Cryptic speciation in Hymenoscyphus albidus

Ash dieback caused by the mitosporic ascomycete Chalara fraxinea is a novel disease of major concern affecting Fraxinus excelsior and Fraxinus angustifolia in large parts of Europe. Recently, its teleomorph was detected and assigned to Hymenoscyphus albidus, which has been known from Europe since 1851. In this study, we present molecular evidence for the existence of two morphologically very similar taxa, H. albidus, which is lectotypified and Hymenoscyphus pseudoalbidus sp. nov. Differences were found between the species in the loci calmodulin, translation elongation factor 1‐α and the internal transcribed spacers of the rDNA genes, and strong differentiation was obtained with ISSR markers. It is likely that H. albidus is a non‐pathogenic species, whereas H. pseudoalbidus is a virulent species causing ash dieback. Genotyping herbarium specimens showed that H. pseudoalbidus has been present in Switzerland for at least 30 years prior to the outbreak of the epidemic.     

Development of the population size, contribution of foreign breeds, inbreeding and degree of relationships of the entire Hanoverian scenthound population registered in the stud book of the kennel club Hirschmann e.V

The entire dog population of Hanoveranian Scenthounds registered since the foundation of the kennel club Hirschmann in the year 1894 was analysed for the development of the inbreeding and relationship coefficient and the contribution of Hanoveranian Scenthound population of foreign countries. The analyses were performed using all available pedigree information. In the history, the breeding of the Hanoveranian Scenthound was difficult because of the low number of breeding dogs which was additionally reduced during World War I and II. The mean coefficient of inbreeding of the entire German population was 6.35%. From 1950 to 1990, the mean coefficient of inbreeding increased from 8.3% to 9.7%. In the birth years from 1990 to 2002, the mean coefficient of inbreeding decreased slightly to 9.2%. The rates of inbreeding decreased since 1950. For the last 8 generations the increase of the coefficients of inbreeding per generation was 0.71%. The mean degree of relationship of the entire population was 7.17%, whereby values higher than 75% were found. Gene contributions of 8 other European stud books for the Hanoveranian Scenthound could be found in the German population. Hereby, the Austrian Hanoveranian Scenthounds had the largest impact on the German population with 24.4%. The proportion of genes from the German stud book amounted to 67%.     

Analysis of relationships between German heavy horse breeds based on pedigree information

We analysed the relationship coefficients (R) between the four German heavy horse breeds South German Coldblood, Rhenish German Draught Horse, Schleswig Draught Horse and Black Forest Draught Horse. The relationship coefficient makes it possible to ascertain crossbreeding between the breeds over time, or autonomous developments of the breeds, respectively. The investigation revealed that the relationship coefficients between the German draught horse breeds were very low. The mean relationship coefficients between the four German heavy horse breeds were largest between the South German Coldblood and Schleswig Draught Horse (0.103%), whereas mean relationship coefficients were lowest between the Rhenish German and Black Forest Draught Horse (0.001%). The Rhenish German Draught Horse showed largest relationship coefficients with the Schleswig Draught Horse (0.09%), while the Black Forest Draught Horse was mostly related to the South German Coldblood (0.06%). The results reveal the presence of very few common progenitors of the breeds. The gene flow between the breeds is primarily due to crossbreeding of stallions and, especially, in the Rhenish German Draught Horse population breeding with a few mares from other German draught horse breeds.     

Body and claw measurements and pressure distribution under the claws in calves of different cattle breeds

In 58 female calves of the three breeds German Holstein (GH), German Brown (GB) and German Red (GR) the body weight and height were determined at the age of 79 to 188 days. At the right front limb and the left hind limb the following claw measurements were taken: dorsal border length, diagonal length, heel length and height, angle of the dorsal border and hardness of the claw horn. Furthermore, the punctual pressure under the medial and the lateral claw of the right front limb and the left hind limb were determined using an electronic measuring system. The GH calves weighing 136.8 kg were heavier than GB, which was the tallest breed with 106.2 cm height at the sacral bone. GR calves were the smallest (99.1 cm) and weighed 121.1 kg. The length of the diagonal and the angle of the dorsal border were smaller at the hind limb of all breeds which resulted in a smaller area of ground surface for the claw of this limb. The GR calves had the longest and flattest claws. The GB showed the highest pressures per cm2 at the front limb with 25.6 N/cm2 under both claws as well as at the hind limb with 26.7 N/cm2. The AR had the smallest pressure load with 20.8 N/cm2 at the front limb and 20.2 N/cm2 at the hind limb. The animals showed a larger relative weight load and area of ground surface on the medial claws of the front and hind limbs than on the lateral claws. The highest pressures were found underneath the rear part of the medial claw in all breeds. GB calves showed the highest average pressures (33.3 N/cm2 at the front limb) while GR calves had the lowest (26.3 N/cm2 at the hind limb). GR calves had the highest claw hardness at all measuring positions.     

Genotype effects of milk protein polymorphisms on milk production in East Friesian dairy sheep

The frequencies of milk protein variants alphas1-casein, alphas2-casein, beta-casein and beta-lactoglobulin were determined in 182 milk sheep from 7 flocks in Lower Saxony and Saxony. The genotype effects of these polymorphic milk protein variants on milk performance traits were estimated for 173 ewes using a test day model with fixed regression.The model included the fixed effects of colour variant of the breed, region, lambing season, lambing year, lactation number and number of lambs born. The herd and animal effect were treated as random and the days in milk as linear and non-linear covariates. The milk protein variants of alphas1-casein and beta-casein showed a significant relationship to protein content and the variants of beta-casein to milk fat content. Milk fat yield was significantly associated with the milk protein variants of alphas2-casein, whereas the other milk performance traits were not significantly correlated.     

Genetic-statistical analysis of environmental and genetic influences on the outcome of the juvenile and breeding performance tests for behaviour traits in Hovawart dogs

The objective of the present study was to evaluate the importance of genetic and environmental sources of variation for results of behaviour tests recorded at juvenile and breeding performance tests in the Hovawart dog. For these analyses behaviour test results of 1882 (juvenile evaluation), respectively 929 dogs (breeding performance test) born in 1995 to 2000 had been used. Variance component estimation was performed for the traits appearance, play instinct, hunting affinity, group of people, shoot, acoustical and optical influences and temperament using multivariate linear animal models and Residual Maximum Likelihood (REML). The models included test-year-season, sex, litter size, age and inbreeding coefficient of the animal as fixed effects. Additive genetic effects of the animal, permanent environmental effect of the litter and the effect of the kennel were considered as random factors.The sex of the dog was significant for appearance, play instinct, hunting affinity, acoustical and optical influences of juvenile evaluation and for the traits temperament, play instinct, hunting affinity, acoustical and one of the optical influences of breeding performance test.The age of the dog at test significantly influenced the traits play instinct, hunting affinity and acoustical influences of juvenile evaluation and optical influences and hunting affinity of breeding performance test. All traits with exception of hunting affinity and group of people were significantly affected by the test-year-season. The inbreeding coefficient was significant for appearance of juvenile evaluation and play affinity of breeding performance test. The effect litter size did not influence any of the traits significantly.The estimated heritabilities for the behaviour traits of juvenile and breeding performance test ranged from h2 = 0.01 to h2 = 0.13, respectively h2 = 0.01 to h2 = 0.14, with standard errors of up to 0.03. The additive genetic correlations between most of the traits were moderately to highly positive (r(g) = 0.20 to r(g) = 1.0, respectively r(g) = 0.29 to r(g) = 1.0). Negative additive genetic correlations were only found for a few traits of juvenile (r(g) = -0.02 to r(g) = -0.58) and breeding performance test (r(g) = -0.28 to r(g) = -0.83). Progress in breeding for the behaviour traits investigated here may only be meaningful when information from all relatives is used in an animal model instead of selection based on the phenotype of the single animal.     

A molecular toolkit for population genetic investigations of the ash dieback pathogen Hymenoscyphus pseudoalbidus

The recently described ascomycete fungus Hymenoscyphus pseudoalbidus (anamorph: Chalara fraxinea) causes the current dieback of ash (Fraxinus excelsior) in large parts of Europe. The origin of this species and its relation to the native cryptic species Hymenoscyphus albidus are still enigmatic. The spatiotemporal pattern of the epidemic is typical for an introduced invasive species. However, the presence of two cryptic species indicates that hybridization or mutation might have been involved in driving speciation in this case. In this study, we present a set of 18 polymorphic microsatellite markers to study these processes in more detail on a population genetic level. Markers were designed such that they can be amplified in three individual multiplex PCRs and analysed in two fragment analysis runs. We thoroughly tested the marker set for pairwise linkage among loci, selective neutrality and Mendelian inheritance. Additionally, the markers were applied on two large collections of isolates derived from study sites in Germany. Population genetic calculations suggested a low yet significant level of differentiation, a large genotypic diversity and a limited genetic diversity within populations. Furthermore, we present additional data concerning the phylogenetic relation between H. albidus and H. pseudoalbidus, which seems to be more distantly related to each other than expected previously.     

On the longevity of Hymenoscyphus pseudoalbidus in petioles of Fraxinus excelsior

Air‐dried pseudosclerotia produced by the ash dieback pathogen Hymenoscyphus pseudoalbidus (anamorph: Chalara fraxinea) can survive up to 3 months. Under field conditions, they are capable of postponing fructification for 1 year. The implications of this observation for epidemiology and control of ash dieback are discussed.