رديابي سريع اگروباكتريوم مولد گال در رز

چكيده انگليسي :

Rapid Detection of Agrobacterium tumefaciens in Rose Mansoureh Abdollahpour m abdollahpoor@ag iut ac ir Department of Plant Protection Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiMasoud Bahar mbahar@cc iut ac ir AbstractCrown gall is an economically important disease which occurs most frequently on greenhouse grown roses inIsfahan The main symptom of the disease is gall formation on the stem or roots Young galls are light colored andsmooth but as they mature they become dark and woody The development of galls results in an overall weakness reduction in foliage water stress and loss of vigor of the infected plants Crown gall is caused by different biovars ofa bacterium Agrobacterium tumefaciens belong to the family Rhizobiaceae which survives in the soil Thebacterium enters the plant through wounds and subsequently results in tumor formation within a few weeks Thepathogen also sustains systemically inside the plant and spreads through vegetative propagation of rose plants Theinfected plants remain symptomless until favorable conditions in greenhouse lead to gall development Therefore tracing the contamination source and distinguishing the causal agent in detail is necessary for identification of theorigin of infection and its discarding To do so the purpose of this study was to identify tumor inducingAgrobacterium biovar on roses in Isfahan and determine the presence of the same tumorigenic pathogen in soil andhost sap During 2009 2010 over 40 rose plants with characteristic galls were collected from 10 greenhouseslocated in Isfahan Enrichment and plating method on selective media and PCR assays were used for isolation ofagrobacteria from surface sterilized galls and checking the presence of agrobacteia in fluidal sap and potting soilmixture of the hosts According to colony characteristics on TY agar containing antibiotic kanamycin 50 mg ml 27 isolates were initially characterized as Agrobacterium sp On the basis of tumor inducing capability on geranium tomato and carrot discs and biochemical properties the isolates were identified as Agrobacterium tumefaciensbiovar 1 In PCR the primer pair VCF VCR amplified a target of 730 bp fragment from the virC operon of the 24pathogenic strains in this study but failed to amplify the band in three isolates The banding pattern of PCR RFLPof the PCR products from VCF VCR for all of the isolates were similar indicating their close relatedness Nucleotidesequence analyses of theVCF VCR fragment from the representative strain strain T9 indicated that A tumefaciensisolates inducing gall formation on greenhouse grown roses in Isfahan share high similarity with A tumefaciensstrain C58 biovar 1 and the related agrobacteria previously deposited in the GenBank database PCR assays using14vir 44vir tms2A tms2B virD2 A C and virD2 A E also confirmed that all the isolates belong to A tumefaciens The positive PCR results for the RBF RBR primer pair to amplify an approximately 206bp DNA bandand negative result for primer pair ocsF ocsR suggest that the isolates collected from in current study are nopalinetype of A tumefaciens Although repeated attempts using plating method combining with PCR assay was partiallysuccessful in detecting Agrobacterium from the sap of infected plant or potting soils it seems that using TY mediumcontaining kanamycin followed by PCR technique using primer pairs tms2A tms2B virD2 A C or virD2 A E could be an appropriate approach to detect pathogenice agrobacteria from rose plants or their rhizosphere Key Words Crown Gall Disease Rose Antibiotic Detection PCR

عبدالله پور، منصوره

رديابي سريع اگروباكتريوم مولد گال در رز

بيماري گال طوقه , آنتي بيوتيك , واكنش زنجيره اي پليمراز