Profile of Penicillium species in the pear supply chain

Postharvest fruit decay caused by Penicillium pathogens is considered to be one of the most important challenges in the pear industry resulting in market‐end losses. Moving export fruit through different environments exposes the product to extensive handling, temperature variations and microbes. Therefore, the profile of Penicillium spp. present in the pear export chain from South Africa (SA) to the UK was studied over a four‐year period. Sampling was done at two packhouse facilities, controlled atmosphere and cold storage areas in SA and at two repack facilities and cold storages as well as a distribution centre and a retailer in the UK. Sampling consisted of swabbing walls and floors and using active and passive air sampling. In total, 5056 isolates were obtained, purified and grouped into 282 morphological groups. Of these, 350 representative isolates were selected for further identification. The five most dominant species in the pear chain were: P. glabrum (23·40%), P. chrysogenum (15·13%), P. crustosum (14·16%), P. brevicompactum (8·96%) and P. expansum (8·39%), of which the latter three were confirmed pathogenic on pears. This study provides a framework to monitor the inoculum potential in environments that fruit move through while being exported.     

ENABLING CROP DIVERSIFICATION TO SUPPORT TRANSITIONS TOWARD MORE SUSTAINABLE EUROPEAN AGRIFOOD SYSTEMS

• Crop diversification is a dynamic pathway towards sustainable agrifood systems.• Technological and institutional barriers restrict uptake of crop diversification.• More coordination and cooperation among agrifood system stakeholders is required.• The European Crop Diversification Cluster calls for multiactor networks.European cropping systems are often characterized by short rotations or even monocropping, leading to environmental issues such as soil degradation, water eutrophication, and air pollution including greenhouse gas emissions, that contribute to climate change and biodiversity loss. The use of diversification practices (i.e., intercropping, multiple cropping including cover cropping and rotation extension), may help enhance agrobiodiversity and deliver ecosystem services while developing new value chains. Despite its benefits, crop diversification is hindered by various technical, organizational, and institutional barriers along value chains (input industries, farms, trading and processing industries, retailers, and consumers) and within sociotechnical systems (policy, research, education, regulation and advisory). Six EU-funded research projects have joined forces to boost crop diversification by creating the European Crop Diversification Cluster (CDC). This Cluster aggregates research, innovation, commercial and citizen-focused partnerships to identify and remove barriers across the agrifood system and thus enables the uptake of diversification measures by all European value-chain stakeholders. The CDC will produce a typology of barriers, develop tools to accompany actors in their transition, harmonize the use of multicriteria assessment indicators, prepare policy recommendations and pave the way for a long-term network on crop diversification.     

<Emphasis Type="Italic">Pectobacterium carotovorum</Emphasis> subsp. <Emphasis Type="Italic">brasiliensis</Emphasis> causing blackleg on potatoes in South Africa

In South Africa during the 2006/2007 potato growing season, outbreaks of blackleg occurred, causing severe economic losses in commercial potato production fields. Symptoms were initially observed on only one stem per plant, on which the top leaves rolled upwards, wilted and became necrotic. As symptoms progressed to the lower leaves with subsequent leaf desiccation, a light to dark brown discolouration of the vascular system at the stem base developed, followed by external darkening. Under prevailing wet and humid conditions stems became slimy and pale. In the stems, the pith became necrotic and hollow. These symptoms were similar to those described in Brazil, where the causal agent was identified as a new subspecies, Pectobacterium carotovorum subsp. brasiliensis (Pbcb). Isolations from plants showing typical blackleg symptoms were made on CVP medium. Sequences and phylogenetic analysis of the partial 16S–23S rDNA intergenic spacer region indicated that the isolates were Pbcb. Comparison of PCR-RFLP patterns of the 16S–23S rDNA of isolates to reference cultures confirmed the identity of the South African blackleg strains as Pbcb, identical to strain 8 isolated in Brazil. This is the first report of Pbcb in South Africa and it appears to be the most important causal agent of blackleg in South Africa. The disease poses a major potential threat to the South African potato industry especially in terms of seed exports, tuber quality and yield.     

Prokaryotic diversity--magnitude,dynamics, and controlling factors

There are probably millions of species in the microorganismal domains Bacteria and Archaea (the prokaryotes), and we are only just beginning to work out the basic principles governing their distribution and abundance in natural environments. One characteristic that has become clear is that prokaryote diversity in aquatic environments is orders of magnitude less than in sediments and soils. Hypotheses and models explaining such differences are under development and are beginning to offer promising insights into the mechanisms governing prokaryote diversity and ecosystem function.     

属间体细胞杂交创建甘蓝型油菜细胞质雄性不育系及其鉴定

 利用原生质体融合技,获得了甘蓝型油菜品种中双4号与新疆野生油菜野油18的对称性体细胞杂种。杂种当代建成的6株植株中有2株雄性不育株。用中双4号做轮回亲本与不育株回交,不育株率随回交代数增加而升高,至BC3代大部分株系的不育株率接近100%,到BC4代不育性稳定,群体中无育性分离现象。用波里马CMS的恢复系和保持系与其测交,6个甘蓝型油菜品系均可保持该不育系的不育性,表明该雄性不育胞质与Pol不育胞质不同。     

Occurrence of Anoplocephala perfoliata infection in horses in Ontario, Canada and associations with colic and management practices

Infection with the tapeworm Anoplocephala perfoliata has been found to be associated with equine colic in horses in the United Kingdom. Using a matched case-control study design, data collected from 117 pairs of horses in Ontario were examined for evidence of associations between risk of colic and A. perfoliata infection, and between seropositivity to infection and management practices. Cases were horses in southern Ontario diagnosed with colic by local veterinarians, and control horses were from the same stables as cases and were matched by age, breed and gender where possible. Infection status was defined on the basis of positive results upon coprological examination, and/or seropositivity to a 12/13 kDa A. perfoliata secretory protein. Fifty-six percent of the 234 horses were seropositive for A. perfoliata, but eggs were found in samples from only 6% of horses. Horses dependent on pasture for a large part of their diet were significantly more likely to have ELISA optical density levels above 0.600 compared to other horses (odds ratio [OR]=6.38; p=0.029). This finding identified exposure to pasture as an important source of A. perfoliata infection in the horses used in the study. In a subset of 46 pairs of horses for which control horses had no known history of colic, a statistically significant negative association was found between the risk of colic and optical density (OD) levels >0.200-0.600, relative to OD levels < or = 0.090 (OR=0.08; p=0.017). There was no other statistical evidence of an association between the risk of colic and A. perfoliata infection.     

Prolonged activated prothromboplastin time and breed specific variation in haemostatic analytes in healthy adult Bernese Mountain dogs

Coagulation tests are often performed in dogs suspected of haemostatic dysfunction and are interpreted according to validated laboratory reference intervals (RIs). Breed specific RIs for haematological and biochemical analytes have previously been identified in Bernese Mountain dogs, but it remains to be determined if breed specific RIs are necessary for haemostasis tests. Activated prothromboplastin time (aPTT), prothrombin time (PT), selected coagulation factors, D-dimers, fibrinogen, von Willebrand factor and thromboelastography (TEG) were analyzed in healthy Bernese Mountain dogs using the CLSI model. Three analytes (aPTT, TEG [MA] and TEG [G]) were different according to the CLSI model. For aPTT the new RI was markedly different (0-100s). Whereas the new intervals for TEG (MA) and TEG (G) may be due to breed related biological variation, the cause of the prolonged RI for aPTT is at present uncertain.