The base saturation in acidified Swiss forest soils on calcareous and noncalcareous parent material. A pH–base saturation anomaly

Long‐term soil acidification leads to lower pH values and to a concomitant decrease in base saturation (BS). The relationship between pH and base saturation (BS) in acidified forest soils can be disturbed by processes such as nutrient cycling by vegetation, temporary saturation by ground water that comes into contact with calcareous material, or by upward diffusion of base cations from deeper horizons. This paper examines the relationship between pH and BS in Swiss forest soils developed from calcareous and noncalcareous parent material and identifies some of the factors that can affect the BS in the decalcified parts of soils derived from calcareous parent material. The decalcified zone in the latter soils has a higher BS on average compared to soils from noncalcareous parent material, but their pH values are identical. In the pH range 4.0–4.5, the difference in BS may vary by a factor of three. The mean BS in the decalcified zone tends to decrease with increasing depth of the calcareous layer. The water regime also affects the BS in soils on calcareous parent material. In soils temporarily saturated by groundwater (gleysols), the BS in the decalcified zone is always high (85%–100%) because of the continuous contact between the soil water and the calcareous parent material. In addition, the inhibited drainage impedes the depletion of base cations in these soils. In contrast, soils that are temporarily saturated by rainwater are depleted in base cations due to the alternating wetting‐and‐drying regime and the associated leaching of dissolved ions. In such soils, the depletion of base cations is strongly related to the extent of hydromorphy. Stagnogleyic soils, with the longest period of water saturation, have the highest depletion levels. We conclude that in such soils, the diffusion of base cations from deeper zones is strongly compensated by leaching from the very acidic soil horizons. The pH–base saturation anomaly has consequences for some of the methods used to calculate the critical loads of acidity for forest soils in Switzerland, with many soils being less sensitive than previously reported.     

Pharmacokinetics of buprenorphine following intravenous administration in dogs

OBJECTIVE: To determine pharmacokinetics of buprenorphine in dogs after i.v. administration. ANIMALS: 6 healthy adult dogs. PROCEDURES: 6 dogs received buprenorphine at 0.015 mg/kg, i.v. Blood samples were collected at time 0 prior to drug administration and at 2, 5, 10, 15, 20, 30, 40, 60, 90, 120, 180, 240, 360, 540, 720, 1,080, and 1,440 minutes after drug administration. Serum buprenorphine concentrations were determined by use of double-antibody radioimmunoassay. Data were subjected to noncompartmental analysis with area under the time-concentration curve to infinity (AUC) and area under the first moment curve calculated to infinity by use of a log-linear trapezoidal model. Other kinetic variables included terminal rate constant (k(el)) and elimination half-life (t(1/2)), plasma clearance (Cl), volume of distribution at steady state (Vd(ss)), and mean residence time (MRT). Time to maximal concentration (T(max)) and maximal serum concentration (C(max)) were measured. RESULTS: Median (range) values for T(max) and MRT were 2 minutes (2 to 5 minutes) and 264 minutes (199 to 600 minutes), respectively. Harmonic mean and pseudo SD for t(1/2) were 270+/-130 minutes; mean +/- SD values for remaining pharmacokinetic variables were as follows: C(max), 14+/-2.6 ng/mL; AUC, 3,082+/-1,047 ng x min/mL; Vd(ss), 1.59+/-0.285 L/kg; Cl, 5.4+/-1.9 mL/min/kg; and, k(el), 0.0026+/-0.0,012. CONCLUSIONS AND CLINICAL RELEVANCE: Pharmacokinetic variables of buprenorphine reported here differed from those previously reported for dogs. Wide variations in individual t(1/2) values suggested that dosing intervals be based on assessment of pain status rather than prescribed dosing intervals.     

Aspects of fusion combining ability of dihaploidSolanum tuberosum L.: influence of the cytoplasm

Summary Creation from 4x hybrid clones from protoplast fusion of 2x clones of potato was evaluated. Besides combined nuclear genomes, composition of the cytoplasm significantly influenced the phenotypic traits of hybrid clones. To ascertain the influence of parental cytoplasm on the success of protoplast fusion and regeneration of hybrid plants, data from 74 fusion combinations of 50 dihaploid clones were analyzed. The majority of dihaploid breeding clones belonged to the cytoplasm types Wα, Tβ and Wγ. When the closely related mt types α, β and γ were used, fusion combinations had a better combining ability compared with more distantly related cytoplasms δ and ⃛. Fusions containing the same mitochondrial type (homofusions) were not superior to closely related mitochondrial types. However, homofusions of cytoplasm type Wα yielded significantly more hybrids than homofusions of type Tβ. In general, parental cytoplasm types had little impact on the fusion combining behaviour. Thus the cytoplasm type of the fusion parents is not a suitable marker for predicting the combining ability in protoplast fusion experiments.     

Validation of two models for self‐incompatibility in autotetraploid perennial ryegrass using high resolution melting‐based markers

Perennial ryegrass (Lolium perenne L.) displays a two‐locus gametophytic self‐incompatibility (SI) system that remains intact at the tetraploid level. Two models are plausible for SI in autotetraploids. In Model I: both alleles at the S locus and both at the Z locus in diploid pollen matching the female genotype results in incompatibility. In Model II: only one allele at S and one at Z locus in diploid pollen matching the female results in incompatibility. The goals were to determine which of the models best explains SI in our autotetraploid ryegrass population and to evaluate the efficiency of high‐resolution melting (HRM) genotyping for discriminating different iso‐allelic genotypes. The progeny of a cross between two autotetraploids was characterized with three HRM‐based markers co‐segregating with Z. Segregation ratios were used to make inferences about the mode of action of the SI system. The observed segregation differed significantly (P < 0.001) from the expected under Model I, but not from the expected under Model II (P = 0.463). Thus, Model II explains SI in this population, and HRM is an efficient tool to distinguish different iso‐allelic genotypic classes.     

Ixodid ticks parasitizing Iberian red deer (Cervus elaphus hispanicus) and European wild boar (Sus scrofa) from Spain: geographical and temporal distribution

Commercial hunting of Spanish wild ungulates has made them an important economic resource. Wild ungulates may have an important role in the maintenance of ixodid tick populations, and also as reservoirs of pathogens. We studied the ixodid ticks that parasitize Iberian red deer and European wild boar from Spain. Ixodid ticks (n=6,336) were collected from 431 Iberian red deer and 142 wild boar in different regions of Spain. We found 10 different ixodid tick species parasitizing Iberian red deer, mainly Hyalomma marginatum marginatum (63.7%), Rhipicephalus (Boophilus) annulatus (7.9%) and R. bursa (7.5%). R. (Boophilus) annulatus was only collected in the province of Cádiz (southern Spain). We found 8 ixodid tick species on the wild boar, mainly Hy. m. marginatum (68.7%), R. bursa (14.6%) and Dermacentor marginatus (9.3%). We found one adult Hy. marginatum rufipes and one adult Hy. anatolicum excavatum parasitizing wild boar from south-central Spain. Mean prevalence of ixodid ticks was 41.3+/-0.08% (n=475) and 31+/-0.09% (n=284) and intensity of parasitization was 13.9+/-0.2 (n=283) and 13.6+/-0.3 (n=130) ticks/animal for Iberian red deer and wild boar, respectively. Only 5 of the 13 ixodid tick species found were shared by Iberian red deer and wild boar. This finding could indicate a host preference when Iberian red deer and wild boar share common habitats. In both Iberian red deer and wild boar from south-central Spain the monthly relative frequencies of Hy. m. marginatum and R. bursa presented an inverse pattern. The highest Hy. m. marginatum relative frequencies coincided with the lowest R. bursa relative frequencies along the year. R. bursa and I. ricinus were present in areas from northern to southern Spain while Hyalomma sp. and D. marginatus were exclusively collected in the two southern thirds of Spain. Haemaphysalis sp. and D. reticulatus were collected in northern Spain. Hy. m. marginatum and R. bursa were present during the whole year in red deer and wild boar from south-central Spain, showing more than one life cycle per year. These results are important for understanding the role of wild ungulates in the maintenance of tick infestations and to improve tick control programmes.     

Morphological characters, yields and active principles in wild and cultivated accessions of the Chilean medicinal plant Buddleja globosa Hope

Buddleja globosa is a medicinal shrub native to Chile. Its leaves have been traditionally used for wound and ulcer healing. Different medicinal properties, such as outstanding antioxidant, anti-inflammatory, wound healing and analgesic activities have been shown. Today, all raw materials for pharmaceutical process are coming from wild collection or recently established crops but not from selected plants. Studies of the genetic or environmental variability of the species would permit the optimization of yield and quality factors through the selection of genetic material or suitable production sites and management techniques.To assess which traits are determined genetically some yield related plant and leaf characteristics were studied in three wild populations and the cultivated accessions from the same provenances. The cultivated accessions also included three clones coming from individuals found in rural home gardens. For the cultivation studies individuals were arranged in a randomised block design, and those for the irrigation studies in split plots watered at 20% and 65% field capacity.Plant characteristics such as height and width of the plant, the ratio of both, stem diameter and leaf density differed significantly among natural populations. In leaf characteristics only the presence of stipules showed significant differences. The cultivated progenies or clones may give an idea if these differences among populations are due to environmental or to genetic effects. Compared with other provenances, plants from the coastal provenance Los Ruiles are tallest in both natural populations and cultivated clones and also showed superior leaf yields in spite of their lower leaf density.The hairy leaves may cause allergic reactions at the moment of harvest. This characteristic is not influenced by different irrigation treatments and shows no significant differences between cultivated and wild plants.Because of the significant higher leaf yields per plant in home garden clones we assume that formerly individuals with a higher leaf production were selected for cultivation.