Kopecký, D., Bartoš, J., Zwierzykowski, Z., Doležel, J.
CYTOGENETIC AND GENOME RESEARCH
124:
170-178,
2009
Keywords:
Fescue, chromosome pairing, GISH
Abstract:
A diploid-like pairing system prevents meiotic irregularities
and improves the efficiency of gamete production in allopolyploid
species. While the nature of the system is known
in some polyploid crops including wheat, little is known
about the control of chromosome pairing in polyploid fescues
( Festuca spp.). In this work we studied chromosome
pairing in allohexaploid F. arundinacea, its progenitors F. pratensis
and F. glaucescens, and two intergeneric hybrids Lolium
multiflorum (2x) ! F. arundinacea (6x) and L. multiflorum
(4x) ! F. glaucescens (4x). The use of genomic in situ hybridization
(GISH) permitted the analysis of homoeologous chromosome
pairing and recombination of different genomes
involved. We detected a diploid-like pairing system in polyploid
fescues F. arundinacea and F. glaucescens, the latter being
one of the progenitors of F. arundinacea. The pairing control
system was absent in the second progenitor F. pratensis.
Detailed analysis of intergeneric hybrids confirmed the presumed
haploinsufficiency of the fescue system, which resulted
in homoeologous pairing between all component
genomes. This indicates that introgression of any specific
chromosome segment from one genome to another is possible
in all genome combinations. Our results not only contribute
to the quest to discover the nature of the system controlling
chromosome pairing in polyploid fescues, but may
also have serious implications for design of hybrid breeding
schemes in forage grasses.
Fulltext: contact IEB authors
IEB authors: Jan Bartoš,
Jaroslav Doležel,
David Kopecky
Čeština
English