Physical mapping of 5S and 18S ribosomal DNA in three species of Agave (Asparagales, Asparagaceae)

By

Gomez-Rodriguez, Victor Manuel
Rodriguez-Garay, Benjamin
Palomino, Guadalupe
Martínez, Javier
Barba-Gonzalez, Rodrigo

Type

Article

Date of Publication

2013

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

7

Series / Issue

Issue: 3

Pages

191-203

Subjects

Agave , fluorescent in situ hybridization , karyotype , Physical mapping , ribosomal DNA

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/compcytogen.v7i3.5337

 

Abstract

Agave Linnaeus, 1753 is endemic of America and is considered one of the most important crops in Mexico due to its key role in the country’s economy. Cytogenetic analysis was carried out in A. tequilana Weber, 1902 ‘Azul’, A. cupreata Trelease et Berger, 1915 and A. angustifolia Haworth, 1812. The analysis showed that in all species the diploid chromosome number was 2n = 60, with bimodal karyotypes composed of five pairs of large chromosomes and 25 pairs of small chromosomes. Furthermore, different karyotypical formulae as well as a secondary constriction in a large chromosome pair were found in all species. Fluorescent in situ hybridization (FISH) was used for physical mapping of 5S and 18S ribosomal DNA (rDNA). All species analyzed showed that 5S rDNA was located in both arms of a small chromosome pair, while 18S rDNA was associated with the secondary constriction of a large chromosome pair. Data of FISH analysis provides new information about the position and number of rDNA loci and helps for detection of hybrids in breeding programs as well as evolutionary studies.