Author/Editor		Pirc, Manca; Dreo, Tanja; Rupnik, Maja; Gorkink-Smits, Peggy PMA; Janse, Jaap D; Ravnikar, Maja
Title		Pseudomonas ssp. na vzorcih z bolezenskimi znamenji ožiga
Translated title		Pseudomonas ssp. from samples with blight symptoms
Type		članek
Source		In: Maček J, editor. Zbornik predavanj in referatov 7. slovensko posvetovanje o varstvu rastlin; 2005 mar 8-10; Zreče. Ljubljana: Društvo za varstvo rastlin Slovenije,
Publication year		2005
Volume		str. 508-12
Language		slo
Abstract		Plant pathogenic bacteria belonging to the genus Pseudomonas are common on fruit trees in Slovenia. They reduce fruit quality and may lower yield. Trees infected by pathogenic Pseudomonas species are also more susceptible to other pathogens. In 2003 some Pseudomonas isolates were obtained that were from samples with more severe blight symptoms of apple shoots than are usually observed. Pseudomonas and Erwinia amylovora infections are difficult to distinguish. In the frame of systematic survey of fire blight coordinated by the Phytosanitary Administration of the Republic of Slovenia in 2003, 441 samples showing more or less typical fire blight symptoms were tested. During Erwinia amylovora isolation on sucrose nutrient agar and King's B media Pseudomonas-like colonies were observed and isolated from 34 samples (8 %). In 2004 pathogenic bacteria from genus Pseudomonas were isolated from 26 (20,2%) out of 129 samples tested on Erwinia amylovora. Infected samples included apple and pear trees, quince, Pyracantha, Cotoneaster, Japanese Quince, rose and Photinia. Biochemical (LOPAT) tests were performed for all isolates. On the basis of preliminary tests isolates from different host plants were selected and further tested using fatty acids profile analysis, whole cell protein profiles, toxin production bioassay, pathogenicity tests on various hosts and molecular methods such as 16S rDNA RFLP and rep-PCR. High diversity of the HR-positive strains (most likely pathovars of Pseudomonas syringae or P. syringae pv. syringae) was observed in pathogenicity tests and rep-PCR profiles. Because bacteria from genus Pseudomonas often show inhibitory effects on growth of other bacteria their possible influence on efficacy of Erwinia amylovora detection was checked. Marked inhibitory effects on Erwinia amylovora on King's B media were observed in 4 out of 46 tested isolates.
Summary		Patogene bakterije rodu Pseudomonas so v Sloveniji precej razširjene. Pri okuženih drevesih so sadeži slabše kvalitete, pridelek je manjši, hkrati so rastline bolj občutljive na druge povzročitelje bolezni. V letu 2003 smo bakterije iz rodu Pseudomonas izolirali tudi iz rastlin s posebej hudimi znamenji ožiga. Bolezenska znamenja povzročena z bakterijami iz rodu Pseudomonas in tista, ki jih povzroča okužba z bakterijo Erwinia amylovora je zelo težko razlikovati. Tako smo v letu 2003, v sklopu sistematičnega nadzora bakterijskega hruševega ožiga, ki ga koordinira Fitosanitarna uprava RS, testirali 441 vzorcev z bolj ali manj tipičnimi bolezenskimi znamenji hruševega ožiga. Med izolacijo bakterije Erwinia amylovora na gojiščih SNA in King B, smo pri 34 vzorcih (8%) opazili in izolirali kolonije morfološko podobne bakterijam iz rodu Pseudomonas. V letu 2004 smo patogene bakterije rodu Pseudomonas izolirali iz 26 od skupno 129 vzorcev (20,2%). Okužene gostiteljske rastline pri katerih smo potrdili patogene bakterije iz rodu Pseudomonas so bile jablana, hruška, kutina, ognjeni trn, panešplja, japonska kutina, vrtnica in photinia. Za vse izolate smo izvedli LOPAT teste. Na podlagi preliminarnih testov smo z namenom zajeti čim večjo raznolikost gostiteljev in izolatov izvedli še dodatne teste, kot so profil maščobnih kislin, profil celotnih celičnih proteinov, test patogenosti na različnih gostiteljih ter biotest tvorbe toksinov. Od biološko molekularnih tehnik smo izvedli 16S rDNA RFLP in tipizacijo z rep-PCR. Opazili smo veliko raznolikost HR pozitivnih izolatov (najverjetneje patovarjev Pseudomonas syringae ali Pseudomonas syringae pv. syringae) na testih patogenosti na različnih gostiteljih in tudi po molekularnem profilu, pridobljenem z rep-PCR. (Izvleček skrajšan na 2000 znakov)
Descriptors		FRUIT PLANT DISEASES ERWINIA PSEUDOMONAS DNA, BACTERIAL POLYMERASE CHAIN REACTION POLYMORPHISM, RESTRICTION FRAGMENT LENGTH