Geometric morphometrics of leaves of Cynanchum acutum L. (Apocynaceae) from Egypt

Abstract

This study aimed to revise Cynanchum acutum in Egypt and their relative subspecies that belonging to Section Cynanchum (Old World) and comparing it with an American group of genera Cynanchum laeve subgen. (Sect.) Mellichampia (New World) by using classical taxonomy and Modern geometric morphometric methods (GMMs). The description of 85 specimens depending on 36 quantitative traits was measured for all leaves by ImageJ Tool software. Data of leaf description was further processed using R program. The fan neighbor-joining topology revealed to the relationship between studied taxa and population, however, a PCA biplot showed a total variation 37.7% at first axis and 8.9% at the second axis. Significant variation in taxa and populations estimated using ANOVA and MANOVA. Canonical variate analysis showed a significant difference between taxa (P=0.001***), with a total variation of 67% between three taxa. The total variation checked between two taxa by using discriminant analysis, C. acutum subsp. acutum and C. acutum subsp. sibiricum calculated 77% variation, while as the total variation between then between C. acutum subsp. acutum and C. laeve showed 86% of the variation and significant value (P=0.002**). The study elucidated the situation of Cynanchum acutum in Egypt and confirmed the presence of two subspecies viz.: subsp. acutum and subsp. sibiricum.

Taxonomic Revisionand Anatomical Studies of the Genus Aegilops L. (Poaceae) With Sectional Confirmation

“…Modern geometric morphometric methods (GMMs) increase scientific description accuracy for the essential traits of the phenotypic measurement at biodiversity and proper for differentiating complex taxa. In contrast, classical taxonomy requires handling and admission to specimen's important characteristics of the phenotypic measurement at biodiversity and appropriate for determining problematic taxa (Ellmouni, 2019;Viscosi & Cardini 2011). Anatomical evidence has been used in plant systematics and is considered to be consistent and reliable for solving taxonomic difficulties among plants (EL-Banhawy et al, 2021).…”