全文获取类型
收费全文 | 4777篇 |
免费 | 272篇 |
国内免费 | 996篇 |
出版年
2024年 | 6篇 |
2023年 | 75篇 |
2022年 | 91篇 |
2021年 | 125篇 |
2020年 | 145篇 |
2019年 | 151篇 |
2018年 | 125篇 |
2017年 | 129篇 |
2016年 | 183篇 |
2015年 | 171篇 |
2014年 | 186篇 |
2013年 | 368篇 |
2012年 | 214篇 |
2011年 | 239篇 |
2010年 | 177篇 |
2009年 | 224篇 |
2008年 | 202篇 |
2007年 | 262篇 |
2006年 | 273篇 |
2005年 | 273篇 |
2004年 | 261篇 |
2003年 | 283篇 |
2002年 | 239篇 |
2001年 | 196篇 |
2000年 | 187篇 |
1999年 | 145篇 |
1998年 | 108篇 |
1997年 | 150篇 |
1996年 | 129篇 |
1995年 | 93篇 |
1994年 | 92篇 |
1993年 | 77篇 |
1992年 | 69篇 |
1991年 | 60篇 |
1990年 | 65篇 |
1989年 | 42篇 |
1988年 | 43篇 |
1987年 | 32篇 |
1986年 | 13篇 |
1985年 | 27篇 |
1984年 | 24篇 |
1983年 | 14篇 |
1982年 | 21篇 |
1981年 | 15篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1973年 | 4篇 |
排序方式: 共有6045条查询结果,搜索用时 15 毫秒
151.
Minoru Ameyama Toshikazu Chiyonobu Osao Adachi 《Bioscience, biotechnology, and biochemistry》2013,77(8):1535-1536
The active site of α-glucosidase from Mucor javanicus IFO 4570 was investigated by kinetic studies. Competition between maltose and soluble starch, and linearity of Lineweaver-Burk plots for the mixed substrates were observed. The dependence of the apparent maximum velocities agreed with those predicted for a single active site mechanism. These results suggest that the enzyme hydrolyzes maltose and soluble starch at a single active site. 相似文献
152.
Joydip Karmakar Rajib Roychowdhury Rup Kumar Kar Debal Deb Narottam Dey 《Physiology and Molecular Biology of Plants》2012,18(2):125-132
A total of ten rare indigenous rice landraces of West Bengal were screened for germination potential and seedling growth under varying concentrations of sodium chloride (NaCl) and polyethylene glycol (PEG) solutions as osmotic stress inducing agents. Among the studied rice landraces Kelas and Bhut Moori showed highest degree of tolerance to induced osmotic stresses. Proline content of the studied lines was also determined. Genetic relationship among the studied rice landraces was assessed with 22 previously reported osmotic stress tolerance linked Simple Sequence Repeat (SSR) markers. The identified allelic variants in form of amplified products size (molecular weight) for each SSR marker were documented to find out allele mining set for the linked markers of the studied genotypes in relation to osmotic stress tolerance. A Microsatellite Panel was constructed for the different allelic forms (size of amplified products) of each used marker. Among 22 SSR markers, ten showed unique alleles in form of single specific amplified product for the studied four genotypes which can be used for varietal identification. Genetic relationship among the studied rice lines was determined and a dendrogram was constructed to reveal their genetic inter-relationship. Polymorphism Information Content (PIC) for each used marker was also calculated for the studied rice lines. 相似文献
153.
C. Shanker M. Mohan M. Sampathkumar Ch. Lydia G. Katti 《Biocontrol Science and Technology》2013,23(4):480-484
The diversity of natural enemies harboured by flowering forbs on rice field bunds was recorded. Ageratum conozoides with a maximum Shannon diversity index of 1.8 followed by Acmella uliginosa, Eclipta alba and Tridax procumbens are amenable for ecological engineering, providing nectar, pollen and alternate prey to natural enemies. 相似文献
154.
本研究分别利用SSR标记、InDel标记以及简化基因组测序技术对一套以普通野生稻为供体亲本,9311为受体亲本的染色体置换系进行基因型鉴定,并通过对其不同生育期的耐盐性鉴定,共发掘2个与发芽期耐盐相关的QTL,13个与苗期耐盐性相关的QTL。其中与苗期存活率相关的QTL qSSR5.1、苗期耐盐等级相关的QTL qSSG5.1均被定位于同一位点,该位点对苗期存活率、苗期耐盐等级均具有增效作用,贡献率分别为6.36%、8.13%。在此QTL内包含与非生物胁迫相关基因OsDi19-1。经序列比对发现,OsDi19-1启动子区域在两亲本间存在较大差异,且受到盐胁迫时该基因表达量上升。同时,鉴定出水稻芽期耐盐的优异种质资源CSSL72、苗期耐盐的优异种质资源CSSL23、CSSL153,为水稻育种中耐盐性的改良提供了新的种质资源。 相似文献
155.
156.
157.
Kelei Han Haijian Huang Hongying Zheng Mengfei Ji Quan Yuan Weijun Cui Hehong Zhang Jiejun Peng Yuwen Lu Shaofei Rao Guanwei Wu Lin Lin Xuemei Song Zongtao Sun Junmin Li Chuanxi Zhang Yonggen Lou Jianping Chen Fei Yan 《Molecular Plant Pathology》2020,21(12):1647-1653
The jasmonic acid (JA) pathway plays crucial roles in plant defence against pathogens and herbivores. Rice stripe virus (RSV) is the type member of the genus Tenuivirus. It is transmitted by the small brown planthopper (SBPH) and causes damaging epidemics in East Asia. The role(s) that JA may play in the tripartite interaction against RSV, its host, and vector are poorly understood. Here, we found that the JA pathway was induced by RSV infection and played a defence role against RSV. The coat protein (CP) was the major viral component responsible for inducing the JA pathway. Methyl jasmonate treatment attracted SBPHs to feed on rice plants while a JA-deficient mutant was less attractive than wild-type rice. SBPHs showed an obvious preference for feeding on transgenic rice lines expressing RSV CP. Our results demonstrate that CP is an inducer of the JA pathway that activates plant defence against RSV while also attracting SBPHs to feed and benefitting viral transmission. This is the first report of the function of JA in the tripartite interaction between RSV, its host, and its vector. 相似文献
158.
Nan Zhang Jiyun Yang Anfei Fang Jiyang Wang Dayong Li Yuejiao Li Shanzhi Wang Fuhao Cui Junjie Yu Yongfeng Liu You-Liang Peng Wenxian Sun 《Molecular Plant Pathology》2020,21(4):445-459
The biotrophic fungal pathogen Ustilaginoidea virens causes rice false smut, a newly emerging plant disease that has become epidemic worldwide in recent years. The U. virens genome encodes many putative effector proteins that, based on the study of other pathosystems, could play an essential role in fungal virulence. However, few studies have been reported on virulence functions of individual U. virens effectors. Here, we report our identification and characterization of the secreted cysteine-rich protein SCRE1, which is an essential virulence effector in U. virens. When SCRE1 was heterologously expressed in Magnaporthe oryzae, the protein was secreted and translocated into plant cells during infection. SCRE1 suppresses the immunity-associated hypersensitive response in the nonhost plant Nicotiana benthamiana. Induced expression of SCRE1 in rice also inhibits pattern-triggered immunity and enhances disease susceptibility to rice bacterial and fungal pathogens. The immunosuppressive activity is localized to a small peptide region that contains an important ‘cysteine-proline-alanine-arginine-serine’ motif. Furthermore, the scre1 knockout mutant generated using the CRISPR/Cas9 system is attenuated in U. virens virulence to rice, which is greatly complemented by the full-length SCRE1 gene. Collectively, this study indicates that the effector SCRE1 is able to inhibit host immunity and is required for full virulence of U. virens. 相似文献
159.
Mutations in MIR396e and MIR396f increase grain size and modulate shoot architecture in rice 总被引:1,自引:0,他引:1
Chunbo Miao Dong Wang Reqing He Shenkui Liu Jian‐Kang Zhu 《Plant biotechnology journal》2020,18(2):491-501
Grain size and plant architecture are critical factors determining crop productivity. Here, we performed gene editing of the MIR396 gene family in rice and found that MIR396e and MIR396f are two important regulators of grain size and plant architecture. mir396ef mutations can increase grain yield by increasing grain size. In addition, mir396ef mutations resulted in an altered plant architecture, with lengthened leaves but shortened internodes, especially the uppermost internode. Our research suggests that mir396ef mutations promote leaf elongation by increasing the level of a gibberellin (GA) precursor, mevalonic acid, which subsequently promotes GA biosynthesis. However, internode elongation in mir396ef mutants appears to be suppressed via reduced CYP96B4 expression but not via the GA pathway. This research provides candidate gene‐editing targets to breed elite rice varieties. 相似文献
160.
Yan Li Jiali Li Zhihui Chen Yi Wei Yanhua Qi Changyin Wu 《Plant biotechnology journal》2020,18(10):2015-2026
Rice tiller angle determines plant growth density and further contributes grain production. Although a few genes have been characterized to regulate tiller angle in rice, the molecular mechanism underlying the control of tiller angle via microRNA is poorly understood. Here, we report that rice tiller angle is controlled by OsmiR167a‐targeted auxin response factors OsARF12, OsARF17 and OsARF25. In the overexpression of OsMIR167a plants, the expression of OsARF12, OsARF17 and OsARF25 was severely repressed and displayed larger tiller angle as well as the osarf12/osarf17 and osarf12/ osarf25 plants. In addition, those plants showed compromised abnormal auxin distribution and less sensitive to gravity. We also demonstrate that OsARF12, OsARF17 and OsARF25 function redundantly and might be involved in HSFA2D and LAZY1‐dependent asymmetric auxin distribution pathway to control rice tiller angle. Our results reveal that OsmiR167a represses its targets, OsARF12, OsARF17 and OsARF25, to control rice tiller angle by fine‐tuning auxin asymmetric distribution in shoots. 相似文献