Recurrent hybridization without homoeologous chromosome paring in the &lt;i&gt;Dryopteris varia&lt;/i&gt; complex (Dryopteridaceae)

Hori, Kiyotaka; Okuyama, Yudai; Murakami, Noriaki

doi:10.3199/iscb.13.9

Cited by 12 publications

(30 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hybridization is considered to be common in ferns (Barrington et al., ; Sigel, ); however, surprisingly, no accurate estimation of hybridization rates in natural populations has been published for ferns. Many studies have described fern hybrid taxa, including intergeneric ones (e.g., Brownsey, ; Reichstein, ; Knobloch et al., ; Rothfels et al., ), or studied the presence of hybrids in natural fern populations (Zhang et al., ; Testo et al., ; Ekrt and Koutecký, ; Hori et al., ; Hanušová et al., ). However, hybridization rates have only been described qualitatively in these studies, without any precise evaluation.…”

mentioning

confidence: 99%

Asymmetric hybridization in Central European populations of theDryopteris carthusianagroup

Hornych

Ekrt

Riedel

et al. 2019

American J of Botany

View full text Add to dashboard Cite

Premise Hybridization is a key process in plant speciation. Despite its importance, there is no detailed study of hybridization rates in fern populations. A proper estimate of hybridization rates is needed to understand factors regulating hybridization. Methods We studied hybridization in the European Dryopteris carthusiana group, represented by one diploid and two tetraploid species and their hybrids. We sampled ~100 individuals per population in 40 mixed populations of the D. carthusiana group across Europe. All plants were identified by measuring genome size (DAPI staining) using flow cytometry. To determine the maternal parentage of hybrids, we sequenced the chloroplast region trnL–trnF of all taxa involved. Results We found hybrids in 85% of populations. Triploid D. ×ambroseae occurred in every population that included both parent species and is most abundant when the parent species are equally abundant. By contrast, tetraploid D. ×deweveri was rare (15 individuals total) and triploid D. ×sarvelae was absent. The parentage of hybrid taxa is asymmetric. Despite expectations from previous studies, tetraploid D. dilatata is the predominant male parent of its triploid hybrid. Conclusions This is a thorough investigation of hybridization rates in natural populations of ferns. Hybridization rates differ greatly even among closely related fern taxa. In contrast to angiosperms, our data suggest that hybridization rates are highest in balanced parent populations and support the notion that some ferns possess very weak barriers to hybridization. Our results from sequencing cpDNA challenge established notions about the correlation of ploidy level and mating tendencies.

show abstract

mentioning

confidence: 99%

Asymmetric hybridization in Central European populations of theDryopteris carthusianagroup

Hornych

Ekrt

Riedel

et al. 2019

American J of Botany

View full text Add to dashboard Cite

show abstract

“…We counted chromosomes from living plants of D. dickinsii and D. tsutsuiana collected and their localities were in Appendix 1. The methods are followed by Hori et al (2018). To estimate the reproductive mode of each sample or herbarium specimen, the spores in each sporangium were counted.…”

Section: Methodsmentioning

confidence: 99%

“…For molecular analyses, total DNA was extracted from the silica-dried leaves by using cetyltrimethylammonium bromide solution, according to the method of Doyle and Doyle (1990). ndhF was used as the maternal inherited cpDNA marker (Kuo et al 2016, Hori et al 2018, Table 1. Taxa (cytotypes reported in the previous study with references and newly reported in this study with asterisks), voucher, cytotype in this study and allele constitution of the Dryopteris atrata complex.…”

Section: Methodsmentioning

confidence: 99%

“…DNA data accession numbers of the obtained nucleotide sequences used for the construction of molecular phylogenetic trees in this study. Data quoted from Hori et al (2018) are marked by asterisks.…”

Section: Appendixmentioning

confidence: 99%

“…Such allopolyploid has undergone alternation of generation continuously because they can produce fertile offspring with maintaining their genome constitution (Kihara 1924, 1930, Wagner 1954, Riley and Chapman 1958, Ebihara et al 2005, Griffiths et al 2006, Sessa et al 2012. Apogamous ferns also have much genetic variation because they can get allele from sexual species through hybridization (Morita et al 1990, Ebihara et al 2012, Jaruwattanaphan et al 2013, Hori et al 2018. If they cannot maintain their genome constitutions, they will lose their genetic variation.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Genome Constitution of the <i>Dryopteris atrata</i> Complex (Dryopteridaceae)

et al. 2019

Self Cite

View full text Add to dashboard Cite

We analyzed molecular phylogenetically using two low-copy nuclear markers (AK1 and Esterase) and plastid ndhF DNA sequence in the Dryopteris atrata complex. According to nuclear allele constitution and plastid ndhF sequence, apogamous species of the D. atrata complex seemed to be of hybrid origin. The genome constitution of the D. atrata complex showed that apogamous fern species which produce regularly shaped spores can maintain genome constitution if it is of hybrid origin between apogamous species and sexual species. Otherwise, sterile hybrids will be going to hybrid collapse because they cannot prevent genetic segregation.

show abstract

An adventurous journey toward and away from fern apomixis: Insights from genome size and spore abortion patterns

Ekrt,

Férová,

Koutecký

et al. 2024

American J of Botany

Self Cite

View full text Add to dashboard Cite

PremiseApomixis in ferns is relatively common and obligatory. Sterile hybrids may restore fertility via apomixis at a cost of long‐term genetic stagnation. In this study, we outlined apomixis as a possible temporary phase leading to sexuality and analyzed factors relating to transitioning to and away from apomixis, such as unreduced and reduced spore formation in apomict and apo‐sex hybrid ferns.MethodsWe analyzed the genome size of 15 fern species or hybrids (“taxa”) via flow cytometry. The number of reduced and unreduced gametophytes was established as a proxy for viable spore formation of either type. We also calculated the spore abortion ratio (sign of reduced spores) in several taxa, including the apo‐sex hybrid Dryopteris × critica and its 16 apomictically formed offspring.ResultsFour of 15 sampled taxa yielded offspring variable in genome size. Specifically, each variable taxon formed one viable reduced plant among 12–451 sampled gametophytes per taxon. Thus, haploid spore formation in the studied apomicts was very rare but possible. Spore abortion analyses indicated gradually decreasing abortion (haploid spore formation) over time. In Dryopteris × critica, abortion decreased from 93.8% to mean 89.5% in one generation.ConclusionsOur results support apomixis as a transitionary phase toward sexuality. Newly formed apomicts hybridize with sexual relatives and continue to form haploid spores early on. Thus, they may get the genomic content necessary for regular meiosis and restore sexuality. If the missing relative goes extinct, the lineage gets locked into apomixis as may be the case with the Dryopteris affinis complex.

show abstract

Recurrent hybridization without homoeologous chromosome paring in the <i>Dryopteris varia</i> complex (Dryopteridaceae)

Cited by 12 publications

References 35 publications

Asymmetric hybridization in Central European populations of theDryopteris carthusianagroup

Asymmetric hybridization in Central European populations of theDryopteris carthusianagroup

Genome Constitution of the <i>Dryopteris atrata</i> Complex (Dryopteridaceae)

An adventurous journey toward and away from fern apomixis: Insights from genome size and spore abortion patterns

Contact Info

Product

Resources

About