Porcine circovirus-2 DNA concentration distinguishes wasting from nonwasting pigs and is correlated with lesion distribution, severity, and nucleocapsid staining intensity.

The emergence of severe porcine circoviral disease in North America is associated with Porcine circovirus-2 genotype b (PCV-2b), which has led to speculation that PCV-2b is more virulent than PCV-2a. The objectives of this study were to 1) correlate the PCV-2 DNA concentration and lesions in wasting (WST) and age-matched healthy (HLTH) pigs from 2 clinically affected farms, and unaffected (UNFCT) pigs from a farm with no prior clinical or diagnostic history of PCVD; and 2) to determine the initial estimates of sensitivity and specificity of PCV-2 quantitative polymerase chain reaction (qPCR). PCV-2b was confirmed in all 3 farms. Compared with HLTH pigs, WST pigs demonstrated significantly more prevalent thymic atrophy, failure of normal pulmonary collapse, and ascites (P < 0.017 for all). The HLTH and UNFCT pigs had significantly more pronounced lymphoid germinal centers and proliferative paracortical T-dependent zones, compared with WST pigs (P < 0.017). Across all tissues, PCV-2 DNA concentrations were significantly higher in WST compared with HLTH and UNFCT pigs (P < 0.017 for all). The PCV-2 DNA concentrations were strongly correlated with PCV-2 nucleocapsid staining intensity in lymph node, spleen, Peyer's patches, lung, liver, and kidney (0.60 < or = r < or = 0.84). In the current study, the PCV-2 DNA log10 cutoff concentrations best able to distinguish WST from HLTH and UNFCT pigs were between 7.0 and 8.0 per gram for tissues, and between 4.0 and 5.0 per milliliter for sera. The presence of PCV-2b in UNFCT pigs is evidence that PCV-2b by itself is not sufficient to induce severe disease.     

Foliar sprays against potato common scab: compounds related to 3,5-dichlorophenoxyacetic acid

In glasshouse tests against the soil-borne disease potato common scab (Streptomyces scabies), foliar sprays (0 · 9 mm) of several compounds inhibited symptom development as effectively as 3,5-D (3,5-dichlorophenoxyacetic acid). These compounds were of two main types: (1) compounds very similar in structure to 3,5-D, viz. 3,5-disubstituted phenoxyacetic acids in which the substituents were dibromo-, di(trifluoromethyl)- or any combination of bromo-, chloro- and iodo- except diiodo-; (2) compounds which could be metabolized to 3,5-D within the plant, viz. 4-(3,5-dichlorophenoxy)butanoic acid, 3,5-dichlorophenoxy-acetamide, 3,5-dichlorophenoxy-N,N-diethylacetamide and 2-(3,5-dichlorophenoxy)ethylamine. No compound of either type was significantly more effective than 3,5-D, and those which were as effective shared its effects on tuber yield, number and shape. About 30 other compounds related to 3,5-D were less effective or ineffective.     

A mortality event in wrasse species (Labridae) associated with the presence of viral haemorrhagic septicaemia virus

Viral haemorrhagic septicaemia (VHS) is an infectious disease of farmed and wild fish and has an extensive host range in both freshwater and marine environments. In December 2012, a wrasse population consisting of ballan, Labrus bergylta (Ascanius), corkwing, Symphodus melops (L.), cuckoo, Labrus mixtus L., goldsinny, Ctenolabrus rupestris (L.), and rock cook, Centrolabrus exoletus (L.), held at a marine hatchery in the Shetland Isles, Scotland, experienced a mortality event. Approximately 10 000 wrasse were being held at the facility on behalf of an Atlantic salmon, Salmo salar L., aquaculture company prior to being deployed for the biological control of parasites on marine pen Atlantic salmon, aquaculture sites. Fish Health Inspectors from Marine Scotland Science initiated a diagnostic investigation, and subsequent diagnostic testing confirmed the site to be VHSV positive by qRT-PCR and virus isolation followed by ELISA. A VHSV genotype-specific qRT-PCR assay revealed that the isolates belonged to genotype III, the European marine strain of the virus. The virus genotype was further confirmed by nucleic acid sequencing of the partial nucleoprotein (N) and glycoprotein (G) genes followed by BLAST nucleotide searches. This study reports for the first time the detection of VHSV within multiple wrasse species and highlights the need for a comprehensive risk-based approach to the use of wrasse and other finfish species as biological controls within the aquaculture industry.     

Allelism of two genes for stem rust resistance in triticale

Summary Inheritance studies involving Coorong and Satu triticales showed that each possessed a single dominant gene for resistance. The genes were allelic or closely linked. The relative frequencies of Sr27 (Coorong gene) and Sr _Satuin a sequence of International Triticale Screening Nurseries were similar. However, a significant increase in the frequency of entries with Sr_Satu occurred in the 17 International Triticale Screening Nursery (ITSN).