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21.
One hundred and forty-four heterogeneous tef germplasm accessions collected from 10 major tef growing areas in Ethiopia were evaluated for 18 quantitative traits in a simple lattice design, at Holetta and Ginchi, in 2001 main growing season to study the genetic diversity in tef. The combined analysis of variance revealed the presence of significant variation among germplasm accessions for all traits studied. Cluster analysis revealed the overlapping of the germplasm accessions from different origin and the accessions were grouped into eight distinct clusters of 1–78. Generalized distance square confirmed the presence of significant genetic distance between clusters. In principal component (Prin) analysis, the first four principal components with latent root values above one accounted for about 80.6% of the variability existing among the germplasm accessions. Prin1 constituted about 55% of the variability mainly from almost equal contribution of 10 quantitative traits, indicating that most of the traits are equally important in tef diversity. In this study, the regions and altitudes of origin were not found to have a substantial effect on the genetic diversity in tef germplasm. Diversity within the regions was found to be significant and, hence, an opportunity for exploitation in tef improvement.  相似文献   
22.
This article describes amebic infections in 4 horses: granulomatous amebic encephalitis caused by Balamuthia mandrillaris and Acanthamoeba culbertsoni and systemic infections caused by Acanthamoeba sp. The former infection occurred in 1 of 4 horses spontaneously without any underlying conditions; the latter amebic infection was perhaps "opportunistic" considering the visceral involvement by this protozoan in association with Aspergillus sp. and/or Escherichia coli and Pseudomonas sp. The clinicopathologic findings and demonstration of the amebic organisms using immunohistochemical techniques, culture, polymerase chain reactions, and electron microscopy are presented.  相似文献   
23.
以10种不同山革草细胞质的异质小麦品种Chris为胞质供体,77(2)等一系列1B/1R易位系及两个核不育基因相同而胞质不同的正反杂交后代株(系)为核供体,采用杂交、置换回交和转育等方法,在单、偏、粘、易和二角型5种不育胞质源中,选育出易恢复性能极高的新保持系资源.测交和育性分析结果表明:(1)其不育系的F1杂种恢复度均在90%以上.(2)单型不育性主要由一对主效隐性基因控制;偏、粘、易和二角型(1B/1R不育系)则是一种育性基因位点缺失,而仅由1RS片段与对应4种异质构成的互作不育.(3)单型不育系及F1不产生单倍体;偏、粘、易和二角型1B/1R不育系产生单倍体是1B/1R易位染色体与4种异质专一互作后产生不育所带有的一种副效应;但从这4种异质中由新保持系资源培育出的无单倍体不育系可看出,单倍体性可随不育系核遗传背景不同而消失.此外,上述这5种异质不育系不但具有广泛的易恢复性,而且彼此间还存在着一定的互作关系,为简化制种程序提供了极方便的条件.  相似文献   
24.
Barley is one of Ethiopia's major crops. Cultivation is mostly by traditional varieties that are chosen by farmers for their suitability for end-use or their adaptation to specific farming systems. A collection of 155 barley lines was grouped in 13 varieties, according to the name given by the farmers. The collection was evaluated for simple agronomic traits and resistance to barley scald disease. A large level of diversity was found, mainly between varieties, but also within varieties between farms from which the samples originated. In spite of a certain degree of overlapping, these traditional farmer's varieties showed coherence for the characters measured. Earlier maturing varieties were found to be more susceptible to scald, but a number of accessions combined earliness with scald resistance. It is suggested that the traditional variety name be included, next to the physical characters of the collection site, as a parameter to explain the degree of diversity in Ethiopian barley germplasm evaluation. The cultivated area of a number of traditional barley varieties is declining rapidly and special collection missions are needed to preserve this germplasm.  相似文献   
25.
During the first weeks of 2003, after exotic Newcastle disease (END) was confirmed in commercial layer flocks in Southern California, it became apparent that the virus survival information in the literature varied widely and was difficult to extrapolate to current local conditions. The END Task Force used the information available in the literature and the recommendations of research scientists to establish protocols for safely handling manure from infected and depopulated premises. In an attempt to gain more applicable knowledge in the management of contaminated poultry manure in the course of the END outbreak, this virus survival study was designed and implemented. Environmental drag swabs were tested for END virus from two of the early-infected commercial ranches that consisted of several houses following immediate removal of the infected flocks. A total of 293 samples, composed of 168 manure drag swab pools, 72 dropping board swab pools, and 38 compost swab pools from 3 houses (ranch 1), and 180 manure belt scraper swab pools from ranch 2 were analyzed for ND virus isolation and characterization for 21 consecutive days postdepopulation. Thirteen manure drag swab pools (from houses 1 and 3) and two manure dropping board swab pools (from house 3) collected from ranch 1 were positive for END virus at 0, 1, 2, 3, 4, 7, 10, 12, and 16 days postdepopulation. No END virus was isolated after the 16th day following depopulation from any of the samples. All samples from ranch 2 were negative during the entire observation period.  相似文献   
26.
27.
Therapeutic effects of Sodium Iodide (NaI), Potassium Iodide (KI), ground berries of "Endod" (Phytolacca dodecandra) and Penstrip were evaluated on 70 cases of equine hitoplasmosis (EH). Response to each treatment was assessed using clinical examination of the lesions. Statistically significant difference (P = 0.0036) in therapeutic effect was observed among the different remedies. Cases treated either with a combination of NaI and Penstrip (F = 6.34, P = 0.004) or "Endod" and Penstrip (F = 3.64, P = 0.031) demonstrated significant response. The difference in response to treatment between early and advanced cases of EH was statistically significant (t = 2.22, P = 0.0148).  相似文献   
28.
29.
The prevalence of Taenia saginata cysticercosis in cattle slaughtered for meat in Addis Ababa Abattoir, Ethiopia between September 2004 and August 2005 was reported. The examination of various organs of 11227 cattle in Addis Ababa Abattoir showed that 842 (7.5%) were infected with T. saginata cysticercosis. The tongue, masseter muscles, cardiac muscles, triceps muscles and thigh muscles were the main predilection sites of the cysts. The cysts of bovine cysticercosis were also identified on the spleen, intercostal muscles, diaphragm and liver. Out of 10329 male cattle, examined, 783 (7.6%) had cysts of bovine cysticercosis while 59 (6.6%) of the 898 female animals investigated were infected. The animals slaughtered were all adults. No significant difference in prevalence rates was recorded between the sexes. The prevalence of bovine cysticercosis was higher in local zebu cattle breeds than Holstein-Frisian cattle.  相似文献   
30.
Three thousand tef [Eragrostis tef (Zucc.) Trotter] single panicle derived lines representing 60 populations from western and southern parts of Ethiopia were characterized for panicle form, pigmentation of lemma and anther, caryopsis color, number of main shoot culm internodes, and counts of florets/spikelet at the basal, middle and apical parts of the panicle at Debre Zeit Agricultural Research Center during the 1999 main season. The objectives were to assess the diversity patterns of the germplasm with respect to regions and altitude zones. Among the eight characters, high Shannon-Weaver diversity indices (H’) were noted for anther color (0.71) and number of apical spikelet florets (0.68), and the lowest occurred for panicle form (0.40). Monomorphism (H’ = 0.00) was observed for panicle form, lemma color and number of middle spikelet florets each in three different populations. The overall diversity index for all populations was 0.53. In the analysis of variance of H’ estimates, substantial (p <0.05) regional differences were obtained for lemma color, number of culm internodes, and counts of middle and basal spikelet florets. Clinal variation was significant for panicle form, lemma and seed color, and for the overall mean of traits. Over all traits, mean H’ values declined from 0.60 to 0.46 with an increase in the altitude zone of origin from below 1800 to over 2400 meters above sea level. Overall, the study showed substantial diversity in the test tef germplasm. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
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