Tissue-specific silencing of homoeologs in natural populations of the recent allopolyploid Tragopogon mirus

The definitive version is available at www3.interscience.wiley.com http://dx.doi.org/10.1111/j.1469-8137.2010.03205.

Meiotic analysis of two putative polyploid species of Verbenaceae from Brazil

The natural occurrence of hybrids and polyploids hinders the precise identification of some taxa in Verbenaceae (Lamiales). Since meiotic studies are useful for understanding the chromosomal behavior of plant species, we have examined the meiotic stages and chromosomal behavior of Lippia alba (Mill) N. E. Brown and Lantana camara Plum. in Brazil. Lippia alba and Lantana camara, had normal stages of meiosis, including interphase, leptotene, zygotene, pachytene, diplotene, initial diakinesis, diakinesis, metaphase I, anaphase I, telophase I, prophase II and telophase II Fifteen and 22 bivalents were observed during diplotene and diakinesis in L. alba and L. camara, respectively. The chromosomes segregated normally during anaphase I, telophase I and II. The regular meiotic behavior seen in L. alba and L. camara indicated that polyploidy was established by a diploid-like behavior in meiosis, although this did not exclude a possible diploid origin.58431531

Cytogenetic characterization of Lippia alba and Lantana camara (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.120231732

Ethylene synthesis inhibition effects on oxidative stress and in vitro conservation of Lippia filifolia (Verbenaceae)

This study aimed to investigate the effects of ethylene biosynthesis inhibitors on oxidative metabolisms and the in vitro conservation of Lippia filifolia, using the lipid peroxidation index (TBARS), antioxidative enzymes and pigments as biomarkers. We found that EDTA, sodium thiosulfate (STS) and especially Co had protective effects on oxidative stress in tissues cultured in vitro, resulting in a delay of the senescence and the reduction of subcultures frequency, con-tributing to the germplasm conservation of this species

Ethylene synthesis inhibition effects on oxidative stress and in vitro conservation of Lippia filifolia (Verbenaceae)

This study aimed to investigate the effects of ethylene biosynthesis inhibitors on oxidative metabolisms and the in vitro conservation of Lippia filifolia, using the lipid peroxidation index (TBARS), antioxidative enzymes and pigments as biomarkers. We found that EDTA, sodium thiosulfate (STS) and especially Co had protective effects on oxidative stress in tissues cultured in vitro, resulting in a delay of the senescence and the reduction of subcultures frequency, con-tributing to the germplasm conservation of this species