5445

5105

كارشناسي ارشد

بيماري شناسي گياهي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1389

يازده،72ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

امير مساح، بهرام شريف نبي

غلامرضا بلامي

6/7/89

مسعود بهار، بدرالدين ابراهيم سيد طباطبائي

مهندسي كشاورزي

ID5105

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Detection and Characterization of Double Stranded RNA dsRNA Elements in Rhizoctonia solani Isolates Infecting Potato Avat Sharifi avatsh60@yahoo com Date of Submission 2010 4 18 Department of Plant Protection Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language Farsi1 A Massah Assist Professor Supervisor amassah@cc iut ac ir2 B Sharifnabi Assoc Professor Supervisor sharifna@cc iut ac irAbstractRhizoctonia solani Telemorph Thanatephorus cucumeris is a soil born plant pathogenicfungus with a wide host range and worldwide distribution that causes damages to the fieldcrops fruit trees pasture and ornamental plants The most common symptoms of root cankerdisease which is caused by Rhizoctonia is the black sclerotia on the surface of potato tubers necrotic lesions on the roots stems and under ground parts of potato plants The disease is veryimportant in certified potato seed production and in addition to quantitative damages it iseffected the quality of the product and decreases its value in market One of the important waysto control this fungus which is nowadays considered is the use of hypovirulent isolatescontaining viruses Mycoviruses or fungal viruses are the kind of viruses that can replicate infungal cells and so far more than 100 species of fungi belonging to different taxonomic groupshave been reported Most of these viruses have dsRNA genome usually hidden in the fungalhost and causing changes in their morphological biochemical and pathological characteristics The main purpose of this study is the detection of dsRNA in isolates of R solani as a potatopathogen and study of its effect on morphological and pathological function of this fungus Thesampling were done in two years 2007 and 2008 several times from infected potato fields inIsfahan province samples were collected and finally 55 isolates were obtained their anastomosisgroups and number of nuclei were determined The dsRNA extraction from these mentionedisolates was performed by using cellulose column and after treatment with DNasel RNaseA andS1Nuclease dsRNA pieces with about 0 8 and 3 kb size identified in E1 10 and E1 12 isolatesrespectively that were belonging to Azadegan plain and also four pieces with size of about 0 8 1 2 3 and 22 kb in E4 3 isolate and two pieces with size of about 0 7 and 1 kb in E3 4 isolate both belonging to Sepid Dasht plain were identified The fragment in E1 10 isolate amplifiedafter purification from gel using random PCR and K1 K2 primers and the bands were clonedand sequenced The sequence of this isolate compared with the sequences in GenBank by usingthe Blast search tool in NCBI database no similarity was seen in the sequences Results frompairwise alignment of this sequence with multiple dsRNA sequences which were from GenBankand comparing them with pairwise alignment together showed that the above fragments couldhave a viral origin Finally some isolates without dsRNA were compared with isolates

امير مساح، بهرام شريف نبي

غلامرضا بلامي

مسعود بهار، بدرالدين ابراهيم سيد طباطبائي