Molecular Cytogenetic Analysis of Cucumis Wild Species Distributed in Southern Africa: Physical Mapping of 5S and 45S rDNA with DAPI.
Cytogenet Genome Res
; 146(1): 80-7, 2015.
Article
en En
| MEDLINE
| ID: mdl-26112877
ABSTRACT
Wild Cucumis species have been divided into Australian/Asian and African groups using morphological and phylogenetic characteristics, and new species have been described recently. No molecular cytogenetic information is available for most of these species. The crossability between 5 southern African Cucumis species (C. africanus, C. anguria, C. myriocarpus, C. zeyheri, and C. heptadactylus) has been reported; however, the evolutionary relationship among them is still unclear. Here, a molecular cytogenetic analysis using FISH with 5S and 45 S ribosomal DNA (rDNA) was used to investigate these Cucumis species based on sets of rDNA-bearing chromosomes (rch) types I, II and III. The molecular cytogenetic and phylogenetic results suggested that at least 2 steps of chromosomal rearrangements may have occurred during the evolution of tetraploid C. heptadactylus. In step 1, an additional 45 S rDNA site was observed in the chromosome (type III). In particular, C. myriocarpus had a variety of rch sets. Our results suggest that chromosomal rearrangements may have occurred in the 45 S rDNA sites. We propose that polyploid evolution occurred in step 2. This study provides insights into the chromosomal characteristics of African Cucumis species and contributes to the understanding of chromosomal evolution in this genus.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
ADN Ribosómico
/
Cucumis
País/Región como asunto:
Africa
Idioma:
En
Revista:
Cytogenet Genome Res
Asunto de la revista:
GENETICA
Año:
2015
Tipo del documento:
Article
País de afiliación:
Polonia