title: Divergence between C. melo and African Cucumis Species Identified by Chromosome Painting and rDNA Distribution Pattern.
abstract: The 5S and 45S rDNA sites are useful chromosome landmarks and can provide valuable information about karyotype evolution and species interrelationships. In this study, we employed fluorescence in situ hybridization (FISH) to determine the number and chromosomal location of 5S and 45S rDNA loci in 8 diploid Cucumis species. Two oligonucleotide painting probes specific for the rDNA-bearing chromosomes in C. melo were hybridized to other Cucumis species in order to investigate the homeologies among the rDNA-carrying chromosomes in Cucumis species. The analyzed diploid species showed 3 types of rDNA distribution patterns, which provided clear cytogenetic evidence on the divergence between C. melo and wild diploid African Cucumis species. The present results not only show species interrelationships in the genus Cucumis, but the rDNA FISH patterns can also be used as cytological markers for the discrimination of closely related species. The data will be helpful for breeders to choose the most suitable species from various wild species for improvement of cultivated melon.
authors.affiliation: School of Life Sciences, Jiangsu Normal University, Xuzhou, China.
authors.forename: Kunpeng
authors.initials: K
authors.lastname: Li
authors.forename: Huaisong
authors.initials: H
authors.lastname: Wang
authors.forename: Jiming
authors.initials: J
authors.lastname: Wang
authors.forename: Jianying
authors.initials: J
authors.lastname: Sun
authors.forename: Zongyun
authors.initials: Z
authors.lastname: Li
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Han
mesh_terms: D000349:Africa; D020223:Chromosome Painting; D032461:Chromosomes, Plant / Q000235:genetics; D028462:Cucumis / Q000145:classification / Q000235:genetics*; D015342:DNA Probes; D018744:DNA, Plant / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004171:Diploidy; D017404:In Situ Hybridization, Fluorescence; D010802:Phylogeny; D013045:Species Specificity
chemical_list: D015342:DNA Probes; D018744:DNA, Plant; D004275:DNA, Ribosomal