Race identification of Pseudomonas savastanoi pv. phaseolicola on domestic bean cultivars

Abstract

Halo blight caused by the phytopathogenic bacterium Pseudomonas savastanoi pv. phaseolicola is economically important disease of bean in our area. In the present study, the pathogen was isolated from the leaves of the diseased bean plants, with the leaf samples having been collected from cultivars Oplenac, Slavonski žutozeleni and Zlatko using a nutrient agar (NA) and the medium enriched with 5% sucrose (NSA). Pathogenicity of the obtained isolates was proved by inoculation of young bean pods and by hypersensitive reaction (HR) on tobacco and geranium leaves. Biochemical and physiological characteristics were tested by conventional phytobacteriological methods. The race identity of the isolates was determined using a differential set of Phaseolus spp.: Canadian Wonder, ZAA54 (A52), Tendergreen, Red Mexican U13, 1072 P. acutifolius, ZAA55 (A53), ZAA12 (A43) i Guatemala 196-B). Inoculation was performed with atomizer, by spraying of bacterial suspension onto the undersurface of primary leaves. Obtained results indicated that strains showed the most similarity to race 1 of this bacterium.

Oreolna plamenjača pasulja čiji je prouzrokovač fitopatogena bakterija Pseudomonas savastanoi pv. phaseolicola ekonomski je štetno oboljenje ove gajene kulture kod nas. U ovom radu vršena je izolacija patogena iz obolelog lišća pasulja sorti Oplenac, Slavonski žutozeleni i Zlatko na hranljivi agar (NA) i podlogu obogaćenu saharozom (NSA). Patogenost izolata je dokazana infiltracijom bakterijske suspenzije u mlade mahune boranije i pozitivnom hipersenzitivnom reakcijom (HR) na listu duvana i muškatle. Biohemijsko-fiziološke odlike ispitane su standardnim bakteriološkim metodama. Pripadnost dobijenih izolata fiziološkim rasama određena je korišćenjem diferencijalnog sortimenta Phaseolus spp.: Canadian Wonder, ZAA54 (A52), Tendergreen, Red Mexican U13, 1072 P. acutifolius, ZAA55 (A53), ZAA12 (A43) i Guatemala 196-B. Inokulacija je vršena atomizerom, prskanjem naličja primarnog lišća bakterijskom suspenzijom. Dobijeni rezultati ukazuju na najveću sličnost izolata sa rasom 1 ove bakterije.