Diversification of the P genome among Agropyron Gaertn. (Poaceae) species detected by FISH

By

Zhao, Yan
Xie, Jihong
Dou, QUanwen
Wang, Junjie
Zhang, Zhong

Type

Article

Date of Publication

2017

Original Publication

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

Volume

11

Series / Issue

Issue: 3

Pages

495-509

Subjects

Agropyron , Fish , P genome , rDNA , repetitive sequence

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.v11i3.13124

 

Abstract

The genomes of five Agropyron Gaertner, 1770 species were characterized using all potential di- or trinucleotide simple sequence repeat (SSR) motifs and four satellite DNA repeats as fluorescence in situ hybridization (FISH) probes. The sites of 5S and 45S rDNA were relatively conserved among the diploid and tetraploid species. A number of sites for the dinucleotide SSRs AC, AG, and pSc119.2 was detected in all investigated species except A. mongolicum Keng, 1938. Several different trinucleotide SSRs were identified in different tetraploid species. All Agropyron species were suggested to include the basic P genome, although genome differentiation was still observed. The P genome of A. mongolicum was distinct from that of the diploid A. cristatum (Linnaeus, 1753) Gaertner, 1770. and other tetraploid species, with no hybridizations for AC, AG, or pSc119.2 observed. This finding supports designation of the P genomes of A. cristatum and A. mongolicum as Pc and Pm, respectively. An exceptional 5S rDNA site revealed in one set of homoeologous chromosomes strongly supports the allopolyploid origin of A. desertorum (Fischer ex Link, 1821) Schultes, 1824. However, the diploid donors to A. desertorum need further investigation. Similarly, the unique FISH pattern of a pair of 5S rDNA-carrying chromosomes was indicative of a potential allopolyploid origin for A. fragile (Roth, 1800) Candargy, 1984. The conserved distribution of 5S and 45S rDNA suggests A. cristatum (4x) and A. michnoi Roshevitz, 1929 are closely related. Two forms of B chromosomes were identified among individuals A. mongolicum and A. desertorum plants.