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对鹅观草属、披碱草属、猬草属和仲彬草属23个物种和1份外类群共24份材料进行了细胞质基因组PCR-RFLP分析。3个叶绿体和3个线粒体通用引物扩增出的片段,用15种限制性内切酶对其进行酶切。在47种引物/酶组合中,获得329条DNA片段,其中304条具有多态性,占92.4%。结果表明鹅观草属、披碱草属、猬草属和仲彬草属材料存在属间和种间多态性,遗传相似系数较高。聚类分析显示仲彬草属单独聚为一类,鹅观草属R. grandis、R. aristiglumis、R. elytrigioides、R. alashanica、R. magnicaespes聚为一类,R. caucasica、R. ciliaris、R. amurensis、R. japonensis聚在一起,5个披碱草属材料、3个猬草属材料和1个鹅观草属物种R. kamoji聚为一类。这些结果与前人对其进行的RAPD和RAMP分析的结果基本一致。仲彬草属作为属分类等级处理是恰当的,对于鹅观草属、披碱草属和猬草属的系统地位和一些物种的分类处理,有待进一步研究。 相似文献
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该文报道了广西禾本科(Poaceae)植物二新记录属,即菵草属( Beckmannia Host)和草沙蚕属( Tripogon Roem. et Schult.)。菵草属有2种及1变种,分布较广,我国有1种1变种,广西首次记录到该属的菵草[ Beckmannia syzigachne (Steud.) Fern.]。草沙蚕属约有30种,多分布于亚洲和非洲,我国有11种,广西首次记录到该属的线形草沙蚕( Tripogon filiformis Nees ex Steud.)。同时,还提供了2个新记录属、种的形态描述与照片。 相似文献
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根据外部形态上小穗的结构特征分析了针茅族中三角草属和冠毛草属的系统发育关系,并结合地理分布和生境条件对两属植物的起源中心进行了探讨。结果表明:三角草属和冠毛草属是针茅族中亲缘关系最近的类群;冠毛草属高级于三角草属;三角草属中的三角草是两属植物中最原始的种型,它可能既派生了属内的假冠毛草,同时又派生了属外绝灭了的黑穗茅祖种,而黑穗茅祖种又在自身属内间接衍生出了冠毛草和单蕊冠毛草;冠毛草属和三角草属皆起源于我国的西藏地区,其中三角草属可能源于西藏西部,冠毛草属可能源于西藏东部。 相似文献
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对中国草螟亚科3个近缘属:带草螟属 Metaeuchromius Bleszynski、丽草螟属Euchromius Guenée和双带草螟属 Miyakea Marumo进行了研究。该3属在中国已记录12个种,包括带草螟属Metaeuchromius两新种:黄色带草螟 M. fulvusalis sp. Nov.,模式产地广西,与褐带草螟 M. circe Bleszynski近缘;灰色带草螟 M. grisalis sp. Nov.,模式产地浙江,与云南带草螟 M. yuennanensis (Caradja)近缘。对新种给出了描述、外生殖器特征图和与近缘种的比较。并提供了带草螟属中国已知种检索表。 相似文献
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本文对草蛉科(Chsysopidae)玛草蛉属Mallada做了修正,并建立一新属——纳草蛉属Navasius gen. nov. 同时报道了纳草蛉属6新种:槽纳草蛉N. alviolatus sp. nov. 钩纳草蛉N. ancistroideus sp. nov. 无斑纳草蛉N. epunctatus sp. nov. 曲纳草蛉N. flexuosus sp. nov. 海南纳草蛉N. hainanus sp. nov. 及和纳草蛉N. hesperus sp. nov.。 相似文献
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作者在整理、鉴定生活于杂草中的蓟马种类时,发现蓟马科(Thripidae)1新属,即草蓟马属Graminothrips,新属,及该属的2新种,莎草蓟马Graminothrips cyperi,新种;长鬃草蓟马Graminothrips longisetosus,新种。本文对新属、新种作了详细的记述。 相似文献
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根据叶解剖特征试论赖草属及其相关类群间的亲缘关系 总被引:7,自引:1,他引:6
通过叶片的解剖观察,以表型系统学的原理和方法,对赖草属及其相关类群的亲缘关系进行了分析。在横切面上,赖草属及其相关6个属的结构虽然均属于狐茅型,但在各类群之间存在差异。其中,披碱草属与赖草属含有最大数量的相同性状,与赖草属的亲缘关系最近;新麦草属和偃麦草属均与赖草属的相同性状较少,该2属仅稍接近于赖草属;而大麦属、芒麦草属和鹅观草属与赖草属的相同性状更少,则此3属与赖草属的亲缘关系也相对疏远。同时,本文还对其它6属间的亲缘关系作了进一步探讨,绘制了整个7属的亲缘关系示意图,并与其外部形态特征作了对应比较,从而弥补了过去研究的不足。 相似文献
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国产白酒草亚族(菊科紫菀族)由白酒草属(Conyza)、小舌菊属(Microglossa)和歧伞菊属(Thespis)3个小属组成,且国产白酒草亚族各属间及其与非洲白酒草属植物之间的分子系统发育关系尚无报道,故本研究利用核糖体DNA ITS和ETS序列并采用最大简约法和贝叶斯分析法,重建了国产白酒草亚族的分子系统发育树。结果表明,国产4种白酒草属植物、歧伞菊和非洲白酒草属植物组成一支,而劲直白酒草的两变种和小舌菊嵌入田基黄亚族分支;小舌菊与Psiadia pascalii近缘。基于这些结果,我们认为:(1)劲直白酒草和Conyza incisa应处理为田基黄亚族的一个独立的属;(2)国产4种白酒草属植物和歧伞菊以及大多数非洲白酒草属植物属于Eschenbachia属,而且Eschenbachia属代表一个新的亚族,歧伞菊可处理为Eschenbachia属的一个组。Eschenbachia属可能从非洲经数次长距离传播到达我国南部;(3)Welwitschiella和小舌菊属应保持属的地位,Psiadia pascalii、Conyza scabrida和C.pyrrhopappa可并入小舌菊属。 相似文献
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本文详细描述了菱臼齿兽耳区各个部分的基本结构;并指出了耳区结构与某些啮齿类的相似性,以及中耳鼓泡组成成份与戈壁(犭亚)兽(Anagale gobiensis)的区别。 相似文献
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四川自贡大山铺蜀龙动物群——简报Ⅲ.蜥脚类 总被引:4,自引:2,他引:2
本文记述了中侏罗世蜥脚类一新属种——巴山酋龙(Datousaurus bashanensts gen. et sp. nov.)对李氏蜀龙(Shunosaurus lii)的特征进行了补充,讨论了它们在蜥脚类进化过程中的位置。 相似文献
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This paper reports the studies of megasporogenesis and microsporogenesis, development of female and male gametophytes, fertilization, and development of embryo and endosperm, The anther wall consists of four layers, i.e. epidermis, endothecium, middle layer and tapetum. Part of the tapetum cells originates from the primary parietal cells, and the other part comes from the basic tissue of the anther partition. Tapeta? cells are uninucleate or binucleate, and belong to the secretory type. Microsporocyte originates directly from the primary sporogenous cell, Cytokinesis is of the simultaneous type. Arrangement of microspores in tetrad is isobilateral. Mature pollen grain is of the 2-celled type. The ovary is tricarpellum, trilocular with many ovules. The ovule is mono-integinous, tenui-nucellar and anatropous. The embryo sac originates from the single-archesporial cell. The one chalazal megaspore in linear tetrad is the functional megaspore. The development of embryo sac is of the Polygonum type. Before fertilization, two polar nuclei fuse in to a secondary nucleus and the antipodal cells degenerate. Fertilization is porogamy, fusion of one sperm with secondary nucleus is faster than that of one sperm with egg nucleus. The development of endosperm is of the cellular type. The first three divisions of endosperm ceils are regular. Two endosperm cells near the ends of chalaza and the micropyle develop into haustorium without division. The haustoria gradually degenerate at the late stage of globular embryo. The mature seeds contain abundant endosperm. The development of embryo is of the Solanad type. The suspensor consists of 12–20 cells. The optimum development of the suspensor is at the early stage of the globular embryo. It begins to degenerate after late globular stage. The embryo develops from proembryo, heartshaped embryo, dicotyledenous- to mature embryo. 相似文献
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The flower develops in March and blossoms in early May in Nanjing. The
cytokinesis of microsporocytes is simultaneous and most tetrads are tetrahedral. The tapetum
is secretory and the nuclei become polyploid at last. The style is solid and most ovaries are
unilocular, rarely bilocular. The ovule is pendulous, anatropous and unitegmic. The nucellus is
pseudocrassinucellate. An obturator formed by transmitting tissue covers the micropyle. The
raphe vascular strand extends into the integument when it reaches the chalaza and on a whole
keeps a “U” shape. The endothelium cell is uninucleate. In most cases no nucellar cap is
formed. No hypostase is found below the embryo sac. The archesporium is one-celled. The
embryo sac development conforms to the Polygonum or Allium types. The degeneration of
the megaspores in the linear tetrad usually occurs from the chalazal toward the micropylar
end. Two synergids persist during fertilization. Three antipodal cells are uninucleate and
ephemeral. Two polar nuclei fuse at the time of fertilization. The fertilization type accords
with porogamy. The syngamy is premitotic. The development of endosperm is cellular.
The initial four successive divisions of the primary endosperm cell are transverse-verticaltransverse-transverse subsequently, giving rise to sixteen cells of the early endosperm. The
mature embryo is straight and nearly as long as the endospermous seed. The cotyledons are
more or less cordate at base. The seedoat is thin and composed of 5-11 layers of compressed
cells. Neither embryo nor endosperm contain the alkaloid camptothecine.
The major similarities of Nyssa sinensis to the American nyssas in embryology, which
may be a counted as the generic features, are the polyploid tapetum cells, the unitegmic ovule
with U-shaped vascular strand, the direct enlargement of the archesporial cell to produce the
megasporocyte, the pseudocrassinucellus, the usual absence of the nucellar cap, the
Polygonum or Allium type of the embryo sac development, the first degeneration of the
metachalazal megaspore, the ephemeral antipodal cells, a single nucleolus in the nucleus ofthe primary endosperm cell, the more or less cordate base of the cotyledons. 相似文献
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日本沼虾雄性生殖系统的研究:Ⅱ.精子的形态及超微结构 总被引:9,自引:2,他引:7
运用电镜和细胞化学技术研究了日本沼虾精子的形态结构,结果表明:日本沼虾精子属无鞭毛精子,为单一棘突型,呈图钉样,由主体和棘突构成;主体部分为帽状体,精核和细胞质带。帽状体由约20根辐射状纤丝组成,纤丝上具横纹,并汇合帽状基部,由此向后延伸形成棘突。 相似文献
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巨龙竹生殖器官形态结构及雌、雄配子体的发育 总被引:2,自引:0,他引:2
通过石蜡切片的方法对巨龙竹生殖器官结构、大小孢子的发生和雌、雄配子体的发育过程进行了观察研究。 巨龙竹为一心皮组成的单室单子房,子房内具有一个胚珠,倒生、双珠被、厚珠心。大孢子母细胞减数分裂形成线形排列的4个大孢子,合点端大孢子具功能。胚囊的发育为蓼型,具多个反足细胞。巨龙竹的花药壁由4层结构组成,包括表皮、药室内壁、中层、绒毡层;花药壁发育为单子叶型,绒毡层为腺质型。小孢子母细胞减数分裂中的胞质分裂为连续型,四分孢子为四面体型;成熟花粉粒为2细胞型,具1个萌发孔。小穗发育雌雄异熟,雌蕊的发育早于雄蕊的发育。 相似文献