دي ان آرپيوزومي ITS براساس توالي بخش ERYSIPHE S.LAT. ارتباط فيلوژنتيك بين جدايه هاي ايراني و

PHYLOGENETIC RELATIONSHIPS BETWEEN IRANIAN ISOLATES OF MICROSPHAERA AND ERYSIPHE S. LAT. BASED ON rDNA INTERNAL TRANSCRIBED SPACERS SEQUENCES

To study the phylogenetic relationships between Erysiphe s. lat. and Microsphaera, the nucleotide sequences of internal transcribed spacers of rDNA including 5.8S rDNA gene were determined for 23 taxa. The results showed that Erysiphe. section Erysiphe and Microsphaera are closely related and clustered together with strong bootstrap support (100%). All of taxa belonging to this group produce conidia singly. Whereas, these genera are distinguished by the morphology of appendages which is dichotomously branched in Microsphaera and mycelioid in Erysiphe. Erysiphe. sect. Golovinomyces and Erysiphe. sect. Galeopsidis, both of which are well characterized by conidia produced in chains, formed two different groups. The percentages of sequence divergence ranged from 2 to 7.8% between Microsphaera and Erysiphe. sect. Erysiphe. In contrast, there was high diversity between E. sect. Erysiphe and two other Erysiphe sections (I 8.5-22.4%). Moreover, divergence between E. sect. Golovinomyces and Erysiphe. sect. Galeopsidis was also high (17.3-18.7%), which is similar to those between distantly related genera.These results show that Erysiphe. sect. Erysiphe is closely related to Microsphaera more than to two other sections of Erysiphe.