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21.
In 2001 a new Pestivirus (Family Flaviviridae) was associated with an outbreak of a previously unreported disease in Pyrenean chamois (Rupicapra pyrenaica) in the Pyrenees (NE Spain). Molecular characterization assigned this virus to the Border Disease Virus (BDV) cluster, BDV-4 genotype. A retrospective study was performed in archived sera and spleen of 74 Pyrenean chamois and in archived sera of 28 mouflon (Ovis ammon), 56 red deer (Cervus elaphus), 43 roe deer (Capreolus capreolus) and 29 fallow deer (Dama dama) from the Pyrenees between the years 1990 and 2000. Thirty six of 74 (48.6%) sera of Pyrenean chamois, one of mouflon and one of red deer were positive by an ELISA antibody test. Comparative virus neutralization tests were performed on 26 seropositive chamois, one mouflon and one red deer, using five pestivirus strains. An ELISA antigen test was performed on 37 seronegative chamois and yielded positive results in one chamois and inconclusive result in two. RT-PCR and virus isolation performed on spleen samples from these three animals gave positive results in the positive and one inconclusive animal. Sequence analysis in the 5' unstranslated region revealed that they were grouped into the BDV-4 genotype. Virological and serological data of the present study indicate that BDV infection has been present in the chamois population since at least 1990, 11 years before the first outbreak of disease. Therefore, the emergence of the disease in 2001 is apparently due to other factors rather than the introduction of a new virus in the chamois population.  相似文献   
22.
For two consecutive years nine hybrids and three varieties of tomato, four Lycopersicon peruvianum and four Lycopersicon chilense accessions were screened for Tomato yellow leaf curl virus (TYLCV) resistance. Three inoculation techniques using Bemisia tabaci, the vector of TYLCV, were compared: (1) artificial mass inoculation-simultaneous infection of cultivated and wild material in greenhouses; (2) artificial cage inoculation-individual infection in insect-proof cages; (3) natural field infection. Artificial inoculations led to higher levels of infection, but different patterns of response to each inoculation technique were found depending on the resistance level. Tomato varieties showed an important fruit set reduction after both artificial and natural inoculations. In contrast, field infection was milder in tomato hybrids, in which yield was barely affected. These hybrids showed a wide range of reactions with the two artificial inoculation techniques, but infection was always more severe after mass inoculation. Extreme severity of mass infection made it difficult to differentiate among variable degrees of resistance that were more reliably detected with cage inoculation. The hybrids F3524, F3522, Fiona, and Tyking showed the highest level of resistance. F3524 and F3522 had an acceptable yield in field and cage assays, but their resistance collapsed under massive conditions of infection. Tyking and Fiona exhibited the best response in all conditions, although their yield was moderately reduced in mass assays. Mass inoculation was not adequate for the screening of wild Lycopersicon. Some susceptible plants escaped infection, probably as a consequence of non-preference mechanisms and loss of vector infectivity. Individual inoculation in cages prevented the risk of non-infection, ensuring 100% disease incidence. This technique allowed the selection of highly resistant wild sources. L. chilense LA 1969 and LA 1963 had the highest level of resistance with the three inoculation techniques. L. peruvianum PI-126944 and L. chilense LA 1932, which were only tested in mass and field conditions, also exhibited a promising response. The results proved that the inoculation technique influences the response of tomato and wild Lycopersicon spp to TYLCV. It is concluded that artificial cage inoculation, although more time-consuming, is the most efficient, adequate, and reliable technique to screen both cultivated and wild Lycopersicon species for resistance to TYLCV. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
23.
S. Roselló    S. Soler    M. J. Díez    J. L. Rambla    C. Richarte  F. Nuez 《Plant Breeding》1999,118(5):425-429
Mechanical inoculation and transmission by thrips in a growth chamber were used in order to screen Lycopersicon peruvianumand Lycopersicon chilense germplasm for tomato spotted wilt virus (TSWV) resistance. Two highly aggressive Spanish TSWV isolates (HA-931100 and T-941117), having different restrictotypes were used. L. peruvianum accessions PI-126935, PI-126944, CIAPAN 16, PE-18 and CIAPAN 17 showed high resistance to both isolates in mechanical and thrips transmission. Their resistance appears useful in breeding programmes.  相似文献   
24.
Tomato mosaic virus (ToMV) is a limiting factor for the success of pepino (Solarium muricatum) as a new crop. The effects of ToMV infection on total and marketable yield, fruit weight, length/width ratio and soluble solids content (SSC) have been studied in two commercial clones (`Sweet Long' and `Sweet Round'). ToMV infection depressed total yield in infected plants of `Sweet Long' (43.1%), while it had no effect on this trait in `Sweet Round' . Marketable yield was dramatically reduced by ToMV infection in both clones, 94% in `Sweet Long' and 100% in `Sweet Round'. Infected plants of clone `Sweet Long' had a lower weight than healthy plants. Although no differences in fruit weight were detected in `Sweet Round' between ToMV infected and healthy plants, many fruits from infected plants showed deformities. Changes in fruit length/width ratio and SSC as a result of ToMV infection were not relevant, but fruit quality was lower in infected fruits, most of which had corky-like flesh. Forty-two clones from cultivated (S. muricatum), wild (S. caripense and S. tabanoense) and interspecific hybrids were tested for ToMV resistance. All but seven clones (four from S. muricatum and three from interspecific hybrids S. muricatum × S. caripense) were susceptible. Non-susceptible clones showed variable degrees of resistance and developed hypersensitive local lesions. Among these clones the most promising as sources of variation for resistance to ToMV are those belonging to the cultivated species. Although no immunity was found, plants from these clones remained asymptomatic and absorbance values resulting from the DAS-ELISA tests in these plants were always lower than those of the susceptible control (cv. `Sweet Round'). These sources of resistance may be of great utility in developing commercial clones resistant to this severe disease affecting pepino. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
25.
1 概况西班牙是欧洲蔬菜作物的主要出口国 ,在产量上仅次于意大利 (Edican ,1998)。许多地区气候温和 ,可以生产反季节蔬菜 ,接近 (EU)欧盟市场 ,交通便利 ,使产品在收割之后几天或几小时即可上市 ,建立在现代生产和存贮技术、优良品种及蔬菜生产者的经验之上的高质量的产品 ,促成了西班牙在这一农业领域的发展 (Ali&Briz,2 0 0 0 )。这使西班牙成为世界上蔬菜生产发展及技术水平最高的国家之一(Nuez,Liacer,2 0 0 0 )。现在蔬菜的产量比 1950年高 3倍 ,而蔬菜种植面积只是原来 1 7倍 (MAPA ,1997)。产量的…  相似文献   
26.
The aim of this study was to identify ultrasound accessible blood vessels in the loggerhead sea turtle (Caretta caretta) and describe their Doppler waveform patterns, peak systolic velocity, mean velocity, systolic/diastolic ratio as well as pulsatility and resistive indices. B-mode, colour and pulsed-wave Doppler examinations were performed on 10 turtles. Flow measurements were recorded for the left and right aorta, epigastric and internal iliac arteries, and right hepatic vein. Additionally, the large blood vessels of three dead turtles were injected with latex and dissected for anatomical support. A parabolic flow velocity profile was observed in all arteries. The waveforms of the right and left aortic arteries showed an unusual pattern when compared with mammals. The hepatic vein flow velocity waveform of the loggerhead sea turtle was found to be similar to that in the dog, although the flow velocity in the C-wave was higher than that in the A-wave. The low resistance flow pattern observed suggests that the loggerhead sea turtle's organs require a continuous blood supply.  相似文献   
27.
28.
The Capsicum genus is native to tropical America and consists of 27 species, five of which are used as fresh vegetables and spices: Capsicum annuum L., Capsicum chinense Jacq., Capsicum frutescens L., Capsicum baccatum L. and Capsicum pubescens R. et P. The study of the relationships among species of cultivate Capsicum species will be useful for breeding new cultivars or hybrids. This study is focused on the genetic diversity and relationships of these species that were collected in the Andean region. Ten microsatellites and four AFLP combinations were used to characterize 260 Capsicum accessions. The AFLP tree turned out to be informative regarding relationships among species. The data clearly showed the close relationships between C. chinense and C. frutescens. Moreover, C. cardenasii and C. eximium were indistinguishable as a single, morphologically variable species. Our data showed C. baccatum and C. praetermissum to be distinct species that form a compact group. In the present work, AFLP fingerprinting indicated that C. chacoense was placed in the C. baccatum complex and showed C. tovarii as a separate species. In addition, SSR data indicated that there is intraspecific differentiation in the species C. chinense, C. baccatum and C. pubescens, as the PCoA-based clustering showed a clear geographic division related to country. Even though Bolivia is considered to be the nuclear area for these species, we have found similar variability in Ecuador and Peru for several Capsicum species.  相似文献   
29.
Chamois have been translocated for more than 100 years but their stress response to transport remains to be elucidated. In this study, 21 free-ranging Southern chamois were captured, physically restrained and then transported. The animals were randomly injected intramuscularly with acepromazine (nine adult males, one adult female and one yearling male) or saline (five adult males, two adult females and three yearling males). Heart rate and body temperature were monitored with telemetric devices, and blood samples were obtained at capture, immediately before and immediately after transport to determine haematological and serum biochemical parameters. Heart rate and blood parameters (erythrocytes, haemoglobin, packed cell volume, leukocytes, monocytes, band neutrophils, lactate, muscular enzymes and creatinine) indicated that transport was more stressful than previous physical restraint. Acepromazine reduced the adverse consequences of transport stress, as demonstrated by heart rate, body temperature, cortisol, creatinine, muscular enzymes, urea, sodium and potassium.  相似文献   
30.
An additive-dominance, additive × additive (ADAA) and genotype × environment interaction mix model was used to study the genetic control of β-carotene and l-ascorbic acid in six basic generations (P1, P2, F1, F2, BC1P1 and BC1P2) of tomato derived from the cross CDP8779 accession (Solanum lycopersicum L.) × CDP4777 accession (S. lycopersicum var. cerasiforme). The study was performed in two environments: (1) open field; (2) protected environment, consisting of hydroponic cultivation in a glasshouse. The results indicate that β-carotene accumulation was mainly additive (32.2% of the genetic component), with a small dominant component (4.2%) and an important additive × environment interaction contribution (63.6%). In target environments with moderate to high temperatures and no limiting radiation, this the expression additive × environment interaction could substantially enhance the β-carotene content. This trait showed also a high narrow-sense heritability (h 2 = 0.62). Ascorbic acid accumulation was also mainly additive (61.7% of the genetic component), with a minor additive epistatic component (21.5%). This epistatic effect caused a negative heterosis that reduced the positive main additive effect. Nevertheless, in the described target environments, the additive × environment interaction contribution (16.8%) may enhance the ascorbic acid content and compensate for the negative heterosis effect. The total narrow-sense heritability of this trait can be considered useful (h 2 = 0.52). In conclusion, the CDP4777 accession is a very interesting donor parent for the joint improvement of β-carotene (without diminishing lycopene content) and ascorbic acid content in commercial nutraceutical tomato breeding programmes; the F1 hybrids derived from this accession showed nearly 450% of the commonly reported average β-carotene content and close to 130% of the ascorbic acid content of the female parent.  相似文献   
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