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.

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.

In dairy cows shedding of Coxiella burnetii in milk can be persistent, sporadic to absent. Persistent heavy shedder cows are mostly highly-seropositive. Serological response due to C. burnetii antigenic phase demonstrates acute or chronic infection (serological response to phase II (PhII) or phase I (PhI) antigen, respectively). The aim of this study was to detect dynamics of C. burnetii DNA in milk and phase-specific serological response. In this study, the sera samples from 46 animals and milk samples from 34 were collected initially. Milk and sera samples from 36 animals were collected repeatedly. Samples were collected in five herds with previous history of C. burnetii infection from different parishes in Latvia – in 2017 and 2018. Milk samples were tested by detection of C. burnetii DNA by realtime PCR amplification using ‘ADIAVET™ COX REALTIME’ (ADIAGENE). Sera were tested by ‘VetLine Coxiella Phase1 and Phase2 ELISA’ (NOVATEC). Three cows (9%) in the first sampling and five (14%) in second sampling demonstrated shedding of C. burnetii DNA in milk . Six cows (13%) in the first sampling and eight (22%) in second sampling demonstrated positive serological response to PhI. Three cows (7%) in the first sampling and one (3%) in second sampling demonstrated a questionable serological response to PhI. Two cows (6%) in the second sampling demonstrated a questionable serological response to PhII . In herds with previous history of C. burnetii infection the number of animals demonstrating PhI positve serological response increases significantly (p0.05) during six months. In cows demonstrating positive serological response to PhI it continues and mostly remains unchanged during six months.

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.