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

Abstract

Abstract:The essential oil components and a karyotypic analysis of five Lippia alba (Verbenaceae) accessions from Brazil were performed with the objective of investigating the variation among different populations. The chemistry analysis allowed the grouping of the accessions in two main chemotypes: neral chemotype (LaCat, LaJF and LaRJ) and linalool chemotype (LaGua and LaVC). However, large karyotypic differences, verified by different chromosome banding techniques, were not detected. The results presented the same chromosome number for all accessions (2n = 30) with 10 metacentric chromosomes and 5 submetacentric. The chromosome banding showed great blocks of constitutive heterochromatin (C-bands) around the centromeric region, which was rich in AT bases (DAPI+), while the CMA bands were observed only in terminal regions of six chromosomes. Through Ag-NOR techniques, only two active pairs of NORs were detected on the three pairs of secondary constrictions (the NOR activity is discussed). This work relates the pattern of heterochromatin for Lippia alba for the first time.

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

“…Brazil, one of the most important centers of diversity possesses nearly 75% of the 160 described species that can be easily found in Brazilian rocks environments with high altitudes (Salimena 2000, Viccini et al 2006. Although many species have been considered as an important source of chemical constituents for pharmaceutical, food and cosmetic industry, few studies have been done in order to amplify their biological, anatomical, morphological, physiological, phenological, genetic and evolutionary knowledge (Salimena 2000, Pascual et al 2001, Viccini et al 2006, Sousa et al 2009, Campos et al 2011.…”

“…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.…”

“…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. Considering the small number of species karyomorphologically studied in Lippia, the present paper reports karyomorphological aspects of twelve Brazilian species of Lippia, with eleven of them studied for the first time.…”

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.…”

“…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. Besides, variations in heterochromatin amounts have proved to be useful in karyosystematic and phylogenetic studies (Grif 2000, Sousa et al 2009, Schwarzacher et al 1980. Many studies indicate that the presence of few heterochromatin in one species is a plesiomorphic condition, while large blocks indicate an apomorphic condition (Greilhuber 1979, Redi et al 2001).…”