Identification and characterization of plant defense molecules is the first step towards creation of improved methods for pathogen control based on naturally occurring molecules.

Talaromyces minioluteus is one of the important species of genus Talaromyces, which has cosmopolitan distribution and is encountered on a wide range of different habitats. This species has not been considered as an important plant pathogen, even though it has been isolated from various plant hosts. Fruits and vegetables with Penicillium-like mold symptoms were collected from 2015 to 2017 from markets in Serbia. Isolates originating from quince, tomato, and orange fruits, onion bulbs, and potato tubers were identified and characterized on a morphological, physiological, and molecular level. Morphological and physiological examination included observing micromorphology, testing growth on six different media and at five different temperatures, and production of three enzymes. Molecular identification and characterization were performed using four molecular markers: internal transcribed spacer, β-tubulin, calmodulin, and DNA-dependent RNA polymerase II second largest subunit. The results of morphological and molecular analyses were in agreement, and they proved that the obtained isolates are T. minioluteus. In the pathogenicity assay, T. minioluteus was confirmed as a pathogen of all species tested with the exception of potato tubers. This is the first report of T. minioluteus as a postharvest plant pathogen on quince, tomato, and orange fruit and onion bulbs. Also, this is the first record of T. minioluteus in Serbia.

Pears are one of the oldest and the third most important fruit species grown in temperate regions. They are consumed because of their nutritional and health benefits, in fresh form or as various processed products. This paper resolves the etiology of the Penicillium-like mold symptoms on pear fruits in Serbia. Samples of pear fruits with blue mold and other Penicillium-like mold symptoms were collected in Serbia from 2016 to 2019, from four storages. The recovered isolates were identified and characterized using polyphasic approach. Morphological and physiological analyses were performed on three media and five temperatures, respectively. Four loci (internal transcribed spacer, beta-tubulin, calmodulin, and DNA-dependent RNA polymerase II second largest subunit) were used for sequencing, genetic identification and phylogenetic analyses. The results of the identification using conventional and molecular methods were in agreement and they revealed that the obtained isolates belong to five species: Penicillium crustosum, P. expansum, P. italicum, Talaromyces minioluteus and T. rugulosus. In a pathogenicity test, P. crustosum, P. expansum, T. minioluteus and T. rugulosus produced decay on artificially inoculated pear fruits, and P. italicum induced tissue-response lesions. The results of this study are the first reports of T. minioluteus and T. rugulosus as postharvest pear pathogens. Also, these are the first world records of T. minioluteus, T. rugulosus and P. italicum on fruits of European pear. Further, this is the first finding of P. crustosum, P. expansum, P. italicum, T. minioluteus and T. rugulosus on pear fruit in Serbia.

Soft rot symptoms were observed on broccoli plants in several commercial fields in the western part of Serbia. Six strains of bacteria were isolated from diseased tissues and identified as Pectobacterium carotovorum subsp. carotovorum using conventional bacteriological and molecular methods. All strains were non-fluorescent, gram-negative, facultative anaerobes, oxidase-negative and catalase-positive, causing soft rot on potato and carrot slices and did not induce hypersensitive reaction on tobacco leaves. They grew in 5% NaCl and at 37°C, did not produce acid from α-methyl glucoside, sorbitol and maltose, nor reducing substances from sucrose, but utilized lactose and trehalose, and did not produce indole or lecithinase. The investigated strains showed characteristic growth on Logan's medium and did not produce blue pigmented indigoidine on GYCA medium nor "fried egg" colonies on PDA. The identity of strains was confirmed by ITS-PCR and ITS-RFLP analyses and by sequence analysis of the 16S rRNA gene. In a pathogenicity assay, all strains caused tissue discoloration and soft rot development on inoculated broccoli head tissue fragments.

REZIMEPoslednjih 20 godina virus žutog mozaika cukinija (Zucchini yellow mosaic virus, ZYMV) se javlja kao značajan patogen biljaka iz familije tikava. Kod nas ovaj virus, takođe, izaziva značajne gubitke, naročito u proizvodnji uljane tikve. Iako je biološka i molekularna varijabilnost ZYMV dosta ispitivana, još uvek nema dovoljno informacija o varijabilnosti evropskih izolata ovog virusa. Ovaj rad predstavlja prvu analizu fenotipske varijabilnosti izolata ZYMV poreklom iz Srbije, koji su tokom 2008. godine sakupljeni iz različitih lokaliteta gajenja uljane tikve sorte Olinka. Mehaničkim inokulacijama C. pepo hibrid Ezra F1, dobijeno je 12 izolata, od kojih su četiri odabrana za dalju biološku karakterizaciju. Na osnovu različitog kruga domaćina, tipa i jačine simptoma na test-biljkama, utvrđena je fenotipska varijabilnost ispitivanih izolata. Par prajmera ZYMV CPfwd/Cprev testiran je radi utvrđivanja pogodnosti za rutinsku detekciju izolata ZYMV poreklom iz Srbije. Na osnovu pojave traka očekivane veliči-ne u gelu, ZYMV je detektovan i u pojedinačnim i mešanim infekcijama u biljkama sa različitih lokaliteta, što dokazuje pogodnost ovih prajmera. Kako ovi prajmeri amplifikuju hipervarijabilni deo genoma virusa, pogodni su ne samo za rutinsku molekularnu detekciju, već i za molekularnu karakterizaciju izolata ZYMV iz Srbije.Rezultati dobijeni u ovom radu omogućiće dalja proučavanja genetičke varijabilnosti izolata ZYMV iz Srbije, kao i njihove evolutivne povezanosti sa izolatima iz drugih delova sveta.