Mute swan grazing on winter crops: estimation of yield loss in oilseed rape and wheat

Yield loss due to grazing by mute swans was measured on two fields each of autumn-sown oilseed rape and winter wheat, located in three regions of the UK. Using a paired plot design, a 33.7% reduction in yield (total dry weight of seed) and a 12.1% reduction in the thousand-seed weight was measured in the rape field subjected to the highest grazing intensity. No significant yield loss was measured in the other three fields. Yield loss was related to: (i) the timing of the onset of grazing, and (ii) the duration of grazing (both estimated from counts of mute swan droppings). Management measures which delay the onset of grazing and/or reduce the duration of grazing are therefore likely to reduce yield loss.     

Cross-species identification of Mendel's I locus

A key gene involved in plant senescence, mutations of which partially disable chlorophyll catabolism and confer stay-green leaf and cotyledon phenotypes, has been identified in Pisum sativum, Arabidopsis thaliana, and Festuca pratensis by using classical and molecular genetics and comparative genomics. A stay-green locus in F. pratensis is syntenically equivalent to a similar stay-green locus on rice chromosome 9. Functional testing in Arabidopsis of a homolog of the rice candidate gene revealed (i) senescence-associated gene expression and (ii) a stay-green phenotype after RNA interference silencing. Genetic mapping in pea demonstrated cosegregation with the yellow/green cotyledon polymorphism (I/i) first reported by Gregor Mendel in 1866.     

Dry-matter production and botanical composition of multispecies and perennial ryegrass swards under varying defoliation management

Multispecies swards, comprised of different plant functional groups have comparable production potential to high N input L. perenne swards at reduced N when legumes are included. However, information on the appropriate management of multispecies swards is limited. The effect of differing management practices on the herbage dry-matter (DM) production and botanical composition of different sward types was investigated using a 3 × 2 × 2 factorial design plot experiment. The experiment consisted of three sward types: L. perenne-only receiving (LP; 250 kg N ha⁻¹ a⁻¹); L. perenne-Trifolium repens (LP-TR); multispecies sward containing L. perenne, Phleum pratense, Trifolium repens, Trifolium pratense, Plantago lanceolata and Cichorium intybus (MSS). LP-TR and MSS received 90 kg N ha⁻¹ a⁻¹. Harvesting of plot herbage took place every 21 or 28 days to a defoliation height of 4 or 6 cm, over two growing seasons (March to November 2020 and 2021 inclusive). Annual herbage produced by both LP and LP-TR was not significantly affected by defoliation frequency. However, MSS produced 1923 kg DM ha⁻¹ a⁻¹ more herbage when harvested less frequently. Unsown species contributed significantly less to the herbage DM of MSS compared to LP and LP-TR and remained similar in 2020 and 2021, whereas the contribution of unsown species to herbage DM increased in LP and LP-TR from 2020 to 2021, with noxious species more associated with LP and LP-TR than MSS. Results demonstrate the role of multispecies swards in improving the sustainability of grass-based agricultural systems in an environment of reduced fertilizer inputs.     

Long-term use of cyclosporine in the treatment of canine atopic dermatitis

This retrospective study of 51 dogs with atopic dermatitis (AD) treated with cyclosporine (CsA) for a minimum of 6 months assessed the frequency of dosing and the need for continual treatment to control clinical signs. The study evaluated both medical records and information supplied by the owners in the form of written questionnaires and telephone follow-up. Laboratory parameters, possible adverse effects and owner satisfaction were assessed. The dose of CsA was 5 mg/kg orally per day and dogs received CsA for 6-30 months. At the conclusion of the study period, 28 dogs (55%) needed ongoing CsA to control clinical signs of AD: 8 (15%) received CsA 2-3 days per week, 10 (20%) 4-5 days per week, and 10 (20%) daily. CsA was discontinued in 23 dogs (45%) after 6-24 months due to either a limited response (22%) or after achieving a clinical response (24%). The results suggest that some dogs with AD treated with CsA may not require daily or even ongoing treatment to control clinical signs. Laboratory abnormalities were detected in 13 dogs (25%) during their CsA treatment. Two dogs developed oral growths and three developed hirsuitism. Forty owners (78%) reported no adverse events in their dogs during the treatment period. Thirty-six owners (71%) were satisfied with CsA as treatment for their atopic dog.     

澳大利亚"恐龙植物"出击全球市场

4月1日,澳大利亚开始对“恐龙植物”——瓦勒迈杉(WollemiPine)进行解禁,开放销售,很快,其他国家陆续开始引进瓦勒迈杉。瓦勒迈杉属南洋杉科,是世界最古老的物种之一,与恐龙同时出现在侏罗纪时代,距今已有将近两亿年。以前考古学家曾多次找到过该树种的化石。不过,长期以来人们     

Assessing general combining ability for gangrene resistance by means of a glasshouse seedling test

Summary A seedling progeny test for resistance to gangrene (Phoma foveata) was used to evaluate progenies from a 15×15 half diallel set of crosses, including 14 selfs and 25 reciprocal crosses, which was originally made to investigate the inheritance of resistance to late blight and cyst nematodes. Nine out of the 14 selfs were more susceptible than the crosses involving their parents, so that overall the selfs were slightly more susceptible than the crosses, thus providing evidence of non-additive gene action in favour of resistance. However, when the selfs were omitted from the analysis, all of the variation between progenies could be attributed to differences in the General Combining Abilities (GCAs) of their parents. The four parents with the best GCAs for gangrene resistance all had sizeable contributions fromSolanum tuberosum subsp.andigena in their pedigrees.     

Ciclosporin A therapy is associated with disturbances in glucose metabolism in dogs with atopic dermatitis

The effect of ciclosporin A (CsA) on glucose homeostasis was investigated in 16 dogs with atopic dermatitis by determining plasma glucose, serum fructosamine and insulin concentrations, and serial insulin and glucose concentrations following a glucagon stimulation test, before and 6 weeks after CsA therapy at 5 mg/kg once daily. All dogs completed the study. Following CsA treatment, the median serum fructosamine concentrations were significantly higher (pretreatment 227.5 μmol/L; post-treatment 246.5 μmol/L; P = 0.001; reference range 162-310 μmol/L). Based on analyses of the areas under concentration-time curves (AUC) pre- and post-CsA treatment, plasma glucose concentrations were significantly higher (AUC without baseline correction 31.0 mmol/L/min greater; P = 0.021) and serum insulin concentrations were significantly lower (AUC without baseline correction 217.1 μIU/mL/min lower; P = 0.044) following CsA treatment. Peak glucose concentrations after glucagon stimulation test were significantly higher following CsA treatment (10.75 versus 12.05 mmol/L; P = 0.021), but there was no significant difference in peak serum insulin (52.0 versus 35.0 μIU/mL; P = 0.052). There was a negative correlation between baseline uncorrected insulin AUC and trough serum log CsA concentrations (r = -0.70, P = 0.005). The administration of CsA to dogs with atopic dermatitis leads to disturbances in glucose homeostasis. The clinical significance of this is unclear, but it should be taken into account when considering CsA treatment in dogs that already have such impairments.