental species was not significantly decreased compared with intraspecific offspring. The results indicate that intrinsic postzygotic reproductive isolation between these closely related species is limited. We conclude that the observed chromosomal rearrangements are probably not the result of an accumulation of postzygotic incompatibilities preventing hybridization. Alternative explanations, such as adaptation to new host plants, are discussed.

A Paedomorphocline in Eucalyptus: Natural Variation in the E. risdonii/E. tenuiramis Complex

1991 ◽  
Vol 39 (6) ◽  
pp. 545 ◽  
Author(s):  
RJE Wiltshire ◽  
BM Potts ◽  
JB Reid
Keyword(s):  
Morphological Variation ◽  
Natural Variation ◽  
Natural Populations ◽  
Morphological Data ◽  
Closely Related Species ◽  
Leaf Habit ◽  
Juvenile Leaf ◽  
Adult Leaf ◽  
Morphological Differences ◽  
Fruit Characters

Ontogenetic and morphological variation in 40 natural populations of the closely related species, E. risdonii and E. tenuiramis, were assessed in a multivariate study of juvenile and adult leaf and fruit characters. The present taxonomic separation of the two taxa is based mainly on ontogenetic differences, but this study reveals that the variation between the two taxa in the retention of the juvenile leaf habit is continuous and may represent a paedomorphocline. The morphological data suggest that at least four phenetic groups are required to summarise the morphological variation in the E. risdonii/ E. tenuiramis complex. When ontogenetic variation is removed, the morphological variation between some E. risdonii and some E. tenuiramis populations is also continuous and much smaller than the morphological differences within E. tenuiramis. This suggests that E. risdonii may be the product of relatively recent changes in developmental timing (heterochrony) from E. tenuiramis.

Molecular genetic evidence for allotetraploid hybrid speciation in the genus Crocus L. (Iridaceae)

Phytotaxa ◽  
2016 ◽  
Vol 258 (2) ◽  
pp. 121 ◽  
Author(s):  
ÁGNES MOSOLYGÓ-L ◽  
GÁBOR SRAMKÓ ◽  
SÁNDOR BARABÁS ◽  
LEVENTE CZEGLÉDI ◽  
ANDRÁS JÁVOR ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Parental Species ◽  
Molecular Genetic ◽  
Parallel Evolution ◽  
Carpathian Basin ◽  
Hybrid Origin ◽  
F1 Hybrids ◽  
Aflp Data ◽  
F1 Hybrid

Although dysploidy and polyploidisation events are known to be important drivers in the evolutionary history of the genus Crocus, only a few examples of natural hybrid origins have so far been documented. Here, we describe the phylogenetic affinities of five taxa in the Crocus vernus species complex from the Carpathian Basin in Central Europe. Genetic variability was evaluated using chloroplast DNA sequences of the accD-psaI intergenic spacer and amplified fragment length polymorphism (AFLP) in combination with karyological observations. Genetic diversity and differentiation of the seven investigated Crocus species were also evaluated using AFLP data. We created a phylogenetic hypothesis using both sequences and AFLP fingerprinting data under maximum parsimony (MP). AFLPs were also analysed by means of multivariate statistics using principal coordinate (PCoA) analysis and Bayesian clustering (BC) to test for hybridity. Both the AFLP and plastid phylogenetic trees separated the taxa into two groups: (1) a ‘Balkan’ clade, and; (2) an ‘Adriatic’ clade. The Balkan clade contained Crocus heuffelianus samples and one Crocus vittatus from Croatia as well as Crocus tommasinianus samples from Hungary; the Adriatic clade included Crocus vittatus and Crocus vernus samples from Hungary and Croatia as well as Crocus neapolitanus from Italy. A hard incongruence was found in the placement of the Slovakian Crocus scepusiensis which clustered inside the Balkan clade on our plastid tree, while it fell in the Adriatic clade on the AFLP tree. The same populations occupied intermediate position on the PCoA plot. The BC analysis assigned all Crocus scepusiensis specimens as F1 hybrids, while Crocus vernus and Crocus heuffelianus were assigned as parental species. Together with our cytological investigation that determined a 2n=18 chromosome number of Crocus scepusiensis, we conclude an allopolyploid hybrid origin for this Northern Carpathian taxon as the result of a cross between members of the 2n=10 Balkan clade (e.g., Crocus heuffelianus from Transylvania) and the 2n=8 Adriatic clade (Crocus vernus). A similar origin is postulated for the North Balkan Crocus vittatus (2n=18), which was clustered as an F1 hybrid in the BC analysis; thus, parallel evolution may have taken place in the northern and southern part of the Carpathian Basin beginning from the same parental species but leading to different allopolyploid derivatives.

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