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991.
Syed Jawad Ahmad Shah Shaukat Hussain Musharaf Ahmad Farhatullah Iftikhar Ali Muhammad Ibrahim 《Journal of General Plant Pathology》2011,77(3):174-177
Fifty wheat varieties along with Jupateco-73 and Morocco were studied for the expression of leaf tip necrosis (LTN), a trait
linked with the durable rust resistance gene pair Lr34/Yr18. LTN was frequent (i.e., ≥6) in nine replications of a field experiment over 3 years in 17 genotypes, and the varieties were
considered positive for LTN. In molecular analyses of these varieties, having relative severity values up to 78 for yellow
rust and 45 for leaf rust, the 150-bp Lr34/Yr18-linked allele was consistently amplified. Expression of LTN in six of nine replications is an appropriate threshold for predicting
the presence of Lr34/Yr18 gene pair, and genotypes can be selected using this trait. 相似文献
992.
Jun Ohnishi Toshio Kitamura Fumihiro Terami Ken-ichiro Honda 《Journal of General Plant Pathology》2011,77(1):54-59
The ability of the whitefly Bemisia tabaci to transmit two strains of Tomato yellow leaf curl virus, the Israel and Mild strains, was studied after serial transfers of individual whiteflies that were viruliferous for both
strains to tomato plants. After single whiteflies had successive acquisition feedings first on a single plant infected with
one strain and then on a plant infected with the other strain, the single whiteflies later transmitted intermittently one,
the other, or both strains to the test plants during serial transfers at 1-day intervals. Because both strains were found
in the head, abdomen, and legs dissected from whiteflies during the retention period after the two successive acquisition
feedings, both strains apparently circulate from midgut cells to salivary glands through the hemolymph. 相似文献
993.
Kuko Fuke Kana Takeshita Nanako Aoki Toshiyuki Fukuhara Mayumi Egusa Motoichiro Kodama Hiromitsu Moriyama 《Journal of General Plant Pathology》2011,77(4):248-252
Strains of the Japanese pear pathotype of Alternaria alternata were screened for double-stranded RNAs (dsRNAs). Four strains had several dsRNAs; strain N18 was associated with several
dsRNAs and had impaired growth phenotypes such as irregular mycelium and abnormal pigmentation. We isolated dsRNA-cured isolates
from strain N18 by single-conidium isolation. The dsRNA-cured isolates had recovered normal growth and pigmentation. Enlarged
vesicles were observed in mycelial cells of the original dsRNA-carrying N18 strain. DAPI nuclear staining revealed regression
of the nuclei in dsRNA-carrying N18 cells. These results indicate that the dsRNAs might have negative effects, such as apoptosis-like
cell death, on the host fungus. 相似文献
994.
Shinpei Banno Hidenari Saito Hiroshi Sakai Toshihiko Urushibara Kentaro Ikeda Takeshi Kabe Isao Kemmochi Makoto Fujimura 《Journal of General Plant Pathology》2011,77(5):282-291
Verticillium longisporum and V. dahliae, causal agents of Verticillium wilt, are spreading through the cabbage fields of Gunma Prefecture. Using the V. longisporum-specific intron within the 18S rDNA and differences between ITS 5.8S rDNA sequences in Japanese isolates of V. longisporum and V. dahliae, we developed three quantitative nested real-time (QNRT) PCR assays. The QNRT-PCR quantification of V. longisporum or V. dahliae in cabbage field soil was consistent with the severity of Verticillium wilt disease in those fields. In field trials of resistant
cultivar YR Ranpo grown for three seasons in soil infested with the pathogen, disease severity and pathogen density in the
soil were significantly reduced in a field moderately contaminated by V. dahliae, but only slightly reduced in a highly contaminated field. These results suggest that continuous cultivation of a resistant
cultivar is an effective way to reduce the pathogen population. QNRT-PCR assays provide a powerful analytical tool to evaluate
the soil population dynamics of V. longisporum and V. dahliae for disease management. 相似文献
995.
Here Fusarium oxysporum was killed in exudates obtained from soil biologically disinfested with ethanol, indicating that physical interaction with
soil microorganisms was not essential. Because acetic acid was confirmed to accumulated during the treatment, we evaluated
the effect of acetic acid amendment against the pathogen in plastic containers. A drop in the soil redox potential seemed
to be correlated with the fungicidal efficacy of acetic acid. Under reductive soil conditions, metal ions such as Mn2+ and Fe2+ formed, and the pathogen was effectively suppressed in Mn2+ and Fe2+ solution. Therefore, Fe2+ and Mn2+ may be the agents that induce suppression of the pathogen during biological soil disinfestation. 相似文献
996.
Background
Safflower (Carthamus tinctorius L.) is a difficult crop to genetically transform being susceptible to hyperhydration and poor in vitro root formation. In addition to traditional uses safflower has recently emerged as a broadacre platform for the production of transgenic products including modified oils and pharmaceutically active proteins. Despite commercial activities based on the genetic modification of safflower, there is no method available in the public domain describing the transformation of safflower that generates transformed T1 progeny.Results
An efficient and reproducible protocol has been developed with a transformation efficiency of 4.8% and 3.1% for S-317 (high oleic acid content) and WT (high linoleic acid content) genotypes respectively. An improved safflower transformation T-DNA vector was developed, including a secreted GFP to allow non-destructive assessment of transgenic shoots. Hyperhydration and necrosis of Agrobacterium-infected cotyledons was effectively controlled by using iota-carrageenan, L-cysteine and ascorbic acid. To overcome poor in vitro root formation for the first time a grafting method was developed for safflower in which ~50% of transgenic shoots develop into mature plants bearing viable transgenic T1 seed. The integration and expression of secreted GFP and hygromycin genes were confirmed by PCR, Southern and Western blot analysis. Southern blot analysis in nine independent lines indicated that 1-7 transgenes were inserted per line and T1 progeny displayed Mendelian inheritance.Conclusions
This protocol demonstrates significant improvements in both the efficiency and ease of use over existing safflower transformation protocols. This is the first complete method of genetic transformation of safflower that generates stably-transformed plants and progeny, allowing this crop to benefit from modern molecular applications.997.
Antonio Evidente Rossitza Rodeva Anna Andolfi Zornitsa Stoyanova Carmen Perrone Andrea Motta 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):173-182
Recently, a new fungal disease caused by Diaporthe angelicae (anamorph Phomopsis foeniculi) has been found with increasingly frequency on fennel (Foeniculum vulgare) in Bulgaria. Using a bioassay-guided isolation and purification procedure, different metabolites were isolated from the
fungal culture filtrates. They were identified by spectroscopic methods as nectriapyrone, a pentaketide monoterpenoid, and
altersolanols A and J and macrosporin, three octaketides anthracenones. Leaf puncture bioassay was applied on detached tomato
leaves to prove the phytotoxic activity of the fractions and of pure compounds. Nectriapyrone and altersolanols A and J showed
a modulated phytotoxicity, while macrosporin was not toxic. Altersolanol A was the most active compound. 相似文献
998.
Abu Shamim Mohammad Nahiyan Louisa Robinson Boyer Peter Jeffries Yoh-ichi Matsubara 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):197-203
The diversity of Fusarium populations in asparagus (Asparagus officinalis L.) decline fields in Japan was estimated by PCR-SSCP (single-stranded conformational polymorphism) analysis of the ITS2
regions of the nuclear rRNA genes. This method was used to rapidly and objectively identify pathogens associated with roots
of plants showing symptoms of asparagus decline collected from fields in five regions across Japan. Over 651 fusarial isolates
were obtained, and were easily differentiated into three principal species. Fusarium oxysporum f. sp. asparagi was most frequently isolated from the domestic five regions (68%), whereas Fusarium proliferatum (28.6%) was less frequent. Fusarium solani was found much rarely (2.5%). The frequency of isolation of Fusarium proliferatum increased gradually from the north to the south of Japan, though considerable differences were found between fields in each
region, as well as regional differences among the Fusarium populations. Most of the fusarial isolates were highly pathogenic in vitro. These results reveal that Fusarium oxysporum f. sp. asparagi and Fusarium proliferatum are important biotic factors which lead to asparagus decline in Japan. 相似文献
999.
Yared Tesfai Tewoldemedhin Mark Mazzola Lizel Mostert Adéle McLeod 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(4):637-651
Cylindrocarpon species are known to be a component of the pathogen/pest complex that incites apple replant disease. In South Africa, no
information is available on apple associated Cylindrocarpon species and their pathogenicity. Therefore, these aspects were investigated. Among the isolates recovered from apple roots
in South Africa, four species (C. destructans, C. liriodendri, C. macrodidymum and C. pauciseptatum) were identified using β-tubulin gene sequencing and phylogenetic analysis. This is the first report of C. liriodendri, C. macrodidymum and C. pauciseptatum on apple trees. Cylindrocarpon macrodidymum was the most prevalent. Isolates within each of the four species were pathogenic towards apple seedlings, but varied in their
virulence. With a single exception, all isolates were able to induce lesion development on seedling roots. Only 57% of the
isolates, which represented all four species, were able to cause a significant reduction in seedling weight and/or height.
The greatest seedling growth reductions were caused by two isolates of C. destructans, and one isolate each of C. liriodendri and C. macrodidymum. A quantitative real-time polymerase chain reaction (qPCR) method was developed for simultaneous detection of all four Cylindrocarpon species. qPCR analyses of Cylindrocarpon from the roots of inoculated seedlings showed that the amount of Cylindrocarpon DNA in roots was not correlated to seedling growth reductions (weight and height) or root rot. The qPCR method is, however,
very useful for the rapid identification of apple associated Cylindrocarpon species in roots. The technique may also hold potential for being indicative of Cylindrocarpon disease potential if rhizosphere soil rather than roots are used. 相似文献
1000.
Avia E. Rubin Ayelet-Chen Werdiger Mathias Blum Ulrich Gisi Helge Sierotzki Dietrich Hermann Yigal Cohen 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(2):339-351
Wild type (WT) field isolates of Bremia lactucae failed to germinate in vitro or infect lettuce leaves in the presence of CAA (carboxylic acid amide) fungicides. Minimal
inhibitory concentrations (MIC) for mandipropamid, dimethomorph, benthiavalicarb and iprovalicarb were 0.005, 0.5, 0.5 and
5 μg ml−1, respectively. Mutagenesis experiments showed that spores exposed to EMS (ethyl methane sulphonate) or UV irradiation (254 nm)
could infect lettuce leaves in the presence of up to 100 μg ml−1 CAA. The proportion of infected leaves relative to the number of spores inoculated (infection frequency) was inversely related
to the concentration of CAA used, ranging between 0 and 160 per 1 × 106 spores. Resistant mutants (RM) lost their resistance within 1–14 reproduction cycles on CAA-treated plants. Crosses were
made between RMxWT isolates and RMxRM isolates with an attempt to obtain stable homozygous resistant off-springs. Such crosses
yielded few resistant but unstable progeny isolates. Mutagenic treatments given to hybrid isolates also failed to produce
stable resistance. Previous gene sequencing data showed that stable resistance to CAAs is based on a single SNP in the cellulose synthase 3 (CesA3) gene of Plasmopara viticola. Therefore, we sequenced a 582 bp DNA fragment of Ces3A of WT, RM and hybrid isolates of B.lactucae. No mutation in this gene fragment was found. We conclude that mutagenic agents like EMS or UV may induce resistance to CAA
in Bremia lactucae but this resistance is not stable and not linked to mutations in CesA3 gene. 相似文献