Čížková, J., Hřibová, E., Christelová, P., Van den Houwe, I., Häkkinen, M., Roux, N., Swennen, R., Doležel, J.
PLoS ONE
10:
e0134096,
2015
Keywords:
Abstract:
The production of bananas is threatened by rapid spreading of various diseases and
adverse environmental conditions. The preservation and characterization of banana diversity
is essential for the purposes of crop improvement. The world's largest banana germplasm
collection maintained at the Bioversity International Transit Centre (ITC) in Belgium is
continuously expanded by new accessions of edible cultivars and wild species. Detailed
morphological and molecular characterization of the accessions is necessary for efficient
management of the collection and utilization of banana diversity. In this work, nuclear DNA
content and genomic distribution of 45S and 5S rDNA were examined in 21 diploid accessions
recently added to ITC collection, representing both sections of the genus Musa. 2C
DNA content in the section Musa ranged from 1.217 to 1.315 pg. Species belonging to section
Callimusa had 2C DNA contents ranging from 1.390 to 1.772 pg. While the number of
45S rDNA loci was conserved in the section Musa, it was highly variable in Callimusa species.
5S rRNA gene clusters were found on two to eight chromosomes per diploid cell. The
accessions were genotyped using a set of 19 microsatellite markers to establish their relationships
with the remaining accessions held at ITC. Genetic diversity done by SSR genotyping
platform was extended by phylogenetic analysis of ITS region. ITS sequence data
supported the clustering obtained by SSR analysis for most of the accessions. High level of
nucleotide diversity and presence of more than two types of ITS sequences in eight wild diploids
pointed to their origin by hybridization of different genotypes. This study significantly
expands the number of wild Musa species where nuclear genome size and genomic distribution
of rDNA loci is known. SSR genotyping identified Musa species that are closely
related to the previously characterized accessions and provided data to aid in their classification.
Sequence analysis of ITS region provided further information about evolutionary
relationships between individual accessions and suggested that some of analyzed accessions
were interspecific hybrids and/or backcross progeny.
Fulltext: contact IEB authors
IEB authors: Pavla Christelová,
Jana Čížková,
Jaroslav Doležel,
Eva Hřibová
Čeština
English