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

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.

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0239499
Author(s):  
Rusly Rosazlina ◽  
Niels Jacobsen ◽  
Marian Ørgaard ◽  
Ahmad Sofiman Othman

Natural hybridization has been considered a source of taxonomic complexity in Cryptocoryne. A combined study of DNA sequencing data from the internal transcribed spacer (ITS) of nuclear ribosomal DNA and the trnK-matK region of chloroplast DNA was used to identify the parents of Cryptocoryne putative hybrids from Peninsular Malaysia. Based on the intermediate morphology and sympatric distribution area, the plants were tentatively identified as the hybrid Cryptocoryne ×purpurea nothovar. purpurea. The plants were pollen sterile and had long been considered as hybrids, supposedly between two related and co-existing species, C. cordata var. cordata and C. griffithii. The status of C. ×purpurea nothovar. purpurea was independently confirmed by the presence of an additive ITS sequence pattern from these two parental species in hybrid individuals. An analysis of the chloroplast trnK-matK sequences showed that the hybridization is bidirectional with the putative hybrids sharing identical sequences from C. cordata var. cordata and C. griffithii, indicating that both putative parental species had been the maternal parent in different accessions.


2007 ◽  
Vol 85 (7) ◽  
pp. 659-666 ◽  
Author(s):  
Ting-Ting Feng ◽  
Zhi-Qin Zhou ◽  
Jian-Min Tang ◽  
Ming-Hao Cheng ◽  
Shi-Liang Zhou

Malus toringoides (Rehd.) Hughes was suggested to have originated from hybridization between Malus transitoria Schneid. and Malus kansuensis Rehd., followed by repeated backcrossing to one of the putative parents. In the present study, the sequence information of the internal transcribed spacer (ITS) of nuclear ribosomal DNA (nrDNA) was used to re-examine the origin of this species. A total of 69 accessions from three natural populations (Maerkang, Xiaba and Kehe, Aba Autonomous Region, Sichuan, China) of M. toringoides and 10 accessions of its putative parents were analyzed. Using Malus angustifolia (Ait.) Michx., Malus ioensis (Wood) Britt. and Malus doumeri Chev. as outgroups, our phylogenetic analysis of the ITS sequences of M. toringoides and its putative parents showed that M. toringoides was not monophyletic, and two different types of ITS sequences which were obtained from each of the six accessions of M. toringoides were found to have clustered separately with those of the two putative parent species on the gene tree. A comparison of the sequence variation between M. toringoides and its putative parents revealed an additive variation pattern of ITS sequences in the putative hybrid species. These results are consistent with the previous morphological and amplified fragment length polymorphism (AFLP) data which suggested that M. toringoides was of hybrid origin. Our ITS data provide new molecular evidence for the hybrid origin hypothesis of M. toringoides and these results are of great importance for future study on hybridization, polyploid speciation and evolution of the genus Malus Miller.


Author(s):  
Vera S. Bogdanova ◽  
Natalia V. Shatskaya ◽  
Anatoliy V. Mglinets ◽  
Oleg E. Kosterin ◽  
Gennadiy V. Vasiliev

AbstractPlastids and mitochondria have their own small genomes which do not undergo meiotic recombination and may have evolutionary fate different from each other and nuclear genome, thus highlighting interesting phenomena in plant evolution. We for the first time sequenced mitochondrial genomes of pea (Pisum L.), in 38 accessions mostly representing diverse wild germplasm from all over pea geographical range. Six structural types of pea mitochondrial genome were revealed. From the same accessions, plastid genomes were sequenced. Bayesian phylogenetic trees based on the plastid and mitochondrial genomes were compared. The topologies of these trees were highly discordant implying not less than six events of hybridisation of diverged wild peas in the past, with plastids and mitochondria differently inherited by the descendants. Such discordant inheritance of organelles is supposed to have been driven by plastid-nuclear incompatibility, known to be widespread in pea wide crosses and apparently shaping the organellar phylogenies. The topology of a phylogenetic tree based on the nucleotide sequence of a nuclear gene His5 coding for a histone H1 subtype corresponds to the current taxonomy and resembles that based on the plastid genome. Wild peas (Pisum sativum subsp. elatius s.l.) inhabiting Southern Europe were shown to be of hybrid origin resulting from crosses of peas similar to those presently inhabiting south-east and north-east Mediterranean in broad sense.


Botany ◽  
2011 ◽  
Vol 89 (3) ◽  
pp. 191-201
Author(s):  
Jennifer DeWoody ◽  
John D. Nason ◽  
Marian Smith

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Robert W. Taylor ◽  
Hirotami T. Imai ◽  
Eisuke Hasegawa ◽  
Colin D. Beaton

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.


2018 ◽  
Vol 285 (1887) ◽  
pp. 20181535 ◽  
Author(s):  
Adam C. Schneider ◽  
Harold Chun ◽  
Saša Stefanović ◽  
Bruce G. Baldwin

Foundational studies of chloroplast genome (plastome) evolution in parasitic plants have focused on broad trends across large clades, particularly among the Orobanchaceae, a species-rich and ecologically diverse family of root parasites. However, the extent to which such patterns and processes of plastome evolution, such as stepwise gene loss following the complete loss of photosynthesis (shift to holoparasitism), are detectable at shallow evolutionary time scale is largely unknown. We used genome skimming to assemble eight chloroplast genomes representing complete taxonomic sampling of Aphyllon sect. Aphyllon, a small clade within the Orobanchaceae that evolved approximately 6 Ma, long after the origin of holoparasitism. We show substantial plastome reduction occurred in the stem lineage, but subsequent change in plastome size, gene content, and structure has been relatively minimal, albeit detectable. This lends additional fine-grained support to existing models of stepwise plastome reduction in holoparasitic plants. Additionally, we report phylogenetic evidence based on an rbcL gene tree and assembled 60+ kb fragments of the Aphyllon epigalium mitochondrial genome indicating host-to-parasite horizontal gene transfers (hpHGT) of several genes originating from the plastome of an ancient Galium host into the mitochondrial genome of a recent common ancestor of A. epigalium . Ecologically, this evidence of hpHGT suggests that the host–parasite associations between Galium and A. epigalium have been stable at least since its subspecies diverged hundreds of thousands of years ago.


Phytotaxa ◽  
2019 ◽  
Vol 406 (1) ◽  
pp. 71
Author(s):  
ZBIGNIEW SZELĄG

Two apomictic, polyploid (x=9) species in Hieracium sect. Alpina are described from the Western Bieszczady Mountains, Eastern Carpathians, Poland, and illustrated with photos of the holotypes. These are H. jasiewiczii (4x) which combines the morphological features of H. alpinum and H. bifidum, and H. wojcickii (4x) of presumably hybrid origin between H. alpinum and H. pseudobifidum. Both new species are probably relicts originated from diploid, sexual H. alpinum with a wider primary range covering also the Western Bieszczady Mountains, which presently occurs only in the Romanian and Ukrainian Carpathians.


Zootaxa ◽  
2004 ◽  
Vol 634 (1) ◽  
pp. 1 ◽  
Author(s):  
Oscar Arribas ◽  
Salvador Carranza

Iberolacerta cyreni martinezricai is elevated to the species level (I. martinezricai) based on both morphological and molecular data. The phylogenetic analysis using two mitochondrial and one nuclear gene shows I. martinezricai is more closely related to I. monticola than to I. cyreni. A multivariate analysis of the morphological data also supports the affinities between I. martinezricai and I. monticola but, at the same time, clearly indicates that I. martinezricai is morphologically distinct from both I. monticola and I. cyreni. The molecular data suggests I. cyreni and the clade formed by I. monticola + I. martinezricai split approximately 6.1 Mya, during the Mesinian Salinity Crisis, when climatic conditions around the Mediterranean area changed dramatically as a result of the desiccation of the Mediterranean Sea. Separation between I. martinezricai and I. monticola occurred approximately 2 Mya but, with at least two equally plausible alternative hypotheses, their biogeography is still unclear. New data on the habitat and distribution of I. martinezricai indicates its distribution area is very small (12 15 km 2 ), and that it lives in a climatically extreme habitat for this kind of mountain species. As a result of that and the low numbers of individuals, I. martinezricai is considered here as Critically Endangered.


Phytotaxa ◽  
2016 ◽  
Vol 258 (2) ◽  
pp. 121 ◽  
Author(s):  
ÁGNES MOSOLYGÓ-L ◽  
GÁBOR SRAMKÓ ◽  
SÁNDOR BARABÁS ◽  
LEVENTE CZEGLÉDI ◽  
ANDRÁS JÁVOR ◽  
...  

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.


Evolution ◽  
1959 ◽  
Vol 13 (4) ◽  
pp. 511-525
Author(s):  
Harlan Lewis ◽  
Carl Epling

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