Data/hora: 09/06/2024 17:15:54

Biblioteca(s): | Embrapa Mandioca e Fruticultura.
Data corrente: | 04/04/2000
Data da última atualização: | 04/04/2000
Autoria: | PEDROSA, A.; SCHWEIZER, D.; GUERRA, M.
Afiliação: | Department of Cytology and Genetics, Institute of Botany, University of Vienna, Rennweg, Vienna, Austria.
Título: | Cytological heterozygosity an d the hybrid origin of sweet orange [citrus sinensis (L.) osbeck].
Ano de publicação: | 2000
Fonte/Imprenta: | Theor Appl Genet, v.100, p.361-367, 2000.
Idioma: | Inglês
Conteúdo: | Citrus sinensis chromosomes, although small in size, present a remarkable differentiation of bands with the fluorochromes CMA and DAPI. These bands suggest that some heteromorphisms are fixed in this species. To investigate the of these heteromorpisms, ten cultivars of C. sinenesis were analysed with CMA/DAPI staining and, in some of them, the 18S-5.8S rRNA and 5S rRNA genes were located by in situ hybridization. CMA/DAPI staining showed e exactly the same CMA+/DAPI-banding pattern for all cultivars. In situ hybridation revealed three 18S-5.8S-25S rRNA gene sites, two proximally located on two similar chromosomes and one terminally located on a third non-related chromossome. Two 5S rRNA gene sites were observed in this species, with one located proximal to the telomeric 18S-5.8S-25S rRNA site. Both cytological approaches revealed an invariable, heterozigotic karyotype among sweet orange cultivars.
Categoria do assunto: | --
Registro original: | Embrapa Mandioca e Fruticultura (CNPMF)
Exemplares: | CNPMF - (17772-1) - ADD - SP - -- - S11824 -  - S11824 - DIS