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1.
 This paper deals with the use of cladistic methods and cladograms in phylogeny reconstruction in plant groups containing numerous taxa. How accurate are the cladograms as to details? Accuracy tests at the level of details require an independently known phylogeny, which excludes most plant groups, but such tests can be carried out in domesticated and experimental plant groups which have documented pedigrees. Four such tests are known and are presented here: a new case in Gilia and three previously published cases in Avena, Hordeum, and Helianthus. The four cases include domesticated and experimental plants, use of morphological and molecular evidence, and presence of dichotomous as well as reticulate phylogenies. The cladograms of the four plant groups all differ in significant details from the known pedigrees. These results are discussed in relation to problems of interpretation of cladograms. Received March 21, 2000 Accepted August 16, 2001  相似文献   
2.
Two major subgroups of erycine snakes, designated Charina and Eryx , are delimited with a cladistic analysis of 75 morphological characters. The hypotheses of species relationships within the two clades are ( reinhardtii ( bottae, trivirgata )) and ( colubrinus, conicus, elegans, jayakari, muelleri, somalicus ( miliaris ( tataricus ( jaculus, johnii )))), respectively. This pattern of grouping obtains without assuming multistate character additivity. At least 16 synapomorphies indicate that reinhardtii is an erycine and that it is the sister lineage of the ( bottae, trivirgata ) clade. Calabaria and Lichanura are synonymized with Charina for reasons of taxonomic efficiency, and to emphasize the New-Old World geographic distribution of the three species in that assemblage. Further resolution of Eryx species relationships is required before Gongylophis (type species conicus ) can be recognized.  相似文献   
3.
Lomatium is the largest North American genus ofApiaceae (=Umbelliferae). Relations amongLomatium and other genera have not been well understood. TheApiaceae-Araliaceae lineage and genera of North AmericanApiaceae were analyzed phenetically and cladistically in turn, and seven phenetic alliances of genera are identified. Data on frequencies of character-state combinations were assembled and usingSporne's notions of maximal and minimal co-variation of states, two character-states were identified that are derived among Umbellifer genera. Using cladistic analysis of the alliance consisting ofLomatium and six other genera we identified three sister groups toLomatium:Polytaenia alone;Polytaenia withPseudocymopterus, and a group of four genera. Not all genera in the group of seven withLomatium are supported by autapomorphies impeding phylogenetic reconstructions. Both phenetics and cladistics have helped to suggest and evaluate relationships; to call attention to groups requiring further study, and in particular to identify derived character-states.  相似文献   
4.
A classification of the genus Nothofagus (Fagaceae)   总被引:2,自引:0,他引:2  
PHILIPSON, W. R. & PHILIPSON, M. N., 1988. A classification of the genus Nothofagus (Fagaceae). The genus Nothofagus is subdivided into two subgenera, two sections and three subsections, employing characters of the pollen, cupule and vernation, together with the incidence of leaf-fall. The subdivision into subgenera also agrees with present geographical distribution and with characters of the secondary xylem. One subgeneric and one subsectional name are new. Reasons are given for departures from previous classifications.  相似文献   
5.
6.
A cladistic analysis of the genusAnisopappus (Asteraceae: Inuleae) has been undertaken. A hypothesis of species interrelationships in the genus is presented for the first time. The analysis also includedArctotis (Arctoteae), used as outgroup, and five additional genera from theInuleae: Geigeria, Calostephane, Asteriscus, Buphthalmum, Pulicaria, andInula. It is concluded thatAnisopappus is a monophyletic group situated at the base of the tribe, diagnosed by, e.g., their obtuse stylar sweeping-hairs. The species with acute sweeping-hairs were found to be derived within the genus. Problems concerning species delimitation, biogeography and character evolution in the genus are briefly discussed.  相似文献   
7.
菊科蒿属Artemisia的腺毛蒿组和白苞蒿组共有26种8变种,为亚洲特有植物。前主产我国西南中、高海拔地区;后主产秦岭以南横断山脉以东各省区的中、低海拔地区,少数种在亚洲南部、东南部也有分布。除泰国艾A.boreali-siamensis外,其余国内均产。它们在蒿属蒿亚属中进化程度较高,且与其它组有明显的区别。选择亲缘关系最近的艾组为外类群。在外类群比较原则和形态演化原则的基础上,对大量性状  相似文献   
8.
Cladistic analyses of 17 wild and cultivated pea taxa were performed using morphological characters, and allozyme and RAPD (random amplified polymorphic DNA) markers. Both branch-and-bound and bootstrap searches produced cladograms that confirmed the close relationships among the wild species and cultivars of Pisum proposed by a variety of systematic studies. Intraspecific rankings were supported for northern P. humile, southern P. humile, P. elatius and P. sativum, which together comprise a single-species complex. P. fulvum, while clearly the most divergent of the pea taxa, could also be assigned to the same species complex without violating the hierarchial logic of the cladogram. Its inclusion or exclusion depends on whether the level of interfertility it displays with other pea taxa or its overall morphological and chromosomal distinction are emphasized. As suggested by previous studies, northern P. humile was the most likely sister taxon to cultivated P. sativum; although, rigorous phylogenetic evaluation revealed a close genealogical affinity among P. elatius, northern P. humile and P. sativum. Despite their limited number, the 16 morphological characters and allozyme markers used precisely organized the pea taxa into established taxonomic groupings, perhaps in part reflecting the role morphology has played historically in pea classification. The RAPD data also generally supported these same groupings and provided additional information regarding the relationships among the taxa. Given that RAPDs are relatively quick and easy to use, are refractory to many environmental influences, can be generated in large numbers, and can complement traditional characters that may be limited in availability, they provide a valuable new resource for phylogenetic studies.  相似文献   
9.
姬缘蝽科系统发育初探:(异翅亚目:缘蝽总科)   总被引:4,自引:1,他引:3  
本文通过对姬缘蝽科14属的比较形态学研究,以支序分析方法探讨了各类间的系统发育关系,3其结果证明姬缘蝽科为一明显单系群,并支持Chopra(1967)系统中大部分族的划分意见,但因支序图中玛缘蝽族和姬缘蝽亚科为并系群,从而对Chopra系统中亚科的划分及玛缘蝽族是否成立提出疑问,并认为已有系统中的“红缘蝽亚科”应降为族级。文中还将支序分析结果与经前作者的系统发育意见相比较,认为本文所提出的关于该科  相似文献   
10.
Variation in pollen morphology is described and illustrated for 36 genera of Acanthaceae with contorted corolla aestivation. A parsimony analysis of pollen characters is presented.  相似文献   
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