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报道了鳞毛蕨科的4个属(毛枝蕨属Leptorumohra、石盖蕨属Lithostegia、黔蕨属Phanerophlebiopsis和柳叶蕨属Cyrtogonellum)6种植物的染色体数目及生殖方式。其中柳叶蕨Cyrtogonellum fraxinellum 'n'=123, 2n=123; 离脉柳叶蕨C. caducum 'n'=123; 斜基柳叶蕨C. inaequalis 2n=123; 四回毛枝蕨Leptorumohra quadripinnata n=41; 石盖蕨Lithostegia foeniculacea 2n=164; 长叶黔蕨Phanerophlebiopsis neopodophylla 2n=82。石盖蕨属、黔蕨属和柳叶蕨属的染色体数目为首次报道。结果表明这3个属的染色体基数和鳞毛蕨科中其他属一样均为x=41。细胞学证据支持将石盖蕨属、黔蕨属置于鳞毛蕨科的处理。本文还发现柳叶蕨属与贯众属Cyrtomium的一些种一样, 具有无融合生殖方式, 而其他3个属仅具有在蕨类植物中较为常见的有性生殖方式。 相似文献
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报道了水龙骨科丝带蕨属丝带蕨Drymotaenium mivoshianum Makino的染色体数目、核型及生殖方式.结果表明:丝带蕨体细胞的染色体数目为2n=72,核型公式为2n=2x=72=18m 26sm 24st 4T,核型为3B,核型不对称系数As.K=71.24%,丝带蕨的核型为首次报道.丝带蕨是有性生殖二倍体.结合前人的研究结果,讨论了染色体数目、核型在水龙骨科系统学研究中的意义. 相似文献
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中国凤尾蕨属细胞学的初步研究 总被引:3,自引:0,他引:3
本文报道了中国产10种凤尾蕨属植物和2种蕨属和栗蕨属植物的细胞学研究结果。 在凤尾蕨
属中,8种是多倍体或具有多倍体细胞型,4种是无性孢子繁殖的后代,6种实际上是种复合体或种复合体成员,单纯有性生殖的二倍体只有2种。凤尾蕨至少具有9条孢子发生路线,在其同一个体上除了产生二倍孢子外,还可能产生少量加倍或多倍孢子;广义的蜈蚣草实际上是个种复合体,其祖先的二倍体细胞型广泛分布于中国亚热带地区说明这里可能是该复合体的起源中心;岩凤尾蕨具有不寻常的染色体数目n=55,这说明在本属和本科中可能存在着非整倍体进化。 相似文献
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报道了中国云南产鳞毛蕨科Dryopteridaceae鳞毛蕨属Dryopteris Adanson 13种植物的染色体数目。其中4个种:多雄拉鳞毛蕨D.alpestris(2n=82)、哈巴鳞毛蕨D.habaensis(2n=82)、脉纹鳞毛蕨D.lachoongensis(2n=82)和永自鳞毛蕨D.yungtzeensis(2n=82)的染色体数目为首次报道;无融合三倍体的川西鳞毛蕨Dryopteris rosthornii、无融合四倍体的大羽鳞毛蕨D.wallichiana以及无融合二倍体的栗柄鳞毛蕨D.yoroii为3个新发现的细胞类型。细胞学研究结果支持高山鳞毛蕨组sect.CaespitosaeS.G Lu应该为鳞毛蕨属内一个独立的组;中国喜马拉雅地区的鳞毛蕨属植物中存在着大量的无融合二倍体细胞类型。对蕨类植物中同一植株产生不同倍性孢子的现象进行了讨论。 相似文献
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膜叶铁角蕨属隶属于铁角蕨科,全世界约有30种,我国分布有18种,是该属植物的分布中心之一。到目前为止,膜叶铁角蕨属的物种数目和物种分类还存在很大争议,一些物种的界限和定义还模糊不清,为了得到一个自然的膜叶铁角蕨属分类系统,还需要对膜叶铁角蕨属的物种分类做进一步研究。该文在前人研究的基础上,对膜叶铁角蕨属10种植物的形态特征,包括孢子形态特征、叶柄和根状茎上的鳞片形态特征、叶片形态、羽片形状以及叶脉特征等进行详细观察分析,探讨了各个形态特征间的关系以及膜叶铁角蕨属植物的物种分类。结果表明:膜叶铁角蕨属植物的叶片及羽片等形态特征存在很大区别,叶柄和根状茎上的鳞片以及孢子形态的种间差异虽然不大,但其在大小、形状、颜色等方面的细微差别仍可作为部分种类的鉴定依据。该研究结果为膜叶铁角蕨属植物的物种分类及进一步研究提供了重要依据。 相似文献
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本文报道12种中国产蕨类植物的细胞学情况,其中9种的染色体数目是第一次被计数,它们是四川峨眉山产的月牙铁线蕨 Adiantum edentulum n=30、直立假蹄盖蕨 Athyriopsiserecta n=40、九老洞鳞毛蕨 Dryopoerris julaodongensis“n”=82(及n=41?)、稀羽鳞毛蕨 Dryopteris sparsa var.nitidula n=41、粉红方秆蕨 Glaphyropteridopsis rufostraminea n=36、芒齿耳蕨 Polystifhum hecatopteron n=41、披针叶新月蕨 Pronephrium penangiana n=36和北京产的麦秆蹄盖蕨 Athyrium fallaciosum n=40(及“n”=80?)、河北峨眉蕨 Luna-thyrium ucgetius n=80。麦秆蹄盖蕨和新种九老洞鳞毛蕨在同一植株上的不同孢子囊里,分别产生32个和64个两种孢子数目,说明它们可能是有性生殖和无融合生殖兼性的二倍体种。荚果蕨 Matteuccia struthiopteris 的观察结果表明这个属的染色体基数(x)是39。其他2个种的观察结果是:团羽铁线蕨 Adiantum capillus-iunonis n=30和北京铁角蕨 Asplenium pe-kinense n=72。 相似文献
11.
Wang Zhong-ren 《植物学报(英文版)》1987,29(2)
Mecodium paniculiflorum (Presl) Copel. and M. osmundoides (v. d. B.) Ching from Sichuan Province have been examined cytologically. They have the chromosome numbers n = 26 and n=28 respectively, which are recorded for the first time. Their spores produced after normal meiosis are seemly available. Both the species are sexual diploid. The chromosome number n=26 of M. paniculiflorum shows that it is distinct from M. polyanthos (Sw.) Copel. with the chromosome number n=28. However, M. osmundoides has the same chromosorrie number with M. polyanthos. Therefore, it may be an Asian member of M. polyanthos group. The occurrence of the basic number 26 in the genus Mecodium has given a strong evidence of the close relationship between Mecodium and Hymenophyllum, Meringium. It has been known that in Hymenophyllaceae, they are the only three genera with more than four base numbers. They have shared the base numbers 21 and 28. Now, they have the third common base number 26 (or 13) which is a spicific basic number in the family. In addition, all they have bivalved involucres and other similar characters, so it is reasonable that they are treated as subgenera or section under the same genus Hymenophyllum by C. V. Morton[13] and K. lwatsuki[7,8]. During the sporogenesis of M. paniculiflorum and M. osmundoides, the initial archesporiaI cell in a developing sporangium usually divides successively five times by mitosis resulting 32-spore mother cells, and then meiosis occurs regularly, giving rise to 128 spores finally. In a few cases, 64-SMC or 256-spore sporangia are also produced in M, osmundoides. It is suggested that besides forming 64-spore sporangium, forming 128-spore and 256-spore sporangia should be conscidered as normal sporogenesis lines in sexually-reproducing ferns, especially in Hyme- nophyllaceae and other ancient group of leptosporangiate ferns. The voucher specimens are deposited in the Herbarium of our Institute (PE). 相似文献
12.
Wang Zhong-Ren 《植物分类学报:英文版》1989,27(6):421-438
Cytological and biosystematic studies on the genus Pteris have made a great
contribution to the theory of speciation and evolution in ferns. Sino-Japanese area is one of the
speciation centers of this genus. But only a few Chinese species have been known cytologically.
As a preliminary study, ten species of the genus Pteris and two species of the related genera
Pteridium and Histiopteris were observed. All the materials were collected from southwest
and south China. Their young sori were fixed in ethanol and glacial acetic acid (3:1), in the
field. The preparations were made with acetocarmine squash method. The vouchers are deposited in PE.
The results of observation are summarized in Table 1. Of Pteris, four species are agamosporous, eight are polyploid, six are actually the members of species complexes. Only two species
are purely sexual diploids.
Pteris cretica L. var. nervosa (Thunb.) Ching et S. H. Wu has 58 autobivalents at meiosis
of spore mother cell, and usually produces 32 diplospores per sporangium. It is obviously an
agamosporous diploid. Apart from 32-spored sporangium, some 4-, 8-, 16-, 64-, 13-, 34-, 36-spored, completely abortive or partly abortive sporangia were also found in the fixed material
of a single individual. For explaining these unusual types of sporangia at least nine sporogenesis routes can be inferred. It may not be impossible that besides mainly producing functional diplospores, P. cretica var. nervosa also gives a few functional giant spores with a doubled
or multiplied somatic chromosome number, which means that polyploids may be simply derived
from the spores produced by their diploid parent. The spores in a sporangium are usually
tetrahedral, but a few bilateral ones are also found in some sporangia. Sometimes, the bilateral spores are even more than the tetrahedral ones in a sporangium.
Pteris vittata L. from the type locality shows 58 bivalents at diakinesis of meiosis. Without
doubt, it is a sexual tetraploid, which was also found in south Guangdong and south Yunnan.
However, Its natural ancestral diploid has been widely found in the subtropical regions of
China, such as Sichuan, Guizhou, Yunnan and Hubei provinces. A sterile triploid with the
chromosome number of n=201Ⅰ+26Ⅱ+5Ⅲ and a sterile tetraploid hybrid with the chromosome
number of n=9Ⅰ+45Ⅱ+3Ⅲ+21Ⅴ were found in south Yunnan and south Guangdong respec tively. It is evident that P. vittata L. sensu lato is a species complex which includes several cy totypes. Its hexaploid form was reported from south India by Abraham et al. The distribu tion pattern of different cytotypes in P. vittata complex may indicate that the tropics is more
favourable to formation and surviving of polyploid than the subtropics. However, it is most
possible that Chinese subtropics is the origin place of the ancestral member in the P. vittata
complex. In gross morphology, the tetraploid and triploid forms are only bigger and stronger
than the diploid form. But the diploid can also grow rather big in cultivation. They can har dly be distinguished from each other. Therefore, they are not given formal names here. The
author fully agree with Prof. T. Reichstein when he said in 1983 that it was hoped that a new
nomenclature could be adopted for the cytotypes of species complex in future.
The special chromosome number of Pteris deltodon Bak .was counted in this work for the
first time. It has 55 bivalents at meiosis of SMC. This number is the only exception in the
genus Pteris, and shows that aneuploidy may have taken place in this genus. However, the pos sibility can not be ruled out that P. deltodon is an allotetraploid came from two diploid species respectively with the chromosome number 26 and 29.
Pteris gallinopes described by Prof. Ching in i983 is an agamosporous tetraploid with 116
autobivalents at meiosis, different from the related triploid species P. dactylina Hook. and P.
henryi Christ.
P. ensiformis Burm。 P. muftifida Poir. and P. semipinnata L. are sexual tetraploids with
n=58. P. excelsa Gaud. and P. oshimensis Hieron. var. paraemeiensis Ching are agamosporous
triploids with n = 87 autobivalents. P. wallichiana Agardh is a sexual diploid with n=29.
The high frequency of polyploids and agamospory among these random sampled Chinese
species futher confirms the conclusion that both polyploidy and apomixis have played an important role in speciation and evolution of the genus Pteris.
Pteridium aquilimum (L.) Kunh var. latiusculum (Desv.) Underw. ex Heller and Histiopteris incisa (Thunb.) J. Sm. have n=52 and n=96 respectively. They are both sexual tetraploids. Their chromosome numbers show again that the genera Pteridium and Histiopteris
are distinquished from the genus Pteris by different basic numbers.
This project is supported by the National Natural Science Foundation of China. 相似文献
13.
Rincón Barón EJ Forero Ballesteros HG Gélvez Landazábal LV Andrés Torres G Hilda Rolleri C 《Revista de biología tropical》2011,59(4):1845-1858
Studies on the ontogeny of the strobilus, sporangium and reproductive biology of this group of ferns are scarce. Here we describe the ontogeny of the strobilus and sporangia, and the process of sporogenesis using specimens of E. giganteum from Colombia collected along the Rio Frio, Distrito de Sevilla, Piedecuesta, Santander, at 2200m altitude. The strobili in different stages of development were fixed, dehydrated, embedded in paraffin, sectioned using a rotatory microtome and stained with the safranin O and fast green technique. Observations were made using differential interference contrast microscopy (DIC) or Nomarski microscopy, an optical microscopy illumination technique that enhances the contrast in unstained, transparent. Strobili arise and begin to develop in the apical meristems of the main axis and lateral branches, with no significant differences in the ontogeny of strobili of one or other axis. Successive processes of cell division and differentiation lead to the growth of the strobilus and the formation of sporangiophores. These are formed by the scutellum, the manubrium or pedicel-like, basal part of the sporangiophore, and initial cells of sporangium, which differentiate to form the sporangium wall, the sporocytes and the tapetum. There is not formation of a characteristic arquesporium, as sporocytes quickly undergo meiosis originating tetrads of spores. The tapetum retains its histological integrity, but subsequently the cell walls break down and form a plasmodium that invades the sporangial cavity, partially surrounding the tetrads, and then the spores. Towards the end of the sporogenesis the tapetum disintegrates leaving spores with elaters free within the sporangial cavity. Two layers finally form the sporangium wall: the sporangium wall itself, with thickened, lignified cell walls and an underlying pyknotic layer. The mature spores are chlorofilous, morphologically similar and have exospore, a thin perispore and two elaters. This study of the ontogeny of the spore-producing structures and spores is the first contribution of this type for a tropical species of the genus. Fluorescence microscopy indicates that elaters and the wall of the sporangium are autofluorescent, while other structures induced fluorescence emitted by the fluorescent dye safranin O. The results were also discussed in relation to what is known so far for other species of Equisetum, suggesting that ontogenetic processes and structure of characters sporoderm are relatively constant in Equisetum, which implies important diagnostic value in the taxonomy of the group. 相似文献
14.
The spore mother cells of six species of Chinese homosporous ferns have been examined, among them the chromosome numbers of five species, Adiantum capillus-junonis
Rupr. (n= 30), Ctenitis rhodolepis (Clarke) Ching (n = 41), Cyclogramma flexilis
(Christ) Tagawa (n = 68), Leptogramma scallani (Christ) Ching (n = 36) and Vandenboschia auriculata (B1.) Copel. (n=36), from Emei Shan (Omei) Sichuan province
are recorded for the first time. The chromosome number n=68 from the species
Cyclogramma flexilis suggests that the base number for this genus is 34. Another
species, Athyrium brevifrons Nakai from Wuling Shah Beijing (Peking) has a gameticchromosome number n=40, as already reported by K. Mitui and H. Hirabayashi. 相似文献
15.
Hennequin S 《Comptes rendus biologies》2003,326(6):599-611
The phylogenetic relationships of Hymenophyllum and its segregate genera Cardiomanes, Hymenoglossum, Rosenstockia, Serpyllopsis and Microtrichomanes are addressed, using 31 morphological characters of the sporophyte and one cytological character. As expected, this study reveals considerable morphological heterogeneity within the genus sensu lato, but several apomorphic changes allow support for some clades. Four unresolved taxa, Cardiomanes, Hymenoglossum, Diplophyllum and Mecodium pro parte are probably the most basal elements in Hymenophyllum. The analysis also suggests the polyphyly of Mecodium, and two unexpected associations: Sphaerocionium together with Microtrichomanes; and a broad clade composed of subg. Hymenophyllum, Hemicyatheon and Craspedophyllum, genera Rosenstockia and Serpyllopsis, and subsect. Leptocionium and Amphipterum. These associations appear justified by morphological, cytological or geographical data, and most of them are in agreement with preliminary molecular results. 相似文献
16.
Dispersal is a key process in plant population dynamics. In ferns, two successive vectors are needed: the sporangium catapulting mechanism, and wind or gravity. However, some rock ferns have a growth habit that suggests a kind of autochory by placing spores on the rock surface. Moreover, some ferns show modifications of the sporangial dehiscence. To determine the role of growth habit in spore dispersal, we checked the sporangial opening mechanism and explored the spatial distribution of plants on the walls. The presence of spores of Asplenium celtibericum, a rupicolous fern, in the rock surface was checked. In addition, its sporangial dehiscence, plant size and position in the wall were analysed. Spores and indehiscent sporangia were present on walls at each sampling moment. Their highest number was found close to the plants. There was a positive correlation between crack width and plant size. However, most plants occupy the upper half of the cliffs. The growth habit of A. celtibericum is instrumental to deposit the spores over the neighbouring rock surface, thus enhancing the probability of spores to find suitable crevices for germination. Furthermore, dispersal of indehiscent sporangia might promote intergametophytic mating, and the modified sporangial opening mechanism extends the dispersive period. 相似文献
17.
Idanothekion glandulosum gen. et sp. n. is a synangiate pollen organ represented by approximately 30 specimens contained in coal balls from the middle Pennsylvanian of Illinois. Each synangium is composed of seven to nine elongate sporangia that are fused laterally for approximately four-fifths of their length, and are radially arranged about, and fused to, a short central column; the central column is restricted to the proximal one-third of the synangium. Distal to the column the sporangia surround a hollow central area. Dehiscence occurred by means of a longitudinal slit along the mid-line of the inner face of each sporangium. The outer walls of the sporangia have a complex histology involving an external epidermis, a middle presumably glandular layer containing scattered enlarged cells, and an inner layer made up of thin-walled parenchyma. Vascular tissue is present in the central column and outer walls of the sporangia. Each sporangium has a prominent, attenuate, multicellular tip. Large numbers of saccate pollen grains similar to those found in numerous fossil and extant coniferophytes as well as some Mesozoic pter-idosperms were produced in each sporangium. Idanolhekion resembles some synangia assignable to Paleozoic members of the Marattiales; however, the new genus compares most closely with pollen organs believed to have been produced by members of the Pteridospermales. It seems most likely that Idanothekion represents the pollen organ of some member of the Lyginopteridaceae that produced pollen of a type which up to now has not been known from Paleozoic seed ferns. 相似文献
18.
四十五种叶蝉的染色体研究(同翅目:叶蝉总科) 总被引:2,自引:2,他引:0
研究观察了45种中国雄性叶蝉的减数分裂,其中44种的核型为首次报道,染色体数目变化在2n=12~26之间,性别决定均为XO型。从叶蝉总科的组型图来看,该科染色体数目变化在2n=8~28之间,峰值为2n=18(16+XO),另外几种类型2n=16,20,22也有较高的出现频率。科内染色体数目的进化不具有明显的方向性,2n=22(20+XO)是该科的原始核型,易位导致的不均等互换可能是染色体数目进化的主要机制。从精子发生来看叶蝉总科与角蝉总科的关系较为密切,两者的共同特点是:①精母细胞体积较大,显著不同于沫蝉和蝉科;②减数分裂行为及精子变态过程相似;③染色体数目较少,染色体体积较大;④减数分裂前期具有典型的花束期,没有弥散期,因而不同于蜡蝉。但是由于叶蝉总科的染色体变异范围明显大于角蝉总科,而角蝉总科的核型相对较为保守,从核型上来说角蝉总科是比叶蝉总科较为原始的类群。 相似文献
19.
Molecular systematics of the fern genus Hymenophyllum s.l. (Hymenophyllaceae) based on chloroplastic coding and noncoding regions 总被引:4,自引:0,他引:4
Hennequin S Ebihara A Ito M Iwatsuki K Dubuisson JY 《Molecular phylogenetics and evolution》2003,27(2):283-301
We investigated the phylogenetic relationships of the filmy fern genus Hymenophyllum s.l. using the rbcL and rps4 genes and the intergenic spacer rps4-trnS. Because of variation in length of the noncoding marker, we tested and compared three methods for integrating indels. They proved to be useful for estimating a phylogeny of the genus. The rps4-trnS marker, with coded indels integrated, produced better resolution than analysis of either rps4 or rbcL, and combining the three data sets allowed us to obtain a well resolved and strongly supported topology. We interpret our data as showing support for the classical bigeneric system for the family, and call into question several classifications proposed in the past century. The segregate genera Cardiomanes, Hymenoglossum, Serpyllopsis, and Rosenstockia are embedded within Hymenophyllum s.l. Although the deepest relationships within the genus remain uncertain, two subgenera described by Morton do have some support: (1) Sphaerocionium, in which the problematic section Microtrichomanes is embedded; and (2) a diverse Hymenophyllum, including species that were placed originally in Serpyllopsis, Rosenstockia, Hemicyatheon, and Craspedophyllum by Copeland. Subgenus Mecodium appears to be polyphyletic; nevertheless, a subgroup within Mecodium is strongly supported. Several unexpected associations gain support from cytological data and certain morphological characters not previously used to distinguish species groups within Hymenophyllum s.l. 相似文献
20.
Gerald J. Gastony 《American journal of botany》1974,61(6):672-680
The literature on cyatheaceous spore morphology relative to the presence of a perine layer is reviewed, and evidence based on a sodium-hydroxide assay is presented indicating that the outer scultpine layer in certain cyatheaceous spores is perine. Perine so defined characterizes Metaxya, paleotropical and certain neotropical species of Sphaeropteris, nearly all species of Alsophila, all species of Nephelea, and certain species of Trichipteris and Cyathea. It is lacking in Lophosoria, many species of Trichipteris and Cyathea, and all species of Cnemidaria. Two major patterns of spore number per sporangium in the family are reported. Lophosoria, Sphaeropteris, Trichipteris, Cyathea, Cnemidaria, and probably Metaxya are characterized by 64-spored sporangia, whereas most species of Alsophila and all species of Nephelea are characterized by 16-spored sporangia. The congruence of this generic distribution of sporangial-capacity types with Tryon's phyletic arrangement of cyatheaceous genera supports the naturalness of his system. The intrasporangial germination of spores retained in dehisced and dispersed sporangia supports the suggestion that decreased spore number per sporangium in Alsophila and Nephelea may relate to the role of the sporangia as dispersal units. The decreased number of spores per sporangium is associated with a trend toward increase in the number of sporangia per sores, with the highest known count approaching 1000 sporangia per sorus. The Alsophila-Nephelea evolutionary line has probably not been ancestral in the phylogeny of the more advanced groups of ferns. 相似文献