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121.
Perumal Venkatachalam Natesan Geetha Narayanasamypillai Jayabalan 《Journal of Plant Biology》1998,41(1):1-8
This study was designed to evaluate the effect of phytohormones on plant regeneration from epicotyl and hypocotyl explants
of two groundnut (Arachis hypogaea) cultivars. Explants cultured on media with auxins and in combination with cytokinin produced high frequency of callus. After
four weeks, callus from these cultures was transferred to medium with cytokinin and reduced auxin, shoot buds regenerated
from the cultures. A high rate of shoot bud regeneration was observed on medium supplemented with 2.0 mg/L BAP and 0.5 mg/L
NAA. Among the different auxins tested, NAA was found to be most effective, producing the highest frequency of shoot buds
per responding cultures. Of the two explants tested, epicotyl was found to be best for high frequency shoot bud regeneration.
Multiple shoots arose on MS medium supplemented with BAP or kinetin (1.0–5.0 mg/L) plus IBA (1.0 mg/L), with maximum production
occurring at 5.0 mg/L. The elongated shoots developed rootsin vitro upon transfer to MS medium supplemented with NAA or IBA (0.5–2.0 mg/L) and kinetin (0.5 mg/L) for 15 days.In vitro produced plantlets, were transferred to soil and placed in a glasshouse developed successfully, matured, and set seeds. 相似文献
122.
Thidiazuron either alone or in combination with IAA induced high frequency shoot regeneration from primary leaf segments of
three pigeonpea cultivars. Transfer of the cultures to medium with reduced concentration of thidiazuron resulted in further
development of the shoots. The regenerated shoots were subsequently transferred to medium supplemented with BA, IAA and gibberellic
acid where 5-10% of the shoots elongated further. Rooting of shoots could be obtained on half strength MS medium supplemented
with NAA. Histological studies confirmed the mode of regeneration as shoot organogenesis.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
123.
In vitro regeneration from leaf explants of Neoregelia cruenta (R. Graham) L.B. Smith,an endemic bromeliad from Eastern Brazil 总被引:1,自引:0,他引:1
Carneiro L.A. Araújo R.F.G. Brito G.J.M. Fonseca M.H.P.B. Costa A. Crocomo O.J. Mansur E. 《Plant Cell, Tissue and Organ Culture》1998,55(2):79-83
An efficient plant regeneration system was developed for the induction of direct shoot formation from leaves derived from
seedlings of Neoregelia cruenta, an endemic Bromeliaceae of Eastern Brazil. Shoot differentiation occurred directly from the
leaf bases. In vitro responses were influenced by seedling age and growth regulator combinations. Highest regeneration rates
were obtained from explants excised from 7-week-old seedlings cultured in the presence of 22 μM BA and 2.5 μM NAA. Shoot conversion
to whole plants was most effective in shoots formed in response to 4.4 or 8.8 μM BA combined with 2.5 μM NAA.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
124.
Lambé Pascal Mutambel Hity S.N. Deltour Roger Dinant Monique 《Plant Cell, Tissue and Organ Culture》1998,55(1):23-29
Three genotypes of Pearl millet were screened in vitro for induction of embryogenic callus, somatic embryogenesis and regeneration.
Shoot apices excised from in vitro germinated seedlings or immature embryos isolated from green house established plants were
used as primary explants. The frequency of embryogenic callus initiation was significantly higher in shoot apices in comparison
with immature zygotic embryos. Moreover, differences between genotypes were minimal when using shoot apices. Friable embryogenic
calli (type II) developed on the initial nodular calli after 1 to 3 months of culture. The frequency of type II callus is
related to the composition of the maintenance medium and they were more often found in ageing cultures. The transfer of embryogenic
calli onto auxin-free medium was sufficient for inducing somatic embryo development in short-term culture (3 months) while
a progressive loss in regeneration potential was observed with increasing time of subcultures. Maturation of embryogenic calli
on medium supplemented with activated charcoal, followed by germination of somatic embryos on medium supplemented with gibberellic
acid, restored regeneration in long-term cultures.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
125.
Several experiments were conducted to investigate in vitro regeneration of adventious shoots from cultured leaves of Japanese
pear (Pyrus pyrifolia). A protocol was developed and regeneration achieved from six cultivars. Leaves harvested from shoot
cultures which had been preconditioned on B5 medium with 5 μM thidiazuron plus 0.25 μM gibberellic acid were placed on regeneration
medium of the same composition. Frequency of regeneration per leaf was as high as 23% but cultivar and environmental factors
influenced the result. More mature (basal) leaves regenerated more frequently than younger ones from the shoot tip. Leaf orientation
during regeneration and photoperiod was not a strong influence but regeneration from leaf pieces was less than from uncut
leaves. An alternative regeneration procedure was developed in which first, shoot cultures were grown on the preconditioning
medium. Leaves of the intact shoot cultures were then induced to regenerate directly when adventitious shoots formed on leaves
of the intact shoot culture leaves without excision. Adventitious shoots from both procedures developed into typical shoot
cultures when transferred to shoot culture maintenance medium.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
126.
Ethanolic sprays of gibberellins were applied to developing shoots of about 12-year-old Scots pine (Pinus sylvestris L.) grafts during the shoot elongation period in two consecutive years. Both male and female flowering was increased by these treatments in both years. The effect was particularly distinct in male flowering. However, different clones showed varying responses to the treatment. This variation was associated with both the genotype and the environmentally determined year-to-year fluctuation in flowering. Differences among clones were analysed further by introducing a model earlier developed for comparisons of the growth rhythm in various woody and herbaceous species. 相似文献
127.
K. Gebhardt 《Plant science》1985,39(2):141-148
In order to improve the availability of oxygen for shoot tip cultures during the course of rooting and to overcome some further agar-related problems a sterile foam cultivation system was developed. Three commercially available foam substrates have been tested, but only a wide pore phenol resin foam proved to be useful in the rooting of red raspberry shoots (Rubus idaeus cv. ‘Gigant’). In comparison to root growth in agarous medium, the newly developed foam cultivation system improved the ramification of the root system, increased the number of root hairs significantly and reduced the friability (lignification) of roots. Also shoot length increased significantly. From the growth experiments it can be concluded that the chemical rather than physical properties of the foam substrate are growth limiting. Still some efforts must be made to improve and standardize the properties of the foam substrate for routine use in mass propagation of organ cultures in vitro. 相似文献
128.
Peter W. Price Takayuki Ohgushi Heikki Roininen Michihiro Ishihara Timothy P. Craig Jorma Tahvanainen Sharon M. Ferrier 《Ecological Entomology》2004,29(4):467-481
Abstract. 1. A group of six unusual sawfly species, which do not conform to the phylogenetic constraints hypothesis as it has been applied to sawflies, was examined in natural populations. All species were in the genus Pontania (Hymenoptera: Tenthredinidae), which induce galls on leaves of willow species (Salicaceae). An understanding of these non‐conformist species was important as a test of the validity of the general hypothesis. 2. The six species of sawfly, Pontania mandshurica, P. cf. arcticornis, P. aestiva, P. arcticornis, P. pacifica, and P. nr. pacifica, showed no oviposition preference for long, vigorous shoots, in contrast to 37 documented tenthredinid species that have demonstrated such a preference. Rather, the non‐conformist species attacked the shortest shoot length classes more frequently and larval establishment in galls was successful. 3. The evident escape from the phylogenetic constraint, which commonly limits sawfly attack to the most vigorous shoots in a willow population, resulted from low apparent heterogeneity of the resources exploited by these Pontania species. At the time of female oviposition, shoots and leaves were too uniform to allow discrimination by females among shoot length classes, resulting in random, or near random attack of shoots. 4. The unusual relative uniformity of resources to which sawflies were exposed resulted from several characteristics. (1) Females emerged early relative to shoot growth phenology, making discrimination among shoot length and vigour difficult or impossible. (2) Low heterogeneity in leaf length resulted in resource similarity independent of shoot length. (3) Abscission of leaves occurred after emergence of larvae from leaf galls so that differential abscission of leaves in relation to shoot length became irrelevant. (4) In some cases, low variance in shoot lengths was evident in old ramets lacking long, vigorous shoots. Probably as a result of low resource heterogeneity, larvae survived well across all shoot length classes, revealing no ovipositional preference and larval performance linkage related to the exploitation of the longest shoot length classes in a population of willows, as in the conformist species. Therefore, larval survival did not provide positive feedback on female preferential behaviour for long shoots, as in the conformist species studied. 相似文献
129.
Yunxia Fang Jiang Hu Jie Xu Haiping Yu Zhenyuan Shi Guosheng Xiong Li Zhu Dali Zeng Guangheng Zhang Zhenyu Gao Guojun Dong Meixian Yan Longbiao Guo Yonghong Wang Qian Qian 《植物学报(英文版)》2015,57(2):151-161
The aerial parts of higher plants are generated from the shoot apical meristem(SAM). In this study, we isolated a small rice(Oryza sativa L.) mutant that showed premature termination of shoot development and was named mini rice 1(mini1). The mutant was first isolated from a japonica cultivar Zhonghua11(ZH11) subjected to ethyl methanesulfonate(EMS)treatment. With bulked segregant analysis(BSA) and map-based cloning method, Mini1 gene was finally fine-mapped to an interval of 48.6 kb on chromosome 9. Sequence analyses revealed a single base substitution from G to A was found in the region, which resulted in an amino acid change from Gly to Asp.The candidate gene Os09g0363900 was predicted to encode a putative adhesion of calyx edges protein ACE(putative HOTHEAD precursor) and genetic complementation experiment confirmed the identity of Mini1. Os09g0363900 contains glucose-methanol-choline(GMC) oxidoreductase and NAD(P)-binding Rossmann-like domain, and exhibits high similarity to Arabidopsis HOTHEAD(HTH). Expression analysis indicated Mini1 was highly expressed in young shoots but lowly in roots and the expression level of most genes involved in auxin biosynthesis and signal transduction were reduced in mutant.We conclude that Mini1 plays an important role in maintaining SAM activity and promoting shoot development in rice. 相似文献
130.