Phytomonas: analysis of polymorphism and genetic relatedness between isolates from plants and phytophagous insects from different geographic regions by RAPD fingerprints and synapomorphic markers

摘要

The random amplified polymorphic DNA (RAPD) technique was used for easy, quick and sensitive assessment of genetic polymorphism within Phytomonas to discriminate isolates and determine genetic relationships within the genus. 48 species of Phytomonaswere examined, including 31 isolates from plants and 17 from insects, from different geographical regions. Topology of the dendrogram based on RAPD fingerprints segregated the species into 5 main clusters, despite the high genetic variability within this genus. Similar clustering was obtained by both visual and cross-hybridization analysis of randomly amplified synapomorphic DNA fragments. There was some concordance between the genetic relationship of isolates and their plant tissue tropism. Moreover,Phytomonas from plants and insects were grouped according to geographical origin, revealing that this complex taxon comprises several clusters of very closely related organisms.