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71.
湖南省果梅品种资源种质杂化状况的初步研究   总被引:8,自引:0,他引:8  
刘连森  贺善文 《园艺学报》1993,20(3):225-230
  相似文献   
72.
将红檬实生苗培养于改良无土基质中,接种泡囊-丛枝菌根Glomuscitrocolum,以不接种菌根为对照,并分别施用含氮量相等的3种氮肥,即硝酸按(NO3-N)、尿素(NH2-N)和硫酸铵(NH4-N)。接种菌根16周后,施不同氮肥的红檬实生苗均有效地感染了菌根,并促进了植株的生长。试验证明,红实生苗施硝态氮(NO3-N)使植株的菌根依赖性有明显提高。  相似文献   
73.
In a dose response study in foxes, the median protective dose of ERA BHK21 vaccine in a blister pack bait was 10(6.0) tissue culture infective doses (TCID)/mL, while artificially aged baits with titers of 10(6.3) TCID/mL induced seroconversion in 78% of foxes. There was no significant difference in the development of antibodies in foxes receiving 1, 2 or 3 mL volumes of vaccine in the bait. When baits were exposed to the elements and fed to foxes over a 21 day period, 85% of the animals seroconverted. Age, sex and the way in which the vaccine container was contacted did not appear to be factors in the responses of these animals. Juvenile foxes, approximately six months of age, were marked more readily with the tetracycline bait marker than older animals. Approximately 25% of foxes did not appear to respond well to vaccination and the titer of the vaccine was a critical factor in producing seroconversion in these animals.  相似文献   
74.
Electromyography (EMG) was used to detect myotonic discharges in Quarter Horse breeding stock and to follow the results of mating horses with hyperkalemic periodic paralysis (HPP). The studies were performed on two brood mare farms. A total of six breeding stock showed myotonic discharges and 15 were nonmyotonic. Myotonic discharges were seen in five of six horses belonging to the blood line previously implicated as being predisposed to HPP. Two of these horses had shown clinical signs of HPP. Only one of 15 breeding horses unrelated to the HPP predisposed blood line showed myotonic discharges. When both parents were non-myotonic on EMG than the F1 generation (n = 6) were also nonmyotonic. When a stallion with HPP and myotonic discharges was mated to eight nonmyotonic mares over a six year period half the animals of the F1 generation (n = 25) showed myotonic discharges. When both parents showed myotonic discharges four F1 offspring were myotonic and two were nonmyotonic on EMG testing. There was no evidence of sex linkage. The results are consistent with an autosomal dominant mode of inheritance. Hyperkalemic periodic paralysis and myotonic discharges on EMG may be different manifestations of the same underlying defect.  相似文献   
75.
76.
Multispecific resistance to benzimidazoles was studied in three selected farms. These farms had bred dairy goats for more than 15 years. The helminths were introduced with the goats at the establishment of the farms which afterwards remained isolated. Nematode resistance could then be related to their own management practices. Faecal egg count tests and egg hatch assays were performed to assess intensity of resistance. The generic (infective larvae in faecal cultures) and specific richness (adult worms) were assessed. The resistant species were Trichostrongylus colubriformis, Teladorsagia circumcincta, Haemonchus contortus and Oesophagostomum venulosum. Faecal egg count reduction tests and egg-hatch assays did not match exactly. Faecal larval counts after treatments gave a distorted picture of multispecific resistance: Haemonchus and Oesophagostomum were very largely over represented. The number of species found in the three farms was relatively low compared with other reports in goat farms of the area. This reduction of diversity might also be due in part to characteristics of breeding management and history (use of permanent pasture and introduction of goats at the establishment of farm).  相似文献   
77.
应用已建立的鸡肿瘤病快速鉴别诊断技术对源自安徽省5个不同地区的46个鸡群的肿瘤病、抑制病疑似病、死鸡305羽进行检测。结果表明,马立克氏病的阳性率为39.34%(120/305),禽网状内皮组织增生征阳性率为8.52%(26/305),禽白血病阳性率为2.624%(8/305);另对17群未进行MD免疫的肉鸡进行随机抽样检测,其中5个鸡群检测出马立克氏病病毒强毒,阳性率为29.41%(5/17),阳性群的平均检出率为24 %。  相似文献   
78.
川北地区稻田养殖中华绒螯蟹试验初探   总被引:2,自引:0,他引:2  
本试验在四川山间湿地利用农田0.62公顷养殖中华绒螯蟹,放养苗种为1272只(135只/667m^2),个体均重7g/只左右,经160d饲养,捕获绒螯蟹875只,个体均重136.7g/只,回捕率为68.8%,饵料系数为2.45,同时水稻产量3529.7kg(375.5kg/667m^2),其总收获利润为416元/667m^2。  相似文献   
79.
介绍了不确定度理论及其评定方法,结合车辆碰撞事故的具体特点,给出了基于能量守恒的车速计算表达式.通过选择适当的输入参数作为不确定因子,分别计算各分量等效速度标准不确定度.考虑不确定度累积和传播,得到车速输出结果的合成标准不确定度和展伸不确定度,以此检验事故再现结果的准确程度.通过具体事故案例的分析计算和计算机检验,验证该方法的适用性.  相似文献   
80.
利用高分辨快原子轰击质谱(HR-FABMS),以(甘油 氯化钠)为基质测定了9个新的β-二氢沉香呋喃倍半萜多酯和生物碱的HR-FABMS。结果表明,所有该类化合物均可以精确地获得[M Na] ,[M H] ,[M H-H2O] 等特征离子的质量和元素组成,从而方便地获得原有该类化合物的分子量和分子式。  相似文献   
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