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321.
Melon aphid performance on chrysanthemum as mediated by cultivar, and differential levels of fertilization and irrigation 总被引:4,自引:0,他引:4
James A. Bethke Richard A. Redak Ursula K. Schuch 《Entomologia Experimentalis et Applicata》1998,88(1):41-47
Population parameters of the melon aphid, Aphis gossypii Glover, were compared for insects grown on six cultivars of chrysanthemum, Dendranthema grandiflora Tzvelev ('Fontana', 'Iridon', 'Pink Lady', 'Splendor', 'White Diamond', and 'White View Time') fertilized with 3 different levels of nitrogen (80, 160 and 240 mg N/l) and 2 levels of irrigation (high 300 ml and low 210 ml every other day). Fecundity, longevity, and survivorship of aphids were significantly affected by the cultivar treatment, but were not affected by irrigation or fertilizer treatments or by any combination of interactions among cultivar, fertilizer and irrigation. Significantly fewer aphids survived on the cultivar 'Pink Lady' (populations reduced by 20.8%) than any other cultivar examined. Intrinsic rates of increase r
m
, finite rates of increase (R
0), and population doubling times (DT) for aphids were different among fertilizer levels and cultivars, but were not different among irrigation levels. There were no significant fertilizer by irrigation interaction effects upon r
m
, R
0, or DT. The highest rate of fertilizer applied (240 mg N/liter) adversely affected the intrinsic rate of increase of melon aphids; however, aphid intrinsic rate of increase was weakly correlated with foliar soluble protein levels (r=0.989, P=0.0954). Foliar soluble protein levels were not associated with fertilization treatment. Melon aphids perform consistently better on the cultivars 'White Diamond', 'Fontana', and 'Splendor', relative to those aphids growing on 'Iridon', 'Pink Lady', or 'White View Time'. In general, melon aphids performed best on 'White Diamond' and poorest on 'Pink Lady'. 相似文献
322.
Water-soluble polysaccharide material comprising d-galactose (53·0%), l-arabinose (33·2%) and d-glucuronic acid (13·8%) has been isolated from the leaves of Phaseolus atropurpureus. Acid hydrolysis, periodate oxidation and methylation have indicated a highly branched structure. The principal interglycosidic linkages have been tentatively identified as 1,3- and 1,6-linked d-galactopyranose and 1,3-linked l-arabinofuranose residues. In synthesising polysaccharide with these structural features, P. atropurpureus differs from other legumes such as soybean, lucerne and Centrosema. 相似文献
323.
In flag leaves of four cultivars of barley (Hordeum vulgare L.) grown in the field under a triple-line-source sprinkler system,
that produces a linear soil salinity gradient, a decrease in net carbon dioxide assimilation rate (PN) and stomatal conductance for water vapour (gs) was found. These changes were related to salinity tolerance at moderate salinity.
With increasing salinity, PN was saturated at low irradiances and stomatal frequencies increased. A decrease in photosystem 2 (PS2) efficiency was not
found in the field after dark adaptation even at high salinity. Salinity induced only small decreases in the actual PS2 efficiency
at midday steady-state photosynthesis, indicating that the photosynthetic electron transport was little affected by salinity.
Therefore, using PS2 efficiency estimates in attached leaves is probably not a useful tool to screen barley genotypes grown
under saline conditions in the field for salinity tolerance. In contrast, excised flag leaves from high salinity plots, once
in the laboratory, exhibited a decrease in the variable to maximum chlorophyll fluorescence ratio as compared to excised leaves
from control plants. On the other hand, the PN rate might allow for a good discrimination between tolerant and non-tolerant
cultivars.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
324.
Effect of sorbitol concentration on regeneration of embryogenic calli in upland rice varieties (Oryza sativa L.) 总被引:1,自引:0,他引:1
Pengpeng Geng Honggui La Huaqi Wang Elliot J. C. Stevens 《Plant Cell, Tissue and Organ Culture》2008,92(3):303-313
This study describes the impact of sorbitol on plantlets regeneration frequency (PRF) of four rice cultivars (japonica, Oryza sativa L.) both of which mature and immature embryo-derived calli were investigated. The variance analysis results showed that PRF
of the three elite upland rice cultivars, Handao297 (HD297), Handao502 (HD502), Handao65 (HD65) and one lowland rice cultivar
Zhongzuo93 (ZZ93) were significantly increased with addition of appropriate amount of sorbitol in culture media. Supplementing
appropriate sorbitol in the media of a continous culture from induction and maintenance to regeneration for mature embryo-derived
calli could improve PRF dramatically, originally from 27.6% up to a maximum of 71.8%. Especially to low regenerative capacity
(LRC) cultivar HD65, the PRF was increased over 7-fold (from 9.7% to 74.0%). The optimum concentrations of sorbitol for calli
induction, subculture and differentiation were 5, 20 and 40 g/l, respectively. Adding sorbitol, only in maintenance media
at concentration of 20 g/l, also enhanced the PRF greatly in all the cultivars from 27.6% to 43.3%. Similar results were observed
when incorporating with maltose in regenerating media both in immature and mature embryo-derived calli. The optimal concentration
was 25 g/l sorbitol + 20 g/l maltose and 20 g/l sorbitol + 25 g/l maltose, respectively. HD297 appeared to be the most responsive
genotype compared to other cultivars in PRF, 99.2% in immature embryo-derived calli and 76.8% in mature embryo-derived calli.
The results and relevant conclusions might be valuable to establish an efficient plant regeneration system from somatic embryogenesis
culture in upland rice. 相似文献
325.
Increasing canopy photosynthesis in rice can be achieved without a large increase in water use—A model based on free‐air CO2 enrichment
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Hiroki Ikawa Charles P. Chen Martin Sikma Mayumi Yoshimoto Hidemitsu Sakai Takeshi Tokida Yasuhiro Usui Hirofumi Nakamura Keisuke Ono Atsushi Maruyama Tsutomu Watanabe Tsuneo Kuwagata Toshihiro Hasegawa 《Global Change Biology》2018,24(3):1321-1341
Achieving higher canopy photosynthesis rates is one of the keys to increasing future crop production; however, this typically requires additional water inputs because of increased water loss through the stomata. Lowland rice canopies presently consume a large amount of water, and any further increase in water usage may significantly impact local water resources. This situation is further complicated by changing the environmental conditions such as rising atmospheric CO2 concentration ([CO2]). Here, we modeled and compared evapotranspiration of fully developed rice canopies of a high‐yielding rice cultivar (Oryza sativa L. cv. Takanari) with a common cultivar (cv. Koshihikari) under ambient and elevated [CO2] (A‐CO2 and E‐CO2, respectively) via leaf ecophysiological parameters derived from a free‐air CO2 enrichment (FACE) experiment. Takanari had 4%–5% higher evapotranspiration than Koshihikari under both A‐CO2 and E‐CO2, and E‐CO2 decreased evapotranspiration of both varieties by 4%–6%. Therefore, if Takanari was cultivated under future [CO2] conditions, the cost for water could be maintained at the same level as for cultivating Koshihikari at current [CO2] with an increase in canopy photosynthesis by 36%. Sensitivity analyses determined that stomatal conductance was a significant physiological factor responsible for the greater canopy photosynthesis in Takanari over Koshihikari. Takanari had 30%–40% higher stomatal conductance than Koshihikari; however, the presence of high aerodynamic resistance in the natural field and lower canopy temperature of Takanari than Koshihikari resulted in the small difference in evapotranspiration. Despite the small difference in evapotranspiration between varieties, the model simulations showed that Takanari clearly decreased canopy and air temperatures within the planetary boundary layer compared to Koshihikari. Our results indicate that lowland rice varieties characterized by high‐stomatal conductance can play a key role in enhancing productivity and moderating heat‐induced damage to grain quality in the coming decades, without significantly increasing crop water use. 相似文献
326.
This paper presents estimates of yield for effort of the cultivar, ‘Taputini,’ which is sweet potato that was eaten by the
Māori of New Zealand before European contact in the 18th century. The two experimental archaeology gardens were planted at
sites on either side of Cook Strait: the one with clay soils is on the South Island at Robin Hood Bay; the one with sandy
soils is at Whatarangi on the North Island. The records of labor input required to cultivate these gardens over seven years
for Robin Hood Bay and six years for Whatarangi compared with crop yields provide data on the economics of pre-European kũmara
gardening. Also reported are some of the properties of the soil. These gardens produced an average of 12 metric tons (1,000
kilograms=1 metric ton) per hectare (ha), which is not much less than contemporary yields for modern cultivars and 3 to 4
times most previous estimates of pre-European production. 相似文献
327.
Activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) in heated crude extracts from seedlings of the rice cultivars
Hitomebore and IR28 was investigated in the presence of proline and betaine. Both solutes retarded the inactivation of the
enzyme extracted from the leaves of both cultivars at temperature-stress from 35 to 45 °C. At 50 °C, however, betaine was
effective in both cultivars. Stabilization of RuBPCO activity was independent of the added solute from 1 to 2 M concentration.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
328.
329.
Elisabetta Schiliro Stefano Predieri Assunta Bertaccini 《Plant Molecular Biology Reporter》2001,19(3):271-272
Pyrus communis L. is the most important pear species for European production. Very few cultivars satisfy standards for fruit quality and
clonal fidelity; thus, accurate verification of cultivar identity for checking propagation material and patent protection
is important. We evaluated the randomly amplified polymorphic DNA (RAPD) technique for its ability to identify genetic differences
among standard pear (Pyrus communis L.) cultivars, William, Passa Crassana, and Conference, and three gamma-ray induced variants. To identify genotype-specific
markers, we used thirty 10-mer and two 11-mer sequences, annealing temperatures from 36–45°C, 2Taq polymerases (AmpliTaq and Stoffel fragment, both from former Perkin Elmer Cetus), and 2–4 replicate amplifications. Of the
32 primers (30 from Operon Technologies, Alameda, CA, USA), very few distinguished William from Passa Crassana, and only 1
could clearly differentiate all 3 cultivars. Two primers that did not reveal polymorphisms when used singly, generated polymorphic
patterns that distinguished standard from gamma-ray-treated material when used in combination. We show that RAPD analyses
can discriminate pear genotypes and suggest this technique as a reliable and inexpensive method for marker-facilitated screening
of propagation material and for patent protection. 相似文献
330.
Sahidur Rahman 《Archives Of Phytopathology And Plant Protection》2013,46(6):620-634
Among the pesticides evaluated against the jute pests under field conditions, endosulfan 35 EC at 350 g a.i./ha was found to be the most effective insecticide for controlling semilooper, Bihar hairy caterpillar and myllocerus weevil. Endosulfan and fenpropathrin provided good control of yellow mite as well. Even, endosulfan-treated plots gave maximum fibre and stick yield with greater benefit–cost ratio (BCR) over others. Next to endosulfan and chlorpyriphos, neemazal (azadirachtin 50,000 ppm) are useful and safer options against semilooper, Bihar having caterpillar, myllocerus and yellow mite. Methoxyfenocide 10 EC at 200g a.i./ha provided good control (70.60%) of S. obliqua even after 14 days of spraying, but it was not effective against other pests of jute. Further, almost similar efficacy of neemazal and chlorpyriphos was found against the pest complex of jute and based on BCR, neemazal could be an alternative choice over chlorpyriphos. 相似文献