High throughput phenotyping for aphid resistance in large plant collections

ABSTRACT: BACKGROUND: Phloem-feeding insects are among the most devastating pests worldwide. They not only cause damage by feeding from the phloem, thereby depleting the plant from photo-assimilates, but also by vectoring viruses. Until now, the main way to prevent such problems is the frequent use of insecticides. Applying resistant varieties would be a more environmental friendly and sustainable solution. For this, resistant sources need to be identified first. Up to now there were no methods suitable for high throughput phenotyping of plant germplasm to identify sources of resistance towards phloem-feeding insects. RESULTS: In this paper we present a high throughput screening system to identify plants with an increased resistance against aphids. Its versatility is demonstrated using an Arabidopsis thaliana activation tag mutant line collection. This system consists of the green peach aphid Myzus persicae (Sulzer) and the circulative virus Turnip yellows virus (TuYV). In an initial screening, with one plant representing one mutant line, 13 virus-free mutant lines were identified by ELISA. Using seeds produced from these lines, the putative candidates were re-evaluated and characterized, resulting in nine lines with increased resistance towards the aphid. CONCLUSIONS: This M. persicae-TuYV screening system is an efficient, reliable and quick procedure to identify among thousands of mutated lines those resistant to aphids. In our study, nine mutant lines with increased resistance against the aphid were selected among 5160 mutant lines in just 5 months by one person. The system can be extended to other phloem-feeding insects and circulative viruses to identify insect resistant sources from several collections, including for example genebanks and artificially prepared mutant collections.     

The pre-emptive effect of epidural ketamine on wound sensitivity in horses tested by using von Frey filaments

Objective To evaluate the pre‐emptive analgesic effect of pre‐incisional epidural ketamine. Study Design A blinded, randomized experimental study. Animals Sixteen mixed breed mares, 7.6 ± 2.8 years old, weighing 352 ± 32 kg. Methods In a pilot study, an incision was made on one lateral thigh using a lidocaine block and no further analgesics, and it was verified that the nociceptive threshold was lower on the incised side than nonincised side (p ≤ 0.05), and that von Frey filaments evoked a pain response. The 16 animals were divided into group A (ketamine, n = 9) and B (saline, n = 7). An epidural catheter was inserted 24 hours before the trials. The thigh was shaved bilaterally, and the right side was blocked (incised side) using lidocaine. Twenty‐five minutes later, ketamine (A) or saline (B) was administered epidurally. Five minutes later, a 10‐cm skin incision was made on the right side, and then sutured. Nociceptive threshold was determined with von Frey filaments at 1, 3, and 5 cm around the incision at 15‐minute intervals for 2 hours, then at 4, 6, and 8 hours. Behavioral alterations, heart and respiratory rates were recorded. Nociceptive thresholds from these points were averaged to obtain mean values at each time, converted to a logarithmic scale, and submitted to a nonparametric analysis (Mann–Whitney and one‐way repeated measures anova test, p ≤ 0.05). Results After 8 hours, the global range score revealed reduced hyperalgesia (p < 0.01) around the incision in 92% (4.65–4.27) of evaluated intervals in group A (ketamine). There were no significant changes in behavior, heart and respiratory rates. Conclusions It was concluded that pre‐emptive epidural ketamine reduced post‐incisional pain in the horse, and that von Frey filaments were able to quantify cutaneous sensitivity after tissue damage. Clinical relevance Epidural ketamine injection can reduce post‐incisional sensitivity in the horse.     

Mikro- und makroskopische Untersuchungen an Straßenbaumveredelungen im Hinblick auf die Beeinflussung ihrer Bruchsicherheit

Aim of the study was to identify changes within xylem structure of grafted trees which could possibly lead to a higher risk of breakage. Therefore, 83 trees from the genera Prunus, Sorbus, Carpinus, Quercus, Robinia and Crateagus were examined at the macro- and microscopic level. All wood samples showed changes in their xylem structure in the areas at or around the contact zone of stock and scion. Cells were deviated in different angles from the stem axis in the tangential direction. Furthermore, whirled grain areas were found adjacent to the contact zone. Abnormal xylem structures could be found in various quantum's. Despite the observed changes in the xylem structure, the risk of breakage is not significantly increased. An e-mail based survey among 496 administrations of rural districts in Germany and bigger towns all over Germany including 64 botanical gardens and arboretum, revealed only nine cases of stem breakage at the contact zone of grafted trees. These breaks were found in the genera Tilia, Fagus and Robinia. Further studies are recommended to gain more knowledge about how xylem structure develops during the lifespan of a tree under stress conditions, especially in urban environments.     

A pilot study on the effect of short-term consumption of a polyphenol rich drink on biomarkers of coronary artery disease defined by urinary proteomics

Polyphenol rich diets have been associated with a reduced risk of cardiovascular disease. We examined the effect of a polyphenol rich (P-R) drink on biomarkers assessed by urinary proteomics. Thirty nine middle aged and overweight subjects were randomized to P-R drink (n = 20) or placebo (n = 19) in addition to their normal diet. After two weeks urine samples were obtained for assessment of the urinary proteome using capillary electrophoresis coupled to a mass spectrometer. A total of 93 polypeptides were found to be candidates for differential distribution with a nominal p-value <0.05, though these differences did not reach significance when multiple testing was accounted for. Sequences were determined in 19 of these demonstrating that they originate from alpha-1 antitrypsin, collagens, fibrinogen alpha and IgG kappa. Levels of 27 polypeptides were greater than 4-fold different between the two groups. Of these, 7 were previously found to be part of a coronary artery disease (CAD) specific urinary biomarker pattern. Their direction of expression was closer to the healthy state in the P-R drink group and closer to CAD state in the placebo group. Our data suggest that the P-R drink may have beneficial effects on urinary biomarkers of CAD. The data encourage the planning of future prospective studies, aimed at investigating significant effects of polyphenol rich dietary products.     

Schwermetallgehalte in landwirtschaftlich relevanten stoffen

Die Gehalte für die sechs Schwermetalle Cd, Cr, Cu, Ni, Pb und Zn in landwirtschaftlich relevanten Stoffgruppen (mineralische und organische Düngestoffe, Kulturpflanzen und tierische Produkte) wurden aus Literaturdaten für die beiden statistischen Maßzahlen Mittelwert und Spannweite der Mittelwerte in Übersichtstabellen zusammengefasst.     

Soil heterogeneity at the field scale: a challenge for precision crop protection

Crop protection seldom takes into account soil heterogeneity at the field scale. Yet, variable site characteristics affect the incidence of pests as well as the efficacy and fate of pesticides in soil. This article reviews crucial starting points for incorporating soil information into precision crop protection (PCP). At present, the lack of adequate field maps is a major drawback. Conventional soil analyses are too expensive to capture soil heterogeneity at the field scale with the required spatial resolution. Therefore, we discuss alternative procedures exemplified by our own results concerning (i) minimally and non-invasive sensor techniques for the estimation of soil properties, (ii) the evidence of soil heterogeneity with respect to PCP, and (iii) current possibilities for incorporation of high resolution soil information into crop protection decisions. Soil organic carbon (SOC) and soil texture are extremely interesting for PCP. Their determination with minimally invasive techniques requires the sampling of soils, because the sensors must be used in the laboratory. However, this technique delivers precise information at low cost. We accurately determined SOC in the near-infrared. In the mid-infrared, texture and lime content were also exactly quantified. Non-invasive sensors require less effort. The airborne HyMap sensor was suitable for the detection of variability in SOC at high resolution, thus promising further progress regarding SOC data acquisition from bare soil. The apparent electrical conductivity as measured by an EM38 sensor was shown to be a suitable proxy for soil texture and layering. A survey of arable fields near Bonn (Germany) revealed widespread within-field heterogeneity of texture-related ECa, SOC and other characteristics. Maps of herbicide sorption and application rate were derived from sensor data, showing that optimal herbicide dosage is strongly governed by soil variability. A phytoassay with isoproturon confirmed the reliability of spatially varied herbicide application rates. Mapping areas with an enhanced leaching risk within fields allows them to be kept free of pesticides with related regulatory restrictions. We conclude that the use of information on soil heterogeneity within the concept of PCP is beneficial, both economically and ecologically.     

Effect of Pre‐Treatment of Ovine Sperm on Male Pronuclear Formation and Subsequent Embryo Development Following Intracytoplasmic Sperm Injection

The objective of this study was to determine the effects of various methods of sperm pre‐treatment on male pronuclear (MPN) formation and subsequent development of ovine embryos derived from in vitro‐matured oocytes and intracytoplasmic sperm injection (ICSI). The effect of treatment of injected oocytes with dithiothreitol (DTT) on embryo development was also assessed. In Exp. 1, the injected oocytes with non‐treated sperm were activated with three different procedures. The cleavage and blastocyst rates in those activated with DTT was lower (p < 0.05) than those activated with either ionomycin (Io) + 6‐dimethylaminopurine (6‐DMAP) or DTT + I + 6‐DMAP. In Exp. 2, the effects of sperm pre‐incubated with DTT, sodium dodecyl sulphate (SDS) or DTT + SDS as well as two‐time frozen/thawed sperm (without cryoprotectant) on MPN formation and oocyte activation were examined. The non‐treated sperm served as controls. The MPN formation in DTT + SDS group was higher (p < 0.05) than other groups except for freeze–thaw group. No difference in the rate of activated ICSI oocytes was observed among groups. In Exp. 3, the effect of pre‐treatment of sperm on subsequent development of ICSI embryos and blastocyst cell numbers were examined. The rates of cleavage and blastocyst formation as well as the blastocyst cell numbers were similar among the pre‐treated and control groups. In conclusion, pre‐treatment of sperm with DTT + SDS positively affected MPN formation, although the subsequent development capacity of the resulting embryos remained limited. Moreover, DTT was not effective on oocyte activation compared with Io + 6‐DMAP after ICSI.     

Schiff-Sherrington syndrome in a 7-year-old zebra mare (Equus quagga)

A 7-year-old plains zebra (Equus quagga) mare was presented to the Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Germany as an emergency. The owner reported that the mare was unable to stand after a suspected traumatic episode at the home yard. The mare was transported in lateral recumbency in a trailer. Clinical examination revealed tachycardia (up to 102 beats/min), tachypnoea (28 breaths/min), mild fever (38.7°C) and clinical dehydration with elastic skin and dry and red mucous membranes. Neurological examination showed paraplegia with complete loss of nociception of the mid-thoracic region and caudal to it. In contrast, examination of the thoracic limbs revealed marked extensor rigidity and hyperaesthesia resulting in an enhanced acute response to minimal touch of the neck and shoulder region. Lateral radiographs of the thoracic vertebral column led to the diagnosis of a complete fracture of the vertebral body of the 7th thoracic (T) vertebra with suspected traumatic compression of the spinal cord. Post-mortem examination confirmed the diagnosis. Gross pathology revealed a complete comminuted fracture of T7 with marked compression of the spinal cord. This is the first report describing the clinical, radiological and pathological findings of a fracture of a thoracic vertebra leading to a Schiff-Sherrington syndrome in a zebra (Equus quagga).