INVESTIGADORES
FERRUCCI Maria silvia
artículos
Título:
Karyotypic study of some species of Serjania and Urvillea (Sapindaceae; Tribe Paullinieae)
Autor/es:
ZAMPIERI NOGUEIRA, C.; RUAS, PABLO M.; RUAS, CLAUDETE F.; FERRUCCI M.S.
Revista:
AMERICAN JOURNAL OF BOTANY
Editorial:
BOTANICAL SOC AMER INC
Referencias:
Lugar: St. Louis; Año: 1995 vol. 82 p. 646 - 654
ISSN:
0002-9122
Resumen:
Karyotypes of six species (in ten populations) of the genus Serjania and one species of the genus Urvillea were studied using root tip mitotic metaphases. Al1 species of Serjania were diploids with 2n = 24 chromosomes and the species of Urvil!ea was octoploid with 2n = 86 chromosomes. Analysis of the karyotypes of Serjania showed that the species are differentiated by chromosomic structural changes. Chromosome lengths showed great differences among the species that may be explained by chromosomal deletion or addition. The basic chromosomic number is x = 12 for Serjania and x = 11 for Urvillea. In Urvillea the evolutionary trend may be toward polyploidy followed by reductional aneuploidy. The Giemsa (C-band) staining technique was applied in Serjania; however, no clear blocks of heterochromatin were observed. This result agrees with the presence of semireticulate nuclei. The Nucleolar Organizing Region (NOR-banding) technique was applied in S. communis and S. laruotteana, which showed one and two pairs stained, respectively. Variation in the number of nucleoli was observed among the different populations of Serjania. This variation could be explained by the presence of small nucleolar organizer regions that occur scattered along the genome and are not detected by the silver staining methodology.