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1.
滇产菟丝子种子形态的观察   总被引:3,自引:0,他引:3  
郭凤根  李扬汉   《广西植物》2000,20(4):332-334+387
应用解剖镜和扫描电镜观察了产于云南的 3种 12份菟丝子的种子形态 ,结果如下 :( 1)大花菟丝子种脐线形或弧形凹陷 ,晕轮椭圆形具网状纹饰 ,种皮具条状纹饰 ,条纹宽大呈块状 ,绞链状连接 ,排列致密 ;( 2 )中国菟丝子的种脐呈衣领状突起 ,晕轮圆形具不规则网状纹饰 ,种皮具复网状纹饰 ;( 3)日本菟丝子的种脐线形或弧形凹陷 ,晕轮圆形至椭圆形 ,具规则的网状纹饰 ,种皮具规则条状纹饰或网状纹饰 ,条纹狭长 ,排列稀疏 ;( 4 )种子形态不仅可用于菟丝子种及变种的检疫和鉴定 ,而且支持形态聚类分析所得结论。  相似文献   

2.
Macro- and micromorphological analysis of the caryopses of 58 taxa belonging to 45 genera of Chloridoideae allows the recognition of three caryopsis types according to differences in ventral face and hilum morphology. First is the convex ventral face, corresponding with a leaf-shaped hilum, observed in the tribe Pappophoreae. Second is the flat ventral face, corresponding with a rudimentary, needle-shaped or oblong hilum, observed in the tribes Eragrostideae and Leptureae. The third type, observed in the tribe Cynodonteae, is the concave ventral face, corresponding with a grooved or triangular hilum. The ventral face and hilum, together with other useful caryopsis characters, including six different shapes, seven types of spermoderm sculpture and three types of stylopodium, may be used as diagnostic characteristics of genera, and even species, in Chloridoideae. A key to identify the different species of 45 genera is provided.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 57–72.  相似文献   

3.
国产打碗花属植物种子形态及其分类学意义   总被引:1,自引:0,他引:1  
温学森  李爱国 《植物研究》1995,15(3):363-367
本文借助于又目解剖镜和扫描电电镜对我国打碗花属5种植物的种子进行了观察。结果表明:1、该属植物的种子可分为两类,一类为旋花型,较小,表面具疣状突起,种皮纹饰呈网状,包括打碗花、毛打碗花及旋花;另一类为藤水苗型较大,无疣状突起,种皮纹饰呈咀烂状,包括藤长苗和肾叶打碗花。2、疠状突起由数个相邻种皮细胞胞间壁强烈突出而成,呈山峰状,相连或单独存在。3、该属植物种子形态存在明显区别,可作为分种的依据。  相似文献   

4.
The present paper describes the pollen morphology of 26 species and 2 varieties in Nothofagus from Australia, New Zealand, New Caledonia, New Guinea and South America. Pollen grains were all examined with light microscope (LM), scanning electron microscope ( SEM ) and transmission electron microscope(TEM). A comparative analysis of pollen exine ultrastructure was made for some species. The results are summarised as follows: Pollen grains are oblate to peroblate, 5~8-short-colpate, rarely 4- or 9-colpate; colpi generally thickened at margins; pollen surface spinulose. The exine ultrastructure of Nothofagus differs considerably from that of the other genera in the Fagaceae. The pollen grains of the species examined here show great differences in shape, size, colpal number and characteristics of colpi at margins and could be divided into three distinct types, i.e. N. brassii type; N. menziesii type and N. fusca type.  相似文献   

5.
Seeds ofDactyloctenium Willd. andEleusine Gaertn. may be distinguished from each other by spermoderm patterns.Dactyloctenium seeds are transversed by ridges crossed by wavy lines forming a verrucated, reticulate pattern.Eleusine seeds have a pitted, tuberculate spermoderm pattern.  相似文献   

6.
对螺序草属(Spiradiclis B1、)16种2变型共18个样品的种子形态特征的初步研究表明,本属植物种子为小型(0.2—0、3mm)或中型(0.3—2mm),整体形状不太规则,表面纹饰为蜂窝状,种脐稍突出。种子的外壁由内外2层种皮组成。依据表面突起分布方式,螺序草属的种子大致分为2种类型:(1)平周壁微下陷,疣突均匀分布于其上,如大叶螺序草、螺序草、尖叶螺序草、柳叶螺序草、峨嵋螺序草和龙州螺序草;(2)平周壁下陷成穴状,突起分布在穴边缘,如红花螺序草、心叶螺序草、两广螺序草、广东螺序草、海南螺序草、宽昭螺序草、疏花螺序草、多枝螺序草、罗氏螺序草、小叶螺序草、石生螺序草和紫花螺序草。螺序草属的种子形态特征对属下类群的划分具有重要的参考价值。  相似文献   

7.
This paper deals with the distribution, category, ultrastructure and lammelar changes ofplastids in the stem of the dodder at four development stages. The qualitative assay wasmade oil the photosynthetic capacity of each period with spectrofluorimeter. The results are asfollows: The dodder is a semi-parasitic plant because it contains chlorophyll and chloroplasts whichare capable of photosynthesis. Chloroplasts exist only in phloem parenchyma, and containwell developed lammelar system during the development of haustoria. In this plant, the lammelar system has a rather unusual arrangement, similar to that of semi-parasite Viscum albumbut different from that of the typical seed plants. “Green amyloplasts” (GA) were observedin cortical parenchyma. The photosynthetic and parasitic ability of the dodder is the strongestin the seedling stage when the best effective control on dodder can be obtained.  相似文献   

8.
Ultrastructure of the endolymphatic sac in the mouse.   总被引:1,自引:0,他引:1  
H Furuta  N Mori  M Fujita  S Sakai 《Acta anatomica》1991,141(3):193-198
The ultrastructure of the endolymphatic sac (ES) in the mouse was examined by light and electron microscopy. This organ was divided into three parts: proximal, intermediate and distal. In the proximal portion of the ES, the epithelium consisted of thin squamous cells. The epithelial cells had acquired basolateral processes, numerous small vesicles and well-developed Golgi apparatus. In the intermediate portion, the epithelium consisted of columnar or cuboidal cells. The epithelial cells could be classified into two types: type I and type II. The type I cells had abundant microvilli, pinocytotic vesicles, vacuoles, multivesicular bodies, lysosomes and mitochondria. The type II cells had fewer numbers of these organelles. A few free-floating cells could be observed in the lumen of this intermediate portion, most of which were macrophages. In the distal portion, the epithelium consisted of squamous or cuboidal cells. The epithelial cells had a few cytoplasmic organelles. In the ultrastructural study, each portion of the mouse ES was found to have a very distinct morphological feature. It was suggested that each of these three portions has a different function.  相似文献   

9.
国产藜科14种植物种皮微形态特征比较研究   总被引:1,自引:0,他引:1  
应用扫描电子显微镜和光学显微镜观察了中国产藜科(Chenopodiaceae)5族10属14种植物的种子形态和种皮微形态结构。观察结果表明:供试的14种藜科植物的种子多为卵形和圆形,少数为双凸镜形;种皮表面都具有网状纹饰,包括浅网纹、负网纹和穴状网纹。种皮可分为膜质和壳质2类,其中,膜质型种皮表面不光滑,除网状纹饰外,还有瘤状或褶皱状等纹饰,网眼无规则,纹饰排列无序,猪毛菜族(Salsoleae C.A.Mey.)的松叶猪毛菜(Salsola laricifolia Turcz.ex Litv.)及樟味藜族(Camphorosmeae Moq.)的地肤〔Kochia scoparia(L.)Schrad.〕、全翅地肤(K.krylovii Litv.)、黑翅地肤(K.melanoptera Bunge)、雾冰藜〔Bassia dasyphylla(Fisch.et Mey.)O.Kuntze〕、钩刺雾冰藜〔B.hyssopifolia(Pall.)O.Kuntze〕、樟味藜(Camphorosma monspeliaca L.)、兜藜(Panderia turkestanica Iljin.)和棉藜(Kirilowia eriantha Bunge)均属此类;壳质型种皮表面近光滑,网眼规则,排列整齐有序,少数为不规则浅穴,网脊平而不明显或凹陷,滨藜族(Atripliceae C.A.Mey.)的滨藜〔Atriplex patens(Litv.)Iljin.〕、碱蓬族(Suaedeae Reich.)的角果碱蓬〔Suaeda corniculata(C.A.Mey.)Bunge〕、纵翅碱蓬〔S.pterantha(Kar.et Kir.)Bunge〕和异子蓬(Borszczowia aralocaspica Bunge)以及藜族(Chenopodieae C.A.Mey.)的刺藜(Chenopodium aristatum L.)均属此类。各族之间种皮微形态结构也有一定的区别。根据种皮微形态,地肤属(Kochia Roth)与雾冰藜属(Bassia All.)的关系较近,属的界限和部分种类的亲缘关系需要进一步界定。藜科植物种皮表面大部分凹凸不平,这种结构可能与荒漠干旱生境下吸收和保留水分有关。  相似文献   

10.
Seed size and shape, seed coat surface pattern, seed coat thickness, and endosperm structure were investigated in Androsace septentrionalis, Cortusa matthioli, Hottonia palustris, Primula elatior, Soldanella carpatica (Primulaceae), Anagallis arvensis, A. minima, Cyclamen purpurascens, Glaux maritima, Lysimachia nemorum, L. vulgaris, Trientalis europaea (Myrsinaceae), and Samolus valerandi (Theophrastaceae). Three seed size categories were distinguished on the basis of biometric measurements. Almost all seeds examined were found to be small with an angular shape classified as sectoroid or polyhedral. A new type of seed shape, suboval, was identified for H. palustris. Cyclamen purpurascens seeds differed from seeds of all other species examined because of their large size, subglobose shape, and concave hilar area. Despite the different shape types, the length/width ratio of the seeds examined was constant, while their hilum length/width ratio was a highly variable feature. Three types of seed surface patterns were observed: (1) reticulate, (2) tuberculate with secondary striations, and (3) poroid-alveolate with the presence of a spongy outer layer. For seeds of Anagallis arvensis, A. minima, Cortusa matthioli, Lysimachia nemorum, and Soldanella carpatica, secondary seed sculpture was described. The seed coats of all species examined were two-layered, and great differences in testa thickness were found (9.9?C128.6???m). In general, seeds of the Myrsinaceae species were more often characterized by thick testa. Different proportions in thickness of the inner and outer testa layers were observed. In seeds with reticulate seed patterns, the inner testa layer was twice to several times thicker than the outer layer, while the opposite proportions were observed in seeds with the tuberculate or poroid-alveolate seed sculpture pattern. In seeds of all species examined, oxalate crystals were present on the surface of the inner testa layer. Thus, the presence or absence of oxalate crystals in testa is not a feature distinguishing species with angular or subglobose seeds. Four types of endosperm structure were identified according to the thickness of the endosperm cell walls and the relief of their inner surface: (1) with evenly thickened and smooth cell walls, (2) with evenly thickened cell walls and circular or helical thickenings on their inside surfaces, (3) with very thick, but not evenly thickened cell walls with constrictions (??pitted??), and (4) with very thin papery and undulate cell walls. There is no rule concerning the seed shape, type of the seed sculpture, testa thickness, or endosperm structure that corresponds to the family affiliation of the species examined.  相似文献   

11.
羊蹄甲属植物种子表面微形态观察   总被引:1,自引:0,他引:1  
利用光镜和扫描电镜对羊蹄甲属21种(含1亚种、2变种)的种子进行观察,结果显示,羊蹄甲属植物的种子颜色、形状和外种皮纹饰多样,还发现种脐位置、假种皮裂片、拟透镜状突起和种皮表面纹饰有一定的相关性:即没有假种皮裂片,拟透镜状突起在种子表面不明显,具网状纹饰的种子其种脐位于种子亚顶部的位置,而非顶部位置。此外,大部分羊蹄甲亚属种子的表面纹饰为皱波状,而显托亚属的纹饰没有皱波状纹饰,却以网状纹饰居多。分析认为,羊蹄甲属植物中种皮网纹状纹饰可能是比较进化的特征;并认为种脐在亚顶部位置,没有假种皮裂片,拟透镜状突起在表面不明显,具网状纹饰的种子应是羊蹄甲属内较进化的式样。  相似文献   

12.
张广骅  李杭萍 《遗传学报》1995,22(3):223-229
控制大豆白花亲本籽粒脐色的基因有带R与r之分,带R基因的白花产本与紫花亲本杂交,F1代籽料出现蓝脐性状,其基因型为I-R-W1-tt。当控制脐色的基因有两对相差时(R、r;W1、w1)F2代籽粒脐色分离蓝脐与无色脐之比为9∶7。  相似文献   

13.
The grain amaranths (Amaranthus hypochondriacus, A. caudatus and A. cruentus) have a long history and a unique process of domestication. They are supposedly derived from a weed progenitor. The hypothesis proposing a monophyletic origin of the grain amaranths from the close relative A. hybridus is widely favoured. The present study applied morphological and biochemical tools, and revealed a close affinity between A. hypochondriacus and A. caudatus, and a distinct divergence of A. cruentus from the others, in accordance with previous observations. Accessions of A. cruentus showed a prominent variability, especially in seed surface features, which strongly proposed a segregation of the population into two groups; one having rusty brown seeds with reticulate spermoderm and another group having greyish white seeds with rugulate spermoderm: Amaranthus cruentus var. albus var. nov. and Amaranthus cruentus var. cruentus var. nov. This introduction was well supported by cluster analysis, showing a clear delimitation of brown and greyish white seeded accession of A. cruentus.  相似文献   

14.
Examinations were made on the morphology of caryopses of 324 grass species representing over 109 genera and 31 tribes. The evolutionary tendency of the important characteristics and the relation with distribution areas and habitats are discussed. According to the shape of caryopses, the morphology of ventral faces and hilum, the proportion of embryos to caryopses in size, the existence or absence of the top fine hairs, the persistence or shedding of styles, the size of fruits and especially the outline of the middle cross section, etc., the caryopses may be divided into three major types and seven subtypes: Bambusoid (including True Bambusoid, Arundinoid, Oryzoid, Stipoid), Panicoid (including True Panicoid, Eragrostoid) and Pooid (including the Subtype Pooid only). In this study, the different types of caryopses are found to be correlated with the characteristics of embryos, seedlings, habits and chromosomes, and on these grounds, the genera of the Gramineae are grouped into seven corresponding subfamilies: Bambusoideae, Oryzoideae, Arundinoideae, Stipoideae, Eragrostoideae, Panicoideae and Pooideae.  相似文献   

15.
The seed surface of 12 species of Impatiens L. from Mt. Omei was observed under SEM for the first time. The important characters used in the paper include cell specialization on seed surface, arrangement pattern of the cells, the degree of the cell elevation, chalazal zone morphology and appendix at the tail of the seed. According to these characters, the seed surface morphology of 12 species can be divided into two types: 1. the seed without conspicuous differentiation of surface cells, laevigate on the surface, represented by I. wilsoni; the seeds of species indicated by 3-colpate pollen grains are expected to belong to the type. 2. the seed with the large cell elevation at different levels, surface scabrous, represented by the other 11 species; most species with 4-colpate pollen have this kind of seeds. The results verify that the seed morphology of the genus can supply characters significant to taxonomy of the genus at species level. The evolution of seed surface of Impatiens has close correlation with that ofthe flower and pollen morphology.  相似文献   

16.
采用扫描电镜方法对中国18种棱子芹属植物的果实表面微形态进行了首次研究,结果表明:所研究的棱子芹属植物果实微形态在外果皮细胞轮廓、表面纹饰和表皮分泌物表现出丰富的多样性和一定的规律性,可作为棱子芹属下分组及种间鉴定的重要参考性状.根据外果皮细胞轮廓及果实表面纹饰类型等微形态特征将所研究的棱子芹属植物分成了3种类型,该结论与形态学和分子系统学研究结果基本一致,说明果实微形态对研究棱子芹属属下分类和鉴别有重要意义,并据此对该属属下个别存疑种及一些种的亲缘关系进行了探讨.综合前人研究,我们支持喜马拉雅地区不仅是棱子属的分布中心,也是其分化变异中心.  相似文献   

17.
八角属(八角科)植物的种子形态   总被引:4,自引:1,他引:3  
林祁  李超  刘长江  杨志荣 《植物研究》2007,27(2):145-150
在光学显微镜和扫描电镜下对八角属(Illicium Linn.) 15种植物(33个样品)的种子形态进行了观察和描述。八角属植物种子形态多为倒卵球形,少椭球形或卵球形,侧向压扁;外种皮石质,中种皮革质,内种皮膜质;外种皮淡黄色、卵黄色至橙褐色,具蜡被,极光滑,有光泽,无纹饰,腹部有一凸起的纵棱(种脊),由种脐延伸至顶端;种脐位于基端偏向腹部一侧或位于基端,卵形或椭圆形,下凹;胚微小,胚乳丰富,含油。该属植物种子的形态特征非常相似,表明该属是一个自然的单系类群。  相似文献   

18.
This study investigated changes in dormancy and germination over 8 months for 23 common species (annual and perennial grasses, legumes and other dicotyledons) from herbaceous communities in northern Australia. Seeds were exposed to three storage treatments: relatively constant laboratory conditions, an oven with fluctuating temperatures similar to those found on the soil surface (25/60°C), or exposed on the soil surface at Townsville. There were wide ranges of initial levels of dormancy (9–100%), rates of change of dormancy and response to the different storage conditions showing that species with several types of dormancy characteristics are able to coexist in these communities. The general trend in dormancy levels was a decline with time with the rate of decline greatest for seeds exposed on the soil surface and least for those stored in the laboratory. The species were divided into groups based on dormancy levels in seeds on the soil surface during the late dry and mid wet seasons. The dormancy characteristics of the groups were related to the ecology of the species in the groups. There was an approximately linear increase in germination rate (i.e. a decrease in the number of days to 50% of final germination) over time for all storage treatments; rates for seeds on the soil surface increased more rapidly than those of seeds in laboratory and oven samples.  相似文献   

19.
In shoots of the dodder Cuscuta odorata mycoplasma-like organisms (MLO) were observed to occur in nearly all mature sieve elements. Their frequency within the sieve elements varied from a few organisms to high concentrations. In addition, MLO, were found in other cell types. By identifying these cells and investigating the location in the vascular tissue three different types of cells infected with MLO could be distinguished: (1) phloem parenchyma cells, (2) parenchyma cells separating the five vascular bundles of C. odorata and (3) cells in the outer region of the vascular system next to the cells looking like an endodermis. Within the cells of the types 2 and 3, MLO occurred in large numbers and at different morphological structures., Therefore, we assume that the MLO multiply in these cells.  相似文献   

20.
The ultrastructure of symbiotic bacteria colonizing the mucous membrane of the gut of freshwater fish and the tegument surface of their cestodes was studied. A comparative analysis of published and original data made it possible to define the ultrastructure peculiarities promoting the adaptation of bacteria to the digestive transport surfaces of fish and their intestinal parasites. The studied peculiarities may be split into three groups: (1) the structure and composition of the bacterial cell surface, which allows the colonization of gut epithelia and cestode tegument; (2) the intracellular ultrastructure of the bacteria; and (3) the reorganization of cell types, i.e., the formation of the dormant cells and nanobacteria.  相似文献   

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