Caracterização citogenética em Schlumbergera truncata (Haworth) Moran e Schlumbergera × buckleyi (T. Moore) Tjaden (Cactaceae)
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Data
2007-06-01
Autores
Ortolani, Flavia Aparecida [UNESP]
Mataqueiro, Márcia Fiorese [UNESP]
Moro, José Roberto [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Botânica do Brasil
Resumo
O número cromossômico diplóide de Schlumbergera truncata e Schlumbergera x buckleyi, de indivíduos com diferentes tipos de coloração de pétalas, foi determinado usando-se pontas de raízes. A utilização de 8-hidroxiquinoleína 0,003 M à 36 °C por 3 horas possibilitou melhor separação cromossômica. Técnica de bandeamento C e de coloração Giemsa permitiram o estudo cariológico dessas espécies. O híbrido Schlumbergera × buckleyi (rósea) apresenta 2n = 22 cromossomos com fórmula cariotípica 16 M + 6 SM. Schlumbergera truncata, apresentando pétalas nas cores vermelha, branca e pink, possui 2n = 22 cromossomos, formulação cariotípica idêntica à de Schlumbergera × buckleyi, enquanto a planta com flores de coloração amarelada mostrou 2n = 34 cromossomos. A classificação cromossômica foi baseada no índice centromérico. Nas plantas que apresentam coloração vermelha, branca, pink e rósea nas pétalas, o melhor período de obtenção de metáfases corresponde ao período de florescimento. Schlumbergera truncata com flores amareladas apresenta dois picos anuais de divisão mitótica. Esses resultados dão suporte à um melhor entendimento da biologia no gênero Schlumbergera e auxiliam na classificação taxonômica nos casos onde apenas as características fenotípicas não são suficientemente confiáveis para a classificação das plantas no mesmo táxon.
The diploid chromosome number of Schlumbergera truncata and Schlumbergera × buckleyi, in individuals with different types of petal color, was determined using root tips. The use of 8-hydroxyquinolein 0.003 M at 36 ºC provided better chromosome separation. C-banding technique and Giemsa coloration allowed the karyological study of these species. Schlumbergera × buckleyi hybrid (light pink) species has 2n = 22 chromosomes with karyotype formula 16M + 6SM. Schlumbergera truncata with red, white, and pink petals and 2n = 22 chromosomes has karyotype formula identical to Schlumbergera × buckleyi, while the plant with yellowish flowers has 2n = 34 chromosomes. Chromosome classification was based on the centromeric index. In plants with white, red, pink and light pink petal color, the best time to obtain metaphases is during flowering. Schlumbergera truncata with yellowish flowers has two annual peaks of mitotic division. These results give us a better understanding of the biology of the genus Schlumbergera and aid in taxonomic classification where phenotypic characteristics alone are not reliable enough to classify plants of the same taxon.
The diploid chromosome number of Schlumbergera truncata and Schlumbergera × buckleyi, in individuals with different types of petal color, was determined using root tips. The use of 8-hydroxyquinolein 0.003 M at 36 ºC provided better chromosome separation. C-banding technique and Giemsa coloration allowed the karyological study of these species. Schlumbergera × buckleyi hybrid (light pink) species has 2n = 22 chromosomes with karyotype formula 16M + 6SM. Schlumbergera truncata with red, white, and pink petals and 2n = 22 chromosomes has karyotype formula identical to Schlumbergera × buckleyi, while the plant with yellowish flowers has 2n = 34 chromosomes. Chromosome classification was based on the centromeric index. In plants with white, red, pink and light pink petal color, the best time to obtain metaphases is during flowering. Schlumbergera truncata with yellowish flowers has two annual peaks of mitotic division. These results give us a better understanding of the biology of the genus Schlumbergera and aid in taxonomic classification where phenotypic characteristics alone are not reliable enough to classify plants of the same taxon.
Descrição
Palavras-chave
Cactaceae, Cariótipo, Número cromossômico, Banda-C, Cactaceae, karyotype, chromosome numbers, C-banding
Como citar
Acta Botanica Brasilica. Sociedade Botânica do Brasil, v. 21, n. 2, p. 361-367, 2007.