Taxus baccata: un approccio citogenetico e molecolare
Author(s)
Tomasino, Maria Paola
Date Issued
May 27, 2013
Type
Doctoral Thesis
Abstract
The interest in Taxus baccata, universally known as a dioecious species, recently raised mainly for
conservation concerns and biotechnological applications, the latter primarily associated with anticancer
metabolites such as taxol.
This work aims to investigate ecology and sexual behavior of T. baccata, in order to throw light on sexreversal
phenomenon and on cases of monoecism find out in yew population of Carpineto Romano (RM).
The possible occurrence of sex chromosomes in T. baccata has been studied in this work, giving new insight
into yew cytogenetic. Indeed, karyotype analyses on English yew (Taxus baccata L., 2n =24) were
performed by examining root tip meristematic cells derived from plant cuttings. Yew vegetative propagation
was exploited to overcome seed deep dormancy and slow germination.
However, by use of an image analysis software, the identification of 12 homologous pairs was achieved:
most pairs resulted metacentric and submetacentric, but two, markedly shorter and acrocentric chromosome
pairs could also be distinguished.
Multicolor fluorescence in situ hybridization (FISH) was successfully applied to metaphase spreads, using as
probes a 5S rDNA and a 18S-5.8S-28S rDNA sequences. Both sequences were found to hybridize on the
same metacentric pair of chromosomes.
Work is in progress to further describe T. baccata karyotype with additional FISH probes, including
microsatellites sequences. This approach is expected not only to help characterizing each member of the
chromosome set, but also to contribute to shed some light on yew genome structure and sex chromosome or
sex-linked genes.
Additional information
Dottorato di ricerca in Scienze e tecnologie per la gestione forestale e ambientale
File(s)![Thumbnail Image]()
Name
mptomasino.pdf
Size
13.57 MB
Format
Adobe PDF
Checksum (MD5)
d7a286ebded74ae99fe5077787fb5941