Measurement of color in potatoes

Reproducible, objective methods which conformed closely to visual appraisal were developed for measuring color differences in either cooked or raw potatoes. Experimental samples, selected from lots stored at various temperatures for different periods of time, differed in extent of graying and yellowing. Ricing was found to be preferable to mashing as a method of cooked sample preparation. A comparison of methods of sample presentation using the Gardner Color Difference Meter showed thin-layer measurement was most successful in separating cooked samples differing in amount of yellow pigment; deep-layer measurement was most successful in separating grayed samples. A simple method for measurement of color differences in raw tubers successfully separated the samples. All three methods of sample presentation were significantly correlated with visual ranking.     

Resistance of Corynespora cassiicola from soybean to QoI and MBC fungicides in Brazil

Fungicide sprays on soybean in Brazil have contributed to the selection of less sensitive isolates of Corynespora cassiicola. We collected 59 isolates of C. cassiicola from three Brazilian states and two isolates from Paraguay. We investigated their EC₅₀ to quinone outside inhibitors (QoI) and methyl benzimidazole carbamate (MBC), any cross-resistance to compounds within QoI and MBC groups, and characterized the polymorphisms in their cytb and β-tubulin genes. Local associations of polymorphisms identified in each gene were statistically correlated with assays results. In total, 79% and 74% of the isolates were classified as resistant to QoI and MBC fungicides, respectively. There was positive cross-resistance to active ingredients within QoI and MBC groups. For QoI, all isolates presented heteroplasmy in G143A of cytb gene; the mutations F129L and G137R were not found. For MBC, 63% of isolates possessed E198A and 21% possessed F200Y mutations, associated with reduced control by MBC fungicides. Heteroplasmy was identified in two and one isolates from Brazil with E198A and F200Y mutations, respectively. The resistance factor for isolates with E198A (10.9) was statistically similar to the isolate with F200Y (8.8) mutation. Genic association analysis of the in vitro assays using discriminatory doses proved them to be accurate. Reduced sensitivity of C. cassiicola to QoI and MBC was also identified in isolates from Paraguay and resistance to QoI and MBC was widely present in C. cassiicola isolates from the main soybean-producing states in Brazil. Thus, integrated management measures should be adopted to manage soybean target spot in these countries.     

Identifying resistance in wild and ornamental cherry towards bacterial canker caused by Pseudomonas syringae

Bacterial canker is a major disease of stone fruits and is a critical limiting factor to sweet cherry (Prunus avium) production worldwide. One important strategy for disease control is the development of resistant varieties. Partial varietal resistance in sweet cherry is discernible using shoot or whole tree inoculations; however, these quantitative differences in resistance are not evident in detached leaf assays. To identify novel sources of resistance to canker, we used a rapid leaf pathogenicity test to screen a range of wild cherry, ornamental Prunus species and sweet cherry × ornamental cherry hybrids with the canker pathogens, Pseudomonas syringae pvs syringae, morsprunorum races 1 and 2, and avii. Several Prunus accessions exhibited limited symptom development following inoculation with each of the pathogens, and this resistance extended to 16 P. syringae strains pathogenic on sweet cherry and plum. Resistance was associated with reduced bacterial multiplication after inoculation, a phenotype similar to that of commercial sweet cherry towards nonhost strains of P. syringae. Progeny resulting from a cross of a resistant ornamental species Prunus incisa with susceptible sweet cherry (P. avium) exhibited resistance indicating it is an inherited trait. Identification of accessions with resistance to the major bacterial canker pathogens is the first step towards characterizing the underlying genetic mechanisms of resistance and introducing these traits into commercial germplasm.     

Effects of a highly purified fucoidan from Undaria pinnatifida on growth performance and intestine health status of gibel carp Carassius auratus gibelio

A six‐week feeding trial was conducted to determine the effects of different concentrations of fucoidan (1 g/kg, 10 g/kg and 30 g/kg; w/w) from Undaria pinnatifida on gibel carp (Carassius auratus gibelio). Our results demonstrated that 30 g/kg fucoidan significantly increased (p < .05) growth performance, intestinal digestive enzyme activities, acid phosphatase activity and immunoglobulin M content. Histological examinations revealed that gibel carp receiving 30 g/kg fucoidan had significant higher abundance of mucin‐containing goblet cells in middle and distal intestine as compared with control treatment (p < .05). Intestinal microbiota analysis showed that 30 g/kg fucoidan supplementation significantly increased (p < .05) the abundance of Cetobacterium and Aeromonas, but lowered (p < .05) the prevalence of pathogenic bacteria Plesiomonas and a mucin‐degrading bacterium Mucinivorans. Furthermore, RNA‐seq and RT‐qPCR analysis indicated that 30 g/kg fucoidan caused significant changes (p < .05) in the expression of genes involved in immune regulation (such as interleukin‐8 and cyclooxygenase), signal transduction (such as phosphatidylinositol‐4,5‐bisphosphate 3‐kinase and protein kinase B) and nutrition utilization (maltase–glucoamylase and muscarinic acetylcholine receptor 3). Together, the current study shows that fucoidan supplementation could elevate the activity of intestinal digestive enzymes, modulate intestinal microbial communities and potentiate a higher state of immune readiness, which might consequently improve growth performance and intestine health status of gibel carp.     

Quantitative resistance to Cercospora leaf spot disease caused by Pseudocercospora cruenta in cowpea

Six populations (Parent 1, Parent 2, F1, F2, BC1 and BC2) generated from each of four crosses involving four resistant and two susceptible varieties of cowpea (Vigna unguiculata L. Walp) were evaluated for resistance to Cercospora leaf spot (CLS) disease caused by Pseudocercospora cruenta under induced epiphytotic conditions, in four separate field experiments. Climatic conditions determined the onset of CLS disease in the susceptible cultivar and varied in the four experiments from 35 to 48 days after planting (DAP). Genetic analysis revealed that the mode of inheritance of resistance to P. cruenta can be oligogenic or polygenic depending upon the cross. This is the first report of polygenic inheritance of CLS resistance. Number of nodes infected fitted a simple additive dominance model with predominance of additive effects based on generation mean analysis. Oligogenic resistance was observed for the other three crosses, with the most plausible models being: a single gene model with incomplete dominance in CB27 × IT87D-939-1; a single gene model with complete dominance in CB27 × VRB-10; and a triger model in Los Banos Bush Sitao × IT86D-792, based on segregation analysis of symptomatic : non-symptomatic plants. The role of minor genes was also indicated in the above crosses. Suggested approaches to breeding for resistance to CLS are discussed.     

A MUCOSAL DISEASE VIRUS INFECTION OF THE PREGNANT EWE AS A CAUSE OF A BORDER DISEASE-LIKE CONDITION

An experiment was designed to investigate whether a condition in Australian sheep with clinical and pathological similarites to Border Disease was caused by the infection of the pregnant ewe with a Mucosal Disease virus (MDV). Forty ewes, at 58 to 63 days after mating, were inoculated with material from lambs in which all, some or none of the tissues examined contained MDV. The clinical condition was observed only in lambs born to ewes inoculated with MDV-positive material and then only to ewes in the group which had serological evidence of MDV infection. It is concluded that the Border Disease-like condition in Australian sheep is caused by the infection of the pregnant ewe with a Mucosal Disease virus.     

Short-term effects of organo-mineral enriched biochar fertiliser on ginger yield and nutrient cycling

Purpose

Biochar has agronomic potential but currently is too expensive for widespread adoption. New methodologies are emerging to reduce the cost such as enriching biochar with nutrients that match crops and soil requirements. However, the effects of biochar-based fertilisers on plant yield and soil nutrient availability have not been widely examined. This study investigated the effects of a novel organo-mineral biochar fertiliser in comparison to organic and commercial biochar fertiliser on ginger (Zingiber officinale Canton).

Materials and methods

There were four treatments: (1) commercial organic fertiliser (5 t ha^?1), as the control; (2) commercial biochar-based fertiliser (5 t ha^?1); (3) organo-mineral biochar fertiliser at low rate (3 t ha^?1); and (4) organo-mineral biochar fertiliser at high rate (7.5 t ha^?1). A replicated pot trial was established with black dermosol soil and ten replicate pots for each treatment. Ginger was planted and grown for 30 weeks. Plant growth, biomass, foliar nutrients and water extractable soil nutrients including phosphorus (P), potassium (K) and calcium (Ca) were examined.

Results and discussion

High rate organo-mineral biochar fertiliser increased soil P and K availability at week 30 (harvest) after planting, compared to all other treatments and low rate organo-mineral biochar fertiliser performed similarly to the organic control for P and K. High rate organo-mineral biochar fertiliser increased total foliar nutrient content at week 30 in P, K and Ca compared to commercial biochar fertiliser. High rate organo-mineral biochar fertiliser improved the commercial value of ginger (+?36%) due to a shift in the proportion of higher grade rhizomes. Low rate organo-mineral biochar fertiliser plants displayed similar yield, total dry and aboveground biomass to commercial organic fertiliser. Commercial biochar fertiliser had significantly lower biomass measures compared with other treatments as the rate applied had lower nutrient concentrations.

Conclusions

Our results show organo-mineral biochar fertilisers could be substituted for commercial organic fertilisers at low rates to maintain similar yield or applied at high rates to increase commercial value where economically feasible.

     

Determination of angiotensin I-converting enzyme activity in equine blood: lack of agreement between methods of analysis

Angiotensin-I converting enzyme (ACE) is a key regulator of blood pressure, electrolytes and fluid homeostasis through conversion of angiotensin I into angiotensin II. Recently, a genetic polymorphism of the ACE gene, which accounts for 47% of the variation of ACE activity in blood, has been advocated as a biomarker of athletic aptitude. Different methods of analysis and determination of ACE activity in plasma have been used in human and equine research without a consensus of a "gold standard" method. Different methods have often been used interchangeably or cited as being comparable in the existing literature; however, the actual agreement between assays has not been investigated. Therefore, in this study, we evaluated the level of agreement between three different assays using equine plasma obtained from 29 horses. Two spectrophotometric assays using Furylacryloyl-phenylalanyl-glycyl-glycine as substrate and one fluorimetric assay utilizing o-aminobenzoic acid-FRK-(Dnp)P-OH were employed. The results revealed that the measurements from the different assays were not in agreement, indicating that the methods should not be used interchangeably for measurement of equine ACE activity. Rather, a single method of analysis should be adopted to achieve comparable results and critical appraisal of the literature is needed when attempting to compare results obtained from different assays.     

The Schmallenberg virus epidemic in Europe—2011–2013

During the Schmallenberg virus (SBV) epidemic, the European Food Safety Authority (EFSA) collected data on SBV occurrence across Europe in order to provide an assessment of spread and impact. By May 2013, twenty-nine countries were reporting to EFSA and twenty-two countries had reported cases of SBV. The total number of SBV herds reported was 13,846 and the number of SBV laboratory confirmed herds was 8730. The surveillance activities were based on the detection of SBV clinical cases (either adults or newborns). Malformation in newborns was the most commonly reported clinical sign of SBV-infection. All countries were able to provide the date when the first suspicion of SBV in the herd was reported and nineteen could report the location of the herd at a regional level. This allowed the spread of SBV in Europe to be measured both temporally and spatially. The number of SBV confirmed herds started to increase in December 2011 and two peaks were observed in 2012 (February and May). Confirmed herds continued to be reported in 2012 and into 2013. An increase during winter 2012 and spring 2013 was again observed, but the number of confirmed herds was lower than in the previous year. SBV spread rapidly throughout Europe from the initial area of detection. SBV was detected above the latitude of 60° North, which exceeds the northern expansion observed during the bluetongue virus serotype 8 epidemic in 2006–2009. The impact of SBV was calculated as ratio of the number of herds with at least one malformed SBV positive foetus and the total number of herds in this region. The 75th percentile of the malformations ratio in the various affected countries for the whole reporting period was below 1% and 3% for cattle and sheep herds, respectively. International data collection on emerging diseases represents a challenge as the nature of available data, data quality and the proportion of reported cases may vary widely between affected countries. Surveillance activities on emerging animal diseases are often structured only for case detection making the estimation of infection/diseases prevalence and the investigation of risk factors difficult. The impact of the disease must be determined to allow risk managers to take appropriate decisions. Simple within-herd impact indicators suitable for emerging disease outbreaks should be defined that could be measured as part of routine animal health surveillance programmes and allow for rapid and reliable impact assessment of emerging animal health diseases.