ISSN:0017-0070    

DOI:10.1080/11263509509436092

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263509509436093

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263509509436094

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263509509436095

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263509509436096

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263509509436097

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

During the last years molecular data have been shown to be essential for a modern phylogenetic analysis of plant taxa. In consequence of such additional data sets many ideas of plant phylogenies will be modified. New fields of research in systematics will be advantageous, for example to recognize and analyse the morphologically interesting parallel evolutionary lines of a plant group. It should be kept in mind, however, that one of the first attempts to use molecular methods was serology, which has been sucessfully applied for a long time. An example is given.Modernmolecular biology methods, however, have still to be introduced into the mind and hand of many systematists, being exclusively trained in classical taxonomical methods. A program should be raised to support a rapid introduction of molecular methods into plant systematic research. Intensive training courses for DNA analysis and sequencing, for the handling and processing of the huge amount of data should be installed, meetings organized to exchange experiences, ideas, and results, and a network of cooperation between the working groups adapted. Since genes and gene segments of considerably different evolutionary rates exist, molecular data are available for relationship studies of high as well as low taxonomic groups. Slowly evolving genes or gene segments (e.g., rbcL) enable the resolution of plant subclasses, classes or phyla, fast evolving genes of genera, species or infraspecific taxa. The recently detected genotypic variation ofArabis alpinais a convincing example of the latter.

ISSN:0017-0070    

DOI:10.1080/11263509509436098

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263509509436099

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263509509436100

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The nucleotide sequences of the internal transcribed spacers (ITS1 and ITS2) of the nuclear ribosomal DNA were analyzed in species belonging to angiosperms, gymnosperms and pteridopthytes. It has been proved that these regions are a useful source of characters for phylogenetic studies in many angiosperm families. The size of the ITS1 and ITS2 is not exceeding 300 bp for both regions in the angiosperm species. The lengths of the ITSs of sixteen species of gymnosperms and five species of pteridophytes were estimated. The gymnosperms have ITS1 regions larger than those observed in the pteridophytes and angiosperms (c. 630–3160 bp versus 214–3160 bp). The ITS2 regions were 182–370 bp, with the exception ofGinkgo bilobawhere multiple–size lengths were recorded. By cloning or by PCR products, we have determined the complete nucleotid sequence of ITS regions from five gymnosperm species and three pteridophyte species. Sequence analysis showed the presence of five tandem arranged subrepeat with the size ranging between 219 bp and 239 bp within the 2631 bp ofPinus pinea,and three shorter tandem arranged subrepeats of about 70 bp in the 1112 bp of the ITS1 ofEphedra fragilis.DNA segments of 40–50 bp pyrimidine rich (about 90% were observed in the ITS1 ofGinkgo bilobaand at beginning of the five subrepeats ofPinus pinea.A 20 bp short sequence highly conserved in the ITS1 of the angiosperms species has been also found in the ITS1 of the shorter ribosomal genes ofPinus pineaand in the ITS1 ofTaxus baccataandEphedra fragilis.The secondary structures of some ITS1 and ITS2 are shown.

ISSN:0017-0070    

DOI:10.1080/11263509509436101

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor