优良豆科牧草--东方山羊豆的研究与利用   总被引：12，自引：1，他引：11  

沈禹颖  张自和  谢田玲 《草业学报》2003,12(6):105-109

开发新豆科牧草资源不仅是改善饲草料品质，提高草地畜牧业生产力的基础，还可为我国实施退耕还林还草，恢复生态环境建设的战略部署提供草本植物物种。东方山羊豆是自1980年后，在前苏联、北欧等国家得到重视的一种新兴豆科牧草，它具有产量高，植株蛋白质含量高，生态适应性强，草地持续稳定性好的特点。本文综述了国内外对该草种的产量及饲用价值评定，回顾了影响山羊豆草地建植和生长的因素，提出了在我国西北地区开展东方山羊豆研究和利用推广的潜力和前景。  相似文献   

东方蝾螈外部体型指数回归方程的建立     

宁方勇白秀娟  任海英 《经济动物学报》2003,7(4):52-53

为了探讨东方蝾螈在人工养殖效果评估方面 ,在确定屠宰或捕捞的大小与时间的适宜度方面 ,在生理、病理分析时 ,在治疗时间和用药量等诸方面 ,都达到取材时期的合理性问题 ,测定了东方蝾螈的身型指数 ,并初步建立了回归方程Y =- 2 5 0 +0 .6 2X1 ,并对相关数据的处理方法进行了探讨。  相似文献   

Theileria orientalis: a review     

JG Watts  MC Playford  KL Hickey 《New Zealand veterinary journal》2016,64(1):3-9

Theileria orientalis (also known historically as T. sergenti and T. buffeli) is responsible for benign or non-transforming theileriosis, and exerts its major effect through erythrocyte destruction. The life cycle of T. orientalis is essentially similar to that of other Theileria species, except that the schizonts do not induce transformation and fatal lymphoproliferation. The pathogenesis of anaemia as a result of infection is not clearly established and may be multifaceted. Clinical signs of weakness, reluctance to walk and abortion are early but non-specific indications of disease, particularly if accompanied by a history of cattle being moved. Physical examination may reveal pallor (pale eyes, vaginal mucosa), pyrexia, and elevated heart and respiratory rates. T. orientalis is an economically important parasite of cattle in New Zealand, Australia and Japan, especially where naïve animals are introduced into an endemic area or in animals under stress. Increased awareness of the risks posed by the parasite is required to enable management practices to be implemented to minimise its impact.  相似文献   

酸碱预处理对三球悬铃木落叶同步糖化发酵产氢的影响     

张全国  李亚猛  荆艳艳  蒋丹萍  张志萍 《农业机械学报》2015,46(5):202-207

对三球悬铃木(俗称法国梧桐)落叶酸碱预处理及其同步糖化发酵产氢工艺进行实验研究,利用修正的冈珀茨模型(Gompertz model)对产氢曲线加以拟合,以累积产氢量和产氢速率为考察指标,研究不同酸碱预处理方法(添加质量分数为2%、4%、6%、8%的H2SO4和Ca(OH)2)对三球悬铃木落叶光合生物产氢性能的影响规律,优化出最佳酸碱预处理工艺条件为:稀酸预处理后的落叶试样的产氢性能优于氢氧化钙预处理后的落叶试样,其中H2SO4质量分数为4%时处理效果最佳,发酵产气中的氢气最大体积分数达66.34%,累积产氢量为369 m L,最高产氢速率11.03 m L/h。稀酸处理液可以实现3次有效回收利用。  相似文献   

Bigeye tuna (Thunnus obesus) vertical movements in the Azores Islands determined with pop-up satellite archival tags   总被引：2，自引：0，他引：2  

H. ARRIZABALAGA  J. G. PEREIRA  F. ROYER  B. GALUARDI  N. GOÑI  I. ARTETXE  I. ARREGI  M. LUTCAVAGE 《Fisheries Oceanography》2008,17(2):74-83

Movement patterns of 17 bigeye tuna (Thunnus obesus) near the Azores Islands were analyzed between April and May 2001 and 2002 using pop‐up satellite archival tags. Despite short attachment durations (1 to 21 days, 8.2 days on average), their vertical movements revealed much shallower distribution of bigeye tuna in comparison with previous studies in the tropical Pacific and tropical Atlantic. Depth and temperature histograms were unimodal, although overall depth distribution during the day was deeper than during the night due to daily incursions in deeper waters. Although generalized additive models showed significant non‐linear relationships with weight of the fish and sea level anomaly (as a proxy for variability of thermocline depth), the effect of these variables on bigeye depth appeared minor, suggesting that vertical movements of bigeye in the Azores during the spring migration may be influenced by food availability in upper water layers.  相似文献   

侧柏种源试验苗期的初步研究   总被引：7，自引：3，他引：4  

石文玉 《北京林业大学学报》1986,8(1):74-83

在北京的3个不同海拔高度,对来自31个地区的侧柏种子进行了种源试验。对一年生苗的分析表明,种源间差异显著。一年生苗生长快的种源比生长慢的高3.6倍。通过根系调查及苗高生长量与地表温度和土壤含水量的相关分析,可以看出天然林子代比人工林子代的适应性强。初步研究结果可为北京地区选择适宜的侧柏种源和侧柏的种源区划提供参考。  相似文献   

Molecular evidence for cosmopolitan distribution of platyhelminth parasites of tunas (Thunnus spp.)     

Hamish M Aiken  Nathan J Bott  Ivona Mladineo  Francisco E Montero  Barbara F Nowak  & Craig J Hayward 《Fish and Fisheries》2007,8(3):167-180

Global distribution of platyhelminth parasites and their host specificities are not well known. Our hypothesis was that platyhelminth parasites of large pelagic fishes are common around the world. We analysed molecular variation in three different taxa of platyhelminth parasites infecting four species of tunas: yellowfin tuna (Thunnus albacares, Scombridae) from Western Australia, southern bluefin tuna (Thunnus maccoyii, Scombridae) from South Australia, Pacific bluefin tuna (Thunnus orientalis, Scombridae) from Pacific Mexico and northern bluefin tuna (T. thynnus, Scombridae) from two localities in the Mediterranean (Spain and Croatia). Comparisons of ITS2 and partial 28S rDNA demonstrated two congeneric species of blood flukes (Digenea: Sanguinicolidae) from multiple hosts and localities: Cardicola forsteri from southern bluefin and northern bluefin tunas, and Cardicola sp. from Pacific bluefin and northern bluefin tunas; and a gill fluke, Hexostoma thynni (Polyopisthocotylea: Hexostomatidae), from yellowfin, southern bluefin and northern bluefin tunas. Partial 28S rDNA indicates that a second type of fluke on the gills, Capsala sp. (Monopisthocotylea: Capsalidae), occurs on both southern bluefin and Pacific bluefin tunas. This appears to be the first report of conspecific platyhelminth parasites of teleosts with a wide‐ranging geographical distribution that has been confirmed through molecular approaches. Given the brevity of the free‐living larval stage of both taxa of flukes on the gills (H. thynni and Capsala sp.), we conclude that the only feasible hypothesis for the cosmopolitan distribution of these flatworms is migrations of host tunas. Host migration also seems likely to be responsible for the widespread occurrence of the two species of blood flukes (Cardicola spp.), although it is also possible that these were translocated recently by the spread of infected intermediate hosts.  相似文献   

遮荫处理对侧柏种子萌发的影响     

闫兴富  周立彪  杜茜 《北方园艺》2009,(5)

在不同光照梯度55.44%自然全光照(Natural sonlight,NS)、21.12%NS、3.47%NS 和0.86%NS的人工遮荫条件下,研究了侧柏(Platycladus orientalis)种子萌发的特点.结果表明:4个光照梯度处理的侧柏种子的萌发率分别为68.9%、82.2%、44.4%和42.2%;随着光照强度的减弱,种子萌发进程减慢;萌发指数和幼苗活力指数均在21.12%NS处理最大,分别为1.89和770.8.  相似文献   

壳聚糖对长白落叶松和侧柏种子萌发的影响   总被引：7，自引：2，他引：7       下载免费PDF全文

李庆梅  付增娟  张洪燕 《林业科学研究》2007,20(4):524-527

用0.5、1.0、1.5、2.0 g·L-14种浓度的壳聚糖溶液分别对长白落叶松和侧柏种子浸种处理18、24 h,对照为始温45℃清水浸种24 h、恒温25℃培养21、28 d.结果表明:经不同浓度的壳聚糖溶液处理后,长白落叶松种子发芽率、发芽势、平均发芽速率和发芽指数都有显著提高,以1.0 g·L-1壳聚糖浸种24 h效果最佳;侧柏种子发芽率、发芽速率以2.0 g·L-1壳聚糖浸种24 h后效果最好.  相似文献   

杨树新植林区黑绒金龟子虫害最佳防治方法的研究     

赵殿洲  牟淑文  邹本琪  段明非 《防护林科技》2005,(Z1):29-30

黑绒金龟子是杨树新植林最重要的食叶害虫,通过不同方法的防治实验,选择蘸农药插枝诱杀,是防治黑绒金龟子最有效的办法,并且省工、省力,消灭虫害较为彻底。  相似文献