Race identification of Pseudomonas syringae pv. Glycinea on commercial soybean varieties in Serbia

Abstract

Bacterial blight is important and frequent disease of soybean in Vojvodina province. Isolation of the pathogen was carried out from infected soybean leaves of several cultivar grown in Vojvodina province using beef extract and the medium enriched with 5% sucrose. Only the representative isolates were chosen for further investigation. Pathogen city of the obtained isolates including referent strain (National Collection of Plant Pathogenic Bacteria, United Kingdom-NCPPB 3318) was proved by inoculating soybean plants in cotyledon stage (Balkan variety), by spraying with bacterial suspension (conc.108CFU/ml). Pathogen city of studied isolates was also confirmed by infiltration on tobacco leaves. Cultural and biochemical-physiological characteristics were tested. Differential soybean cultivars: Acme, Chippewa, Flambeau, Harosoy, Lindarin, Merit and Norchief were used to determine physiological race of the bacterium. Young plants were inoculated in two ways: by leaves rubbing with sterile cotton swab dipped into the bacterial suspension, and by spraying leaves under the pressure. Based on the results obtained it was shown that strains which cause bacterial blight of soybeans in Vojvodina, belong to Pseudomonas syringe pave. lysine race 4.

Bakteriozna pegavost soje čiji je prouzrokovač Pseudomonas syringae pv. glycinea (Coerper) Young, u Srbiji se javlja redovno i to često u jakom intenzitetu. Izolacija patogena vršena je sa obolelih delova lista soje različitih sorti. Izolacije su vršene na podlogu od mesnog ekstakta (MPA) i podlogu obogaćenu saharozom (NSA). Patogenost izolata je dokazana pozitivnom hipersenzitivnom reakcijom (HR) na duvanu. Provera patogenosti dobijenih izolata, kao i referentnog izolata ove bakterije (NCPPB 3318), dokazana je i inokulacijom mladih biljaka soje u fazi kotiledona (sorta Balkan), prskanjem i potapanjem u suspenziju bakterija. Odgajivačke i biohemijsko-fiziološke odlike ispitane su standardnim bakteriološkim metodama. Pripadnost dobijenih izolata fiziološkim rasama određena je korišćenjem diferencijalnog sortimenta soje: Acme, Chippewa, Flambeau, Harosoy, Lindarin, Merit i Norchief. Mlade biljke su inokulisane na dva načina: prskanjem pod pritiskom i povredom listova sunđerom natopljenim suspenzijom bakterija. Zaključeno je da izolati bakterije P. s. pv. glycinea, sa soje u Vojvodini, pripadaju rasi 4.