全文获取类型
收费全文 | 313篇 |
免费 | 22篇 |
国内免费 | 44篇 |
出版年
2023年 | 1篇 |
2022年 | 9篇 |
2021年 | 9篇 |
2020年 | 2篇 |
2019年 | 10篇 |
2018年 | 12篇 |
2017年 | 7篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 29篇 |
2012年 | 12篇 |
2011年 | 14篇 |
2010年 | 16篇 |
2009年 | 19篇 |
2008年 | 9篇 |
2007年 | 21篇 |
2006年 | 12篇 |
2005年 | 16篇 |
2004年 | 11篇 |
2003年 | 11篇 |
2002年 | 18篇 |
2001年 | 14篇 |
2000年 | 17篇 |
1999年 | 12篇 |
1998年 | 13篇 |
1997年 | 14篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有379条查询结果,搜索用时 46 毫秒
271.
272.
In a laboratory study, indica and japonica rice (Oryza sativa L.) seeds were exposed to thermal hardening (heating followed by chilling followed by heating; chilling followed by heating followed by chilling; heating followed by chilling or chilling followed by heating). In indica rice, heating followed by chilling followed by heating resulted in decreased mean germination time, time to start germination, electrical conductivity of seed leachates, and time to 50% germination, as well as increased germination index, energy of germination, radicle and plumule length, root length, root/shoot ratio, root fresh and dry weight, radicle and plumule growth rate, and shoot fresh weight. In japonica rice, chilling followed by heating followed by chilling performed better than all other treatments, including control. 相似文献
273.
A rice RFLP map with 233 loci based on a population of 81 doubled haploids (DH) from the indica/japonica hybrid of "Gui 630'/"02428" was used to analyse the genome ratios and graphical genotypes of DH lines. The “Gui 630” genome ratio of the individual DH lines varied from 29.3% to 78.6% with an average of 49% while the ratios of most DH lines ranged between 44% and 49%. Of the mapped RFLP markers 130 showed skewed segregations with a significant deviation from the expected monogenic ratio, but the numbers of the markers deviated towards male and female parent were approximately equal. It was found that the markers with the segregation deviation in the same direction tend to cluster on some chromosomes and some of their regions. The average "Gui 630' genome ratios of different chromosomes in the DH population varied greatly between 29% and 65 %. In addition, several chromosomes were inherited completely from either one of the parents in some DH lines, indicating the rare occurrence of crossover along the pairing homologous chromosomes during meiosis. 相似文献
274.
与芒果子叶切段不定根形成相关基因的cDNA片段的克隆 总被引:7,自引:0,他引:7
在研究芒果子叶横切所形成的远轴面和近轴面的不定根形成时发现,只在近轴面形成不定根.该研究利用抑制性扣除杂交(suppres sive subtractivehybridization,SSH)方法,以子叶切段远轴切面作为参照样品,近轴切面作为检测样品,构建正向差异cDNA文库,分离与芒果子叶切段不定根形成相关基因的cDNA片段.经VirtualNorthern杂交分析,获得6个阳性克隆.序列分析和同源性比较结果表明这些cDNA片段均为首次报告,它们分别与转运蛋白、转录调控因子及酶基因的DNA序列同源. 相似文献
275.
Nymphoides indica, an aquatic plant, is an invasive species that causes both ecological and economic damage in North America and elsewhere. However, the lack of genomic data of N. indica limits the in-depth analysis of this invasive species. Here, we report a chromosome-level genome assembly of nine pseudochromosomes of N. indica with a total size of ∼ 520 Mb. More than half of the N. indica genome consists of transposable elements (TEs), and a higher density of TEs around genes may play a significant role in response to an ever-changing environment by regulating the nearby gene. Additionally, our analysis revealed that N. indica only experienced a gamma (γ) whole-genome triplication event. Functional enrichment of the N. indica-specific and expanded gene families highlighted genes involved in the responses to hypoxia and plant–pathogen interactions, which may strengthen the ability to adapt to external challenges and improve ecological fitness. Furthermore, we identified 160 members of the nucleotide-binding site and leucine-rich repeat gene family, which may be linked to the defence response. Collectively, the high-quality N. indica genome reported here opens a novel avenue to understand the evolution and rapid invasion of Nymphoides spp. 相似文献
276.
籼稻明恢63成熟种子愈伤组织的诱导及转基因水稻的抗性检测 总被引:17,自引:0,他引:17
利用不含附加营养成分的2,4-D培养基(2mg/L)诱导明恢63的成熟种子,9天预诱导后获得了大量的愈伤组织。利用基因枪辅助的土壤农杆菌转化法将天花粉蛋白(Trichosanthin, TCS)基因转入籼稻明恢63的愈伤组织,并通过再生(含有3mg/L 6-BA, 0.5mg/L ABA和1mg/L NAA的N6培养基)获得了转基因植物。 Southern blot分析和Western blot检测证明外源基因已经插入到T0代明恢63的基因组中并获得了表达。初步研究结果表明,转基因水稻对稻瘟病菌侵染具有抗性。 相似文献
277.
The antiatherogenic effect of a herbal formulation, Caps HT2, was evaluated as antioxidant, anticoagulant, platelet antiaggregatory, lipoprotein lipase releasing, anti-inflammatory and hypolipidaemic activity in rats. The formulation contained the methanolic extracts of selected parts of plants, Commiphora mukul, Allium sativum, Plumbago indica, Semecarpus anacardium, Hemidesmus indicus, Terminalia arjuna, Tinospora cordifolia, Withania somnifera and Ocimum sanctum. The formulation, Caps HT2 was found to scavenge superoxide and hydroxyl radicals; the IC50 required being 55.0 and 610.0 microg/ml respectively. The lipid peroxidation was found inhibited (50%) by 48.5 microg/ml of Caps HT2. The intravenous administration of the formulation (5 mg/kg) delayed the plasma recalcification time in rabbits and enhanced the release of lipoprotein lipase enzyme significantly (p < 0.001). The formulation also inhibited ADP induced platelet aggregation in vitro, which was comparable to commercial heparin. The anti-inflammatory action of the formulation was significant (p < 0.001) with acute and chronic inflammations induced by carrageenan and formalin respectively in rats. The hypolipidaemic effect of Caps HT2 was significant (p < 0.001) with the administration of the formulation, in diet-induced hyperlipidaemia of rats for a period of 30 days. Oral administration of the formulation, Caps HT2 (100, 200, 300 and 400 mg/kg) significantly raised HDL cholesterol levels. The atherogenic index and the reduction in body weight were significant indicating the effectiveness against hyperlipidaemia and obesity. All these results revealed the therapeutic potential of Caps HT2 against vascular intimal damage and atherogenesis leading to various types of cardiovascular problems. 相似文献
278.
富含多糖和次生物质的芒果子叶总RNA的提取 总被引:20,自引:0,他引:20
为了提取芒果子叶总RNA,去除次生物质和多糖等杂质的严重干扰,采用了正交试验快速优化提取方法。实验证明70%的丙酮能有效地去除大部分杂质,提取过程一天内可完成,RNA含量可达677μgg·FW,A260A280比值为195,RNA的纯度及质量适合后续反应。 相似文献
279.
Genetic analysis of morphological index and its related taxonomic traits for classification of indica/japonica rice 总被引:7,自引:0,他引:7
A doubled haploid population derived from anther culture of ZYQ8/JX17 F1, a typical indica and japonica hybrid, was used in this study. Morphological index and its related taxonomic traits were investigated in 121 DH lines. The quantitative trait loci (QTLs) for morphological index and its related taxonomic traits were analyzed. Two major QTLs for leaf hairiness, three QTLs for length/width of grain, one QTL for color of hull when heading, one QTL for hairiness of hull, two QTLs for length of the first and second panicle internode, and one major QTL and two QTLs for phenol reaction were detected. Four QTLs for morphological index were also identified on chromosomes 1, 3, 4 and 6, respectively, three of which on chromosomes 1, 3 and 6, respectively, were found to be located in the same chromosome regions where some QTLs for the related taxonomic traits were located. 相似文献
280.
Chiang YC Tsai CM Chen YK Lee SR Chen CH Lin YS Tsai CC 《American journal of botany》2012,99(3):e117-e119
? Premise of the study: Twenty microsatellite loci for mango (Mangifera indica), an important commercial fruit tree in East Asia, were developed to evaluate the genetic diversity and identification of cultivars. ? Methods and Results: The 20 new microsatellite markers were isolated from mango using a magnetic bead enrichment method, and polymorphisms were identified in 22 mango cultivars. The number of alleles ranged from one to nine, with expected heterozygosity ranging from 0 to 0.826. The polymorphism information content ranged from 0 to 0.756 with a mean of 0.525. ? Conclusions: These new microsatellite loci should be useful and convenient for further studies of the genetic diversity and identification of cultivars in mango. 相似文献