نخستین گزارش قارچ گونه Pseudeurotium ovale از ریشه گیاه کلزا Brassica napus از شمال ایران

Endophytes are most commonly defined as those organisms which cause infections that are inconspicuous, the infected host tissues are at least transiently symptomless and the microbial colonization can be demonstrated to be internal. In this study, to separate and identify the root endophytic fungi, samples of annual plant roots were collected in the central regions of Mazandaran province during 2015-16. In the laboratory, each root sample was divided into 5-10 mm pieces after three stages of surface washing and disinfection, it was cultured on PDA medium and was incubated for a month at 25°C and in continuous darkness. Purification was carried out by using the hyphal tip method. Phenotyping characteristics of the isolate were investigated by growing on PDA at 25°C. The colony growth was slow on the PDA medium, filling eight centimeters of the petri dish in a month, very short white aerial mycelia in the center of the colony, the color of the colony was black with a white center and in the reverse, it was black, the black ring of the colonial margin was filled with a dark brown spherical cleistothecium, ranging in diameter from 150-200 μm, spherical, transparent, the asci were spherical and translucent with ellipsoidal and hyaline eight ascospores, 3-4 μm. In order to molecular identification of this isolate, the DNA was extracted by the CTAB method, and ITS4,5 primers were used to perform polymerase chain reaction (PCR). The sequences were compared with the other sequences in the NCBI, by using the Blasts software in this gene bank. This isolate was identified by 98% query coverage and 99% probably as Pseudeurotium ovale species. In this research, on the basis of morphological studies and sequencing of the ITS region from the rDNA, Pseudeurotium ovale from the root of canola was identified as the endophytic fungus of the annual plants and for the first time, this species is reported from Iran. It is also the first report of this species of canola roots in the world.