不同生物质炭对污灌区土壤铜形态及玉米吸收转运富集的影响

【目的】研究菌糠生物质炭对污灌区土壤重金属铜形态及玉米吸收转运富集的影响,横向比较3种菌糠生物质炭和玉米秸秆生物质炭及水稻稻壳生物质炭对其效果的优劣。【方法】通过盆栽试验,对施用5种生物质炭的山西某污灌区土壤中重金属铜形态及玉米各部位重金属铜含量和玉米各部位对重金属铜元素转运及富集系数进行分析。【结果】5种不同生物质质炭处理土壤中可交换态铜含量均低于空白对照,其中灵芝菌糠生物质炭处理土壤中可交换态铜含量最低,为1.005 mg/kg,比空白对照降低31.4%;土壤中碳酸盐结合态铜含量比空白对照均为减少,猴头菇菌糠生物质炭处理土壤中碳酸盐结合态铜含量减少量最多,数值降到5.91 mg/kg,比空白对照降低40.65%;除了猴头菇菌糠生物质炭处理土壤中铁锰氧化物结合态铜含量比空白对照升高2.25%之外,其余4种处理土壤中铁锰氧化物结合态铜含量均有所下降;有机结合态铜含量变化不一致,残渣态铜含量比空白对照均有所上升,上升最多的是猴头菇菌糠生物质炭处理的土壤,含量为104.55 mg/kg,比空白对照增加15.76%;各处理之间玉米对铜元素的转运系数均小于1,不同处理玉米对铜的富集系数变化均不统一。【结论】5种不同生物质炭均可以增加土壤中非活性态重金属铜含量,并降低活性态铜含量,为有效利用生物质炭、降低重金属污染土壤中铜的有效性提供一定的科学依据。     

Phytophthora nicotianae transmission and growth of potted kalanchoe in two recirculating subirrigation systems

Recirculating subirrigation systems are frequently exposed to the risk of plant pathogens transmission, which may deteriorate the growth and quality of the plants. The transmission of Phytophthora nicotianae was examined using Kalanchoe blossfeldiana cv. New Alter in two recirculating subirrigation systems, a nutrient-flow wick culture (NFW) system and an ebb and flow (EBB) system. When the nutrient solution was infested, the pathogen was recovered from roots in both subirrigation systems. However, foliar blights and browning of roots appeared 4 and 7 weeks, respectively, after inoculation in the EBB system. Only a little discoloration appeared in the NFW system. The fresh and dry weights were lower in the EBB system than in the NFW system. When growing medium was inoculated, the pathogen was unable to be isolated from the plants in the NFW system. However, disease symptoms appeared in the EBB system 4 weeks after inoculation, and the pathogen was observed in the basal leaves and roots. Similar to the infested nutrient solution, the plant growth in the EBB system was inhibited. These results suggested that when the nutrient solution was infested, pathogen transmission could occur in plants in both systems, although differences existed with regard to disease symptoms and the time it took for symptoms to appear. However, we observed that when growing medium was inoculated the pathogen was not transmitted to adjacent plants in the NFW system using wick.     

Contrast-enhanced ultrasonography to assess blood perfusion of skeletal muscles in normal dogs

This study evaluated perfusion of skeletal muscle using contrast enhanced ultrasonography in humerus, radius, femur and tibia in normal dogs. Contrast enhanced ultrasonography for each region was performed after injecting 0.5 mL and 1 mL of contrast medium (SonoVue) in every dog. Blood perfusion was assessed quantitatively by measuring the peak intensity, time to the peak intensity and area under the curve from the time–intensity curve. Vascularization in skeletal muscle was qualitatively graded with a score of 0–3 according to the number of vascular signals. A parabolic shape of time–intensity curve was observed from muscles in normal dogs, and time to the peak intensity, the peak intensity and area under the curve of each muscle were not significantly different according to the appendicular regions examined and the dosage of contrast agent administered. This study reports that feasibility of contrast enhanced ultrasonography for assessment of the muscular perfusion in canine appendicular regions.     

Diffuse idiopathic skeletal hyperostosis with prominent appendicular bone proliferation in a dog

This report described radiographic and CT features of atypical diffuse idiopathic skeletal hyperostosis in a 5 year-old, female Shih-tzu showing marked proliferative bone lesions in the appendicular skeleton with minor spinal changes. Continuous or flowing bony bridge formation of vertebrae is used as the gold standard for diagnosing diffuse idiopathic skeletal hyperostosis. However, this criterion seems not to be suitable for appendicular type diffuse idiopathic skeletal hyperostosis, as in the present case. Diffuse idiopathic skeletal hyperostosis is a progressive skeletal disease, and thus, enthesophytosis and the multiple bony proliferations at insertion sites of ligaments and tendons to appendicular bones in a lamellar or trabecular pattern were considered diagnostic features of the appendicular type of diffuse idiopathic skeletal hyperostosis.     

绿茶施用铵态氮和硝态氮后木质部导管中N运移模拟

An experiment was carried out to study the transport process of nitrogen （N） assimilation from tea roots by monitoring the dynamic composition of N compounds in xylem sap after 15^N-NO3 and 15^N-NH4 were fed to the root of tea plants （Camellia sinensis L.）. Results showed that the main amino acids were glutamine, theanine, axginine, asparic acid and glutamic acid, which accounted for 49%, 17%, 8%, 7%, and 4%, respectively, of the total amino acids in the xylem sap. After the tea plants were fed with 15^N-NO3 and 15^N-NH4 for 48 h, the amount of total amino acids in xylem sap significantly increased and those fed with 15^N-NH4 had higher increment than those with 15^N-NOa. Two hours after 15^N- NO3 and 15^N-NH4 were fed, 15N abundance in glutamine, asparagine, glutamic acid, alanine, and arginine were detected and increased quickly over time. This indicated that it took less than 2 h for NO3-N and NH4-N to be absorbed by tea roots, incorporated into the above amino acids and transported to the xylem sap. Rapid increase in 15^N-NO3 in the xylem sap of tea plants fed with 15^N-NO3 indicated that nitrate could be directly transported to the xylem sap. Glutamine, theanine, and alanine were the main amino acids transported in xylem sap of tea plants fed with both 15^N-NO3 and 15^N-NH4.     

Productivity and energy partition of late lactation dairy cows during heat exposure

Three late-lactation Holstein cows were used to determine the effects of environmental temperature on performance and energy partitioning. Each cow was housed in a respiratory chamber for 30 consecutive days and exposed to three different conditions of environmental temperature: (i) 20°C and 20°C (20°C), (ii) 25°C and 20°C (25°C), (iii) 30°C and 25°C (30°C) during the day and night, respectively. The temperature was switched in an interval of 10 days. Humidity in the chamber was maintained at 55–65% through the entire experimental period. The daily mean as well as morning and evening rectal temperatures of Holstein cows increased linearly ( P  < 0.05) as chamber temperature increased. There was a significant linear reduction in dry matter (DM) intake ( P  < 0.05) and an increase in DM digestibility ( P  < 0.05). The response in milk yield, however, was not affected by heat stress. There were no significant differences among treatments for intake energy, heat production, net energy for lactation and net energy for gain. This results of this study disagreed with the assumption that late lactation cows gave priority to increasing body tissue at the expense of milk production under thermal stress.     

COMPUTED TOMOGRAPHY ANGIOGRAPHY FOR EVALUATION OF PULMONARY EMBOLISM IN AN EXPERIMENTAL MODEL AND HEARTWORM INFESTED DOGS

This study was performed to characterize pulmonary embolism with computed tomography pulmonary angiography in experimental pulmonary embolism and heartworm infected dogs. In the experimental group, there were pulmonary changes after pulmonary embolism induction as follows: hypoattenuating round filling defects in pulmonary arteries, arterial dilations with straight and abrupt cut‐off appearances in the pulmonary embolism regions, pulmonary infarctions, a cavity formation and spontaneous pneumothorax, and emboli migration. In the heartworm‐infected group, three out of eight dogs developed pulmonary embolism, especially in the right caudal arteries. Arterial dilations with typical tortuosity were also identified, mainly in the right caudal arteries in five dogs. Computed tomography pulmonary angiography can be an important imaging modality in the diagnosis of pulmonary embolism and the evaluation of pulmonary arterial and parenchymal changes in dogs.     

Effect on Field Fertility of Addition of Gelatine,Different Dilution Rates and Storage Times of Cooled Ram Semen After Vaginal Insemination

In a field trial, 633 ewes from 24 farms were inseminated vaginally using liquid semen (150 × 10⁶ per dose) collected from 15 rams. The semen was either diluted with a milk‐based extender (M), filled in 0.2 ml straws and stored for 12 or 24 h (M12, M24) or diluted with M but with the addition of gelatine, filled in 0.5 ml straws and stored for 12 or 24 h (G12, G24). The hypothesis was that a larger volume and the addition of gelatine would prolong the survival of the spermatozoa. The ewes, aged between 6 months and 5.5 years, were allocated into four groups and inseminated after natural oestrus by the farmers themselves with a dose of 150 × 10⁶ spermatozoa. Inseminations in the groups (M12, M24, G12, G24) resulted in lambing rates of 69.6%, 63.6%, 69.4% and 58.3% (overall 65.2%), respectively. Farmer (p < .0002) had a significant effect on the lambing rate, while ram, age of the ewe and dilution rate/addition of gelatine/storage time had not. A pair‐wise comparison of the lambing rates between the four groups showed that significant lower results were only achieved for G24 compared with M12. None of the other comparisons showed significant differences. In conclusion, a higher dilution rate of the AI‐dose together with the addition of gelatine to the semen extender did not lead to improved fertility results after storage for 24 h when compared with standard AI‐doses used in Norway.