Assessing the effects of water quality on leaf morphoanatomy, ultrastructure and photosynthetic pigment content of Salvinia auriculata Aubl. (Salviniaceae).

The objective of this study is to evaluate the effects of physical-chemical and biological variables of the water of the Capibaribe River (state of Pernambuco, Brazil) on leaf anatomy, including ultrastructure and photosynthetic pigment of Salvinia auriculata. Specimens of S. auriculata collected in the Gurjaú River, an area with a low pollution degree, were acclimatized in Hoagland's solution and then subjected to three water samples of the Capibaribe River with different levels of pollution. Twenty-one physical-chemical and biological variables were analyzed according to the Standard Methods for the Examination of Water and Wastewater. The results showed that the samples of the Capibaribe River presented nine parameters that did not comply with the current Brazilian legislation. After 15 days of bioassay, S. auriculata presented variations in mesophyll and cuticle thickness, changes in trichome morphology and accumulation of phenolic compounds. No significant differences were observed for photosynthetic pigment content and leaf length of S. auriculata. Multivariate analyses (PCA and Cluster) showed that the point in the Capibaribe River with the highest number of variables that do not comply with the current legislation was responsible for major structural and chemical changes observed in S. auriculata.

Anatomical features of ecological importance and taxonomic value revealed by scanning electron microscopy and light microscopy in Camonea umbellata (L.) A.R. Simões & Staples (Convolvulaceae).

This article describes detailed and novel data on the anatomy and histochemistry of leaves, stems, and roots of Camonea umbellata (L.) A.R.Simões & Staples in different environments for the identification of characters with taxonomical value and of ecological importance, with provision of light and scanning electron microscopy images. To analyze the characters, we collected samples of the vegetative organs of three individuals in each of three populations, which were in a grazing area, an urban environment, and a biological reserve. The main diagnostic anatomical markers for the identification of C. umbellata include amphistomatic leaves, tetracytic and brachyparatetracytic stomata, peltate trichomes, long simple trichomes, epidermis with striated cuticle ornamentation, mesophyll with acute borders, presence of druses, secretory channels, angular collenchyma, fibrous pericycle in the stem, intraxylary phloem in the vegetative organs, oil bodies throughout the midrib, petiole, stem and root, and epicuticular waxes of the crust and coiled rodlet types. Since the characters above did not show variation in the environments evaluated, we consider these characters taxonomically useful for the identification of C. umbellata. RESEARCH HIGHLIGHTS: The anatomy of the aerial vegetative organs of Camonnea umbellata retains common Convolvulaceae characters. The sinuosity of the epidermal cell walls and the density of trichomes in the epidermis of the petiole were visually variable characters among the analyzed individuals. Amphistomatic leaves, tetracytic and brachyparatetracytic stomata, peltate trichomes, epidermis with striated cuticle ornamentation, dorsiventral mesophyll with border acute, presence of druses, secretory structures, angular collenchyma, fibrous pericycle in the stem, intraxillary phloem, presence of oil bodies in all organs, and epicuticular waxes of the crust type and coiled rods were considered important anatomical markers for the recognition and correct identification of Camonea umbellata.