Elliptic Fourier Analysis of leaf outline shape in forest fragment populations of Anthurium sinuatum and A. pentaphyllum (Araceae) from Northeast Brazil

Abstract

A field-based comparative study of leaflet outline shape in five populations of Anthurium sinuatum Benth. ex Schott from Amazonia and humid brejo forests of Ceara, Northeast Brazil, and ten populations of A. pentaphyllum (Aubl.) G. Don var. pentaphyllum from Amazonia and the Brazilian Atlantic forest is reported. 1,120 leaflets from 561 individuals in 15 populations were sampled. Using images, leaflet outlines were captured by digitisation and subjected to Elliptic Fourier Analysis (EFA) to produce matrices of Fourier coefficients based on 40 harmonics; lateral and central leaflets were analysed separately. Twelve shape variables, extracted from the Fourier coefficient matrices, described the leaflet outlines of 531 individuals. Between-population relationships were estimated using cluster analysis, Canonical Variates Analysis and non-parametric MANOVA. Amazonian populations showed the greatest within-population variability. In A. sinuatum the Pacatuba population was the most distinct in Ceara and the Para population (Amazonia) was not significantly different from those at Ibiapaba and Maranguape (both Ceara). In A. pentaphyllum 80% of population pairs were significantly different and three significantly different groups of populations were observed. Although the populations of A. pentaphyllum displayed considerable variation, the morphological patterns did not correlate with previously reported molecular ones. The two species were found to be slightly but significantly different on leaf outline data.