عنوان المقالة:اول تسجيل لتعفن جذور نباتات اكليل الجبل المتسبب عن الفطر رايزكتونيا سولاني في العراق FIRST RECORD OF ROOT ROT OF ROSEMARY (ROSMARINUS OFFICINALIS) CAUSED BY RHIZOCTONIA SOLANI IN IRAQ
Ali Kareem Mohammed Al-Taae* and Huda Hazim Wafi Al-Taae
Abstract
Rosmarinus officinalis, which commonly known as rosemary is one of the most economically important species of the family
Lamiaceae. In October, 2017, root rot symptoms were observed on rosemary in gardens of Horticulture Department, Collage
of Agriculture & Forestry, Mosul University, Ninevah governorate, North Iraq specifically, the leaf tissues were blighted and
white mycelial growth was seen on the stems. The fungus was isolated from diseased tissue and cultured on potato dextrose
agar for identification. The young hyphae had acute angular branching near the distal septum of the multinucleate cells and
mature hyphal branches formed at an approximately 90o angle. This is morphologically identical to Rhizotonia solani.
Pathogenicity of the fungus in rosemary plants was also confirmed by Koch’s postulates. Molecular identification
of R.solani isolate was done by amplifying the internal transcribed spacer (ITS) region of the conserved ribosomal DNA using
primers ITS1 and ITS4. All the ITS sequences were compared for gaps and similarity sequences of the fungus were homologous
to those of R.solani isolates in the GenBank database with a similarity percentage of 97%, thereby confirming the identity of
the causative agent of the disease. The nucleotide sequence of ITS from the Iraqi isolate has been assigned GenBank
Accession No MN 396663.1. Here, for the first time we report R. solani as the causal agent of root rot of rosemary in Iraq.
ا.د.علي كريم محمد الطائي | Prof.Dr.Ali Kareem Mohammed Al-Taae | 10453