3311

3176

كارشناسي ارشد

﴿ بيماري شناسي گياهي ﴾

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1385

هجده ، 130 ، [II] ص . : مصور ، جدول ، نمودار

مسعود بهار ، قدرت اله سعيدي

محمد رضا لك

بهرام شريف نبي ، محسن تقوي

مهندسي كشاورزي

ID3176

به فارسي و انگليسي : قابل رؤيت در نسخه ديجيتال

Abstract Bean common blight is one of the most destructive diseases of bean world wide During recent yearsthe disease caused a serious yield loss in Iran Since infected seed is a major source of primary inoculumand is the exclusive tool of pathogen to disseminate to far distant area in the first part of this study severaldetection methods including Indirect ELISA Direct PCR Bio PCR and Ic PCR were used to detect X axonopodis pv phaseoli in bean seeds Infected bean seeds were collected from Arak bean farms Seedsamples were incubated in seed washing buffer Indirect ELISA was done using IgG purified from X axonopodis pv phaseoli polyclonal rabbit antiserum In Direct PCR seed extracts were boiled and 10 lapplied for PCR amplification In Ic PCR 100 l of seed extracts were loaded in wells which were coatedwith 10 1 dilution of purified immunoglobulin After incubation at 37 C for 3 hours 30 l of sterile distilledwater was added to each well and wells were put in 100 C for 10 minutes Then 18 l of each sample wassubjected to PCR In Bio PCR aliquots of the extracts were plated onto semi selective modified nutrientbroth yeast extract agar After 48 hours incubation 1ml of sterile distilled water was added to each mediaplate and the resulted suspension was boiled and 10 l applied for PCR amplification In all PCR basedmethods a species specific pairs of primer X4c X4e was employed The sensitivity of Indirect ELISA waslow and at least 105 cfu was needed as detection threshold Direct PCR was unable to differentiate betweenviable and dead cells and Ic PCR was an expensive method The Bio PCR technique was more sensitivethan the other techniques described previously On the other hand in Bio PCR only the viable cells could bedetected Therefore Bio PCR is recommended for assay of bean seeds for X axonopodis pv phaseoli Inanother part of this study role of factors influence epiphytic population of X axonopodis pv phaseoli inepidemiology of bean common blight was investigated conducting four experiments in greenhouse andfield Greenhouse experiments carried out to clarify the effect of relative humidity rate genotype type ofinfection sampling time and their interactions on epiphytic population size and number of bacterial spotsper plant A factorial experiment using a randomized complete block design with seven replications andtwo different relative humidity rates 53 73 was used in greenhouse The result showed that therewere significant differences among the genotypes type of infections and sampling times for epiphyticpopulation size and number of bacterial spots per plants Generally the epiphytic population size andnumber of bacterial spots per plant were significantly higher on Khomein cultivar and spray infection Therelative humidity rates didn t significantly affect the epiphytic population size and number of bacterialspots per plant The interaction of type of infection and time was significant for epiphytic population size Field experiments carried out to determine the effect of irrigation system type of infection and theirinteractions on epiphytic population size disease severity and agronomic traits A randomized completeblock design with eight replications and two different irrigation systems furrow irrigation and overheadsprinkler irrigation was used in field The effect of sampling time on epiphytic population and diseaseseverity was also investigated The result showed that all of the traits were significantly affected byirrigation system except the number of pods plant type of infection and sampling time for epiphyticpopulation size and disease severity Generally the epiphytic population size and disease severity werehigher on plants in overhead sprinkler irrigation and spray infection Among type of infections sprayinfection artificially seed infection and naturally seed infection had the most decreasing effects onagronomic traits respectively in comparison with control plants The interaction of irrigation system by typeof infection was sign

مسعود بهار ، قدرت اله سعيدي

محمد رضا لك

بهرام شريف نبي ، محسن تقوي