e-journal

Flow cytometry confirms reticulate evolution and reveals triploidy in Central European Diphasiastrum taxa (Lycopodiaceae, Lycophyta)

---

Background and Aims Interspecific Diphasiastrum hybrids have been assumed to be homoploid and to produce
well-formed spores serving sexual reproduction. If this were the case, forms intermediate between hybrids and parents or hybrid swarms should be expected. The purpose of this study was: (1) to check whether homoploidy consistently applies to the three hybrids throughout their Central European range; (2) to examine whether their genome sizes confirm their parentage as assumed by morphology; and (3) to perform a screening for detection of ploidy levels other than diploid and variation in DNA content due to backcrossing.
Methods Flow cytometry was used first to measure the relative DNA values [with 4′,6-diamidino-2-phenylindole (DAPI) staining] and ploidy level as a general screening, and secondly to determine the absolute DNA 2C values [with propidium iodide (PI) staining] in a number of selected samples with the main focus on the hybrids.
Key Results A considerable variation of DNA 2C values (5.26–7.52 pg) was detected between the three
European Diphasiastrum species. The values of the diploid hybrids are highly constant without significant variation between regions. They are also intermediate between their assumed parents and agree closely with those calculated from their putative parents. This confirms their hybrid origin, assumed parentage and homoploid status. Considerably higher DNA amounts (9.48–10.30 pg) were obtained for three populations, suggesting that these represent triploid hybrids, an interpretation that is strongly supported by their morphology.
Conclusions Diploid hybrids have retained their genetic and morphological identites throughout their Central European range, and thus no indications for diploid backcrossing were found. The triploid hybrids have probably originated from backcrossing between a diploid gametophyte of a hybrid (derived from a diplospore) and a haploid gametophyte of a diploid parental species. By repeated crossing events, reticulate evolution patterns arise that are similar to those known for a number of ferns.
Key words: Diphasiastrum, Lycopodiaceae, flow cytometry, nuclear DNA content, homoploidy, triploidy,
hybridization, reticulate evolution.

---

Ketersediaan

Tidak ada salinan data

Informasi Detail

Judul Seri

Annals of Botany

No. Panggil

-

Penerbit

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

Deskripsi Fisik

Annals of Botany 108: 867–876, 2011

Bahasa

English

ISBN/ISSN

-

Klasifikasi

-

Tipe Isi

-

Tipe Media

-

Tipe Pembawa

-

Edisi

-

Subjek

PERTANIAN.

Info Detail Spesifik

-

Pernyataan Tanggungjawab

yuli/agus

Versi lain/terkait

Lampiran Berkas

Komentar

---

Anda harus masuk sebelum memberikan komentar