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231.
232.
After the application of [13 C3 H]-gibberellin A20 to wild-type (tall) sweet peas ( Lathyrus odoratus L.) labelled gibberellin A1 (GA1 ), GA8 , GA29 and 2-epiGA29 were identified as major metabolities by gas chromatography-mass spectrometry after high performance liquid chromatography. By contrast in genetically comparable dwarf ( II ) plants only labelled GA29 and 2-epiGA29 were produced in significant amounts, although evidence was obtained for trace amounts of labelled GA1 and GA8 . The apical portions of dwarf plants contained 8–10 times less GA1 than those of tall plants but at least as much GA20 (measured using di-deuterated internal standards). In conjunction with previous data these results strongly indicate that in genotype ll internode length is reduced and leaf growth altered by a reduction in GA1 levels attributable to a partial block in the 3β-hydroxylation of GA20 to GA1 .
In contrast to dwarf plants, semidwarf plants (genotype lblb ) contained more GA1 in the apical portion than wild-type counterparts. This is consistent with the suggestion that lb alters some aspect of GA sensitivity. 相似文献
In contrast to dwarf plants, semidwarf plants (genotype lblb ) contained more GA
233.
Against the wholly indirect evidence of a lateral gradient of auxin as an explanation of phototropic curvature according to the Cholodny-Went theory, direct measurement of free. extractable or diffusable indoleacetic acid from phototropically curving hypocotyls and coleoptiles invariably shows an even distribution of auxin. On the contrary, growth inhibitors extracted or diffused from these organs turn out to be accumulated at the irradiated side, as proposed already by A. H. Blaauw (Z. Bot. 7: 465. 1915). the classical experiment by F. W. Went (Rec. Trav. Bot. Neerl. 25:1, 1928) has to be interpreted as evidence for a lateral gradient of substance(s) inhibiting auxin activity Phototropic curvature is thus a matter of differential auxin sensitivity across the unilaterally irradiated organ. 相似文献
234.
本文采用黄瓜子叶愈伤组织,研究了不同钙培养下,对愈伤组织生长、硝酸盐吸收,NR活性以及组织中钙、镁含量的影响。结果表明,缺钙后,愈伤组织生长、硝酸盐吸收、NR活性等都比正常钙培养下的愈伤组织降低。这与用整株植物所得结果基本一致,对此结果进行了讨论。 相似文献
235.
J. J. Ross I. C. Murfet 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,76(6):941-946
Summary A second flowering gene, Sp, which influences sensitivity to photoperiod, is identified in the sweet pea, Lathyrus odoratus L. Genes Sp and Dn
h act in a complementary manner to confer the summer-flowering phenotype and a near obligate long day requirement for flowering in the unvernalized state. Mutations sp and Dn
i each diminish the response to photoperiod, and genotypes sp Dn
h and Sp Dn
i confer a spring-flowering phenotype. Response to photoperiod is further reduced in genotype sp Dn
i, which flowers only marginally later than the day-neutral or winter-flowering phenotype characterized by genotypes Sp dn and sp dn (gene dn is epistatic to the gene pair Sp/sp). Like Dn
i, gene sp reduces basal branching, while a branching gene, here resymbolized b, is shown to delay flowering in certain circumstances. Gene dn largely prevents basal branching in either b or B plants, but dn b plants do produce lateral shoots from the upper nodes, leading to a novel phenotype. The implications of the interactions between genes sp, Dn
i, dn and b are discussed with respect to the control of flowering and branching. 相似文献
236.
237.
The behaviour of endogenous Mn2+ was studied by electron spin resonance spectro-scopy during benzyladenine-induced growth of excised cucumber ( Cucumis sativis L. cv. Long green) cotyledons. The level of endogenous Mn2+ was decreased by ben-zyladenine treatment, most pronounced after 96 h. MnCl2 applied alone promoted chlorophyll synthesis at relatively low concentrations but in the presence of ben-zyladenine higher concentrations of MnCl2 were required for stimulation of chlorophyll synthesis. A pronounced increase in growth was observed when Mn2+ was applied with benzyladenine at 96 h, when the decline in the endogenous level of paramagnetic Mn2+ was maximal. 相似文献
238.
Increase in calmodulin level in the early phases of radish seed (Raphanus sativus) germination 总被引:1,自引:0,他引:1
MAURIZIO COCUCCI 《Plant, cell & environment》1984,7(3):215-221
Abstract Calmodulin (Cam), the heat-stable, ubiquitous, Ca2+-dependent regulator protein, has been purified to apparent homogeneity from germinating radish seeds (Raphanus sativus). The characteristics of radish Cam-molecular weight, absorption spectrum, Ca2+-dependent activation of brain phosphodiesterase (PDE)-are very similar to those described for Cam from other plant materials. Radish Cam, like other plant Cam, shows some differences to Cam of calf brain. The total amount of Cam in radish embryos at 24 h of germination is ca. 37 μg g−1 fresh weight. Approximately 95% of the total amount of Cam is present in the soluble fraction (supernatant at 100,000 g). The level in the embryo axis strongly increases in the first 24 h of germination (+540%); this increase is strongly reduced when the germination is inhibited by abscisic acid (ABA). In the presence of Ca2+, no ‘free’ Cam (i.e. not bound to other structures) is present in the soluble fraction, suggesting that, during early germination, Cam level is a limiting factor for the activities of Ca2+ -Cam-dependent systems. These studies suggest that Cam plays an important role in the early phases of seed germination. An inhibitor of the Ca2+-Cam-dependent phosphodiesterase is present in the soluble fraction from radish embryos; this substance decreases during germination. A possible role of this inhibitor during the early germination phases is hypothesized. 相似文献
239.
Susana Silvestre ;Susana de Sousa Araujo ;Maria Carlota Vaz Patto ;Jorge Marques da Silva 《植物学报(英文版)》2014,56(7):610-621
Some species of the Lathyrus genus are among the most promising crops for marginal lands, with high resilience to drought, flood, and fungal diseases, combined with high yields and seed nutritional value. However, lack of knowledge on the mechanisms underlying its outstanding performance and methodologies to identify elite genotypes has hampered its proper use in breeding. Chlorophyl a fast fluorescence transient (JIP test), was used to evaluate water deficit (WD) resistance in Lathyrus genus. Our results reveal unaltered photochemical values for al studied genotypes showing resistance to mild WD. Under severe WD, two Lathyrus sativus genotypes showed remarkable resilience maintaining the photochemical efficiency, contrary to other genotypes studied. Performance index (PIABS) is the best parameter to screen genotypes with improved performance and grain production under WD. Moreover, we found that JIP indices are good indicators of genotypic grain production under WD. Quantum yield of electron transport (wEo) and efficiency with which trapped excitons can move electrons further than QA (c0) revealed as important traits related to improved photosyn-thetic performance and should be exploited in future Lathyrus germplasm improvements. The JIP test herein described showed to be an expeditious tool to screen and to identify elite genotypes with improved drought resistance. 相似文献
240.