e-journal

Dynamics of polyploid formation and establishment in the allotetraploid rock fern Asplenium majoricum

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Background and Aims Successful establishment of newly formed polyploid species depends on several
interlinked genetic and ecological factors. These include genetic diversity within and among individuals,
chromosome behaviour and fertility, novel phenotypes resulting from novel genomic make-up and expression,
intercytotypic and interspecific competition, and adaptation to distinct habitats. The allotetraploid rock fern Asplenium majoricum is known from one small population in Valencia, Spain, and several larger populations on the Balearic island of Majorca. In Valencia, it occurs sympatrically with its diploid parents, A. fontanum subsp. fontanum and A. petrarchae subsp. bivalens, and their diploid hybrid A. × protomajoricum. This highly unusual situation allowed the study of polyploid genetic diversity and its relationship to the formation and establishment of nascent polyploid lineages.
Methods Genetic variation for isozyme and chloroplast DNA markers was determined for A. majoricum and
A. × protomajoricum sampled thoroughly from known sites in Majorca and Valencia. Results were compared
with variation determined previously for the diploid parent taxa.
Key Results A highly dynamic system with recurring diploid hybrid and allotetraploid formation was discovered.
High diversity in the small Valencian A. majoricum population indicates multiple de novo origins from
diverse parental genotypes, but most of these lineages become extinct without becoming established. The populations on Majorca most probably represent colonization(s) from Valencia rather than an in situ origin. Low genetic diversity suggests that this colonization may have occurred only once.
Conclusions There is a striking contrast in success of establishment of the Majorcan and Valencian populations of A. majoricum. Chance founding of populations in a habitat where neither A. fontanum subsp. fontanum nor A. petrarchae subsp. bivalens occurs appears to have been a key factor enabling the establishment of A. majoricum on Majorca. Successful establishment of this polyploid is probably dependent on geographic isolation from diploid progenitor competition.
Key words: Asplenium majoricum, Asplenium × protomajoricum, A. fontanum subsp. fontanum, A. petrarchae
subsp. bivalens, allopolyploid, multiple origins, hybridization, colonization, Balearic islands, polyploid
speciation.

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Informasi Detail

Judul Seri

Annals of Botany

No. Panggil

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Penerbit

: Oxford University Press on behalf of the Annals of Botany Company., 2011

Deskripsi Fisik

Annals of Botany 108: 143–157, 2011

Bahasa

English

ISBN/ISSN

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Klasifikasi

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Tipe Isi

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Tipe Media

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Tipe Pembawa

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Edisi

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Subjek

PERTANIAN.

Info Detail Spesifik

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Pernyataan Tanggungjawab

yuli/agus

Versi lain/terkait

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