全文获取类型
收费全文 | 145篇 |
免费 | 4篇 |
国内免费 | 6篇 |
专业分类
155篇 |
出版年
2021年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 7篇 |
2007年 | 8篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 7篇 |
1999年 | 12篇 |
1998年 | 6篇 |
1997年 | 12篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有155条查询结果,搜索用时 31 毫秒
1.
Isozymes and random amplified polymorphic DNA (RAPD) markers were used for precocious identification of non-maternal plants in progenies of the facultative apomict Poa pratensis. Four progenies obtained from controlled crosses that showed different degrees of apomixis on isozyme analysis of phospho-gluco-isomerases, esterases and peroxidases were chosen for RAPD analysis to generate genomic fingerprints using species-specific primers. At an advanced vegetative stage, a morphological analysis was also performed and characteristics related to growth habit and leaf morphology were observed and recorded. On the basis of the isozyme and RAPD electrophoretic pattern and the morphological appearance, each plant was classified as maternal or aberrant. All three classes of genetic markers employed were able to identify plants that exhibited aberrant traits in the four progenies. Overall, the results of RAPD analysis supported those of isozyme and morphology studies. However, in each progeny, some plants which both isozyme and morphological analyses distinguished as of maternal origin were aberrant according to RAPD analysis. Therefore, the RAPD method proved the most precise screening technique. The greater cost of the molecular approach was offset by its higher accuracy. The use of either three isozyme systems or six primers for PCR amplification seems to be sufficient for reliable estimation of the degree of apomixis. Histological analyses were carried out and the aposporic development of the plant material studied. 相似文献
2.
E. L. Lubbers L. Arthur W. W. Hanna P. Ozias-Akins 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(5):636-642
Two molecular markers, a RAPD (randomly amplified polymorphic DNA) and a RFLP/STS (restriction fragment length polymorphism/sequence-tagged site), previously were found associated with apomictic reproductive behavior in a backcross population produced to transfer apomixis from Pennisetum squamulatum to pearl millet. The occurrence of these molecular markers in a range of 29 accessions of Pennisetum comprising 11 apomictic and 8 sexual species was investigated. Both markers were specific for apomictic species in Pennisetum. The RFLP/STS marker, UGT 197, was found to be associated with all taxa that displayed apomictic reproductive behavior except those in section Brevivalvula. Neither UGT197 nor the cloned RAPD fragment OPC-04600 hybridized with any sexually reproducing representatives of the genus. The cloned C04600 was associated with 3 of the 11 apomictic species, P. ciliare, P. massaicum, and P. squamulatum. UGT197 was more consistently associated with apomictic reproductive behavior than OPC04600 or cloned C04600, thus it could be inferred that UGT197 is more closely linked to the gene(s) for apomixis than the cloned C04600. The successful use of these probes to survey other Pennisetum species indicates that apomixis is a trait that can be followed across species by using molecular means. This technique of surveying species within a genus will be useful in determining the relative importance of newly isolated markers and may facilitate the identification of the apomixis gene(s). 相似文献
3.
R. A. Bicknell 《Plant Cell, Tissue and Organ Culture》1994,37(2):197-199
Hieracium aurantiacum L. is being investigated as a model system for studying the genetic basis of gametophytic apomixis. Micropropagation methods were developed for the multiplication and maintenance of unique genotypes, and to facilitate the development of an Agrobacterium-mediated transformation procedure. A basal medium containing Murashige & Skoog macro- and micro-salts, B5 vitamins and 3% sucrose was used throughout. Shoot regeneration from leaf disks was optimized on a medium supplemented with 2.5 M indole-3-butyric acid (IBA) and 2.2 M 6-benzyladenine (BA). Shoot proliferation was optimized using 2.2 M BA, without additional IBA, giving 5-fold shoot-tip multiplication rates every 4 weeks. Shoots readily formed roots on the basal medium and could be transplanted to potting medium 3 weeks later. Micropropagation was found to have no effect on the expression of apomixis in this species.Abbreviations Ba
6-benzyladenine
- iba
indole-3-butyric acid
- lsd
least significant difference 相似文献
4.
A novel approach to the analysis of the initiation of embryo development in gramineae 总被引:1,自引:1,他引:0
F. Matzk H.-M. Meyer H. Bäumlein H.-J. Balzer I. Schubert 《Sexual plant reproduction》1995,8(5):266-272
An in vivo model system to study the initiation of embryo development is presented. From the so-called Salmon system of wheat (alloplasmic lines with a 1BL-1RS chromosome translocation), three completely isogenic and homozygous lines were produced by selection for uniformity in about 20 selfing/backcross generations as well as between sublines of doubled haploids. The line (aestivum)-Salmon is male fertile and sexual. The lines (caudata)-Salmon and (kotschyi)-Salmon are male sterile and have a parthenogenetic capacity of about 90%. The expression of nuclear-cytoplasmic male sterility is different for the two parthenogenetic lines. The initiation of autonomous embryo development at defined developmental stages of the ovaries and the maximum degree of parthenogenesis are identical in both parthenogenetic lines as proved by the auxin test and progeny analyses. The protein patterns from ovary extracts of the three isogenic lines were identical for more than 200 spots of 2-D polyacrylamide gels, confirming their homogeneity. However, one protein (P 115.1) was found 3 days before and during anthesis only in ovaries of the parthenogenetic lines. It seems to be involved in the initiation of parthenogenesis. 相似文献
5.
Autonomous division of the endosperm was induced by in vitro culture of unpollinated ovaries or placenta-attached ovules in Helleborus niger, Lupinus luteus and Melandrium album. The induction frequencies for the three species were 50%, 10–20% and 0.1%, respectively. The endosperms contained up to 20 free nuclei; only a few ovules with 80–420 endosperm nuclei were found. Induction of autonomous division of the endosperm, which is unusual in amphimictic plants, was observed in three new species. No embryos appeared in the ovules. This suggests a developmental independence of the endosperm from the embryo in the culture of unpollinated ovaries or ovules. 相似文献
6.
F. Matzk 《Sexual plant reproduction》1991,4(2):88-94
Summary In all of the Poaceae tested (Bromus, Festuca, Hordeum, Lolium, Poa, Triticum) the formation of grains without endosperm was induced from unpollinated ovules by treatment with the following synthetic auxins: DIG; 2,4-D; 2,4,5-T; or CPAA. Cytokinins (BAP, ZTN) as well as adenine or gibberellic acid (GA3) alone were ineffective. In parthenogenetic lines auxin treatment resulted in grains with mature embryos without endosperm. Differences in embryo differentiation were found, which were dependent on the synthetic auxins used, their concentrations, and the developmental stages of the treated spikes or panicles. Thus, the regulation of embryogenesis by the endosperm can be replaced by exogenous auxin application. The developing proembryos of grasses did not need nutritive support from the endosperm.Auxin treatment to give mature embryos without endosperm enables the screening of apomictic species for sexual plants and sexual species for parthenogenetic individuals. It opens ways for inducing haploid parthenogenesis and improves methods for overcoming interspecific crossing barriers. 相似文献
7.
G. Ben-Hayyim A. Shani A. Vardi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1982,64(1):1-5
Summary Ten isozymes were analyzed in nucellar calli of nine Citrus species and cultivars and roots of the corresponding apomictic seedlings. The zymograms obtained can be divided into three groups: a) isozyme patterns similar in both calli and roots, b) isozyme patterns similar in calli but variable in roots, and c) isozyme patterns variable in both calli and roots. Analysis of these ten isozyme systems may facilitate identification of fusion products in Citrus.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 354-E, 1982 series 相似文献
8.
单子叶植物无融合生殖的研究进展 总被引:6,自引:0,他引:6
植物的无融合生殖是指不经过雌雄配子融合而产生种子的一种特殊生殖方式。由于利用无融合生殖途径可以固定杂种优势 ,从而改良现有植物的育种策略 ,因此对无融合生殖的研究已成为生物学科的新生长点。本文主要从无融合生殖的概念和类型 ,无融合生殖在单子叶植物中的分布 ,无融合生殖的胚胎学 ,分子生物学和遗传学机制及创造新的无融合生殖种质资源的方法等 6方面对单子叶植物的无融合生殖的研究进展进行了综述 ,并提出了今后开展无融合生殖研究的思路和设想 相似文献
9.
Dott. Flavio Giuseppe Elisei 《Plant biosystems》2013,147(3):674-692
Abstract A survey of all the 154 scientific publications of Emilio Battaglia (1917–2011) is presented, grouped in three main research interests – plant embryology, cytogenetics in plants and cytological terminology – plus other less relevant contributions. Battaglia's past and present role in these disciplines is briefly discussed, in the light of current research on these topics, partly reviewed also in other contributions of the present Plant Biosystems issue. 相似文献
10.