Gemmamyces bud blight of Picea pungens: a sudden disease outbreak in Central Europe          下载免费PDF全文

K. Černý  V. Pešková  F. Soukup  L. Havrdová  V. Strnadová  D. Zahradník  M. Hrabětová 《Plant pathology》2016,65(8):1267-1278

Due to its high tolerance to acid rain, the North American Colorado blue spruce (Picea pungens) has been among the most frequent substitute tree species used in reforestation programmes in spruce mountain forests in the Ore and Sudeten Mountains in the Czech Republic after destruction by sulphur dioxide pollution in the second half of the last century. This species was planted on more than 8800 ha of destroyed mountain forest stands in the Ore Mountains alone. New plantations prospered until a massive outbreak of the gemmamyces bud blight, first identified in 2009. The causal agent, Gemmamyces piceae, induced massive bud blight in infected trees – bud loss progressively increased to 70–80% or more, and because the trees were not able to replace the natural loss of older needles, they quickly withered and died. Many plantations disrupted by the pathogen had to be cut down. Although several resistant genotypes have been identified, the cultivation of this species in forest stands has no future in this area. Because this disease was also identified in several ornamental plantations in the area, the bud blight epidemic haunts public green space administrators and nursery and Christmas tree plantation owners. Other pathogens and pests, such as Lophodermium piceae, Sirococcus conigenus and Elatobium abietinum, have also been identified as involved in the damage to P. pungens.  相似文献   

Feed intake,growth and nutrient retention of common sole (Solea solea L.) fed natural prey and an artificial feed          下载免费PDF全文

Stephan S W Ende  Saskia Kroeckel  Johan W Schrama  Oliver Schneider  Johan A J Verreth 《Aquaculture Research》2016,47(3):681-688

This study compares growth, intake and retention efficiencies of nutrients and energy between common sole (Solea solea L.) fed ragworm (Nereis virens, Sars), blue mussel (Mytilus edulis L.) and an artificial (commercial) feed. Food types were fed to common sole (mean initial body weight: 44.9 ± 2.3 g) in excess three times a day over a 54‐day‐period. The growth rate in common sole fed the natural prey (8.5 g kg^?0.8 d^?1) was significantly higher compared to the growth rate in fish fed the artificial feed (5.1 g kg^?0.8 d^?1). Nutrient and energy intake was significantly lower in common sole fed the artificial feed than in fish fed natural prey. The only exception was fat intake which was higher in common sole fed the artificial feed in contrast to fish fed the natural prey. Nutrient and energy retention efficiencies were significantly lower in common sole fed the artificial feed than in fish fed the natural prey. In conclusion, the low growth in common sole fed the artificial feed was related to lower nutrient and energy intake as well as lower nutrient and energy retention efficiencies. It is suggested that reduced intake of the artificial feed might be related to the high dietary fat content of the artificial feed.  相似文献   

污泥热解工艺参数对残渣吸附性能的影响     

吴迪  徐文英 《安徽农业科学》2013,41(1):256-259

[目的]优化污泥热解工艺条件及增强污泥热解残渣对小分子的吸附性能。[方法]设置不同的温度、保温时间及含水率条件,对污泥进行热解,测定不同条件下得到的热解残渣的失重率、热值、碘吸附值、亚甲基蓝吸附值等指标。[结果]污泥中有机质发生热解反应的主要温度为350～550℃;温度越高,热解剩余残渣率和残渣热值越低,污泥热解越充分;在450℃时,污泥热解残渣的吸附性能最好。当保温时间延长到60 min以后,对热解结果的影响不大,从节能的角度考虑,保温时间应设定为60 min。当含水率增加到50%以后,对热解结果的影响不大,从节能的角度考虑,应将污泥含水率控制在50%之内。[结论]该研究为污泥无害化与资源化处理提供了参考依据。  相似文献   

桂林市青狮潭水库水质现状调查与评价   总被引：1，自引：0，他引：1  

陈磊  钱建平  张力  朱真真  林震 《广东农业科学》2013,40(5):160-164

通过对桂林市青狮潭水库的pH、电导率、总氮、总磷、高锰酸盐指数、溶解氧、五日生化需氧量、汞等8个水质参数进行监测,系统分析了青狮潭水库东湖、西湖的水质现状以及不同水质参数在空间上的变化特征,讨论了不同水质参数之间的相关性,并对青狮潭水库5个水质参数进行了评价.结果表明,人类活动影响下的水体富营养化、生活污染、养殖业污染以及农业污染是造成水库水质污染的主要原因.另外,在评价的基础上就水库的保护和治理提出了建议.  相似文献   

利用亮甲酚蓝染色法预测牛卵母细胞发育潜能的研究     

乔利敏  李向臣  乔富强  姚华  张文秀  关伟军  马月辉 《畜牧兽医学报》2011,42(9)

利用亮甲酚蓝(Brilliant cresyl blue,BCB)对牛未成熟卵母细胞进行染色,根据染色结果的不同对牛未成熟卵母细胞进行分组培养,观察不同组间卵母细胞发育潜能与细胞凋亡的差异,探讨以BCB着色判定牛卵质量的可行性.本试验在牛卵母细胞成熟培养前用26μmol·L-1BCB染色90 min作为处理组(BCB+和BCB-),以未染色卵母细胞作为对照组;以卵内谷胱甘肽的浓度作为胞质成熟的判定指标,以卵母细胞体外受精后囊胚率作为卵子发育能力的判定指标,同时参照卵母细胞的凋亡检测,综合评定卵子的质量.结果表明:(1)着色组(BCB+)卵母细胞成熟率与对照组和无色组(BCB-)间差异显著(P＜0.05);(2)成熟卵母细胞中谷胱甘肽的浓度较培养前差异显著(P＜0.05);(3)经BCB染色,卵母细胞在成熟后,BCB+组的成熟率、凋亡率较对照组、BCB-组差异显著(P＜0.05);(4)体外受精后,BCB+组的囊胚率和囊胚细胞数较对照组和BCB-组差异显著(P＜0.05).由此可见,牛卵母细胞经BCB的染色选择可以作为判断卵母细胞未来发育潜能的一个标记.  相似文献   

贮前苯胺蓝染色预测苹果冷藏末期表皮病害          下载免费PDF全文

李富军  张新华  李香玉  孙希生  于维芹 《农业工程学报》2011,27(1):370-375

为了实现对苹果贮藏末期表皮病害的预测,以红富士苹果（Malus domestica Borkh cv. Fuji）为试材,通过苯胺兰染色的方法,研究了苹果采后苯胺兰染色与果实贮藏末期几种表皮病害的关系。结果表明：富士苹果采后苯胺兰染色指数与贮藏末期的好果率呈明显负相关,相关系数为-0.947;果实苯胺兰染色的级别与二氧化碳伤害指数和腐烂指数密切相关,其决定系数分别为0.9779和0.8394,但苯胺兰染色的级别与贮藏末期果实的虎皮病和皮孔斑点病之间无明显的相关性。因此,苹果采后苯胺兰染色可用于预测果实贮藏末期的好果率。  相似文献   

H.E染色和普鲁氏染色在动物铁过负荷诊断的比较     

张静 《中国饲料》2011,(19)

本试验研究比较铁过负荷猪的淋巴结、脾脏、肝脏、肺脏、肾脏的H.E染色、革兰氏染色的变化。  相似文献   

猪三毛滴虫长春株不同染色方法的比较     

李伟志  李文超  王泽东  宫鹏涛  李建华  张西臣 《中国兽医学报》2011,31(9)

将从长春地区腹泻仔猪盲肠中分离得到的猪三毛滴虫用1640培养基短期培养后,使用碘染色法、瑞氏染色法、姬氏染色法、姬氏-瑞氏复染法、Weigere铁苏木素染色法和鞭毛染色法染色分别对其染色,观察不同虫体形态结构,并比较了不同染色方法的染色效果。结果显示,姬氏染色、瑞氏-姬氏复染和鞭毛染色法对猪三毛滴虫染色效果较好,可获得虫体形态完整、结构清晰的染色标本。  相似文献   

Exposure to blue LED light before the onset of darkness under a long‐day photoperiod alters melatonin secretion,feeding behaviour and growth in female dairy calves     

Mabrouk Elsabagh  Mamiko Mon  Yui Takao  Akiko Shinoda  Takashi Watanabe  Shiro Kushibiki  Taketo Obitsu  Toshihisa Sugino 《Animal Science Journal》2020,91(1)

The effect of blue LED on melatonin secretion, feeding behaviour and growth was addressed in Holstein female dairy calves. In Exp.1, six animals (8 weeks old, 97 ± 4.1 kg BW) were exposed to yellow or blue LED for 2 hr before darkness over 7 days under a long‐day photoperiod (LDPP). In Exp. 2, six animals (8 weeks old, 88.5 ± 4.8 kg BW) were exposed to blue light from a white LED all daytime or a yellow LED for 2 hr before the darkness of LDPP (blue light cut) over 3 weeks. In Exp. 1, blue light mildly suppressed melatonin secretion during the 2‐hr treatment but did not affect the timing of the nightly melatonin rise. However, the rise in nighty melatonin levels was higher with yellow than blue LED. In Exp. 2, white LED completely suppressed melatonin secretion during the 2‐hr treatment, but plasma melatonin concentrations were similar during the darkness. Grass hay intake, rumination time, frequency of water intake and body weight gain were higher in animals exposed to the yellow rather than the white LED. Overall results indicate that exposure to blue light from white LEDs under an LDPP suppresses melatonin secretion and might negatively impact the development of female dairy calves.  相似文献   

植物中紫外光及蓝光信号转导的研究进展   总被引：2，自引：0，他引：2  

范庆书  庄晓蕾 《河北农业大学学报》2001,24(1):95-98

以拟南芥为例，简要论述了近年来有关紫外光及蓝光信号转导方面的研究进展，其中，着重从ＣＨＳ基因表达的调节、ＵＶ－Ｂ和ＵＶ－Ａ／蓝光光信号转导途径研究及其相互作用等小方面进行介绍。  相似文献