全文获取类型
收费全文 | 827篇 |
免费 | 27篇 |
国内免费 | 16篇 |
出版年
2023年 | 9篇 |
2022年 | 8篇 |
2021年 | 18篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 17篇 |
2017年 | 15篇 |
2016年 | 5篇 |
2015年 | 22篇 |
2014年 | 27篇 |
2013年 | 45篇 |
2012年 | 39篇 |
2011年 | 34篇 |
2010年 | 29篇 |
2009年 | 40篇 |
2008年 | 34篇 |
2007年 | 41篇 |
2006年 | 49篇 |
2005年 | 37篇 |
2004年 | 36篇 |
2003年 | 40篇 |
2002年 | 23篇 |
2001年 | 24篇 |
2000年 | 41篇 |
1999年 | 12篇 |
1998年 | 22篇 |
1997年 | 15篇 |
1996年 | 16篇 |
1995年 | 10篇 |
1994年 | 15篇 |
1993年 | 11篇 |
1992年 | 14篇 |
1991年 | 19篇 |
1990年 | 14篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1967年 | 1篇 |
排序方式: 共有870条查询结果,搜索用时 93 毫秒
131.
Axillary shoot proliferation was obtained using explants of Eucalyptus grandis L. juvenile and mature stages on a defined medium. Murashige and Skoog medium (MS) supplemented with benzyladenine (BA), naphthalene acetic acid (NAA) and additional thiamine. Excised shoots were induced to root on a sequence of three media: (1) White's medium containing indoleacetic acid (IAA), NAA and indole butyric acid; (IBA), (2) half-strength MS medium with charcoal and (3) half-strength MS liquid medium. The two types of explants differed in rooting response, with juvenile-derived shoots giving 60% rooting and adult-derived ones only 35%. Thus, the factors limiting cloning of selected trees in vitro are determined to be those controlling rooting of shoots in E. grandis. 相似文献
132.
A Genomic and Molecular View of Wood Formation 总被引:1,自引:0,他引:1
Wood formation is a process derived from plant secondary growth. Different from primary growth, plant secondary growth is derived from cambium meristem cells in the vascular and cork cambia and leads to the girth increase of the plant trunk. In the secondary growth process, plants convert most of photosynthesized products into various biopolymers for use in the formation of woody tissues. This article summarizes the new developments of genomic and genetic characterization of wood formation in herbaceous model plant and tree plant systems. Genomic studies have categorized a collection of the genes for which expression is associated with secondary growth. During wood formation, the expression of many genes is regulated in a stage-specific manner. The function of many genes involved in wood biosyntheses and xylem differentiation has been characterized. Although great progress has been achieved in the molecular and genomic understanding of plant secondary growth in recent years, the profound genetic mechanisms underlying this plant development remain to be investigated. Completion of the first tree genome sequence (Populus genome) provides a valuable genomic resource for characterization of plant secondary growth. 相似文献
133.
Cluster root development in Grevillea robusta (Proteaceae). I. Xylem, pericycle, cortex, and epidermis development in a determinate root 总被引:1,自引:0,他引:1
The cluster roots of Grevillea robusta A. Cunn. ex R. Br. are composed of determinate rootlets that stop growing, but remain physiologically active for several months. Their apical organization, both before and after maturation, was studied by light and transmission electron microscopy. Each cell layer forms a dome, with an initial cell at its end. Xylem elements form a complicated triarch array at the base of the rootlet, passing along the rootlet as two files, and then joining at the tip to form a single file, surrounded by six pericycle cells. At the base of the rootlet, shorter xylem cells and thick-walled support cells are visible. A root cap, present in rootlets grown in vermiculite, was eventually displaced by root hair growth. Rootlets grown in Hoagland's solution lacked root caps and were significantly shorter than those grown in vermiculite. Cell fate was analysed in terms of cell position and is discussed in terms of pattern and development. 相似文献
134.
135.
芋侧球茎发生发育的形态学机理 总被引:4,自引:0,他引:4
观察了魁芋和多子芋腋芽、侧球茎发生发育的形态学变化规律,分析了主球茎顶芽和不同发育期腋芽中蛋白质的组成。结果表明,魁芋每一叶轮上腋芽数目为1;多子芋为3或3个以上,其中一个体积较大。魁芋侧球茎发育初期伸长的速度大于增粗,首先形成圆柱型,然后顶端膨大形成体积很小的侧球茎。多子芽腋芽伸的同时茎部明显变粗,首先形成圆锥型,然后发育成品种特有的形状。根据发育进程将腋芽发育分成AB1-AB9个时期,将主球茎 相似文献
136.
将台湾冬瓜的种子接种于pH值为7.2的1/2MS培养基上预培养,5d左右种子即可萌发,萌发率为100%,幼苗生长正常。切取预培养15-20d的无菌幼苗的茎尖和带腋芽的茎段接种于MS 1mg/LNAA 4mg/L6-BA培养基上,10d左右在茎尖和茎段(带腋芽)切口处长出愈伤组织,30d左右在愈伤组织处分化出丛生芽,丛生芽的诱导频率接近95%,繁殖系数25.6。将小芽切下转入不加任何生长调节剂MS培养基上,培养几天后芽逐渐长大,并在芽的基部长出白色根系。选取生长健壮的试管苗经过炼苗后移栽到大田中,生长良好。 相似文献
137.
Temporal and spatial changes in gene expression,metabolite accumulation and phytohormone content in rice seedlings grown under drought stress conditions
下载免费PDF全文
![点击此处可从《The Plant journal : for cell and molecular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Daisuke Todaka Yu Zhao Takuya Yoshida Madoka Kudo Satoshi Kidokoro Junya Mizoi Ken‐Suke Kodaira Yumiko Takebayashi Mikiko Kojima Hitoshi Sakakibara Kiminori Toyooka Mayuko Sato Alisdair R. Fernie Kazuo Shinozaki Kazuko Yamaguchi‐Shinozaki 《The Plant journal : for cell and molecular biology》2017,90(1):61-78
138.
139.
Wen F Celoy RM Nguyen T Zeng W Keegstra K Immerzeel P Pauly M Hawes MC 《Plant cell reports》2008,27(7):1125-1135
Mitosis and cell wall synthesis in the legume root cap meristem can be induced and synchronized by the nondestructive removal of border cells from the cap periphery. Newly synthesized cells can be examined microscopically as they differentiate progressively during cap development, and ultimately detach as a new population of border cells. This system was used to demonstrate that Pisum sativum L. fucosyl transferase (PsFut1) mRNA expression is strongly expressed in root meristematic tissues, and is induced >2-fold during a 5-h period when mitosis in the root cap meristem is increased. Expression of PsFut1 antisense mRNA in pea hairy roots under the control of the CaMV35S promoter, which exhibits meristem localized expression in pea root caps, resulted in a 50-60% reduction in meristem localized endogenous PsFut1 mRNA expression measured using whole mount in situ hybridization. Changes in gross levels of cell wall fucosylated xyloglucan were not detected, but altered surface localization patterns were detected using whole mount immunolocalization with CCRC-M1, an antibody that recognizes fucosylated xyloglucan. Emerging hairy roots expressing antisense PsFut1 mRNA appeared normal macroscopically but scanning electron microscopy of tissues with altered CCRC-M1 localization patterns revealed wrinkled, collapsed cell surfaces. As individual border cells separated from the cap periphery, cell death occurred in correlation with extrusion of cellular contents through breaks in the wall. 相似文献
140.
The effects of cytokinins on somatic embryogenesis in pepper were studied using a Murashige and Skoog-based medium supplemented
with 2 mg/L 2,4-dichlorophenoxyacetic acid and 10% sucrose. Compared to the medium without cytokinins, N6-(Δ2-isopentenyl)-adenine and kinetin had no significant effect, whereas benzylaminopurine and zeatin significantly reduced somatic
embryogenesis. Coconut water (10%) either had no significant effect or it reduced embryogenesis as well. Induction of somatic
embryogenesis was also dependent on genotype. Appearance of somatic embryos continued after removal of the embryos that developed
first, especially on cultivars with a lower initial induction rate. Although somatic embryos germinated, the apical meristem
did not elongate. 相似文献