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151.
Resistance to western flower thrips in greenhouse cucumber: effect of leaf position and plant age on thrips reproduction 总被引:1,自引:0,他引:1
Willem Jan de Kogel Anneke Balkema-Boomstra Marieke van der Hoek Sierd Zijlstra Chris Mollema 《Euphytica》1997,94(1):63-67
Three greenhouse cucumber (Cucumis sativus L.) accessions, previously selected for low levels of damage after infestation
with Frankliniella occidentalis (Pergande), were tested for resistance against F. occidentalis in a no-choice greenhouse experiment
at the mature plant stage. The three accessions showed a strong reduction in thrips damage compared to the susceptible control.
The effects of leaf position and plant age of the four cucumber accessions on the reproduction of F. occidentalis were determined
in a leaf disc assay. Leaf position had a significant effect on thrips reproduction, whereas plant age, within the test range,
had not. In general, reproduction was higher on young leaves. Reproduction as measured on leaf discs from certain leaf positions
was strongly correlated with resistance of mature plants in the greenhouse, and can therefore be used as a quick test to screen
cucumber accessions for resistance against thrips.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
152.
黄瓜的分子标记和连锁图谱研究进展 总被引:4,自引:0,他引:4
黄瓜分子标记和遗传连锁图谱的研究工作相对番茄、小麦等作物比较落后,至今开展的分子标记研究多围绕黄瓜遗传关系分析进行,现有的几张遗传连锁图谱基本是由美国Staub研究小组完成,已被定位在图谱上的同工酶、RAPD、RFLP、SSR、AFLP等标记总数达到300多个,各标记间平均距离达到2.1cM,被整合在一起的遗传基因不足10个(F、B、de、ll、dm)。 相似文献
153.
Environmental effects on genetic variation for chilling resistance were studied in nine cultivars and breeding lines (referred
to as cultigens hereafter) of cucumber (Cucumis sativus L.). Five experiments were carried out in controlled-environment chambers
to measure the effects of growth temperature, photoperiod, duration of chilling, light level during chilling, and watering
frequency on chilling resistance of seedlings at the cotyledon and first true leaf growth stages. Significant interactions
were found between cultigen and all environmental factors studied except for the photoperiod and watering frequency. Cultigen
rank was affected by growth temperature before chilling, chilling duration, and light level during chilling, but shifts in
rank were not consistent. Genetic variation was largest when the plants were grown at 22/18 °C, most pronounced after a chilling
duration of 5 to 9 hours and a light level during chilling of 270 μmol·m-2·s-1. Variation was larger at the first true leaf stage than at the cotyledon stage. Differences among cultigens in chilling damage
were largest 5 days after chilling. Therefore, it seems that testing for genetic variation in chilling damage can be restricted
to one set of environmental conditions. We recommend the following conditions for screening cucumber for genetic variation
in chilling resistance: grow the plants at 22/18 °C, under a 9-hour photoperiod with a 3-hour night interruption, water them
once daily, subject them at the first true leaf stage to a chilling treatment of 7 hours at 4°C at a light level of 270 μmol·-2·s-1, and evaluate damage 5 days after treatment.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
154.
Inbred lines derived from the Chinese cucumber (Cucumis sativus L.) cultivar, ‘Taichung Mou Gua’ (TMG), have been shown to
be resistant to several potyviruses including: zucchini yellow mosaic virus (ZYMV), zucchini yellow fleck virus (ZYFV), watermelon
mosaic virus (WMV) and the watermelon strain of papaya ringspot virus (PRSV-W). Recently, an additional virus that infects
cucurbits, the Moroccan watermelon mosaic virus (MWMV), has been determined to be a distinct member of the potyvirus group.
This study demonstrates that TMG-1 possesses resistance to MWMV. Rub or aphid inoculated TMG-1 seedlings remain free of symptoms.
Progeny analyses of the F1, F2 and backcross generations show that resistance to MWMV is conferred by a single recessive gene (proposed designation, mwm).
Sequential inoculation of progeny possessing resistance to ZYMV followed by MWMV (or MWMV followed by ZYMV) and analysis of
F3 families derived from F2 individuals selected for resistance to ZYMV indicate that both resistances are conferred by the same gene, or two tightly
linked genes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
155.
Effects of Temperature on Pollen Tube Growth and Fruit Set in Reciprocal Crosses Between Cucumis sativus and C. metuliferus 总被引:1,自引:0,他引:1
Interspecific hybridization between Cucumis sativus and C. metuliferus may be used to introduce disease resistance into the cultivated cucumber. Hybrid plant development, however, is restricted by strong barriers to crossing. The present study was undertaken to examine temperature effects on pollen tube growth and fruit set in reciprocal crosses between C. sativus and C. metuliferus. When crossing C. sativus×C. metuliferus, at 20°C, pollen tube growth was arrested in the stylar region of the pistil and no fruits containing embryos were found. However, at 23° and 26°C, C. metuliferus pollen tubes penetrated into the C. sativus ovules. The enhanced pollen tube penetration was correlated with improved embryo development. Although pre-fertilization barriers were overcome, post-fertilization barriers caused abortion of hybrid embryo development at the globular stage. No effects of higher temperatures were found in the cross C. metuliferus×C. sativus; Pollen tubes were generally arrested in the stylar region of the pistil. 相似文献
156.
A synthetic amphidiploid species Cucumis hyriviis Chen & Kirkbride (2n = 4x = 38; genome designated as HHCC) has recently been created from an interspecific mating between C. sativus L. (2n = 2x = 14: genome designated as CC) and C. hystrx. Chakr. (2n = 2x = 24; genome designated as HH). This amphidiploid is resistant to root knot nematode, tolerant to low irradiance, and has higher nutritional value than standard processing cucumber cultivars. An allotriploid (2n = 3x = 26; HCC) was derived from a cross between C. sativus L. and C. hytivus Chen & Kirkbride. Diploid meiotic behaviour in C. sativus and C. hystrix involves the development of seven and 12 metaphase bivalents respectively. In the derived allotriploid. univalents. bivalents, and trivalents (at relatively low frequency) were observed at metaphase I indicating that some homeologues from the C and H genomes can synapse. Based on a comparative karyotype analysis of cucumber (i.e. chromosome size and pairing behaviour) and aliotriploid plants, the seven bivalents observed at metaphase I were ascertained to be cucumber homologues, while the 12 univalents were of C. hystrix origin thus confirming the allotriploid karyotypic constitution to be HCC. On average, the frequency of trivalents was 0.24 at diakinesis and 0.22 in 100 meiocytes at metaphase I. indicating the possibility of genetic exchange due to the homoeology between the C and H genomes. After simultaneous cytokinesis, only polyads were observed in pollen mother cells (PMCs) at telophase II, which led to the production of sterile pollen grains. Multi‐polarization of chromosomes was dominant at anaphase II. However. in about 20% PMCs. chromosomes separated to form a 7C + 1‐2H complement, suggesting a possible method for the production of alien addition cucumber‐C hystrix lines through further backcrossing of the allotriploid to diploid cucumber. 相似文献
157.
A set of 155 SSR (107) and SCAR (48) markers were used to evaluate 53 cucumber (Cucumis sativus L.) accessions of diverse origin to characterize genetic relationships and to define a standard marker array that was most effective in detecting genetic differences in this germplasm array. A multivariate marker‐based analysis of diverse germplasm using this standard marker array (17 SSR and 5 SCAR markers) was compared with results from a set of 70 previously reported RAPD markers, and then used to explore the potential value of these genetic markers for plant variety protection (PVP) and the establishment of essential derivation (ED) threshold values in this species using elite lines and hybrids and backcross progeny. Diversity analysis allowed identification of distinctly different lines that were used for the construction of three sets of backcross families (BC1‐BC3). While general genetic relationships among accessions were similar in SSR/SCAR analyses (rs= 0.65) using two genetic distance (GD) estimators, differences in accession relationships were detected between RAPD and SSR/SCAR marker evaluations regardless of the estimator used. The GDs among elite germplasm with known pedigrees were relatively small (0.06‐0.23 for any pairwise comparison). GD values decreased and degree of fixation (at three to seven loci depending on the mating) increased with increased backcrossing such that recurrent parent allelic fixation occurred in least one family of each of the BC3 families. In many instances the degree of fixation of loci was not uniformly achieved in the BC3. Although the level of genetic polymorphisms will likely restrict the use of molecular markers for PVP and the establishment of ED values, the use of single nucleotide differences will likely provide opportunities to define specific functional distances that have potential for PVP in cucumber. Nevertheless, without an expanded, genetically robust standard marker array (e.g. 50 codominant markers), ED threshold values will be difficult to define in this species, and perhaps will require the appraisal of single nucleotide polymorphisms as discriminators of difference in this species. 相似文献
158.
M. I. E. Arabi 《Plant Breeding》2005,124(6):605-607
Diallel crosses (without reciprocals) were made among 10 different barley genotypes with genetic variability for spot blotch resistance. Forty‐five F1 hybrids and their parents were assessed for their combining abilities for the disease resistance. Three experiments, two in a growth chamber on detached leaf and seedlings tests and one in the field on adult plant stages, were undertaken using a randomized complete block design with five replicates. A mixed conidial suspension of nine virulent isolates of the pathogen was used for inoculation. Statistical analysis showed genetic variability for spot blotch resistance. Results showed that the cultivar Banteng, the Ethiopian line CI‐5791 and the Syrian line 79‐SIO‐9 had partial resistance in all experiments. General combining ability was significant, with either positive or negative values. Resistant genotypes show favourable GCA‐effects, and they could therefore be successfully used for breeding purposes. 相似文献
159.
An in vitro technique was used to quantify the infection level of common root rot. This disease produces a brown to black discoloration of the subcrown internodes of barley. Quantification was based on the percentage of germinated infected pieces (1.5 mm) of subcrown internodes cultured on potato dextrose agar media. The disease severity was apparent among four different visually classified categories and numerical values for each category were applied. The results were highly correlated (r = 0.97, P < 0.01) among the different in vitro experiments, indicating that this testing procedure is repeatable. Highly significant differences (P < 0.001) were found for the length of first leaf and fresh weight between plants inoculated and uninoculated with common root rot. However, the effect of inoculation on fresh weight only differed significantly (P < 0.02) among the genotypes. 相似文献
160.