Cytogenetic characterization of Lippia alba and Lantana camara (Verbenaceae) from Brazil

Abstract

The aim of this work was to determine the cytogenetic characteristics of Brazilian Lippia alba (Mill) N. E. Brown and Lantana camara Plum. that could be useful for future characterization of these genera. Our analyses revealed that Li. alba has 2n=30 chromosomes consisting of ten metacentric and five submetacentric pairs, while La. camara has 44 metacentric chromosomes. The large blocks of heterochromatin seen in both species suggest an apomorphic condition. Six 45S rDNA sites were detected in both species by fluorescence in situ hybridization (FISH). Two and four 5S rDNA sites were observed in Li. alba and La. camara, respectively. Meiotic analysis revealed a normal chromosomal behaviour. The number of chromosomes and the presence of 45S rDNA and 5S rDNA sites do not exclude a possible polyploid origin. The cytogenetic differences between La. camara and Li. alba may be useful markers for differentiating these species.

Chromosome banding and essential oils composition of Brazilian accessions of Lippia alba (Verbenaceae)

“…However, using the Giemsa staining technique, it was possible to observe that the majority of the metaphases presented only one or two visible pairs of satellite chromosomes. A previous report showed secondary constrictions only in two pairs of chromosomes, but in the same study, the authors observed six sites for the 45S rDNA probes (Brandão et al 2007). The secondary constrictions are formed in active sites with 45S rDNA (NORs) and sites with restricted NOR activation can, but don't have to, form secondary constrictions, thus hindering the real determination of their number and position through conventional techniques (Carvalho & Guerra 2002;Panzara et al 1996;Marcon et al 2005).…”

“…Heterochromatin pattern of five different accessions of Lippia alba. ST = short arm telomere; C = centromeric region; LT = large arm telomere; + = DAPI and C coincidentes bands; * = only DAPI positive bands; = CMA 3 positive band and negative silver nitrate impregnation (AgNOR-); = CMA 3 positive band and positive silver nitrate impregnation (AgNOR+) two (Brandão et al 2007). Furthermore, we always observed a maximum number of four nucleoli (Fig.…”

“…Brandão et al (2005), observed 15 bivalents and confirmed the somatic number of 30 chromosomes. Molecular cytogenetic data was recently obtained and showed three pairs of chromosomes presenting 45S rDNA sites and two chromosome pairs presenting 5S rDNA sites (Brandão et al 2007). …”

Karyological studies in Brazilian species of Lippia L. (Verbenaceae)

“…The chromosome number described for the genus vary from n = 10 for L. rubella (Viccini et al 2006) to n = 30 for L. turbinata and L. fissicalyx (Pastoriza and Andrada 2006). Studies with somatic chromosomes were done only for L. turbinata, L. fissicalyx (Pastoriza and Andrada 2006) and Lippia alba (Brandão et al 2007, Sousa et al 2009, Pierre et al 2011). For L. alba, the most studied species, the karyological studies reveal the centromer position, number of secondary constrictions, heterochromatin distribution and the map of rDNA sites (45S and 5S) by FISH (Brandão et al 2007, Sousa et al 2009.…”

Botanical aspects of Heteropterys umbellata (Malpighiaceae): a cytological and palynological approach

“…In H. umbellata, there are great blocks of heterochromatin revealed by C-banding technique, mainly around the centromere. This characteristic has been described for a great number of species but has not been reported earlier for Malpighiaceae (Brandão et al 2007, Sousa et al 2009). The heterochromatin is considered one of the most important factors in the evolution process (Edelman and Lin 1995) once it can interfere in many other mechanisms such as DNA replication, chromosomal structure, gene expression and the cell cycle (Redi et al 2001, Stace 2000.…”