Chromosome banding and essential oils composition of Brazilian accessions of <Emphasis Type="Italic">Lippia alba</Emphasis> (Verbenaceae)

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.     

Cytogenetic characterization of <Emphasis Type="Italic">Lippia alba</Emphasis> and <Emphasis Type="Italic">Lantana camara</Emphasis> (Verbenaceae) from Brazil

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 numbers in AustralianEuphrasia (Scrophulariaceae)

Chromosome numbers for six Australian taxa ofEuphrasia have been determined. Improved staining techniques have shown that numbers for four of the taxa published previously by the first author were incorrect. The investigated taxa show high ploidy levels with an apparent base number of x = 11, the same as for the genus outside Australia.Dedicated to Prof. DrElisabeth Tschermak-Woess on the occasion of her 70th birthday.     

Chromosome numbers and karyotypes within the Ranunculus alpestris-group (Ranunculaceae)

The Ranunculus alpestris-group comprises six white-flowered species growing in mostly alpine zones of central and southern European mountains. They all are diploid with 2n=16 chromosomes. The common karyotype of the group was established based on 75 metaphases (6–26 metaphases per species). The haploid karyotype consists of four metacentric (chromosomes 1, 3, 6, 7) and four more or less subtelocentric chromosomes (2, 4, 5, 8). This karyotype is similar to that of other white-flowered European Ranunculus species as well as the yellow-flowered R. thora-group. Analysis of karyotypes partly confirms relationships inferred from molecular phylogenies. Species with this karyotype are placed on rather basal branches in existing phylogenies, which may indicate that this karyotype is primitive within the genus Ranunculus.     

Chromosome counts inCephalotus (Cephalotaceae)

Cephalotus follicularis is uniformly n = 10 in all populations surveyed.     

Chromosome numbers and taxonomic implications in the fern genusAzolla (Azollaceae)

Investigation of chromosome numbers of allAzolla species, and for the first time of hybrids, has been undertaken. Removal of wax from the leaf surface proved invaluable in achieving clear cytological preparations and providing unambiguous chromosome numbers. In contrast to previous records, the speciesA. pinnata, A. filiculoides, A. filiculoides var.rubra, A. caroliniana, A. microphylla, andA. mexicana were found to be 2n=44, andA. nilotica to be 2n=52. Several triploids (2n=66) and one tetraploid (2n=88) were identified. No geographical pattern could be observed in the distribution of triploids which probably derive from the function of unreduced gametes. The chromosome number of hybrids occasionally deviates from the diploid chromosome number (2n=44). The small chromosome size limits karyotypic analysis and only differences in overall chromosome size can be observed. Taxonomic implications of chromosome numbers and sizes are discussed.     

The antidepressant-like effects of Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) in mice

The aim of the present work is to evaluate the putative antidepressant-like effects of a hydro-ethanolic extract (CEAp) and their fractions from the aerial parts of Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) on the performance of male mice in the forced swimming test (FST). A single dose (100.0 mg/kg p.o.) of CEAp, in male mice provoked a significant reduction of the immobility time (p<0.01). Such effect was also observed with short-term treatment (7 days) with single doses of 1.0 (p<0.01), 10.0 (p<0.05) and 100.0 (p<0.05) mg/kg/day of CEAp. Additionally, in a different set of experiments, repeated administration in a 24-h period (24, 18 and 1 h before swimming test) with doses of 1.0 (p<0.05) and 10.0 (p<0.05) mg/kg p.o., of CEAp and 10.0 mg/kg p.o., (p<0.05) of ethyl acetate fraction, provoked significant reduction of the immobility time of male mice in the FST. Moreover, it was noted important differences in the onset of the antidepressant-like effect in the FST, depending on the modality of treatment with CEAp (acute, short-term or repeated). Both, efficacy and potency were higher when repeated administration of CEAp was used, and surprisingly the dose of 10 mg/kg (24, 18 and 1 h before swimming test) was more effective than imipramine. In the same way, the short term administration (7 days) improved significantly efficacy and potency of the CEAp in comparison to a single dose treatment. The ethyl acetate fraction submitted to TLC demonstrated that main and minor components are phenolics and terpenes, respectively. In addition, this fraction gives a negative Shinoda's test for flavonoids. These results indicate an antidepressant-like profile of action for the hydro-ethanolic extract and the component(s) of the ethyl acetate fraction obtained from A. polystachya, which deserve further investigation.     

中国云南鳞毛蕨属(鳞毛蕨科)13种植物的染色体数目

报道了中国云南产鳞毛蕨科Dryopteridaceae鳞毛蕨属Dryopteris Adanson 13种植物的染色体数目。其中4个种：多雄拉鳞毛蕨D．alpestris（2n=82）、哈巴鳞毛蕨D．habaensis（2n=82）、脉纹鳞毛蕨D．lachoongensis（2n=82）和永自鳞毛蕨D．yungtzeensis（2n=82）的染色体数目为首次报道;无融合三倍体的川西鳞毛蕨Dryopteris rosthornii、无融合四倍体的大羽鳞毛蕨D．wallichiana以及无融合二倍体的栗柄鳞毛蕨D．yoroii为3个新发现的细胞类型。细胞学研究结果支持高山鳞毛蕨组sect．CaespitosaeS．G Lu应该为鳞毛蕨属内一个独立的组;中国喜马拉雅地区的鳞毛蕨属植物中存在着大量的无融合二倍体细胞类型。对蕨类植物中同一植株产生不同倍性孢子的现象进行了讨论。     

Iridoids from the aerial parts of Verbena littoralis (Verbenaceae)

The iridoids, 6S-hydroxy-8S-methyl-4-methylene-hexahydro-cyclopenta[c]pyran-3-one and 6S,9S-dihydroxy-8S-methyl-4-methylene-hexahydro-cyclopenta[c]pyran-3-one, were isolated from the aerial parts of Verbena littoralis. Their structures and stereochemistry were elucidated by means of NMR spectral data analysis. Both compounds showed moderate in vitro activity against gram positive and negative bacteria as well as moderate in vivo intestinal peristaltic action in mouse. The iridoids also showed moderate free radical scavenging activity against l,l-diphenyl-2-picrylhydrazyl (DPPH) as well as antioxidant activity, the latter being evidenced by redox properties measured using E1CD-HPLC.     

Chemotaxonomic features of iridoids occurring inVerbenoxylum reitzii (Verbenaceae)

The familyVerbenaceae sensu stricto is chemically characterized by the accumulation of 10-hydroxy or 8-methyl-8-hydroxy derivatives of 4-carboxylated iridoids compounds. The former were supposed to be characteristic of some genera of tribeLantaneae, once were never found in another tribe. This paper reports the occurrence of theviridoside (10-hydroxy-iridoid) in leaves ofVerbenoxylum reitzii (tribeCitharexyleae) and its taxonomic implication.     

Morphology and histochemistry of the glandular trichomes of Lippia scaberrima (Verbenaceae)

BACKGROUND AND AIMS: Lippia scaberrima, an aromatic indigenous South African plant, with medicinal application, potentially has economic value. The production of essential oil from this plant has not been optimized, and this study of the chemico-morphological characteristics was aimed at determining the location of oil production within the plant. Furthermore, the locality of other secondary metabolites important in medicinal applications needed to be ascertained. This information would be useful in deciding the protocol required for isolation of such compounds. METHODS: The morphology of the glandular trichomes was investigated using a combination of scanning electron and light microscopy. Concurrently, the chemical content was studied by applying various chemical reagents and fluorescence microscopy. KEY RESULTS: Three types of trichomes were distinguished on the material investigated. Large, bulbous peltate glands containing compounds of terpenoid nature are probably the main site of essential oil accumulation. Small glands were found to be both peltate and capitate and fluorescent stain indicated the possible presence of phenolic compounds. The third type was a slender tapered seta with an ornamented surface and uniseriate base, and evidently secretory in nature. CONCLUSIONS: This study linking the chemical content and morphology of the glandular trichomes of L. scaberrima has contributed to the knowledge and understanding of secretory structures of Lippia spp. in general.     

Chromosome number evolution in the tribeBrassiceae (Brassicaceae): Evidence from isozyme number

Variation in isozyme number was used to assess the evolution of haploid chromosome numbers (n=6–75) and systematic relationships in the tribeBrassiceae, which is believed to be one of the few monophyletic tribes in theBrassicaceae. Ten enzyme systems were surveyed among 108 species in 35 genera of tribeBrassiceae and for 11 species from seven other tribes. The data indicated that taxa with n=7–13 and n=14–18 were similar in isozyme number, suggesting that genera with n=14–18 did not arise from polyploidy (i.e. entire duplication) of the n=7–13 genomes. These results suggest that aneuploidy and/or chromosome fusion/splitting have played a more significant role than polyploidy in the evolution of higher base chromosome numbers in the tribe. The detection of widespread isozyme duplication in the tribe is consistent with reports of extensive gene duplication in theBrassica crop species, and suggests that the common ancestor of the tribe already had undergone a polyploid event, i.e. complete genome duplication, prior to aneuploid divergence. Inheritance studies conducted onSinapis arvensis showed that segregation ratios at seven loci (Fbp-2,Gpi-2,Idh-2,Pgm-2,Pgm-2,Tpi-1,Tpi-1) conformed to those expected under Mendelian inheritance. Isozyme duplications were phylogenetically informative at various taxonomic levels in the tribe. In particular, duplications for cytosolic phosphoglucomutase (Pgm-2,Pgm-2) and plastid triosephosphate isomerase (Tpi-1,Tpi-1) were evident in 33 of the 35 genera examined, supporting the monophyletic status of theBrassiceae with the inclusion ofOrychophragmus and the exclusion of controversial membersCalepina andConringia.     

Chromosome numbers of miscellaneous Malagasy Acanthaceae

Meiotic chromosome numbers are reported for 12 species in eight genera of Acanthaceae from Madagascar. Chromosome numbers of 11 species are reported for the first time. Counts inMendoncia (n=19) andNeuracanthus (n=20) are the first for these genera. A new chromosome number (n=30) is reported inJusticia. Systematic implications of the chromosome counts are addressed and basic chromosome numbers for these eight genera of Malagasy Acanthaceae are discussed.     

Chromosome counts inPosidonia (Posidoniaceae)

The five species ofPosidonia occuring in Western Australia all have a diploid chromosome number of 20.     

Chromosome counts inCalea (Asteraceae-Heliantheae)

Chromosome numbers are reported for six taxa ofCalea, among them tetraploidC. septuplinervia, the only known polyploid inCalea s. str. The base chromosome number ofCalea is interpreted as x = 19.     

Chromosome numbers of Western Australian species ofVillarsia (Menyanthaceae)

Chromosome numbers are reported for eight of the nine Western AustralianVillarsia species.Villarsia albiflora, V. calthifolia, V. capitata, V. congestiflora, V. lasiosperma, V. latifolia, andV. violifolia are diploid with n=9. Five populations ofV. parnassiifolia are diploid and three are tetraploid (n=18). The morphological, ecological, and breeding-system diversity of the Western Australian species is largely not associated with the tetraploidy or hexaploidy that characterizes otherVillarsia species in eastern Australia and South Africa. The majority of Western AustralianVillarsia species are restricted to the high rainfall zone of southwestern Western Australia, where favorable climatic and edaphic conditions may have existed since mid-late Tertiary times.     

Chromosome numbers of the European seagrasses

The chromosome numbers of the five European seagrasses have been determined in material from several sites along the coasts of the Atlantic Ocean, the North Sea and the Mediterranean:Zostera marina L., 2n = 12;Z. noltii Hornem., 2n = 12;Posidonia oceanica (L.)Delile, 2n = 20;Cymodocea nodosa (Ucria)Aschers., 2n = 14, 2n = 28;Halophila stipulacea (Forsk.)Aschers., 2n = 18. The difference in chromosome morphology betweenZ. marina andZ. noltii supports the division of the genus into two subgenera.     

Karyotypes,C-banding and nucleolar numbers inGuizotia (Compositae)

Karyotypes, constitutive heterochromatin and nucleolar numbers of five recognized taxa and two systematically new populations ofGuizotia have been studied using Giemsa or aceto-orcein staining, C-banding and silver nitrate staining. All accessions have 2n = 30 chromosomes, but satellite chromosome number and nucleolar number varied from four to eight. Centromere positions varied from predominantly median to submedian and subterminal in different materials. The satellites and an interstitial region in the short arm of one chromosome pair were C-banded in all materials. Telomeric and centromeric C-bands were also observed. The material could be classified into three groups, indicating possible phylogenetic relationships.     

Chromosome numbers and reproduction inRubus subgen.Malachobatus

A review of current knowledge of chromosome numbers and modes of reproduction in the genusRubus L. is presented. Chromosome numbers from some species of subg.Malachobatus Focke together with results of crossing experiments are reported for the first time.