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971.
以山口红树林保护区互花米草(Spartina alterniflora)为研究对象,对其有性繁殖期(2007年6—11月)的生物量动态变化进行了初步研究。结果表明:在繁殖初期,不同营养器官的生物量随时间呈现不同程度的增加;但在繁殖后期,根、茎和叶的生物量的增长率均出现负值,其中根生物量和叶生物量的负增长导致茎生物量出现负增长。地下部分生物量远小于地上部分生物量,生物量在各器官的分配除6月份外呈现茎>叶>根>繁殖器官。地下部分生物量占总生物量的比例随着时间呈现下降的趋势,其中根系生物量比例从6月份的28.9%下降到11月的14.0%;繁殖器官生物量的比例不大,随着时间呈现增加的趋势。 相似文献
972.
分别对抗旱小麦8139和干旱敏感小麦甘麦8号的幼苗进行两周的水分胁迫和NaCl胁迫,并对其叶片中一些生理指标的变化进行了研究,结果表明,水分胁迫下8139中O2^-和H2O2的含量及膜脂过氧化程度均低于敏感品种,胁迫后第七天与第十四天其中SOD与CAT活性明显高于甘麦8号,盐胁迫下两种小麦中的H2O2,MDA含量及SOD,POX酶活性在各时期均无明显差别,水分胁迫下,8139中多胺(腐胺Put,亚精胺Spd,精胺Spm)含量显著高于甘麦8号,盐胁迫下,两品种中多胺含量有胁迫7d后才表现出差异,由此可见,水分胁迫下两品种清除自由基的能力明显不同。而在盐胁迫下则差别不大。表现在生长上,水分胁迫下8139地上部分干物质的累积量高于甘麦8号,而在NaCl胁迫下两者之间差别不大,该结果表明植物抗旱与抗盐的生理保护机理是不一样的。 相似文献
973.
Microsatellite markers linked to six Russian wheat aphid resistance genes in wheat 总被引:14,自引:0,他引:14
X. M. Liu C. M. Smith B. S. Gill V. Tolmay 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(4):504-510
The Russian wheat aphid (RWA), Diuraphis noxia Mordvilko, is a serious economic pest of wheat and barley in North America, South America, and South Africa. Using aphid-resistant
cultivars has proven to be a viable tactic for RWA management. Several dominant resistance genes have been identified in wheat,
Triticum aestivum, including Dn1 in PI 137739, Dn2 in PI 262660, and at least three resistance genes (Dn5+) in PI 294994. The identification of RWA-resistant genes and the development of resistant cultivars may be accelerated through
the use of molecular markers. DNA of wheat from near-isogenic lines and segregating F2 populations was amplified with microsatellite primers via PCR. Results revealed that the locus for wheat microsatellite GWM111
(Xgwm111), located on wheat chromosome 7DS (short arm), is tightly linked to Dn1, Dn2 and Dn5, as well as Dnx in PI 220127. Segregation data indicate RWA resistance in wheat PI 220127 is also conferred by a single dominant resistance
gene (Dnx). These results confirm that Dn1, Dn2 and Dn5 are tightly linked to each other, and provide new information about their location, being 7DS, near the centromere, instead
of as previously reported on 7DL. Xgwm635 (near the distal end of 7DS) clearly marked the location of the previously suggested resistance gene in PI 294994, here designated
as Dn8. Xgwm642 (located on 1DL) marked and identified another new gene Dn9, which is located in a defense gene-rich region of wheat chromosome 1DL. The locations of markers and the linked genes were
confirmed by di-telosomic and nulli-tetrasomic analyses. Genetic linkage maps of the above RWA resistance genes and markers
have been constructed for wheat chromosomes 1D and 7D. These markers will be useful in marker-assisted breeding for RWA-resistant
wheat.
Received: 17 May 2000 / Accepted: 13 June 2000 相似文献
974.
Detection of loci controlling seed dormancy on group 4 chromosomes of wheat and comparative mapping with rice and barley genomes 总被引:22,自引:0,他引:22
K. Kato W. Nakamura T. Tabiki H. Miura S. Sawada 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(6-7):980-985
Three quantitative trait loci (QTLs) controlling seed dormancy were detected on group 4 chromosomes of wheat (Triticum aestivum L.) using 119 doubled haploid lines (DHLs) derived from a cross between AC Domain and Haruyutaka. A major QTL, designated
QPhs.ocs-4A.1, was identified within the marker interval between Xcdo795 and Xpsr115 in the proximal region of the long arm of chromosome 4A. Two minor QTLs, QPhs.ocs-4B.2 on 4B and QPhs.ocs-4D.2 on 4D, were flanked by common markers, Xbcd1431.1 and Xbcd1431.2 in the terminal region of the long arms, suggesting a homoeologous relationship. These three QTLs explained more than 80%
of the total phenotypic variance in seed dormancy of DHLs grown in the field and under glasshouse conditions. The AC Domain
alleles at the three QTLs contributed to increasing seed dormancy. Comparative maps across wheat, barley and rice demonstrated
the possibility of a homoeologous relationship between QPhs.ocs-4A.1 and the barley gene SD4, while no significant effects of the chromosome regions of wheat and barley orthologous to rice chromosome
3 region carrying a major seed dormancy QTL were detected.
Received: 5 June 2000 / Accepted: 31 August 2000 相似文献
975.
Isolation and characterization of wheat ω-gliadin genes 总被引:1,自引:0,他引:1
C. C. Hsia O. D. Anderson 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(1):37-44
The DNA sequences of two full-length wheat ω-gliadin prolamin genes (ωF20b and ωG3) containing significant 5′ and 3′ flanking
DNA sequences are reported. The ωF20b DNA sequence contains an open reading frame encoding a 30,460-Dalton protein, whereas
the ωG3 sequence would encode a putative 39,210-Dalton protein except for a stop codon at amino-acid residue position 165.
These two ω-gliadin genes are closely related and are of the ARQ-/ARE-variant type as categorized by the derived N-terminal
amino-acid sequences and amino-acid compositions. The ω-gliadins were believed be related to the ω-secalins of rye and the
C-hordeins of barley, and analyses of these complete ω-gliadin sequences confirm this close relationship. Although the ω-type
sequences from all three species are closely related, in this analysis the rye and barley ω-type sequences are the most similar
in a pairwise comparison. A comparison of ω-gliadin flanking sequences with respect to that of their orthologs and with respect
to wheat gliadin genes suggests the conservation of flanking DNA necessary for gene function. Sequence data for members of
all major wheat prolamin families are now available.
Received: 24 August 2000 / Accepted: 15 December 2000 相似文献
976.
977.
978.
Summary. Computer modelling studies of two groups of biologically-active peptides derived from A-gliadin indicated that the most likely
structures were α-helical ones, in the case of serine-containing peptides, and random peptides coil types featuring β-turns, in the case of proline-rich, tyrosine-containing peptides.
The serine-containing group of peptides appear to be essentially cytotoxic in animal models of coeliac disease, whilst the
tyrosine-containing group have the capacity to initiate damaging immunological reactions in patients with coeliac disease.
Both types of activity in coeliac disease are only possible if there is defective digestion of the active peptides, as mucosal
digestion studies indicate. In the case of the serine-containing peptides, activity of the peptides is linked to the presence
of PSQQ and also probably QQQP motifs. With the tyrosine-containing peptides, sequences such as QQPY and/or QPYP are associated
with immunological activity and hence toxicity.
Received November 8, 2000 Accepted December 11, 2000 相似文献
979.
980.
小麦株高性状的QTL分析 总被引:10,自引:0,他引:10
自20世纪60年代农林10号矮秆基因被用于小麦育种以来,矮化育种成为世界范围内势不可挡的趋势,矮秆基因研究被越来越多的育种专家重视,先后鉴定出20余个矮秆基因,并应用其中6,7个基因,培育了大批丰产潜力大的半矮秆品种,应用矮秆冬小麦吕系DN3338(♀)和F390(♂)杂交得到的F2:3群体,研究小麦株高的遗传基础,以控制株高的数量性状基因座进行定位,利用240个F2:3家系,构建了含215个微卫星标记,覆盖3600cM,由21个连锁群组成的遗传 连锁图谱,并对该群体进行了4个环境(2年:2000年和2001年,2点:北京和石家庄)3重复的田间种植;采用区间作图法,对该群体的株高性状进行了QTL分析。结果表明:7个影响株高的QTL分别位于染色体1B,4B(2个),6A(2个),6D和7A上,每个QTL能解释5.2%-50.1%的表型变异,每个环境条件下检测出的所有QTL能解释64.8%-75%,的表型变异,除了7A上的QTL外,其他6个降低株高的QTL均来自ND3338,其效应介于0.94cm-9.33cm之间,且其中的4个在所有的环境下都能被检测出来,具有较高的稳定性,在4BS的Xgwm113标记附近有一主效QTL,其在不同的环境下能降低株高7.91cm-9.33cm,解释27.8%-36.2%,的表型变异,有着同农林10号中Rht-Blb相近的效应;同时在4BS上还发现一个和地点互作的QTL,该QTL在石家庄的两年试验中均被检测到,且有较大的效应值(80cm和7.6cm),因此,认为大部分的QTL能在所有的环境中检测到,这些QTO可以被用于品种改良和分子标记辅助选择育种。 相似文献