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Siegfried Schittenhelm Tina Langkamp-Wedde Martin Kraft Lorenz Kottmann Katja Matschiner 《Journal of Agronomy and Crop Science》2020,206(6):722-733
To examine the extent to which heat stress during grain filling impacts on the development and yield of winter wheat (Triticum aestivum L.), a 3-year field experiment was conducted on a loess soil with high water holding capacity in the North German Plain. Thirty-two mostly European winter wheat cultivars were exposed to heat stress in a mobile foil tunnel with maximum air temperatures of 45.7, 45.4, and 47.2°C in 2015, 2016, and 2017, respectively. The 14-day post-anthesis heat stress treatment caused an average 57.3% grain yield reduction compared to a close-by non-stressed control. The proportion of green crop area after the heat stress phase varied from 7% to 98% in 2016 and from 37% to 94% in 2017. The green crop area percentage did not significantly correlate with grain yield, indicating that the delayed senescence of stay-green phenotypes offers no yield advantage under terminal heat stress. The water soluble carbohydrate (WSC) concentration of the stems at crop maturity varied between 6 and 92 g/kg dry matter, showing that the genotypes differed in their efficiency at using the stem carbohydrate reserves for grain filling under heat stress. The stem WSC concentration correlated positively with the beginning of anthesis (r = 0.704; p < .001) but negatively with the grain yield (r = −0.431; p < .05). For heat tolerance breeding, the stem reserve strategy, i. e. the rapid and full exhaustion of the temporary carbohydrate storage therefore seems more promising than the stay-green strategy. 相似文献
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Indications for bronchoscopy, the equipment and technique performance in dogs and cats are presented. The method is invasive, therefore exact indications such as chronic cough of noncardial origin, foreign bodies, parasitic invasion, paralysis of the larynx or tumours are required. Bronchoscopy enables the surgeon to take samples of bronchial discharge. 相似文献
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Tucker DW Olsen D Kraft SL Andrews GA Gray AP 《Journal of the American Animal Hospital Association》2000,36(2):163-167
An eight-year-old, male castrated bullmastiff presented to the Kansas State University Veterinary Medical Teaching Hospital with left hind-limb paralysis. A mass was identified in the left paralumbar soft tissue adjacent to the fourth (L4) to sixth (L6) lumbar vertebrae by magnetic resonance imaging. The iliopsoas muscle contained the mass which was identified as a hemangiosarcoma on histopathological examination. Hemangiosarcoma is rarely reported as a primary tumor arising from muscle vascular endothelium. 相似文献