Biometry of stomata in Blechnum species (Blechnaceae) with some taxonomic and ecological implications for the ferns

Abstract

Morphological stomatal traits, such as size, form and frequency, have been subject of much literature, including their relationships with environmental factors. However, little effort have focused on ferns, and very few in the genus Blechnum. Stomatal length, width and frequency (as stomatal index) of a number of specimens of fourteen Neotropical species of Blechnum were measured in adult pinnae. The aim of the work was to find biometrical relationships between stomatal traits and between stomatal traits and habit, habitat and ecosystem of the plants. Statistical analyses of data were conducted using Exploratory Data Analysis and Multivariate Statistical Methods. Stomatal length and width showed a very high correlation, suggesting an endogenous, genetic control, thus giving these traits a considerable diagnostic utility. With respect to the relationships between stomatal traits and environment, we found significant statistical relationships between altitude and stomatal index. We also addressed the interpretation of the ecological-selective significance of various assemblages of stomatal traits in a diverse conjunction of habits, habitats and ecosystems.

cpDNA supports the identification of the major lineages of American Blechnum (Blechnaceae, Polypodiopsida) established by morphology

“…Kuhn group, originally named B. buchtienii Rosenst. group (Rolleri et al, 2013) (Tryon & Tryon, 1982;Durán, 1997;Dittrich, 2005;Rolleri & Prada, 2006b;Passarelli, 2007;Prada et al, 2007;Gabriel y Galán et al, 2008;Ramos Giacosa, 2008;Rolleri et al, 2008;Passarelli et al, 2010;Rolleri et al, 2010;Gabriel y Galán et al, 2011;Rolleri et al, 2012a;Rolleri et al, 2012b;Rolleri et al, 2013).…”

“…In order to avoid a taxonomically uncertain scenario, specialists have proposed informal groups within Blechnum using morphological criteria. For the American diversity, where around 80 species are recognised (Rolleri & Prada, 2006a), a first approach involving 8 groups has been made, mostly according to characters of rhizome, frond architecture, dimorphism, and habit (Figure 1 (Tryon & Tryon, 1982;Durán, 1997;Dittrich, 2005;Rolleri & Prada, 2006b;Passarelli, 2007;Prada et al, 2007;Gabriel y Galán et al, 2008;Ramos Giacosa, 2008;Rolleri et al, 2008;Passarelli et al, 2010;Rolleri et al, 2010;Gabriel y Galán et al, 2011;Rolleri et al, 2012a;Rolleri et al, 2012b;Rolleri et al, 2013).…”

Stomatal frequency and gas exchange differs in two Blechnum species (Pteridophyta, Blechnaceae) with contrasting ecological breadth

“…This difference in size could account for the similar g s in both species, despite their difference in SD and SI. Stomatal size seems to be under low environmental control in Blechnum, and depends mainly on the species (Gabriel y Galán et al 2011). This suggest that given stomatal size is internally regulated (Gabriel y Galán et al 2011), and that stomatal size affects SD and SI (in the same area, few stomata can be fit if the size is increased), and if stomatal size affects gas exchange, our results could be explained by phyllogenetically-related differences and not by the ecological breath of the species.…”

Anatomía del esporofito de Anemia phyllitidis var. phyllitidis (Anemiaceae) de un bosque de ribera (Tucumán, Argentina)

“…phyllitidis agrees with that described by Pant and Khare (1972) for the species. This variable decreases under stress conditions, such as drought and high solar radiation, to avoid an excess of transpiration (Cañizares et al, 2003;Gabriel y Galán et al, 2011).…”