Parameters for specific detection ofClavibacter michiganensis subsp.sepedonicus in potato stems and tubers by multiplexed PCR-ELISA

A multiplex PCR-ELISA protocol for detection ofClavibacter michiganensis subsp.sepedonicus (Cms) was developed that is based on primers for amplification of three single-copy, unique DNA sequences, Cms50, Cms72, and Cms85. The three sequences were simultaneously amplified from the genomes of all 42 strains of Cms that were tested including variant mucoid forms, but not from strains representing five related subspecies, andRathayibacter rathayi andRhodococcus faciens. The lowest limit of detection by gel electrophoresis was estimated to be approximately 300 CFU per mL when cells were spiked into potato core fluid, but sensitivity increases approximately 10-fold using PCR-ELISA. Inclusion of a sea anemone DNA fragment engineered so it could be amplified from the Cms72 primer set provided the simultaneous signal that the system functioned properly when any sample was free of the pathogen. The addition of hydrolyzed casein to the reaction mix was demonstrated to markedly reduce or eliminate inhibition of PCR by plant cell components or contaminants. Multiplex PCR-ELISA detection of Cms was determined to be verifiable for analysis of both stems and tubers based on the amplification of multiple sites in its genome, it provides absolute specificity, and it was more sensitive than detection based on gel electrophoresis of PCR products and serological approaches.     

Predicting yield and processing quality of potato breeding selections

The linear relationship between “site mean” and potato cultivar performance was used to develop predictive models for total yield, yield of US No 1 grade, per cent US No 1 grade, specific gravity and fried chip color. The best fitting linear expression for each of the traits was determined by linear regression for specific cultivars. Common limits for “site means” could then be substituted into the expressions for predictive purposes. Application of this method to large and small data sets demonstrated its use for interpreting preliminary yield trial information for the identification of superior breeding selections.     

Genetic analysis of strain differences in pre-laying behaviour in battery cages

The behaviour of hens of two strains during the 10 min before laying in battery cages was studied. Hens of one strain typically exhibited backward-and-forward pacing before laying. Hens of the other strain did not pace and tended to sit. Individual hens of both strains were consistent in their expression of pacing and sitting before laying. There was genetic variation in the expression of both pacing and sitting before laying, and both traits responded to selection. Crosses between the two lines indicated additive genetic variation in the expression of sitting behaviour and non-additive variation in the expression of pacing behaviour.     

A double-blind placebo-controlled study into the efficacy of a homeopathic remedy for fear of firework noises in the dog (Canis familiaris)

Seventy-five dogs that showed a fear response to fireworks participated in a double-blinded, placebo-controlled clinical trial to assess the efficacy of a homeopathic remedy for the alleviation of their behavioural signs. Dogs were randomly assigned to one of two treatments; the homeopathic treatment or the placebo treatment. At the baseline assessments the owners identified the behavioural signs of fear that their dogs normally displayed in response to fireworks, rated their frequency and intensity, and assessed the global severity of their dog's responses. These measures were repeated at the final assessment and owners also completed weekly diaries for the length of the trial. There were significant improvements in the owners' rating of 14/15 behavioural signs of fear in the placebo treatment group and all 15 behavioural signs in the homeopathic treatment group. Both treatment groups also showed significant improvement in the owners' rating of the global severity of their dog's responses. However, there was no significant difference in the response seen between the two treatment groups.