خيارات البحث
النتائج 1 - 8 من 8
Research on genetic aspects of Scots pine resistance to root rot
2010
Skipars, V., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Baumanis, I., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Rungis, D., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Scots pine (Pinus sylvestris) is Latvia's most economically important tree species. It accounts for 38% of the total forest area of Latvia. One of diseases affecting P. sylvestris is root rot caused by the fungus Heterobasidion annosum, which causes large economic losses. There is some evidence of Scots pine trees with higher levels of resistance but no absolutely resistant tree clones have been described so far. Many genes encoding peptides and proteins with direct or indirect antifungal activity have been described in various plant species, but only few of them have been studied in conifers. In our study we have utilised various approaches to research genetic aspects of Scots pine resistance to H. annosum. Here we present our initial results. Initially, H. annosum infection was determined in 300 trees and in a subset of twenty seven trees representing fifteen families (progeny of one mother tree) infection levels were quantitatively characterised. Candidate-genes were selected based on previously published research. Gene copy number variation (CNV) analyses were performed on selected samples. Copy number variation polymorphism was detected for a gene encoding a thaumatinlike protein analogues of which are described as potent antifungal proteins in other plants. As increased gene copy number can lead to increased gene product amounts in cells it is possible that an increased copy number of thaumatin-like protein is beneficial to the pine tree in respect to resistance against H. annosum and other pathogens. Further experiments need to be performed to investigate this in more detail.
اظهر المزيد [+] اقل [-]The influence of kappa-casein and beta-lactoglobulin genotypes on milk coagulation properties in Latvia dairy breed
2017
Petrovska, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Zagorska, J., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ciprovica, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Milk yield, composition and milk coagulation properties can be affected by kappa-casein (κ-CN) and beta-lactoglobulin (β-LG) genotypes and breed. Latvian Brown (LB) and Latvian Blue (LZ) are local dairy breeds in Latvia. These breeds are not so high-yielding than other commercial dairy breeds, besides, the number of those animals decrease each year. The aim of the research was to analyse the influence of κ-CN, β-LG and breed on milk composition and milk coagulation properties. Data were collected from 56 Latvian Brown and 26 Latvian Blue in 2016. Widespread κ-CN genotype was AA (0.593) in LB breed and AB (0.636) in LZ breed, while β-LG highest frequency was BB genotype. Significant effect was not observed on milk yield; however the highest daily milk yield was from AB κ-CN genotype (19.7 ± 1.52 kg) in LB breed. Significant differences were observed in fat content – the highest fat content accordingly κ-CN was from AA genotype in LB (46.3 ± 1.89 g kgE-1) and 45.5 ± 1.37 g kgE-1 from BB β-LG genotype in LB breed (p is less than 0.05). A lower protein content was observed from AA κ-CN genotype in LZ breed (33.8 ± 1.30 g kgE-1), while highest from BB genotype in both breeds. Curd firmness was not significantly different by genotypes and breed. Significantly shorter milk renneting time of β-LG was obtained from LB breed (14.6 ± 2.76 min, p is less than 0.05), while κ-CN genotype was not significantly affected.
اظهر المزيد [+] اقل [-]Occurrence of Lophodermium spp. in young Scots pine stands in Latvia
2017
Polmanis, K., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Gaitnieks, T., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Belevica, V., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Rungis, D., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Baumane, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Scots pine (Pinus sylvestris L.) is one of the most widespread coniferous species in boreal zones and it has a considerable economic importance in the Baltic countries. The impact of fungi on Scots pine has been known also historically, but it is predicted that it will increase in future due to climate changes that will have a positive effect on incidence and vitality of various species of fungi. The aim of the study was to characterize the occurrence of Lophodermium spp. in young stands of Scots pine in Latvia. Needle samples were collected from young pine stands (aged 1 – 14 years) located in all regions of Latvia. DNA extraction from needles was done using modified CTAB protocol, presence of Lophodermium in total extracted DNA was detected using a PCR method. Meteorological data – air temperature and precipitation – were obtained from all 34 observation stations of the Latvian Environment, Geology and Meteorology Centre. The presence of Lophodermium spp. was detected in all surveyed stands, and occurrence differences between the western and eastern regions were significant (p = 0.004). The occurrence of Lophodermium spp. in the eastern and western regions was affected by the meteorological conditions in autumn and winter of the previous years, as well as differences in the given years’ air temperature and precipitation. In 2016, the eastern region of Latvia had a higher May−August precipitation and, to a lesser extent, temperature, which correlated with a higher occurrence of Lophodermium spp.
اظهر المزيد [+] اقل [-]Phytophthora genus pathogens isolated from rhododendrons in Lithuania
2018
Snieskiene, V., Vytautas Magnus Univ., Kaunas (Lithuania). Kaunas Botanical Garden | Stankeviciene, A., Vytautas Magnus Univ., Kaunas (Lithuania). Kaunas Botanical Garden
Rhododendron spp. plants were surveyed for Phytophthora infection in Lithuania during 2010 – 2016. This study aims to identify Phytophthora genus pathogen which infects rhododendrons in Lithuania. Samples were taken from young sick plants with visible infection symptoms. Soil sampling was performed from the rhizosphere of sick plants. DNA from soil and plant was tested for the presence of Phytophthora genus pathogens. Data showed positive results of Phytophthora genus specific probe during real-time PCR. All tested diseased leaves and soil samples have indicated Phytophthora sp. infection during Alert-LF® Phytophthora spp. analysis. The extracted DNA concentrations were not very high for Phytophthora species identification, but in most cases, it was high enough for further researches.
اظهر المزيد [+] اقل [-]The rumen bacterial community of reindeer in different age periods from Russian Arctic regions
2018
Ilina, L., Biotrof, Ltd., Saint Petersburg (Russian Federation) | Filippova, V., Biotrof, Ltd., Saint Petersburg (Russian Federation) | Dubrovin, A., Biotrof, Ltd., Saint Petersburg (Russian Federation) | Yildirim, E., Biotrof, Ltd., Saint Petersburg (Russian Federation) | Dunyashev, T., Biotrof, Ltd., Saint Petersburg (Russian Federation) | Laptev, G., Biotrof, Ltd., Saint Petersburg (Russian Federation) | Laishev, K., North-West Centre for Interdisciplinary Research on Food Security Problems, Saint Petersburg (Russian Federation)
Rangifer tarandus (reindeer) – is actively bred in the northern regions of different countries. Therefore, an urgent task is to deepen information about the features of reindeer adaptations. Rumen symbiotic microorganisms play an important role in the life of Rangifer tarandus, allowing animals to efficiently use scarce nutrient resources of the tundra and forest-tundra. The microbial community of the reindeer rumen, as well as its age-related changes, are the least studied compared to other ruminants. The comparative analysis results of rumen bacterial community composition of calf (4 months), young animals (1–2 years) and adults (3–6 years) Rangifer tarandus of the Russian Arctic are presented for the first time. The reindeer ruminal bacterial community composition was analyzed in the laboratory of the ‘BIOTROF+’ Ltd by T-RFLP method. In the ontogenesis, significant changes in the microorganism representation were noticed, the greatest of which was noted in microorganism involved in carbohydrate fermentation. The content of cellulolytic Clostridia and the acid-utilizing species of the Negativicutes (P is less than 0.05) decreased with age, but bacteria with the amylo- and cellulosolytic properties of the phylum Bacteroidetes increased (P is less than 0.05). A wide range of microorganisms which traditionally belong to the pathogens of various animals and humans diseases was revealed. With age, a tendency to increase the number of pathogens, including the bacteria of the families Campylobacteraceae, Burkholderiaceae, phylum Fusobacteria, and the genus Staphylococcus was noticed. The greatest percent of opportunistic microorganisms, including phylum Actinobacteria and the family Enterobacteriaceae, were detected in young animals.
اظهر المزيد [+] اقل [-]Prevalence of Mycoplasma gallisepticum in the commercial layer flock
2015
Zute, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Valdovska, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Avian mycoplasmosis have been considered a severe problem in poultry diseases; Mycoplasma gallisepticum being one of the most important. This study was conducted in Joint-Stock Company Balticovo, Latvia, to determine the prevalence of M. gallisepticum infection in hen’s flocks in the farm. A total of 904 serum and 335 swab samples from non-vaccinated birds against M. gallisepticum from 65 chicken flocks of different age, from day 1 to 75 weeks old, were all tested. The commercially available enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) tests were used. Results revealed that the seropositive flock rate, based on ELISA tests and, according to ratio that represents the extent to which a light source effectively stimulates the rods: S/P ratios and antibodies titer higher 1.076 were 22/904 (2.43%) and 4/904 (0.44%), respectively, while PCR-positive flock rates were not confirmed. Seroprevalence of M. gallisepticum in commercial layer flock in Latvia was more common seen in birds from 17 to 30 weeks of age.
اظهر المزيد [+] اقل [-]Detection of coronavirus among domestic animals
2024
Sadikaliyeva, Sandugash | Shorayeva, Kamshat | Abay, Zhandos | Jekebekov, Kuanish | Shayakhmetov, Yeraly
This article presents the results of studies on biological samples collected from 640 swabs taken from dogs and cats across various regions of the Republic of Kazakhstan. These samples were part of a monitoring study on the spread of coronavirus among domestic animals. Total RNAs were isolated using the magnetic sorption method with the ALPREP kit and subsequently analysed with the ALSENSE-SARS-CoV-2 RT-qPCR kit. Real-time RT-PCR analysis revealed that 104 samples tested positive within 22–37 amplification cycles. These positive samples were then cultured in Vero cell lines to confirm the presence of the virus. The biological activity of the resulting virus-containing suspension was determined using the Reed-Muench method. During cultivation, one viral isolate with a biological activity of 5.83±0.08 lg TCID50/ml was obtained. A microphotograph of the virus was taken using an electron microscope to determine its size, shape, and structure, which confirmed its morphology corresponding to the Coronaviridae family. The data obtained further indicate that domestic animals can suffer from and carry coronavirus. It is becoming increasingly evident that the virus can infect and replicate in the organs of various farm and domestic animals.
اظهر المزيد [+] اقل [-]PCR-identification of mycobacteria isolated from tuberculin-reacting cattle in Estonia
2001
Sudakov, M. | Suett, S. | Kumar, J. | Haekkinen, L. (Estonian Agricultural Univ., Tartu (Estonia). Agrobiocentre)
However, the last case of tuberculosis to cattle was registered in Estonia in 1986, rapid and accurate diagnosting of the disease is still an actual veterinary problem. On farms, tuberculin testing has been regularly carried out showing that tuberculin positive cattle constitute 5,47% from all the herd. During 1997-2001, 23 clinical samples were isolated from the tuberculin positive cattle. Each sample was analysed with conventional morphological and bacteriological methods and by PCR. None of eleven mycobacterial cultures, isolated from the lymph modes of cattle, belonged to M. tuberculosis complex. There were seven cultures identified as M. avium and one as M. avium complex (MAC). The research confirmed that M. avium is the most frequently isolated bacteria causing NTM-Mycobacterioses in cattle in Estonia (63,6%). Two cultures of MAC were isolated from the milk of tuberculin-positive cows, verifying that milk can be a potential source of MAC transmission to man.
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