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1.
Jameel M. Al-Khayri 《In vitro cellular & developmental biology. Plant》2001,37(4):453-456
Summary This study was conducted to examine the effect of biotin and thiamine concentrations on callus growth and somatic embryogenesis
of date palm (Phoenix dactylifera L.). Embryogenic callus derived from offshoot tip explants was cultured on hormone-free MS medium containing biotin at 0,
0.1, 1, or 2 mg l−1 combined with thiamine at 0.1, 0.5, 2, or 5 mg l−1. Embryogenic callus weight, number of resultant embryos, and embryo length were significantly influenced by thiamine and
biotin concentration. The optimum callus growth treatment consisted of 0.5 mg l−1 thiamine and 2 mg l−1 biotin. This treatment also gave the highest number of embryos. Embryo elongation was greatest at 0.5 or 2 mg l−1 thiamine combined with 1 mg l−1 biotin. Embryos from all treatments germinated and regenerants exhibited normal growth in soil. This study provides an insight
into the importance of optimizing various culture medium components to overcome in vitro recalcitrace of date palm. 相似文献
2.
Genotypic response of cowpea Vigna unguiculata (L.) to in vitro regeneration from cotyledon explants
M. S. Brar J. M. Al-Khayri T. E. Morelock E. J. Anderson 《In vitro cellular & developmental biology. Plant》1999,35(1):8-12
Summary A plant regeneration system applicable to 17 cowpea genotypes was developed. Cotyledons were initiated on 1/3 MS medium containing
15 to 35 mg N6-benzyladenine (BA) per 1 (66.6 to 155.3 μM) for 5 to 15 d. For shoot regeneration, the explants were transferred to a medium containing 1 mg BA per 1 (4.4 μM). Within 1 wk, shoot formation was visible at the proximal end of the cotyledons. Regeneration percentages (1% to 11%) and
the numbers of shoots (4 to 12 per explant) were significantly influenced by genotype. Culture duration and BA concentration
in the initiation stage significantly affected regeneration capacity. Explants initiated on media containing 15 mg BA per
1 for 5 d resulted in the highest percentage of explants capable of regeneration. Conversely, the highest number of shoots
was obtained from explants initiated on media supplemented with 35 mg BA per 1. Whole plants were obtained on a plant growth
regulator-free medium. To our knowledge, this is the first report of plant regeneration from U.S. commercial cowpea cultivars
and breeding lines. This system is adaptable to diverse cowpea genotypes and will facilitate cowpea genetic transformation.
Published with the approval of the Director of the Arkansas Agricultural Experiment Station. 相似文献
3.
4.
M. Bouchet Th. Gaspar T. A. Thorpe 《In vitro cellular & developmental biology. Plant》1978,14(10):819-823
Summary A comparison of the soluble and cell-wall-bound isoperoxidases of normal auxin-requiring and auxin-independent (habituated)
tobacco callus revealed that normal tissues contained a higher level of isoperoxidases. There were also qualitative differences
in these isoperoxidases. Partially purified soluble and ionically bound isoperoxidases of normal callus likewise exhibited
higher auxin-oxidase activities. Normal tissues also were found to contain higher levels of auxin-oxidase inhibitors (auxin
protectors). Overall, however, the data indicate that there is a higher rate of auxin destruction in normal tobacco callus
than in habituated tissue. This presumably leads to insufficient endogenous auxin for growth.
This study was supported in part by grants to T.G. from the Center IRSIA d'Etude de la Reproduction végétale and the FRFC
Contract No. 2.9009. it Was carried out while T.A.T. was the holder of a senior Fellowship under the NATO senior Scientists
Program. 相似文献
5.
The effects of cis. trans abscisic acid on response to chilling was investigated in callused Nicotiana tabacum L. pith explants. Explants pretreated with 10-4M ABA underwent approximately 50% less cellular leakage when chilled at 2°C under short-day conditions for 10 d than the comparable non-treated tissue. Growth in terms of fresh and dry weights, although poor in comparison to non-chilled (20°C, long days) treatments, was more than twice that of the non-ABA-treated material. On an absolute dry weight basis proline content increased on chilling from 0.7 to 3.4 mg g-1 in non-ABA-treated explants, but rose to nearly 17 mg g-1 in the tissue treated with ABA. Only in the case of cold-hardened. ABA-treated tissue could some cells survive subzero temperatures and regenerate callus again. It is suggested that at least part of the ameliorating effects of ABA result from an increase in the level of proline. 相似文献
6.
In vitro rooting of the apple rootstock M 26 in adult and juvenile growth phases and acclimatization of the plantlets 总被引:1,自引:0,他引:1
Margareta Welander 《Physiologia plantarum》1983,58(3):231-238
In order to obtain optimum conditions for in vitro propagation of the apple rootstock M 26 ( Malus pumila Mill.) in adult and juvenile growth phases, several rooting experiments were performed. Supraoptimal concentrations of indole-3-butyric acid (IBA) added to the rooting media resulted in profuse callus formation. Since extensive callus production is detrimental to the survival of the plantlets, modified culture conditions were established to reduce callus formation. A reduction of the time of exposure to IBA to 5 days and, thereafter, transfer to a hormone-free medium did not eliminate callus production. Exposure to darkness during the root initiation phase increased rooting. When the rooting medium was based on the Lepoivre formula instead of the Murashige and Skoog formula, callus formation was reduced. Optimum conditions for rooting were obtained at much lower concentration than earlier reported, being 1.25 μM for the juvenile and 0.5 μM for the adult growth phase in the range of IBA concentrations tested. Anatomical studies revealed that root initials are formed after 5 days of IBA-treatment. Therefore, we transferred shoots directly to non-sterile conditions after the root-inducing phase. This resulted in a 90% survival of the plantlets. Subculture on hormone-free medium can thus be eliminated when the optimum auxin concentration is known. 相似文献
7.
Sung Ho Son Sung Mee Choi Kum Boo Choi Yun Hee Lee Dea Sook Lee Myung Suk Choi Young Goo Park 《Biotechnology and Bioprocess Engineering》1999,4(2):112-118
Calli were induced from 300,000 embryos isolated from immature to mature stage of seeds collected on late September from 14
elite trees. When the embryos were cultured onto plastic Petri-dish containing 20 mL of modified B5 basal medium supplemented
with 3% (w/v) sucrose, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.5% (w/v) polyvinyl polypyrrolidon (PVPP), 2×MS
vitamins, 0.5 mg/L gibberellic acid, and 10 mg/L 2,4-D after 2 weeks of culture, yellowish-white calli were immediately formed
on the surfaces of embryos, and subcultured for 4 weeks in same culture medium. Because most of calli maintained for more
than 3 months were revealed differences in their colors, surface texture, and growth rate, visual selection was made for first
round screening. When the size of visually selected calli larger than 19 mm in their diameter were inoculated, persistent
proliferation was observed. Among the plating methods tested for the selection of rapid growing cell lines at single cell
and/or small cell aggregate level, 2-layer spread plating revealed as the best for single cell cloning. To enhance cell growth
and maintain high rate of viability for long-term culture of yew cells in bioreactor, final cell volume less than 50% in SCV
seemed to be the best. Time course study revealed that 30% of inoculum density was suitable for fed batch culture. Among the
tested conditional media, the rate of 1∶2 (old medium: fresh medium) was recorded at the best for cell growth. 相似文献
8.
ABSTRACT Two types of callus were produced by pepper explants cultured in various media containing auxins, the cytokinin 6-benzylaminopurine (BAP) and the auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA). Callus produced on media containing auxins alone was friable, grey-green or green-orange in colour and more compact, whereas when BAP was added to culture media with a low concentration of auxin or when the medium contained TIBA alone, the callus produced was white and very hard. This type of callus was also produced in cultures of older tissues and of young tissues cultured on hormonefree medium. Results are discussed in relation to the role of cytokinins in wounding, phenylpropanoid metabolism and lignin biosynthesis. 相似文献
9.
Starch, total sugars, reducing sugars and protein contents and the specific activities of hydrolytic enzymes such as amylase,
Phosphorylase, soluble acid invertase, wall-bound acid invertase, sucrose synthetase, acid and alkaline phosphatases and ribonuclease
were determined in root forming, shoot forming and non-organ-forming callus cultures of tobacco. Organ-forming cultures not
only showed higher amounts of the above metabolites but also higher enzyme activities compared to non-organ-forming cultures.
The activities of these enzymes in relation to organogenesis is discussed. 相似文献
10.
Chen Yhiua Zhang Lihua Geng Yuxuan Chen Zhenghua 《In vitro cellular & developmental biology. Plant》2001,37(5):654-657
Summary Somatic meiosis-like reduction was observed in some cells of the embryogenic callus of Arabidopsis thaliana. Two types were identified. One type was somatic chromosome reductional grouping, in wich the chromesomes in a cell were
separated direetly at either prophase or metaphase. Chromosome reductional grouping happened more frequently in polyploid
cells, and the morphology of the chromosomes did not show the role of the spindle fibers. The other type was somatic meiosis
which was analogous to the process of gametogenesis, characterized by the pairing and synapsis of homologous chromosomes.
The roles of somatic meiosis-like reduction in somatic embryogenesis and somaclonal variations are discussed 相似文献