Geometric morphometrics of leaf blade shape inMontrichardia linifera(Araceae) populations from the Rio Parnaíba Delta, north-east Brazil

Abstract

Leaf characters of populations of the aquatic macrophyte Montrichardia linifera were studied using geometric morphometrics to compare variation with traditional circumscriptions of the two recognized species. Two hundred and ten individuals were sampled from seven populations in the delta region of the Rio Parnaíba, north‐east Brazil. Six landmarks of the leaf blade were digitized from images and analysed with MorphoJ software. Procrustes‐aligned configurations were studied using principal component analysis and canonical variates analysis in the pooled data and individual populations. Sinus shape variation was studied using landmark configurations of the posterior lobe basiscopic lamina. Covariation of leaf blade shape, basiscopic lamina shape, secondary vein number and petiole ligule length was investigated with partial least squares analysis. Allometry of these variables with leaf blade centroid size was investigated using multivariate regression, linear modelling and analysis of covariance. Measured variables varied continuously over the ranges previously reported for the two species. The characters of the two species morphotypes covaried and were only partly influenced by allometric effects. Symmetric shape variables predominated, but a distinctive left‐ and right‐handed asymmetry occurred in all populations. Genetic and ecological studies are needed to investigate the significant inter‐population differences further. The study offers a methodology for a broader combined morphometric/molecular investigation. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170, 554–572.

Analyzing Fluctuating Asymmetry with Geometric Morphometrics: Concepts, Methods, and Applications

“…A remarkably clear example of antisymmetry was found in a morphometric analysis of leaf shapes of the plant Montrichardia linifera (Araceae), where multivariate analysis revealed two distinct clusters in the leaf asymmetry [190]. These clusters were not due to differentiation between populations, but the division occurred within populations, indicating a consistent bimodal distribution of asymmetry in leaf shape.…”

Multiscale quantification of morphodynamics: MorphoLeaf, software for 2-D shape analysis

“…However, because these approaches result in smooth, averaged contours, neither of them is appropriate to accurately capture characteristic structures with a variable position such as teeth or lobes (Chitwood et al, 2012(Chitwood et al, , 2013. By contrast, dissection can be analysed using a few landmarks defined by experts, but information about the shape between landmarks is lost Viscosi and Cardini, 2011;Klingenberg et al, 2012;Silva et al, 2012;Chitwood et al, 2014;Wang et al, 2014). Global dissection of the leaves can be analysed through the use of the bending energy of the leaf outline (Backhaus et al, 2010;Kuwabara et al, 2011).…”

Computational Botany

“…Despite the importance of landmark-based techniques in modern morphometrics in biological research studies (Slice 2005;Weber and Bookstein 2010;Cardini and Loy 2013), relatively few botanical applications have been published and this is probably because most interest has focussed on leaf shapes, which have few good landmarks (Jensen et al 2002;Volkova and Shipunov 2007;Magrini and Scoppola 2010;Viscosi and Cardini 2011;Klingenberg et al 2012;Silva et al 2012;Duminil et al 2012).…”