Data/hora: 13/06/2024 21:41:46

Provedor de dados: | 74
País: | Brazil
Título: | Chromosomal and morphological studies of diploid and polyploid cytotypes of Stevia rebaudiana (Bertoni) Bertoni (Eupatorieae, Asteraceae)
Autores: | Oliveira,Vanessa M. de; Forni-Martins,Eliana R.; Magalhães,Pedro M.; Alves,Marcos N.
Data: | 2004-01-01
Ano: | 2004
Palavras-chave: | Asteraceae; Pollen; Polyploidy; Stevia rebaudiana; Stevioside; Stomata.
Resumo: | In this study, we examined the chromosome number and some morphological features of strains of Stevia rebaudiana. The chromosomes were analyzed during mitosis and diakinesis, and the tetrad normality and pollen viability were also assessed. In addition, stomata and pollen were measured and some plant features were studied morphometrically. All of the strains had 2n = 22, except for two, which had 2n = 33 and 2n = 44. Pairing at diakinesis was n = 11II for all of the diploid strains, whereas the triploid and tetraploid strains had n = 11III and n = 11IV, respectively. Triploid and tetraploid plants had a lower tetrad normality rate than the diploids. All of the strains had inviable pollen. Thus, the higher the ploidy number, the greater the size of the pollen and the stomata, and the lower their number per unit area. The triploid strain produced the shortest plants and the lowest number of inflorescences, whereas the tetraploid strain had the largest leaves. Analysis of variance revealed highly significant differences among the strains, with a positive correlation between the level of ploidy and all of the morphological features examined.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000200015
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572004000200015
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.27 n.2 2004
Fonte: | info:eu-repo/semantics/openAccess