Shape outline extraction software (DiaOutline) for elliptic Fourier analysis application in morphometric studies

Abstract

Premise of the Study: Studies of plant cell and organ outline using shape analysis for taxonomic and morphological research have increased in the past decade. However, there are a limited number of available modern, intuitive, and easy software tools to conduct this work. Methods: We developed a tool for shape outline extraction using MATLAB accompanied with R scripts to perform elliptic Fourier analysis. To demonstrate the shape tool, we applied the software and scripts for genera and species shape determinations of diatom (single cell) species with x-, y-, and x- + y-shape symmetries. Results: Using the shape analysis tool, we were able to identify and distinguish different diatom taxa based on forms representing size diminutions associated with population changes. Discussion: Independent of symmetry, species were successfully distinguished using supervised and unsupervised analyses. We hope that these shape analysis tools will be used to add another metric to plant science studies.