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赖草属资料   总被引:1,自引:1,他引:1  
蔡联炳 《植物研究》1997,17(1):28-32
禾本科赖草属二新种及一新变种,即芒颖赖草Leymus aristiglumus L.B.Cai,伊吾赖草Leymus yiwuensis L.B.Cai ex N.R.Cui和疏节赖草Leymus secalinus var.laxinodis L.B.Cai。  相似文献   

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Cannibalism plays a major role in population regulation in Tribolium confusum, accounting for up to tenfold differences in population size between different genetic strains. I characterized the within- and between-strain genetic variation for cannibalism using standard quantitative-genetic methods. The four laboratory strains studied have similar birth and death rates but differ in their strain-specific cannibalistic tendencies. The cannibalism rates of the strains were stable for more than 60 generations of laboratory husbandry. I found considerable genetic variation for cannibalism within each strain. A genetic analysis of the between-strain differences in each of three types of cannibalism (larvae eating eggs, adults eating eggs, and adults eating pupae) showed that all three cannibalism pathways are autosomally inherited and exhibit minor degrees of dominance. Adult cannibalism of eggs and larval cannibalism of eggs appear to be genetically correlated. The differences between the “high” and “low” cannibalism strains appear to be polygenic for two kinds of cannibalism, larvae eating eggs and adults eating pupae. However, strain differences in adult cannibalism of eggs may be due to only two loci. The stability of the between-strain differences for more than 60 generations, the additive nature of inheritance, and the demonstration of considerable within-strain genetic variation suggest that cannibalism may be selectively neutral or under stabilizing selection with many adaptive peaks.  相似文献   

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The pollen of 40 species of Cordia L. was studied by light microscopy and scanning and transmission electron microscopy. Three major types were found, 3-porate with a reticulate sexine, 3-colpate to 3-colporoidate with a striatoreticulate sexine, and 3-colpate to 3-colporate with a spinulose sexine. These pollen types are correlated with significant differences in the inflorescence, flower, and fruit structures found in the sporophyte. The following revisions are suggested and discussed: that Cordia sect. Varronia P. Br. be elevated to generic status; that Cordia sebestena L. and a few close allies be treated as generically distinct; and that Cordia myxa L. be conserved as the lectotype for the genus, thus continuing a wide application of the epithet Cordia.  相似文献   

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中国足角螨属种类记述:(蜱螨亚纲:足角螨科)   总被引:1,自引:0,他引:1  
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中国池蝇属初志(双翅目:蝇科)(英文)   总被引:4,自引:0,他引:4  
本文系统地报告了池蝇属Limnophora R.-D.的研究简史,属征,生态;讨论了其亲缘关系;编制了中国49种池蝇检索表(雄性),并记录了其分布,研究表明,池蝇属在我国的古北界和东洋界,种类各占一半;记述了2新种,双突池蝇L.biprominens sp.nov.和宽额池蝇L.latifrons sp.nov.;将贵州池蝇L.guizhouensis Zhou et Xue,1987订正为阴鬃池蝇L.pubiseta Emden,1965;黑额池蝇L.beckeri Stein,1907为中国新纪录种。新种模式标本保存于沈阳师范学院昆虫研究所。  相似文献   

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中国船甲螨属记述(蜱螨亚纲:甲螨亚目:卷边甲螨科)   总被引:1,自引:0,他引:1  
本文记述中国船甲螨属Scapheremaeus Berlese种类共6种,其中包括5新种:网纹船甲螨S.retestriatus sp.nov.,钩船甲螨S.uncinatus sp.nov.,四网船甲螨S.quarireticulatus sp.nov。,双突船甲螨.Sbituberculatus sp.nov.,指突船甲螨S.digitatus sp.nov和1个中国新纪录种子代船甲螨S.na  相似文献   

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豹子花属的研究   总被引:4,自引:0,他引:4  
梁松筠 《植物研究》1984,4(3):163-178
豹子花属(Nomccharis Franch.)是百合科百合族(Lilieae)中的一个属,分布于青藏高原东南缘。该属作为一个独立的属,虽被普遍承认,但关于属的范围,即其中与百合属(Lilium L.)及贝母属(Fritillaria L.)有密切关系的种的归属问题,则是一直有争议的。本文仅就这一方面以及在地理分布上的一些问题进行简要讨论。  相似文献   

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Walker , S. (Liverpool U., England.) Cytogenetic studies in the Dryopteris spinulosa complex. II. Amer. Jour. Bot. 48(7): 607–614. Illus. 1961.—A comparison of the D. spinulosa complex, as represented in North America, is made with that in Europe. Although in North America, other Dryopteris species are known to hybridize with members of the complex, the report has been limited to species which compare directly with those in Europe. Three tetraploid species and 2 diploids, the latter representing at least 1 ancestral genome in the complex, are discussed together with the interspecific hybrids. Synthetic hybrids have been produced, involving taxa from both sides of the Atlantic. Evidence from these hybrids suggests that D. intermedia, of North America, and D. maderensis, of Madeira, are conspecific.  相似文献   

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A callus or cup at the spikelet base in Eriochloa is a diagnostic character for this genus. In an investigation of Eriochloa and related genera, the callus epidermis of 19 taxa of Eriochloa and the basal portion of Axonopus, Brachiaria, Digitaria, Leptoloma, and Panicum spikelets were examined with a scanning electron microscope. Eriochloa taxa were divided into three types based on callus epidermal characteristics. The callus of E. polystachya more closely resembled the reduced first glume in other panicoid genera than the callus in other taxa of Eriochloa. Bicellular microhairs, silica bodies, and interlocking long cells support the concept that the callus in Eriochloa is in part a remnant of the first glume.  相似文献   

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CYTOGENETIC STUDIES IN TUBEROUS SOLANUM SPECIES   总被引:1,自引:1,他引:0  
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Generic delimitation in the Triticeae has long been problematical because the extensive hybridization in the group is not readily accomodated in a hierarchical classification. The genomic genera of Löve (1984) are one solution, but fully one-third of them are polyphyletic, incorporating 2 or more genomes. The suggestion that the tribe be considered a single genus (Stebbins, 1956) is theoretically defensible—the genus would be strictly monophyletic—but probably impractical. This paper presents a cladistic analysis of the tribe that differs from previous analyses in that it uses only strictly monophyletic (monogenomic) groups as terminal taxa; hybrids (heterogenomic groups) are shown as reticulations. Monophyletic groups can then be delimited to minimize the number of polyphyletic genera. A classification incorporating genomic information is derived from the phylogeny.  相似文献   

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CYTOLOGICAL STUDIES IN THE GENUS RUBUS L.:   总被引:1,自引:0,他引:1  
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A total of 134 chromosome counts representing 21 taxa of the genus Arnica are presented. Counts are published here for the first time for A. lonchophylla (n = 38) and A. nevadensis (n = 38). Ten previously unreported counts representing 9 taxa are also presented. The basic chromosome number of the genus is x = 19. With respect to chromosome number, the genus exhibits maximum diversity in the Rocky Mountains of Colorado and Wyoming. Arnica angustifolia, A. cordifolia and A. mollis are recognized as mature polyploid complexes, containing several wide ranging polyploid races and only a few highly restricted or scattered diploid races. Within the genus in general, diploids tend to be restricted to unglaciated areas while polyploids are much wider ranging, particularly in unglaciated areas.  相似文献   

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本文选取了与海菜花属系统发育有重要关系的19个性状,采用分支分析方法,研究了代表中国海菜花属全部已知分类群的18个居群的系统发育关系;根据简约性原则,构建了18个居群的分支图。结果表明,18个居群可划分为4类,它们分别对应于现知的4个分类学种,而与数值分类学研究中的Q分析结果基本一致;在分类群的划分上,分支分析与Q分析一样有效,并能反映系统发育关系。本文最后对海菜花属的起源和演化作了探索性推测,认为本属可能最迟在白垩纪末起源于冈瓦纳古陆的热带湖沼地区,此后分化成沉水叶多花支、沉水叶单花支和浮水叶单花支繁衍演化。  相似文献   

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