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Pythium oligandrum was consistently isolated from black patches of mushroom compost from two farms. When used in experiments it inhibited the growth of mycelium of Agaricus bisporus and this effect was enhanced in the presence of a compost supplement which contained high levels of nitrogen. The common name pythium-black compost is proposed for the problem. 相似文献
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Objective To evaluate standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals, as techniques for obtaining tissue for assessment of copper status. The techniques were evaluated with respect to ease of use and effect on the animal.
Procedure Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from unrelated horses and sampled to investigate the variability in the distribution of copper in liver tissue.
Result The biopsy technique caused no lasting effect on the mares, but there was an increased risk of viscus penetration associated with taking multiple biopsy cores. The use of ultrasonography to scan the target area for the liver identified four cases that were not appropriate candidates for liver biopsy, because of large intestine being located in the biopsy area. In the foals there were no serious postoperative adverse effects, nor was there any evidence of problems caused by the procedure when the abdomen was examined post-mortem at 5 months of age. In livers collected to investigate the variability of copper concentration, copper appeared to be relatively evenly distributed through the liver.
Conclusion Standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals are convenient procedures for obtaining liver tissue for assessing copper status in horses. The use of ultrasound to identify liver tissue is recommended, especially in older mares. 相似文献
Procedure Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from unrelated horses and sampled to investigate the variability in the distribution of copper in liver tissue.
Result The biopsy technique caused no lasting effect on the mares, but there was an increased risk of viscus penetration associated with taking multiple biopsy cores. The use of ultrasonography to scan the target area for the liver identified four cases that were not appropriate candidates for liver biopsy, because of large intestine being located in the biopsy area. In the foals there were no serious postoperative adverse effects, nor was there any evidence of problems caused by the procedure when the abdomen was examined post-mortem at 5 months of age. In livers collected to investigate the variability of copper concentration, copper appeared to be relatively evenly distributed through the liver.
Conclusion Standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals are convenient procedures for obtaining liver tissue for assessing copper status in horses. The use of ultrasound to identify liver tissue is recommended, especially in older mares. 相似文献
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The effect of wind on the extension growth of young Pinus contortawas investigated using a controlled environment wind tunnel.Extension rates of leader and lateral shoots were reduced byabout 20 per cent by high wind speed. The ratio of the finallength of the laterals to that of the leaders (‘apicalcontrol’) was unaffected, as was the radial growth ofstems. Water potentials were slightly higher in plants subjectto high wind. In another experiment, rates of needle extensionwere reduced 30 per cent by wind. The experiments are discussedin relation to field observations by others and it is arguedthat wind is a potent ecological factor adversely affectingtree growth. 相似文献
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黄脊竹蝗为重大林业害虫,多在竹林造成为害。2020年黄脊竹蝗从老挝、越南等地跨境进入中国云南省并在农区造成了严重为害。本文主要综述了黄脊竹蝗在我国发生的历史与现状、暴发的原因以及主要的防治措施,归纳了黄脊竹蝗不同发育阶段的有效防治措施,重点总结了利用生防天敌和生物农药防治黄脊竹蝗的研究进展,为黄脊竹蝗综合防控提供参考依据。 相似文献
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Possible Impacts of Climatic Warming on Trees and Forests in the United Kingdom: a Review 总被引：2，自引：0，他引：2
There is growing evidence and concern that increasing levelsof greenhouse gases in the atmosphere will increase global temperatures.Temperatures in the UK may increase by 3C± 1.5C overthe next 70 years The tree crop is sensitive to such large andrapid climatic change because of its longevity. This paper reviews(1) changes that might occur in the forest environment, includingsoil, following climatic warming; (2) past and future long-termchanges in the species composition of UK forest; (3) possiblepositive and negative effects.of climatic warming on the growthand yield of UK forests; and (4) the vulnerability of foreststo any change in the frequency of extreme events. 相似文献
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Subjecting young plants of P. contorta to continuous shakingoutdoors caused a 20 per cent reduction in the extension ofleading and lateral shoots, and a 10 per cent reduction in theextension of needles. The ratio of the final length of the lateralsto that of the leaders (‘apical control’) was unaffectedby shaking as was the radial growth of the stems. Shaking foronly 24 minutes per day had almost the same effect as shakingcontinuously. Shaking in 1978 had no effect on fascicles producedin 1979 or on the response to shaking in 1979. The effect ofshaking could not be attributed to an induced water stress.To see whether the shaking treatment affected cell divisionor cell expansion an examination was made of the pith parenchyma.The shorter stems from the shaken treatment contained fewercells than the controls, though cell size was not much affected.The results of the shaking experiment were very similar to theresults of the wind tunnel experiment described in the previouspaper. 相似文献
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Tomato powdery mildew 总被引：2，自引：5，他引：2
A powdery mildew ( Erysiphe sp.) occurred on greenhouse-grown tomato crops in southern England in 1987. White pustules appeared on the upper surfaces of leaves of affected crops and only rarely on the under surfaces. In greenhouse experiments, stems were very severely affected. In host range studies 19 tomato cultivars and six breeders' lines were susceptible as well as Nicotiana tabacum. N. xanthi. Solanium melongena, S. pseudocapsicum, S. tuberosum, Datura stramonium and Petunia hybrida. Conidia germinated readily at 15, 20 and 25 C and were viable for 2 days in the laboratory and at least 6 days in the greenhouse. The disease was well controlled by a range of fungicides including benomyl, bupirimate, carbendazim, chlorothalonil, fenarimol and pyrazophos. All of these except pyrazophos are approved for use on tomatoes in the UK. The pathogen was very sensitive to low concentrations of benomyl and fenarimol but less so to bupirimate. 相似文献