2891

2749

كارشناسي ارشد

بيماري شناسي گياهي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1383

ده، 91، [II]ٌص.: مصور، جدول، عكس﴿رنگي﴾، نمودار

مسعود بهار، بهرام شريف نبي

حسين سماواتيان

حسين سيد الاسلامي

1396/10/26

كتابنامه

كشاورزي

مهندسي كشاورزي

ID2749

به فارسي و انگليسي : قابل رويت در نسخه ديجيتالي

Abstract In order to investigate the genetic relatedness of Iranian isolates of Ralstonia solanacearum causalagentof potato bacterialwilt during 2002 and 2003 37 isolateswere the collected from potato infected tubers plants and the relatedsoil Theseisolateswere obtained from Isfahan Feridan Hamedan Ardebil Semnan Jiroft regions Bacterialisolatesfrom the and samplesproducedcoloniescharacteristicof R solanacearum TZC and PB media Basedon on morphologicaland biochemicalpropertiesand pathogenicitytest all of isolateswere identified as biovar 2 andrace 3 of R solanacearum Also four strainsof the bacteriumwerereceivedthat had beencollected from different areasof Khuzestan province Analysis basedon phenotypic properties and pathogenicitylead to find limited variation amongthe isolates However the differences were not certain enough to separatethe isolates in distinct groups Therefore molecular methodsbasedon polymerasechain reaction PCR techniquewere employedas a supportive tool for classificationof local isolatesof R solanacearum Among the primersused in this study the specific primer pairs RSIF R amplified a 718bp fragmentfrom everyisolate that was tested RFLP profiles obtained from AluI and Hpall digestsof the fragmentfrom all isolates repeatedlyconfirmed that they are identical Since only a limited region of the genome is subjectedto RFLP analysis other methodssuchas RAPD PCR BOX PCR and ERIC PCR that investigatethe expandedarea of the genomewere employedto find variation amongthe isolates Although basedon RAPD techniquefew dissimilaritieswere found amongthe isolates due to non reproducibility of the DNA fragmentsproducedand limitation of working primers application of this technique was ignored to differentiate the strains Using BOX PCR and ERIC PCRtechniquesthe testedstrainswere clusteredinto six main groups at 90 similarityvalue Combining the results of clustering by these primer sets defined sevenmain groups among the isolates of R solanacearumbiovar 2 race 3 in this study In all of the groupingforms isolatesof groups I 2 3 and 4 collected from cool climates suchas Isfahan Feridan Hamedan Ardebil and Semnan were more homogenous more than 80 However dissimilarity and more geneticdiversity was found between groups5 6 and the othermentionedgroups The consistentability of both BOX PCRand ERIC PCRtechniquesin groupingof theisolatesinto different clustersdemonstrated value of theseprimers for discriminationof the thestrainsof R s olanacearum Similarity of thesegroups 5 and 6 thosehad beencollected fromsouthern parts of Iran including Khuzestanprovince and Jiroft in Kerman province wasevaluatedwithin the limits of 55 and 36 Existanceof intragroup variation in group 5 anddistinct genetic variation in groups 5 and 6 with other groups may imply that the membersofthese two groups have been genetically changeddue to their adaptationto warm climate insouthernregions Also it can be concludedthat these strains are different from the sourceofcontaminationof the rest of isolates This conclusionis in contraryto the previoushypothesisthat all the R solanacearum isolatesin Iran maydrive from a primary inoculumintroducedin tothe Isfahanfields which subsequently distributedthroughoutotherprovincesof the country wasthrough potato seed tubers Although in this study based on BOX PCR and ERIC PCRthe isolatesof R solanacearum were found divergenthowever it would be worth to collect more samplesof R solanacearumfrom different locations in Iran and compare their virulences phenotypicandgeneticpropertiesin relationto their geographical environmental and conditions to distinguishclearly distantor closelyrelatedstrains 11t # 41

مسعود بهار، بهرام شريف نبي

حسين سماواتيان

حسين سيد الاسلامي