Effect of allele combinations at Ppd-1 loci on durum wheat grain filling at contrasting latitudes

Flowering time is the most critical developmental stage in wheat, as it determines environmental conditions during grain filling. Thirty-five spring durum genotypes carrying all known allele variants at Ppd-1 loci were evaluated in fully irrigated field experiments for three years at latitudes of 41°N (Spain), 27°N (northern Mexico) and 19°N (southern Mexico). Relationships between weight of central grains of main spikes (W) and thermal time from flowering to maturity were described by a logistic equation. Differences in flowering time between the allele combination causing the earliest (GS100/Ppd-B1a) and the latest (Ppd-A1b/Ppd-B1a) flowering were 7, 20 and 18 days in Spain, northern Mexico and southern Mexico, respectively. Flowering delay drastically reduced the mean grain filling rate (R) and W at all sites. At autumn-sowing sites, an increase of 1°C in mean temperature during the first half of the grain filling period decreased W by 5.2 mg per grain. At these sites, W was strongly dependent on R. At the spring-sowing site (southern Mexico), W depended on both R and grain filling duration. Our results suggest that incorporating the allele combinations GS100/Ppd-B1a and GS105/Ppd-B1a (alleles conferring photoperiod insensitivity) in newly released varieties can reduce the negative effects of climate change on grain filling at the studied latitudes.     

Association mapping reveals loci associated with multiple traits that affect grain yield and adaptation in soft winter wheat

Genome-wide association studies (GWAS) are useful to facilitate crop improvement via enhanced knowledge of marker-trait associations (MTA). A GWAS for grain yield (GY), yield components, and agronomic traits was conducted using a diverse panel of 239 soft red winter wheat (Triticum aestivum) genotypes evaluated across two growing seasons and eight site-years. Analysis of variance showed significant environment, genotype, and genotype-by-environment effects for GY and yield components. Narrow sense heritability of GY (h ²  = 0.48) was moderate compared to other traits including plant height (h ²  = 0.81) and kernel weight (h ²  = 0.77). There were 112 significant MTA (p < 0.0005) detected for eight measured traits using compressed mixed linear models and 5715 single nucleotide polymorphism markers. MTA for GY and agronomic traits coincided with previously reported QTL for winter and spring wheat. Highly significant MTA for GY showed an overall negative allelic effect for the minor allele, indicating selection against these alleles by breeders. Markers associated with multiple traits observed on chromosomes 1A, 2D, 3B, and 4B with positive minor effects serve as potential targets for marker assisted breeding to select for improvement of GY and related traits. Following marker validation, these multi-trait loci have the potential to be utilized for MAS to improve GY and adaptation of soft red winter wheat.     

Effect of wilting,silage additive,PEG treatment and tannin content on the distribution of N between different fractions after ensiling of three different sainfoin (Onobrychis viciifolia) varieties

Sainfoin (Onobrychis viciifolia) is a tanniniferous, leguminous plant that has potentially beneficial effects on protein utilization in ruminants. As ensiling causes protein breakdown and elevated levels of buffer soluble N (BSN), we studied the distribution of N before and after ensiling sainfoin. Three varieties of sainfoin were either direct‐cut and frozen directly or wilted and frozen before later ensiling in mini‐silos with and without acidification with Promyr (PM; an acidifying commercial mixture of propionic and formic acid) and with or without polyethylene glycol (PEG). Extractable tannins (ET) and protein‐bound tannins (PBT) were measured with an HCl/butanol method in an attempt to correlate tannin levels to N fractions. The sainfoin silages showed good ensiling characteristics and had relatively high concentrations of undegraded protein. The effect of wilting on BSN levels (g/kg N) was dependent on sainfoin variety (P < 0·001). PEG increased and PM decreased the level of BSN in the silages (P < 0·001). PM treatment also produced less non‐protein N and ammonia‐N (P < 0·05) as compared with no additive. Addition of PEG to the silage increased the BSN‐proportion 1·8‐ and 2·6‐fold for both DM stages. A strong tannin‐protein binding effect is, therefore, confirmed in sainfoin. However, correlations between tannin levels (ET and PBT) and BSN were poor in the (non‐PEG) silages, indicating either that the HCl/butanol method is unsuitable for measuring tannin in silages or that qualitative attributes of tannins are more relevant than quantitative. The HCl/butanol method seems therefore not to be useful to predict degradation of protein in sainfoin silages.     

IMAGING DIAGNOSIS—MULTIMODALITY FINDINGS IN AN ADULT DOG WITH PRIMARY SARCOMA OF THE PULMONARY ARTERY AND MYOCARDIAL METASTASES

Intravascular pulmonary artery sarcomas in combination with myocardial metastasis are rare in dogs. We describe the radiographic, echocardiographic, and electrocardiographic‐gated (ECG‐gated) computed tomographic angiography (CTA) findings in a dog with pulmonary artery sarcoma. All imaging studies demonstrated severe main pulmonary artery enlargement. Echocardiography and ECG‐gated CTA revealed a mass occluding the lumen of the right pulmonary artery. In addition, CTA revealed focal left ventricular myocardial contrast enhancement and parenchymal lung changes. Postmortem examination confirmed the presence of a large thrombus associated with arteriosclerosis and an intravascular sarcoma in the right pulmonary artery with metastases to the myocardium, lungs and brain.     

Influence of imported sport horses on the genetic evaluation of Swedish Warmblood stallions

There is substantial international influence on the Swedish Warmblood (SWB) sport horse population. The SWB Association suspects that imported horses are pre-selected based on their anticipated performance level, which could lead to biased estimated breeding values (EBVs) for stallions. This study examined different strategies to handle records for imported horses in the genetic evaluation. The stallions were evaluated for 10 traits using 3 different EBV estimation methods that were compared based on ranking comparisons of stallions, accuracy, correlations and absolute differences between EBVs. The results showed that the stallions’ EBVs were affected by imported offspring which, as a group, had higher average scores than horses born in Sweden. Sire EBVs differed by up to 0.6 genetic standard deviation of the trait between methods for stallions with >50% imported offspring. Excluding imported offspring lowered the accuracies and caused larger re-ranking compared with including a fixed effect of origin in the model.     

Effect of propiconazole on substrate amended soil respiration following laboratory and field application

The effect of the fungicide propiconazole (‘Tilt’^TM 250 EC) on substrate-amended soil respiration has been studied in dose-response experiments, following application of the compound in the field and in the laboratory. The field study was supplemented with spray-deposition measurements showing a throughfall at the soil surface of 15-45%, depending on the time of fungicide application. When propiconazole was amended to the soil in low dosages in laboratory conditions, the soil respiration was stimulated. Even at the very high and agriculturally unrealistic dosages in the laboratory experiment, the mean, daily soil respiration almost recovered within the incubation period of 30 days. Given the present conditions, the results did, however, also show that side-effects of the application of the fungicide were provoked at lower dosages in the field, and that they lasted for a considerably longer time than in the laboratory, indicating the importance of indirect effects of fungicide application in field conditions. Possible reasons for the dose-response relationship in the field being different from the one found in the laboratory are discussed.     

Prevalence of herd specific factors and limb disorders,and their associations in intensive swine production

A longitudinal observational study in 180 pig breeding herds was performed to calculate prevalences of herd specific factors as well as typical limb disorders and to estimate their associations in a 2-step regression analysis. Regarding herd size, genetics, feeding and weight gain herds were distributed almost equal. The population density and the hygiene status were considered proper in most herds. In the farrowing units partially slatted floors of metal or plastic with slats > 9 mm, in the weaning units fully slatted floors of plastic, and in the rearing units fully slatted floors of concrete were most common. Less than 6% of the farms housed their pigs on solid concrete with straw bedding. Herd prevalences of fault floors varied between 18 and 43%. As a herd health problem (morbidity > 25%) claw hematomas and limb abrasions in just 1-week old piglets, overgrown claws and bursa swellings in weaned pigs, and bursa swellings in rearing pigs were wide spread. Leg deformations by osteopathy or arthritis occurred only sporadically. In the risk analysis claw hematomas of piglets were associated with slatted floors, particulary with slats < 10 mm. Abrasions were associated with concrete and rough floor surfaces at all. Overgrown claws and bursa swellings in weaned and in rearing pigs were associated with damaged, slippery or rough floor surfaces. Other associations were not detected. The quality of floor might be more important than the type of housing.     

Verocytotoxin-producing Escherichia coli O157:H7 in the Swedish pig population

Verocytotoxin-producing Escherichia coli O157:H7 (VTEC O157:H7) was detected in two of 2446 individual faecal samples collected from pigs slaughtered at five Swedish slaughterhouses, indicating a prevalence of 0.08 per cent, with a 95 per cent confidence interval from 0 to 0.16 per cent Four Swedish VTEC O157:H7-positive farms which kept ruminants and pigs were studied by repeated faecal sampling; VTEC O157:H7 was isolated from the ruminants and pigs on all the farms and the same strains were present in the pigs and the ruminants. On one of the farms, the organism persisted in the pig population for 11 months. On all four farms, management practices which might have influenced the isolation rate in pigs were identified. A group of young VTEC O157:H7-positive pigs was moved from one of the VTEC O157:H7-positive farms to a fattening herd where there were no ruminants. The number of VTEC O157:H7-positive faecal samples decreased gradually and after nine weeks the pigs were all negative; at slaughter none of the pigs was VTEC O157:H7-positive.