Research articles
ScienceAsia 46 (2020):ID 297-307 |doi:
10.2306/scienceasia1513-1874.2020.037
Karyotypic and molecular cytogenetic characterization
of diploid and polyploid accessions of medicinal herbs
in the genus Paris from northern Thailand
Janene Chowa, Tidarat Puangpairoteb, Kesara Anamthawat-Jónssonc, Puangpaka Umpunjuna,*
ABSTRACT: Paris is a genus of medicinal plants in the family Melanthiaceae. For the use in traditional medicine and for trading in local markets, rhizomes of Paris plants are collected from their native habitats. Due to its slow growth and excessive harvesting, the species is currently facing the risk of extinction. The aim of the present study was to cytogenetically characterize Paris plants from the mountainous regions of northern Thailand in order to obtain characteristics that may be species-specific for use in taxonomical and diversity studies. Chromosomes were isolated
from rhizome-grown root tips from the total of 20 Paris accessions. Of these, 12 were diploid (2n = 2x = 10), 2 were triploid (2n = 3x = 15), one was tetraploid (2n = 4x = 20) and 5 were mixoploid accessions. The diploid accessions from Chiang Rai and Nan provinces had the most common basic karyotype 6m+4t whereas those from Chiang Mai province showed 6m+4st and 4m+2sm+4st, indicating differentiation at the species level. The analysis of karyotypes and ribosomal gene mapping by FISH (fluorescence in situ hybridization) indicated autotriploidy arising spontaneously within a diploid population and autotetraploidy via endoreduplication in the mitotic cell division. The ribosomal FISH also revealed a novel map of 5S and 45S rDNA, including the ancestral 5S–45S linked sites. The findings of our research support the ongoing species diversification among Thai Paris taxa.
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a |
Department of Plant Science, Faculty of Science, Mahidol University, Bangkok 10400 Thailand |
b |
Deparment of Biology, Faculty of Science, Prince of Songkla University, Songkla 90110 Thailand |
c |
Institute of Life and Environmental Sciences, School of Engineering and Natural Sciences,
University of Iceland, Reykjav?k 102 Iceland |
* Corresponding author, E-mail: puangpaka.ump@mahidol.ac.th
Received 20 Jan 2020, Accepted 19 Apr 2020
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