Study of the genetic variability of porcine circovirus type 2 detected in Serbia and Slovenia

Recent variants of porcine circovirus type 2 (PCV2) were obtained from tissues of domestic pigs with porcine circovirus associated disease and from randomly selected wild boar samples from Serbia and Slovenia. A 450-base-pair nucleotide sequence was obtained by PCR from the ORF2. The derived nucleotide and amino acid sequences were aligned and compared to the corresponding region of closely related PCV2 sequences determined in previous years and retrieved from the GenBank. The 30 Serbian and 17 Slovenian PCV2 sequences clustered into three previously determined genotypes (PCV2a: 7), (PCV2b: 38) and (PCV2d: 2). Three major variable regions, concerning 29 amino acid position substitutions within the ORF2, were observed, which further supports the segregation of the detected strains into three separate genotypes. This study indicates that PCV2b is the predominant genotype in Serbia and Slovenia and the detected PCV2 strains are closely related to those previously described in Europe and in other parts of the world.     

Quantitative Real-Time PCR Analysis of ‘Candidatus Phytoplasma mali’ Without External Standard Curves

Apple proliferation caused by ‘Candidatus Phytoplasma mali’ is an economically important disease of apple (Malus?′?domestica). The availability of a simple quantitative approach to assess pathogen load in infected host plants would certainly contribute to a better understanding of pathogenesis and epidemiology. This study proposes a quantification approach not requiring the analysis of external standard curves. It is based on the simultaneous detection of the 16S rRNA gene of the pathogen and the 1-aminocyclopropane-1-carboxylate oxidase gene of the host plant in a single-tube reaction using TaqMan chemistry. The quantity of the phytoplasma relative to its host plant is determined as the difference between C_T values of the two target genes (ΔC_T). To assess the agreement of the relative quantification approach with a standard curve-based method, a dataset of 450 DNA samples from infected apple trees was reanalysed. Comparison of the ΔC_T-based relative quantities with the corresponding absolute values revealed high degrees of agreement between the relative and absolute quantification methods. The ΔC_T procedure can thus be considered adequate for quantification of the phytoplasma in infected host plant tissue. In addition, this approach ensures improved methodological standardisation and increased analysis throughput.     

Resolving the Parentage of the Apple Cultivar ‘Meran’

In the mid-1970s, a new apple variety named ‘Meran’ was discovered in South Tyrol (northern Italy), which harbours the largest continuous apple growing area in Europe. The cultivar was registered for varietal protection and patented in several countries, and was declared to be a cross of the varieties ‘Golden Delicious’ and ‘Morgenduft’ (synonym ‘Rome Beauty’). The parentage of ‘Meran’ has, however, been questioned, and the present study aimed to assess the descent of this cultivar by the combined use of molecular genetic and bioinformatic tools. Five accessions of ‘Meran’ were collected from three different European germplasm collections and analysed at 14 variable microsatellite DNA loci. Subsequently, computer software was used to allocate the most likely parent pair from a set of cultivars representative for the apple growing area of South Tyrol in 1975. The molecular genetic data clearly excluded ‘Morgenduft’ as a gene donor to ‘Meran’ and provided strong evidence that ‘Meran’ is a cross of the cultivars ‘Golden Delicious’ and ‘Jonathan’, confirming previous assumptions based on morphological traits of the tree and fruit.     

Molecular Tools Applied to the Advancement of Fruit Growing in South Tyrol: a Review

Molecular biology techniques have become indispensable tools in various areas of research and routine applications. In South Tyrol (northern Italy), molecular methods have been applied to the field of fruit growing over the last decade, and the main applications have been related to plant pathology and identification of apple cultivars. This review article illustrates how the implementation of existing methods and the development of new assays have contributed to gain more insights about the spread and epidemiology of phytoplasma diseases affecting apple trees and grapevine in South Tyrol, to identify and characterise the causal agents of newly emerging disorders, or to describe the local genetic diversity of the apple.     

Changes in the content of free sulphydryl groups during postharvest wheat and flour maturation and their influence on technological quality

The main aim of this study was to determine the changes in free sulphydryl content during postharvest wheat and flour maturation. The content of free sulphydryl groups was determined from wet gluten over 50 days of wheat postharvest maturation and over 14 days of flour maturation by varying incubation temperatures (30 and 37 °C) and incubation times (0, 45, 90 and 135 min). The amount of free sulphydryl groups increased during postharvest wheat and flour maturation as well as with the increase in temperature and gluten incubation time. The additional aim of this study was to find the interrelation between the content of free sulphydryl groups and selected parameters of technological quality by means of Principal Component Analysis. During wheat/flour maturation, the strengthening of protein structure was observed manifested by the increase in gluten index and Mixolab protein network weakening (C2), and changes in dough resistance as well. The incubation temperature of 37 °C affected the weakening of protein structure manifested by the decrease in gluten index and resistance, and increase in extensibility. Strong differentiation of examined varieties in terms of selected quality indicators was observed upon pre-defined maturation period, probably due to the expression of their intrinsic properties.     

Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests

Journal of Soils and Sediments - This study utilizes column tests to investigate the retardation of certain herbicides with different hydrophobicities (atrazine, alachlor and trifluralin) during...     

Transformation of Petroleum Saturated Hydrocarbons during Soil Bioremediation Experiments

This paper presents transformations of saturated hydrocarbons of petroleum type pollutants during ex situ bioremediation of soil on the pilot heap (halde), during a period of 6 months, within the grounds of Petroleum Refinery Pan?evo (Serbia). Samples for analysis were taken in time intervals of 2 weeks (P₁–P₁₂ samples). Organic substance was extracted by Soxhlet’s method and quantified. Isoprenoid aliphatics, in particular pristane and phytane, and polycyclic aliphatics of sterane and triterpane types in saturated hydrocarbon fractions were analysed by GC-MS (SIM method). Significant amounts of n-alkanes have not been detected. The MS-chromatogram revealed only marginal amounts of pristane and phytane in sample P₁. Pristane and phytane occurred in sample P₈, and in even higher quantities in the final sample P_12. The proceeding bioremediation process was accompanied by the decrease of the relative amounts of pentacyclic terpanes of hopane type, compared to tri- and tetracyclic terpanes. In the initial sample P₁ the distribution of steranes and hopanes follows a pattern, which is characteristic for crude oils. However, their identification by SIM method was not possible in samples P₈ and P₁₂ because of the reduced concentration. The observed changes in the alkane fractions’ compositions may be considered as atypical, referring to the fact that during oil biodegradation under natural conditions, decomposition of isoprenoids occurs much easier and faster than decomposition of polycyclic alkanes of tri-, tetra- and pentacyclic terpane, sterane and diasterane types, after the decomposition of n-alkanes has been almost completed.