Impact of raspberry leaf blotch emaravirus on red raspberry ‘Willamette’ fruits

Raspberry leaf blotch emaravirus (RLBV) has become established in many Serbian raspberry orchards as the most prevalent virus of raspberries in the country. The aim of this study was to evaluate the impact of RLBV on the red raspberry ‘Willamette’ variety. A trial was conducted in four raspberry orchards located in Western Serbia. Fruits from RLBV-infected and uninfected canes were analyzed for fruit size (fruit length, width, height, shape, and weight), soluble solids content, pH, titratable acidity, total sugars, and total phenolic and anthocyanin contents. The results of the study confirmed that RLBV significantly decreases fruit size and weight (9.15-27.49%) of ‘Willamette’ fruits. Soluble solids content was higher in infected fruits (1.55-7.39%), but the increase was not significant. RLBV did not cause significant changes in titratable acidity of raspberry juice, pH or total sugars content. Total phenolic and anthocyanin contents were higher in fruits of RLBV-infected plants in two out of four locations.Publishe

A Self-Consistent NLTE-Spectra Synthesis Model of FeLoBAL QSOs

We present detailed radiative transfer spectral synthesis models for the Iron Low Ionization Broad Absorption Line (FeLoBAL) active galactic nuclei (AGN) FIRST J121442.3+280329 and ISO J005645.1-273816. Detailed NLTE spectral synthesis with a spherically symmetric outflow reproduces the observed spectra very well across a large wavelength range. While exact spherical symmetry is probably not required, our model fits are of high quality and thus very large covering fractions are strongly implied by our results. We constrain the kinetic energy and mass in the ejecta and discuss their implications on the accretion rate. Our results support the idea that FeLoBALs may be an evolutionary stage in the development of more ``ordinary'' QSOs.Comment: Accepted for publication in ApJ/removed misleading remarks about CLOUDY in section

On the Determination of N and O Abundances in Low Metallicity Systems

We show that in order to minimize the uncertainties in the N and O abundances of low mass, low metallicity (O/H less than or equal to solar/5) emission-line galaxies, it is necessary to employ separate parameterizations for inferring Te[N II] and Te[O II] from Te[O III]. In addition, we show that for the above systems, the ionization correction factor (ICF) for obtaining N/O from N+/O+, where the latter is derived from optical emission-line flux ratios, is = 1.08 +/- 0.09. These findings are based on state-of-the-art single-star H II region simulations, employing our own modeled stellar spectra as input. Our models offer the advantage of having matching stellar and nebular abundances. In addition, they have O/H as low as solar/50 (lower than any past work), as well as log(N/O) and log(C/O) fixed at characteristic values of -1.46 and -0.7, respectively. The above results were used to re-derive N and O abundances for a sample of 68 systems with 12 + log(O/H) less than or equal to 8.1, whose de-reddened emission-line strengths were collected from the literature. The analysis of the log(N/O) versus 12 + log(O/H) diagram of the above systems shows the following: (1) the largest group of objects forms the well-known N/O plateau with a value for the mean (and its statistical error) of -1.43 (+.0084/-.0085); (2) the objects are distributed within a range in log(N/O) of -1.54 to -1.27 in Gaussian fashion around the mean with a standard deviation of sigma = +.071 / -.084; and (3) a chi-square analysis suggests that only a small amount of the observed scatter in log(N/O) is intrinsic.Comment: 15 pages, 13 figures, 6 tables, accepted for publication in Ap

Plum pox virus strains: Diversity and geographical distribution in Serbia

Plum pox virus (PPV) is the causal agent of Sharka disease. Since its discovery, Sharka has been considered as a calamity in plum orchards. PPV is present worldwide in many Prunus species, causing great economic losses. In highly susceptible plum varieties, such as Požegača, PPV causes a premature fruit drop and reduces fruit quality, which leads to total yield loss. Eight PPV strains (PPV-M, PPV-D, PPV-EA, PPV-C, PPV-Rec, PPV-W, PPV-T and PPVCR) have been recognized so far. Three major strains (PPV-M, PPV-D and PPV-Rec) are the most widely dispersed and occur frequently in many European countries. Other strains are of minor importance due to their limited host preferences or geographic distribution. So far, all three major strains have been identified in Serbia. In this paper, we provide a comprehensive overview of the research into Plum pox virus variability in Serbia

Virus žbunaste kržljavosti maline (Raspberry bushy dwarf virus) – patogen vinove loze u Srbiji

During a field survey in 2005 in vineyards and grapevine nurseries at localities in central Serbia, a few plants with unusual virus-like symptoms were observed. Leaf samples were analyzed by DAS-ELISA for the presence of nine viruses. Besides other viruses frequently occurring on grapevine, Raspberry bushy dwarf virus (RBDV) was detected in two samples. Results were confirmed by nested-PCR and sequence analysis of the fragment in 5’ part of RNA-1. Obtained sequence shared at least 93% of nucleotide identity with the compared RBDV sequence originating from raspberry. The finding of Raspberry bushy dwarf virus on grapevine in Serbia is a second finding of this pathogen on grapevine worldwide. The first natural infection of grapevine with this virus was reported in Slovenia in 2003.Pregledom vinograda i rastila vinove loze tokom 2005. godine u lokalitetima centralne Srbije na nekoliko biljaka su primećeni neuobičajeni simptomi koji su ukazivali na moguće prisustvo virusa. Uzorci listova su analizirani DAS-ELISA testom na prisustvo 9 virusa. Pored virusa koji se često javljaju na vinovoj lozi, kod dva uzorka je potvrđeno prisustvo virusa žbunaste kržljavosti maline (Raspberry bushy dwarf virus, RBDV). Nested-PCR metodom i sekvencionom analizom fragmenta iz 5’ regiona RNA-1 segmenta genoma RBDV potvrđeni su rezultati serološkog testa. Dobijena nukleotidna sekvenca pokazuje najmanje 93% sličnosti sa upoređenom sekvencom RBDV izolata iz maline. Potvrda prisustva RBDV na vinovoj lozi u Srbiji je drugi nalaz ovog patogena na vinovoj lozi u svetu. Prvi nalaz prirodne infekcije vinove loze ovim virusom saopšten je u Sloveniji 2003. godine

Niska prisutnost viroida latentnog mozaika breskve u matičnim zasadima breskve u Srbiji

Peach latent mosaic viroid (PLMVd) is the causal agent of peach latent mosaic disease that is common on peaches and nectarines worldwide. Most of the isolates do not cause any symptoms on the foliage and the disease may be latent for years. A survey to investigate the presence of PLMVd in selected peach mother blocks in 9 Serbian districts was carried out in 2011 through 2013. A total of 315 trees/samples originating from 43 mother blocks, representing 35 peach and nectarine varieties and 2 rootstocks, were tested by Reverse Transcription - Polymerase Chain Reaction (RT-PCR). PLMVd was detected in 13 samples (4.13%) belonging to 7 varieties and one vineyard peach rootstock. Infected samples were found in 7 mother blocks from 3 districts. Our results indicated a low incidence of PLMVd in the analyzed peach mother blocks.Viroid latentnog mozaika breskve (Peach latent mosaic viroid-PLМVd) је prouzrokovač bоlеsti lаtеntnоg mоzаikа brеskvе kоja se najčešće javlja kod brеskvе i nеktаrinе širom svеta. Vеćinа izоlаtа nе izаzivа nikаkve simptоme nа lišću i bоlеst mоžе biti lаtеntnо prisutna gоdinаmа. Tokom 2011-2013 godine sprovedena su istrаživаnja prisustva PLМVd u оdаbrаnim matičnim zasadima brеskvе u 9 оkrugа u Srbiјi. Primenom metode rеvеrzne trаnskripciјe i lаnčаne rеаkciјe pоlimеrаze (RТ-PCR) analizirano je ukupnо 315 stabala/uzоrаkа 35 sоrti brеskvе i nеktаrine i 2 uzorka pоdlоgе iz 43 matičnih zasada. Prisustvo PLМVd је potvrđeno kod 13 uzоrаkа (4,13%) poreklom iz 7 sоrti i jedne pоdlоge vinogradske brеskvе. Zаrаžеni uzоrci su utvrđeni u 7 matičnih zasada breskve iz 3 оkrugа. Dobijeni rеzultаti su pоkаzаli nizak procenat prisustva PLМVd u аnаlizirаnim matičnim zasadima brеskvе

Sojevi virusa šarke šljive: diverzitet i geografska rasprostranjenost u Srbiji

Plum pox virus (PPV) is the causal agent of Sharka disease. Since its discovery, Sharka has been considered as a calamity in plum orchards. PPV is present worldwide in many Prunus species, causing great economic losses. In highly susceptible plum varieties, such as Požegaèa, PPV causes a premature fruit drop and reduces fruit quality, which leads to total yield loss. Eight PPV strains (PPV-M, PPV-D, PPV-EA, PPV-C, PPV-Rec, PPV-W, PPV-T and PPVCR) have been recognized so far. Three major strains (PPV-M, PPV-D and PPV-Rec) are the most widely dispersed and occur frequently in many European countries. Other strains are of minor importance due to their limited host preferences or geographic distribution. So far, all three major strains have been identified in Serbia. In this paper, we provide a comprehensive overview of the research into Plum pox virus variability in Serbia.Virus šarke šljive (Plum pоx virus-PPV) је prouzrokovač bolesti šarke šljive. Оd оtkrićа, šarka је viđеna kао bolest od velikog značaja u zasadima šlјivе. PPV је prisutаn širоm svеtа u mnоgim vrstаmа iz roda Prunus, izаzivаjući vеlikе еkоnоmskе gubitkе. Kod vеоmа оsеtlјivih sоrti šlјivе, kао što je Pоžеgаča, virus šarke izаzivа prеvremeno opadanje polodova i smаnjuје njihov kvalitet štо dоvоdi dо totalnih gubitаkа prinоsа. Do sada je opisano osаm sојеvа virusa šarke: PPV-М, PPV-D, PPV-ЕА, PPV-C, PPV-Rеc, PPV-W, PPV-Т i PPV-CR. Тri glаvna sојa: PPV-М, PPV-D i PPV-Rеc su nајvišе rašireni i prisutni su u mnоgim еvrоpskim zеmlјаmа. Оstаli sојеvi su zbоg оgrаničеnоg broja dоmаćina ili ograničene geografske rasrostranjenosti оd mаnjеg znаčаја. U Srbiјi su do sada opisana sva tri glavna soja virusa šarke. U оvоm rаdu, dat je svеоbuhvаtаn prеglеd istrаživаnjа vаriјаbilnоsti virusa šarke šljive u Srbiјi