Pathogenic and bacteriological characteristics of Erwinia amylovora, the pathogen of pear and quince - trees in Macedonia

Fire blight, caused by Erwinia amylovora (Burrill 1882) Winslow et al. 1920 is very destructive disease for pear, quince and less to apple in Macedonia. The pathogen recently a quarantine bacterium for our country, has already been caused considerable damages with tendency of further spreading. The purpose of the present study was: (1) to show economic importans and distribution of E. amylovora in Macedonia, (2) to test their pathogenicity (3) to verify their properties by morphological, biochemical and physiological tests and (4)to compare the strains isolated in Macedonia with authentic strains from France

Theoretical aspects of several successive two-step redox mechanisms in protein-film cyclic staircase voltammetry

Protein-film voltammetry (PFV) is a versatile tool designed to provide insight into the enzymes physiological functions by studying the redox properties of various oxido-reductases with suitable voltammetric technique. The determination of the thermodynamic and kinetic parameters relevant to protein’s physiological properties is achieved via methodologies established from theoretical considerations of various mechanisms in PFV. So far, the majority of the mathematical models in PFV have been developed for redox proteins undergoing a single-step electron transfer reactions. However, there are many oxido-reductases containing quinone moieties or polyvalent ions of transition metals like Mo, Mn, W, Fe or Co as redox centers, whose redox chemistry can be described only via mathematical models considering successive two-step electron transformation. In this work we consider theoretically the protein-film redox mechanisms of the EE (Electrochemical–Electrochemical), ECE (Electrochemical–Chemical–Electrochemical), and EECat (Electrochemical–Electrochemical–Catalytic) systems under conditions of cyclic staircase voltammetry. We also propose methodologies to determine the kinetics of electron transfer steps by all considered mechanisms. The experimentalists working with PFV can get large benefits from the simulated voltammograms given in this work

REAL TIME PCR METHOD FOR PPV DIAGNOSTIC ON PLUMS AND APRICOT IN THE REPUBLIC OF NORTH MACEDONIA

Real-time PCR (Polymerase Chain Reaction) or qPCR is a method by which the amount of the PCR product can be determined in real-time, and is very useful for investigating gene expression. The main advantages of qPCR are that it provides fast and high-throughput detection and quantification of target DNA sequences in different matrices. The lower time of amplification is facilitated by the simultaneous amplification and visualization of newly formed DNA amplicons. The development and application of molecular methods for the detection of pathogens has significantly changed the diagnosis and control of plant diseases, various environmental samples, including hosts tissues, soil, water and air. With real time PCR method, it is possible not only to identify and detect the presence or absence of the target pathogen, but it is also possible to quantify the amount present in the sample allowing the quantitative assessment of the number of the pathogen in the sample. Detection and accurate identification of plant pathogens is one of the most important strategies for controlling plant diseases to initiate preventive or curative measures. Plum pox virus (PPV), the agent of Sharka, is the most devastating virus infecting stone fruits. The PPV control is mainly based on prevention, and its quick and reliable detection is considered crucial in this strategy. In this study DAS-ELISA and real-time PCR were compared for evaluating their potentialities and limits for large scale surveys. Plum hosts (Prunus domestica) and apricot samples (Prunus armeniaca) from several different place are included for laboratory test analyzes, plant organs (phloem, buds, flowers, leaves and fruits) and parts of them, different periods of the year (spring, summer and winter period 2017/20), the presence or absence of symptoms were considered for comparison. Using DAS-ELISA tests, and use a universal set of antibodies (BIOREBA), has proved the presence of virus of Plum pox in all examined samples, especially from samples collected in summer, but also in checking virus status in winter and early spring season. Testing found high concentrations of viral antigens in plant samples (OD 2.912-2.752, for 30 min / 405 nm). Real time PCR show amplification plot for positive PPV samples on plums and apricot

FORECASTING MODEL BASED ON CUMULATIVE DEGREE DAYS FOR INCUBATION PERIOD OF Plasmopara viticola (Berk. & M.A. Curtis) Berl. & De Toni

The overall development of Plasmopara viticola and its occurrence in time and space cause rapid disease increases. The incubation period is only part of the life cycle of P. viticola between infection and the first appearance of symptoms. The forecasting based on cumulative degree days for determination of incubation allows the prediction of a small number of primary infections whose calculation by based on the temperature factor. This warning model, in essence, is a regression analysis that presents the relationship between average daily temperature and coefficient of incubation. The determination of the incubation allows precise management of the fungicides against Plasmopara viticola and gives the basic assumptions for the possible occurrence of the primary inoculum

Methods for determination of so2 and reducing sugars in wines and alcoholic beverages

In this study, volumetric methods for determination of SO2 (free and total) and reducing sugars in wines and alcoholic beverages were optimized and validated. The linearity, accuracy and precision of the methods were confirmed using standard solutions of SO2 and reducing sugars (fructose and glucose) prepared in appropriate concentration range, as well as with low, medium and high concentrations. Additionally, the accuracy of the methods was checked by standard additions. Repeatability and reproducibility of the methods was confirmed with repeated analyses of real samples, wines and alcoholic beverages. Obtained results for both methods presented satisfactory accuracy and precision, suggesting that these methods are appropriate for analysis of wines and alcoholic beverage

Acidovorax citrulli - Causing Bacterial fruit blotch of watermelon fruits in Strumica region

During August 2019/20, fruit blotch symptoms on mature watermelon fruits caused by Acidovorax citrulli, for the first time were observed in the village of Mokrievo, Strumica region, on the Bibo and Olakala watermelon varieties. Acidovorax citrulli is the causal agent of bacterial fruit blotch (BFB) of cucurbit plants. In recent years, the disease has been spread to many parts of the world, mainly via the inadvertent distribution of contaminated commercial seeds. So far, A. citrulli has already been reported in the Europe EPPO region, such as Turkey, Israel, Greece, Hungary, Italy, and Serbia, but in these reported countries, A. citrulli is under very careful control, and hygiene measures have already been taken. A. citrulli has been added to the EPPO A1 List version 2022-09 (https://www.eppo.int/ACTIVITIES/plant_quarantine/A1_list)

Zygotic embryos culture from apricot (Prunis armeniaca L.)

Obtaining in vitro regenerated plants from apricot (Prunis armeniaca L.) important for production of rootstocks of high quality trait varieties of apricot and for production of starting material for apricot which is disease free, especially from the virus sharka, which will further used for grafting and production of healthy plantlets. In this research are used embryos extracted from mature wild type apricot seeds (Prunis armeniaca L.) collected from natural populations and isolated trees in Eastern Macedonia. MS medium with addition of 1 mg/l BAP + 1 mg/l GA3, 1,6 mg/l BAP + 0,3 mg/l GA3 и 6 mg/l BAP + 1 mg/l GA3 for stimulation of shoots regeneration. From tested growth regulators in different combinations and concentrations only МЅ + 1 mg/l BAP + 1 mg/l GA3 gave positive results. Surprisingly, explants cultured on the rooting medium МЅ + 2 mg/l IBA resulted in generation of roots, callus, newly formed embryos and somatic embryoids

SEM analyses of minerals from Allchar deposite - Republic of Macedonia

The Allchar Sb-As-Tl-Au volcanogenic hydrothermal deposit is situated at the northwestern margins of Kožuf Mts. (Republic of Macedonia), close to the border between Republic of Macedonia and Greece. From the geotectonic point of view, ore mineralization is related to a Pliocene volcano-intrusive complex located between the rigid Pellagonian block in the west, and the labile Vardar zone in the east. From the metallogenic point of view, the Allchar deposit belongs to the Kožuf ore district as part of the Serbo-Macedonian metallogenetic province.The locality is one of the Unique deposits in the world not because of its size but because of its mineral composition and diversity, including an abundance of particularly rare thallium sulfosalts

Bacterial Crown of Grapes with Particular Devote on the Seedling Material

The production of healthy bedding material of grapes are extremely complex and responsible work, which needs high qualifications and knowledge from different aspects. Bedding material can transmit many diseases and pests, and has a bad influence in susceptibility, developing and fruitfulness in grapes. The some problem makes bacterial crown gall indicated by Agrobacterium tumefaciens. The bacterium with its products, affect the meristem tissues and develop tumor tissues. So, the bacterium has an indirect influence perturbing leaf vein and root system. Diseased grafts have got a slow advancement and soon they decay

Presence of Plum Pox virus in the Republic of Macedonia

Viral diseases of fruit cultivars affect the quality of fruits and cause great damage in the field of pomiculture. One of the more significant diseases of fruit cultivars, especially plums and peaches is the plum pox or Sharka virus (Plum Pox virus, PPV). There is very little data about the presence of this virus in Macedonia. Examination of old plum cultivars showed symptoms typical of the sharka virus. Field assessment of the percentage of infection of plum trees was carried out in a part of the territory of Macedonia. Some of the young seedlings that were analyzed failed to develop properly and were withered. Using DAS-ELISA tests and a universal set of antibodies, we demonstrated the presence of the Sharka virus in 94% of the examined samples. The test results showed high concentration of viral antigens in the plant samples (OD: 3.618 - 3.47230min). The laboratory analysis of the young fruits indicated that the infection probably originated from the propagative material