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Scolecopteris Zenker, a kind of anatomically-preserved fertile foliage of Late Paleozoic Marattiales, has been well studied in Euramerican Flora. It is composed of 28 species which can be divided into four forms (groups) mainly based on modified or umodified pinnules, the variation of the outer facing sporangial walls, and with or without a prominent central parenchyma area. In contrast, Scolecopteris Zenker in Cathaysian Flora has been poorly studied so far, and only one species S. sinensis Zhao, was reported in 1991 which was considered as a member of Minor Group. The paper reports a second species of Scolecopteris, i.e.S, shanxiensis sp. nov., which differs from the above four groups in that its outer facing wall of the sporangia is thick at the base and top (2 ~ 3 layers of cells), and a little thinner ( 1~2 layers of cells) at the midlevel of the synangia. So a new group, Shanxiensis group, is set for the new species. The other characteristics of Shanxiensis group is comparable with Minor group. The new species comes from the coal balls in Coal Seam No. 7 in the upper part of Taiyuan Formation (early Early Permian) from Taiyuan, Shanxi, China. The identification of Scolecopteris shanxiensis sp. nov. :The fertile pinnule probably peeopterids, 5.5 ~ 6.0 mm in length and 2.0 ~ 2.2 mm in width. The lateral extensions of the lamina of the pinnule bend abaxially and above the synangia. The synangia arrange along the sides of the midrib of the pinnnle and there are about 10 synangia in each row. The synangium is elliptical in longitudinal section and radial in cross section, 0.7 ~ 0.8 mm in height and 0.6 ~ 0.7 mm in diameter. Each synangium has 5-7 (mostly 6) fusiform sporangia fused at the base and attached to the top of the synangial pedicel. The outer facing wall of the sporangia consists of 2~3 layers of cells at the base and becomes thinner at the midlevel (1~2 layers of cells), and at the top of the synangia the wall become thicker again. The cells of the outer facing wall of the sporangia are elongate in the longitudinal sections. The lateral and inner facing walls of the sporangia are one cell thick. The synangial pedicel is small. Spores in situ are small, generally 11~14 µm in diameter, spherical or rounded-triangular, trilete and smooth-walled. 相似文献
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STUDIES OF PALEOZOIC MARATTIALEANS: AN EARLY PENNSYLVANIAN SPECIES OF THE FERTILE FERN SCOLECOPTERIS
M. A. MILLAY 《American journal of botany》1982,69(5):728-733
Remains of the fossil Marattiales are very rare in Lower Pennsylvanian sediments. The present report describes a new species of the fertile fern foliage Scolecopteris from the Lewis Creek, Kentucky locality (Lower or lower Middle Pennsylvanian). Scolecopteris conicaulis n. sp. has radial synangia composed of a ring of 4–7 elongate, exannulate sporangia. Most features of the synangia of S. conicaulis were previously hypothesized to be primitive in Scolecopteris based on geologically younger species. Supposed primitive characters include the large synangium pedicel with fiber core, an outer-facing sporangial wall lacking differentiation or zonation, and large spores. The anatomy of the sporangium walls, pinnule morphology, and general spore type support an association with the Minor group of Scolecopteris. The new species is similar in several important features to Scolecopteris (Cyathotrachus) altus, the only other anatomically preserved fertile marattialean known from this early time, and indicates a considerably earlier origin for fertile foliage of this type. 相似文献
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XIAO-YUAN HE SHI-JUN WANG JASON HILTON fls YI-LONG ZHOU 《Botanical journal of the Linnean Society. Linnean Society of London》2006,151(2):279-288
Several isolated marattialean synangia and sporangia are reported from coal balls collected from Coal Seam No.1 (C605) in the uppermost Permian Wangjiazhai Formation in Guizhou Province, south-western China. The synangia are radially symmetrical with diameters between 0.8 and 1.2 mm and are 1.7 mm long, consisting of 3–4 elongate sporangia that are fused basally, free distally and possess a pointed apex. The outer-facing sporangial wall is 4–5 cells thick and conspicuously differentiated. Spores are trilete, have a granular ornamentation and are nearly round equatorially with a diameter of 55–60 µm. Comparisons with other anatomically preserved Palaeozoic marattialean synangia from the Euramerican and Cathaysian floras permit their assignment to the genus of Scolecopteris (Zenker) Millay. In this species the thick, outer-facing sporangial walls and large trilete spores are features consistent with those of the Oliveri Group within Scolecopteris , a group that has previously been considered primitive within this genus. Distinctions from all other previously recognized species within the Oliveri Group lead to the creation of a new species, S. guizhouensis sp. nov. This species is the youngest of the reported species of Scolecopteris recognized from the Euramerican and Cathaysian floras, and provides important evidence on the organization of marattialean ferns from the Upper Permian strata of south China. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 279–288. 相似文献
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Two new species of the late Paleozoic fern Scolecopteris (Marattiales) are described and their relationships within the genus are discussed. Scolecopteris charma sp.n., from Steubenville, Ohio (Duquesne Coal, Upper Pennsylvanian), is similar to species in the Oliveri group, while S. gnoma sp.n. from Providence, Kentucky (Baker Coal, Middle Pennsylvanian), compares favorably with the Latifolia species group. Scolecopteris gnoma is most similar to S. fragilis but differs in its smaller synangia and spore type. S. charma appears generally similar to S. iowensis because of its large pedicel and histologically undifferentiated walls, but differs in a number of characters such as vasculature and spore type. Despite its occurrence late in the Pennsylvanian, S. charma is thought to possess a number of primitive character states (large trilete spores, vascularized pedicels, flat pinnules with downturned margins). Using the same criteria for the much older S. gnoma, we note a number of relatively apomorphic character states (small monolete spores, unvascularized pedicels, extended pinnule margins). An outgroup analysis of species-level characters of Scolecopteris gives a better concept of primitive versus derived traits in marattialean and other ferns. Genera in the Paleozoic fern orders Filicales (Ankyropteris) and Zygopteridales (Corynepteris, Musatea) were chosen as outgroups, and the comparisons support suggestions for the polarity of several important characters. Some of these agree with previously proposed evolutionary polarities based on the geological occurrence of marattialean ferns. 相似文献
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The anamorph determination of Cordyceps sinensis remains problematic due to the lack of clear links between the sexual and conidial forms of the fungus. In this study, we applied molecular approaches to analyze the genetic variation of Cordyceps sinensis and its allies to identify the anamorph-teleomorph connection. The sequences of the internal transcribed spacers (ITS1 and ITS2) and 5.8S ribosomal RNA gene of Cordyceps sinensis (teleomorph) collected from Qingzang plateau (altitude over 4000m), Tibet and several related asexual conidial forms were determined. The sequence comparison showed that Cordyceps sinensis was most closely related to Hirsutella sinensis, and was clearly divergent from Paecilomyces sinensis, Stachybotrys sp. or Tolypocladium sp.; distance values, estimated according to Kimura two-parameter models between Cordyceps sinensis and Hirsutella sinensis, were extremely low (<0.02), whereas distance values between Cordyceps sinensis and Paecilomyces sinensis, Stachybotrys sp. and Tolypocladium sp. were 0.34, 0.21 and 0.25, respectively. Taken together, Hirsutella sinensis and Cordyceps sinensis are the different stages of the life cycle stages of the same organism. Hirsutella sinensis is therefore the anamorph of Cordyceps sinensis, rather than Paecilomyces sinensis or other species. The possible reasons as to why different taxa can be obtained when culturing Cordyceps sinensis are also discussed. 相似文献
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经光学显微镜观察,冬虫夏草[Cordyceps sinensis(Berk.)Sacc.]子囊孢子的发育可分为三个阶段:(1)原子囊孢子期:孢子近球形,椭圆形,卵圆形或长圆形,4.8—10×3.6—6μm。(2)孢子伸长期:从孢子一端突出,伸长生长,出现分隔,隔细胞较长,30—37.5μm。(3)子囊孢子形成期:孢子继续伸长并不断出现分隔,隔间长6—12μm。一般仅有两个孢子成熟,其余多数原子囊孢子败育,不萌发或形成极纤细的丝状物。基于子囊孢子发育的过程,讨论了冬虫夏草及其近缘种的分类地位。 相似文献
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不同林分内茶树光合特性及其影响因子和小气候因子分析 总被引:1,自引:0,他引:1
对板栗-银杏-茶(Castanea mollissima-Ginkgo biloba-Camellia sinensis)和板栗-茶(Castanea mollissima-Camellia sinensis)复合林分和纯茶(Camellia sinensis)林分内3个小气候因子[包括光合有效辐射强度(PAR)、空气温度(Ta)和空气相对湿度(RH)]和茶树光合特性[包括净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)]的差异进行了比较,并采用多元回归分析探讨了影响茶树Pn的主要生理生态因子.结果表明:在不同测定时期3种林分内PAR、Ta和RH差异较大;同一时期纯茶林分内的PAR和Ta基本都高于2种复合林分,但纯茶林分内的RH总体上均低于2种复合林分;与纯茶林分相比,板栗和银杏与茶树复合种植有助于调节林分内的PAR、Ta和RH.2种复合林分内茶树的生长均受到板栗或银杏阴蔽的影响,纯茶林分中茶树的Pn最高,与板栗-银杏-茶复合林分内茶树的Pn有显著差异;而纯茶林分中茶树的Gs总体上高于复合林分、Ci与复合林分间差异不显著,且3种林分中茶树的Tr总体上也无显著差异.多元回归分析结果表明:在6个生理生态因子(Gs、Ci、Tr、PAR、Ta 和RH)中,Tr对3种林分内茶树的Pn影响最大,其次是Ta,其他因子在各种林分内的影响程度不同.研究结果表明:茶树复合种植可调节林分内的水热状况,改善茶树生长环境,值得在现有茶园中进行推广和应用. 相似文献
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利用浮游生物控制工厂化养鳖水质的机理研究 总被引:1,自引:0,他引:1
通过利用浮游生物控制工厂化养鳖池水质养殖与工厂化常规养殖的对照试验及浮游生物、水化学指标、池水细 (霉 )菌含量等各项指标的对照观测 ,发现以隐藻为主体的浮游生物可以控制鳖池水质 ,减少鳖病发生 ,有利于鳖的生长 .鳖的生长速度和产量分别比对照高 52 %和 2 9.3% .减少了水量、能源的消耗 ,显著地降低了生产成本 .同时对隐藻在鳖池整个生态系统中的作用和机理进行了探讨 相似文献
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冬虫夏草及其相关类群的分子系统学分析 总被引:24,自引:0,他引:24
为了探明冬虫夏草及其相关类群的亲缘关系,以冬虫夏草、中国被毛孢及中华束丝孢(=冬虫夏草头孢=蝙蝠蛾多毛孢)共6株菌种作为内群和一株蛹草拟青霉作为外群进行了DNA随机多态型(RAPD)分析。此外,基于上述供试材料又在内群中增加了一株蝙蝠蛾拟青霉,并对内群和外群样品的nrDNA间隔区(ITS)碱基序列进行了测定;对于测定的8条序列连同来自GenBank中的4条相关序列进行了分子系统学分析。结果表明:中华束丝孢和中国被毛孢均系冬虫夏草菌的无性型。按照国际植物命名法规,中国被毛孢应为冬虫夏草菌无性型的正确名称。而蝙蝠蛾拟青霉为不同于冬虫夏草菌的另一种真菌;该名称由于不合格发表而不被国际植物命名法规所承认。 相似文献
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当归及其不同炮制品的挥发油提取及成分分析 总被引:1,自引:0,他引:1
采用水蒸气蒸馏法分别提取生当归及其不同炮制品中的挥发油,应用气相色谱-质谱联用(GC-MS)技术测定和分析其化学组分.在相同提取方法和测定条件下,从生当归及其不同炮制品饮片中得到的挥发油组分存在一定的差异,主要表现在E-藁本内酯、Z-藁本内酯和Z-丁烯基酞内酯等化合物的含量差异较大.当归经过炮制后其所含挥发油的化学成分组成发生了较大变化,说明不同炮制方法对当归挥发油成分的影响是显著的,表明根据临床应用目的不同对当归进行炮制有一定的物质基础. 相似文献
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酚氧化酶在昆虫抵抗外来异物黑化和成囊的免疫反应中起重要作用。中华按蚊和白纹伊蚊分别经胸内接种马来丝虫微丝蚴和生理盐水后,测定蚊血淋巴中酚氧化酶活性。结果表明:未接种的两种蚊,其1日龄蚊的酚氧化酶活性显著高于3、12和16日龄蚊。1日龄中华按蚊接种微丝蚴24h后,其酚氧化酶活性比未接种蚊和接种生理盐水蚊高2—3倍。1日龄白纹伊蚊接种微丝蚴24h后,其酚氧化酶活性是未接种蚊的7倍。白纹伊蚊酚氧化酶活性的免疫激活水平显著高于中华按蚊。讨论了中华按蚊和白纹伊蚊酚氧化酶活性的差异与其免疫力差异的关系。 相似文献
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冬虫夏草无性型研究概况* 总被引:13,自引:0,他引:13
文献调查结果表明与冬虫夏草有关的无性型菌种已报道有22个学名,涉及13个属。针对这些名称上存在的命名问题本文展开了讨论,并评述了不同名称与冬虫夏草的关系及其有关菌种的研究进展。在已报道的分离菌种中,作为新种正式描述的名称有8个,其中6个为合格发表,其余2个未能满足名称合格发表的条件;还有4个名称在文献中作为新种提到,但没有合格发表的出处,也有一例只提到名称而无其他要素;另有5个名称则只有属名,尚未鉴定到种的水平。中国被毛孢为多个独立的研究证明为冬虫夏草的无性型,还有3个无性型名称已被证明不可能是冬虫夏草的无性型。其他无性型名称与冬虫夏草的关系有待进一步验证。文中对与冬虫夏草有关的菌种定名、无性型分离和验证方法、复无性型现象,以及有关学名问题作了讨论。 相似文献
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河北侏罗-白垩纪界线最古老的恐爪龙类足迹 总被引:1,自引:0,他引:1
记述中国河北省赤城县倪家沟化石点一组恐龙行迹,并命名一新属新种--中国猛龙足迹(Menglongipus sinensis ichnogen.et ichnosp.nov.).足迹来自土城子组,位于侏罗-白孚纪界线.相邻的义县组曾发现最古老的恐爪龙类骨骼化石,而中国猛龙足迹的发现表明恐爪龙类早在义县组之前便出现在该地区.中国猛龙足迹的造迹者体长约65cm,非常接近于基十的近鸟类.此外,为四川伶盗龙足迹(Velociraptorichnus sichuanensis)的模式标本提供更多细节,并讨论驰龙类足迹型与其他兽脚类足迹之间的联系. 相似文献
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中国特有珍稀植物伯乐树的研究进展和科研方向 总被引:1,自引:0,他引:1
伯乐树系我国特有珍稀植物,然而关于其保护生物学的研究非常薄弱,综述了其地理分布、生态习性和研究进展,并从保护生物学的角度讨论了亟需解决的问题和其今后的科研方向. 相似文献