Pollen morphology and viability in Bromeliaceae

ABSTRACT Pollen morphology characterization is important in taxonomy, conservation and plant breeding, and pollen viability studies can support breeding programs. This study investigated pollen morphology and male fertility in 18 species of Bromeliaceae with ornamental potential. For morphological characterization, pollen grains were acetolyzed and characterization of exine was done using scanning and transmission electron microscopy. Pollen viability was investigated by in vitro germination and histochemical tests. Species belonging to Aechmea and Ananas genera presented medium size pollen, except for Ae. fasciata, with large pollen. Al. nahoumii, P. sagenarius and the Vriesea species analyzed showed large pollen, except for V. carinata, with very large pollen. Pollen of Aechmea, Ananas and P. sagenarius presented bilateral symmetry, diporate, exine varying from tectate to semitectate. Al. nahoumii and Vriesea species presented pollen with bilateral symmetry, monocolpate; exine was semitectate, reticulate and heterobrochate. Germination percentage and tube growth were greater in SM and BKM media. Histochemical tests showed pollen viability above 70% for all species, except for Ananas sp. (40%). Pollen morphology is important for the identification of species, especially in this family, which contains a large number of species. High rates of viability favor fertilization and seed production, essential for efficient hybrid production and conservation.

Anatomia e histoquímica dos órgãos vegetativos de Polygonum hydropiperoides Michx., Polygonaceae / Anatomical and histochemical characters of Polygonum hydropiperoides Michaux, Polygonaceae

Polygonum hydropiperoides Michaux é uma espécie conhecida popularmente como "erva-de-bicho", amplamente utilizada na medicina tradicional como anti-hemorroidal, antiinflamatória e antidiarréica. O presente trabalho tem como objetivo a caracterização anatômica e histoquímica da folha, caule e raiz, que constituem a droga vegetal, visando estabelecer parâmetros para o controle de qualidade. O material vegetal foi fixado e submetido às técnicas usuais de microscopia de luz e aos testes histoquímicos. A folha é anfiestomática, dorsiventral e com estômatos paracíticos e anisocíticos. É comum a presença de estruturas secretoras como: tricomas glandulares capitados e glândulas epidérmicas e subepidérmicas em ambas as faces da lâmina foliar e também no caule. O material secretado pelas glândulas apresenta composição heterogênea de lipídios e flavonóides, segundo análises histoquímicas. Cristais de oxalato de cálcio e grãos de amido são freqüentes em células parenquimáticas da folha e do caule. Compostos fenólicos estão presentes na folha (parênquima paliçádico), no caule (parênquima cortical e floema) e na raiz (parênquima cortical).

P. hydropiperoides is popularly known as "erva-de-bicho", and it is used in traditional medicine as anti-hemorroidal, anti-inflammatory and antidiarrhoeic. The present work has as objective the anatomical and histochemical characterization of leaf, stem and root that are used as drug in order to offer elements for quality control. The botanical material was prepared for the usual optical and histochemical microtechniques. The leaf is amphistomatic, dorsiventral and paracytic and anisocytic stomata. It is common to find the presence of secretory structures as: capitate glandular trichomes and secretory glands on both epidermis, that are also present in stem. The secretion material is heterogeneous composition of lipids and flavonoids. Druses of calcium oxalate and starch are common in parenchyma cells of leaf and stem. Phenolic compounds are present in leaf (palisade parenchyma), in stem (cortical parenchyma and phloem) and root (cortical parenchyma).