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

Abstract

The genus Heteropterys is one of the major genera in Malpighiaceae. However, few cytological and palynological studies were reported. The present work described for the first time the chromosome number, heterochromatin pattern, meiotic behavior, pollen viability and palynological aspects of Heteropterys umbellata, a very spread species. One large Brazilian population was evaluated using conventional techniques for meiotic studies and acetolyse to access the pollen morphology. The species showed 2n = 20 chromosomes, normal meiotic development and viable pollens. Great blocks of heterochromatin were observed around the centromers. DAPI staining was positive for centromeric heterochromatin, while CMA 3 mark was observed just at terminal regions of one pair of homologues chromosomes. This result and the presence of one chromosome pair attached to the nucleoli during the pachytene and diakinesis suggested the presence of only one pair of NORs. Palynological analysis revealed that pollen grains are apolar, 6 porate and with colpoids associated to all pores. The pollen content was positive for the starch test, and the exine was rugulate with little psilate regions.

Contributions to cytogenetics of Plectranthus barbatus Andr. (Lamiaceae): a medicinal plant

“…In spite of intensive pharmacological studies, few studies have been done about biological aspects of the species. Considering the medicinal importance of Plectranthus barbatus and a large number of synonyms reported, basic information such as karyotypic traits are very important, helping the correct plant identification and also the production of commercial varieties in breeding programs ( Sousa et al 2009 , Ferreira et al 2010 , Sousa et al 2010 , Pierre et al 2011 , Sousa et al 2012 , Sousa et al 2013 , Reis et al 2014 , Viccini et al 2014 ). Regarding cytogenetic studies, only the chromosome number and meiosis behavior were reported so far ( De Wet 1958 , Morton 1962 ).…”

An increment in the Duranta repens L. (Verbenaceae) knowledge: DNA content, karyology, meiosis and palynology

“…Some other chromosome markers are too very important in the plant species studies, the C-banding, Ag-NOR and fl uorescent staining methods performed with counter-staining reagents added to Fluorochrome in situ Hybridization (FISH) and Genome in situ Hybridization (GISH) are useful to mark species-distinctive regions of chromosomes. They can also be applied to cytotaxonomy and chromosome evolution, including the comparison among individuals of the same species distributed into and among different populations for example (KOKUBUGATA and KATSUHIKO 1996;SOUSA et al 2009;SOUSA et al 2010).…”

“…Additionaly to cytogenetics, estimation of nuclear DNA content by fl ow cytometry and pollen characters may provide useful information by taxonomists in the delimitation of species (LOUREIRO et al 2007;MACLUF et al 2010;MAR-QUEZ et al 2010, SOUSA et al 2010. Signifi cant developments in systematics atributable to fl ow cytometry and palynology include: improved detection and delineation of species; improved data related to the contribution of chromosomal speciation to species diversity, and increased availability of characters for the inference of phylogenetic relationships and polarity of character evolution (KRON et al 2007).…”