Download Unreduced gamete formation in Curculigo capitulate(Amaryllidaceae)

58º Congresso Brasileiro de Genética
Resumos do 58o Congresso Brasileiro de Genética • 11 a 14 de setembro de 2012
Rafain Palace Hotel e Convention Center • Foz do Iguaçu • PR • Brasil
www.sbg.org.br - ISBN 978-85-89109-06-2
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Unreduced gamete formation in Curculigo
capitulate (Amaryllidaceae)
Silva, N; Pagliarini, MS; Mendes-Bonato, AB
Department of Cell Biology and Genetics, State University of Maringá, Maringá, PR, Brazil.
[email protected]
Keywords: Curculigo capitulata, meiosis, unreduced gametes, microsporogenesis, Amaryllidaceae.
Curculigo capitulata is a perennial species from tropical Asia. It grow about 1 meter in length and the plant does not
develop a stem. Because their leaves resemble palm leaves, it is known as ‘palm-grass’. The rhizomes have medicinal value.
Several chemical compounds were isolated from the rhizomes. It is used as tonic, for rheumatism and dismenorrhoea
and also as an anti-arrhytmic agent. Only a few cytogenetic studies have been developed on this species. 2n = 2x = 18
chromosomes was reported for three species of Curculigo analyzed (C. crassifolia, C. capitulata, and C. sinensis). The
present study reports the formation of unreduced gametes in plants of two Brazilian populations. Flower buds of C.
capitulate for meiotic studies were collected in Piracicaba (SP, Brazil) and Maringá (PR, Brazil). Young inflorescences
were fixed in 3:1 ethyl alcohol: acetic acid for 24 hours at room temperature and then transferred to 70% alcohol and
stored in freezer until the time for use. Microsporocytes were prepared by squashing and staining with 1% propionic
carmine. The chromosome number was determined in meiocytes at diakinesis, and the meiotic behavior was determined
up to this phase to the end of meiosis. Chromosome number was evaluated in 2n = 2x = 18, with homologous pairing
preferentially in bivalents. Some univalents were observed in diakinesis giving rise to some irregular chromosome
segregation mainly in the first meiotic division. Cytokinesis failed to occur in some meiocytes in the second division,
and dyads, triads, and monads occurred in variable frequency among the analyzed plants. Restitutional nuclei were
observed among the meiotic products. The production of 2n gametes in plants is held to be the dominant process involved
in the origin of polyploid plants. It has been estimated that more than 70% of the flowering plants are polyploids.
Financial Support: CNPq.