Morphological and Molecular Studies of Five Euphorbia Species

ABSTRACT

This study attempts to identify species of Euphorbia (Euphorbia peplus, Euphorbia canariensis, Euphorbia heterophyla, Euphorbia milli and Euphorbia hirta) using morphological markers and also determine the genetic polymorphism among them by using DNA markers generated by polymerase chain reaction (PCR). A total of sixteen morphological descriptors were used to characterize the Euphorbia species. The arrangement and attachment of leaves, laminar size, apex,leaf shape and base leaf features, symmetry of base and medial of blade, venation patterns, have been considered to be the most important distinguishable characters in Euphorbia. Leaf morphology and venation characters can be considered as good taxonomic indicators in segregating Euphorbia heterophylla , Euphorbia hirta, Euphorbia spurge from Euphorbia canariensis and Euphorbia milli. Molecular analysis was performed by using five random markers in random amplified polymorphic DNA (RAPD-PCR) technique. RAPD-PCR analyses based on four primers, OPT05, OPT06,OPH04 and OPT07 gave results in term of amplification and polymorphism for the five species studied.. RAPD-PCR technique confirmed the isolation of the four species of Euphorbia obviously. All RAPD primers showed polymorphism. The dendrogram revealed two distinct clusters. Cluster I was the largest and included 3 species with coefficient levels of 0.5, 0.4 and 0.4, while cluster II comprising two species i.e Euphorbia hirta and Euphorbia canariensis. The polymorphic information content value for the RAPD loci ranged from 0.36 to 0.76.This results shows that both morphological and RAPD-PCR technique confirmed the isolation of the five species of Euphorbia obviously