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1.
《Journal of plant physiology》1986,123(4):381-388
In The Bud Of The Great Ash (Fraxinus Excelsior L.) The Reserves Of Starch Stocked During Dormancy — The Presence Of Which Was Demonstrated By Use Of The Schiff-Periodic Acid Method — Were Used Differently In The Shoot Apex And In The Stem Tip Underneath The Meristem. In The Shoot Apex The Starch Was Mobilized Before The Resumption Of Growth Activity. During The Last Days Of Dormancy The Water Content In The Buds Remained Low, Inferior To The Threshold Which Characterized Them During Active Growth; But In The Shoot Apex The Water Potential, Measured In Terms Of The Degree Of Plasmolysis, Rose By Almost 15 - 105 Pa: some water which had been bound was liberated in the cells of the shoot apex, it could contribute to the hydrolysis of the starch into soluble sugars, which modified the requirement of water. This constituted, therefore, a decisive step in the passage from dormancy to active growth, and the interruption of dormancy was thus linked to an adequate increase of the water content in the bud. In contrast, in the stem tip underneath the meristem the progressive hydrolysis of the starch reserves constituted the response to the hydration of the bud which occurred after the resumption of growth, when the energy requirements resulting from the development of the annual branch were manifest. 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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短柄五加大,小孢子发生和雌,雄配子体发育的研究 总被引:6,自引:2,他引:4
短柄五加花药5枚,每个花药四个花粉囊。小孢子母细胞减数分裂时,胞质分裂为同时型,产生正四面体形的四分体。花药壁由表皮、药室内壁、中层和绒毡层四层细胞组成,其发育类型为双子叶型。腺质绒毡层,其细胞为二核。三细胞型花粉。子房5室,每室两个胚珠,上胚珠败育,下胚珠可育。下胚珠倒生,具单珠被,厚珠心。大孢子母细胞减数分裂形成线性排列的四个大孢子,雌配子体发育属蓼型。开花当天,花粉散开,雌配子体尚未成熟,处 相似文献
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德保苏铁茎的解剖学研究 总被引:2,自引:0,他引:2
对德保苏铁茎、叶柄的解剖构造进行观察,结果表明:(1)德保苏铁的茎由周皮、皮层、维管束、髓四部分构成。木栓层的细胞壁完全栓化;皮层大而显著,皮层细胞一般较小,富含淀粉,分布有粘液道;维管束通常较小,主要集中在皮层和髓之间的狭窄区,排列呈环形,具2生长环;少部分稀疏地散生在皮层薄壁细胞之间。(2)叶柄由表皮、绿皮层、下皮层、基本组织、维管束、髓组成。表皮细胞1层,细胞外壁角质化;绿皮细胞2层,有叶绿体;下皮层的厚壁细胞,大小不一,细胞壁强烈增厚;维管束散生,属外韧维管束,排列呈环形,内有零星分布的维管束。 相似文献
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糖蜜草(Melinis minutiflora Beauv.)幼穗分化发育.及花和果实形态的研究 总被引:2,自引:0,他引:2
本文对糖密草(MelinisminutifloraBeauv.)的幼穗分化发育及花和果实的形态作了研究,将幼穗分化发育过程划分为以下九个时期:第一苞原基形成期;第一次枝梗原基形成期;第二、三次枝梗原基形成期;小穗及颖花原基形成期;雌、雄蕊原基形成期;花粉母细胞形成期;花粉母细胞减数分裂期;花粉充实期;花粉成熟期。全过程历时约需42d.从抽穗到颖果成熟约需50d。糖蜜草的花序为圆锥花序。每花序有可育花2000—3000朵.小穗是由小穗轴、内外颖片、不育花外稃和小花构成。小花包括有内外稃各一片、一鳞被、雄蕊三枚和一枚雌蕊,颖果千粒重为91mg。 相似文献
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《Curtis's Botanical Magazine》2001,18(4):229-239
Books reviewed:
David Mabberley, Ferdinand Bauer. The Nature of Discovery
H. Walter Lack, A Garden for Eternity. The Codex Liechtenstein
Damodar Lal Gurjar, Enduring Perfection. Catalogue of an exhibition of paintings
J. Cullen et al , The European Garden Flora VI
John Dixon Hunt, Greater Perfections. The Practice of Garden Theory
E. Charles Nelson, A Heritage of Beauty: The garden plants of Ireland. An illustrated encyclopedia
Elizabeth B. Moynihan, The Moonlight Garden. New Discoveries at the Taj Mahal 相似文献
David Mabberley, Ferdinand Bauer. The Nature of Discovery
H. Walter Lack, A Garden for Eternity. The Codex Liechtenstein
Damodar Lal Gurjar, Enduring Perfection. Catalogue of an exhibition of paintings
J. Cullen et al , The European Garden Flora VI
John Dixon Hunt, Greater Perfections. The Practice of Garden Theory
E. Charles Nelson, A Heritage of Beauty: The garden plants of Ireland. An illustrated encyclopedia
Elizabeth B. Moynihan, The Moonlight Garden. New Discoveries at the Taj Mahal 相似文献
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Allan F. Wolfe 《Journal of morphology》1971,135(1):51-69
The male reproductive system of Artemia was studied by routine histological and histochemical techniques to demonstrate the general histology and distribution of proteins, carbohydrates, lipids, and alkaline and acid phosphatases. The System Consists Of Paired Testes, Vasa Deferentia, Accessory Glands, And Penes. The Testes Contain Germ Cells And Supporting Cells Throughout Their Entire Length. The Former Cells Are Located In Clusters And Undergo A Spermatogenic Maturation Which Is Similar To That Described For OtherAnimals. The Supporting Cells Seem Implicated In The Nourishment Of The Germ Cells. The Vas Deferens, Which Consists Of Secretory Epithelium Surrounded By Circular And Longitudinal Muscles, Secretes The Seminal Fluid, Containing A Neutral Mucopolysaccharide Or Mucoprotein, And Stores The Mature Sperm. The Accessory Gland Consists Of Approximately 20 Pairs Of Gland Cells, Each Pair Drained By A Neck Cell And Duct Cell Into The Collecting Duct. The Glandular Secretion, Mainly A Neutral Mucopolysaccharide Or Mucoprotein, Might Function As A Lubricant, A Copulatory Plug, Or An “Activator Substance” For The Sperm Or For Fertilization. Each Penis Consists Of A Non-Eversible Part And An Eversible Part Which Is A Tortuous Muscular Tube That Connects The Vas Deferens To The Outside. 相似文献
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象牙参种子的解剖学和组织化学研究 总被引:3,自引:0,他引:3
象牙参种子解剖学和组织化学的研究结果表明, 种子包括假种皮、种皮、外胚乳、内胚乳和胚。假种皮没有完全包被种子, 由约4~5 层薄壁细胞构成。种皮可以分为外种皮、中种皮和内种皮。外种皮由1 层表皮细胞构成, 细胞壁明显增厚;中种皮包括下皮层、半透明细胞层和3~4层细胞的色素层, 下皮层和色素层细胞均充满红棕色色素;内种皮由1 层体积小、壁局部增厚的砖形薄壁细胞构成。种子在珠孔端分化出珠孔领、孔盖和种阜状结构, 珠孔领为同形型, 孔盖不具石细胞硬层。合点区内种皮出现缺口, 缺口间充满合点区色素细胞, 其整体轮廓成新月形。外胚乳可分为厚区与薄区两部分, 外胚乳细胞壁平直, 细胞内充满淀粉。内胚乳细胞主要含蛋白质, 也有少量脂类物质, 细胞界限不清楚。胚棒状, 两端略膨大, 含大量脂类物质, 也含蛋白质和多糖。 相似文献
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2004~2005年,在陕西省南部米仓山黎坪国家森林公园研究了秦岭蝎蛉Panorpa qinlingensisChouetRan的年生活史和生物学习性,通过饲养,成功获得卵、幼虫、蛹等虫态。结果表明,秦岭蝎蛉在米仓山1年发生2代,以预蛹在土室里越冬,5月中旬始见越冬代成虫,5月中旬末~6月上旬为越冬代成虫羽化盛期,7月下旬~8月中旬为第1代成虫羽化盛期,成虫在室内可存活35~60 d。羽化近1周后开始交尾,交尾4~8 d后开始产卵,单雌产卵量35~180粒,卵期5~9 d;幼虫型,共4龄,历期38~50d;蛹为强颚离蛹,蛹期8~18 d。记述了主要生物学习性。 相似文献
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采用马来氏网法在山东省临沂市开展了花生田昆虫系统调查(2014年6月-2015年6月),阐明当地花生田的昆虫群落结构及相关群体指数动态规律。结果表明:试验期内共获得昆虫样本65 005头,分属于14目、129科。从目级水平来看,主要花生昆虫以膜翅目、鞘翅目、半翅目、双翅目和弹尾目为主;从科级水平来看,主要花生害虫有叶蝉科、夜蛾科和潜蝇科,主要天敌有花蝇科、长足虻科、金小蜂科、长蝽科和姬蜂科。该地区群落多样性指数在0.4262~3.3212之间,峰值出现在花生生长期(3.3312);相对丰度峰值出现在花生繁育期(9 956);科级丰富度峰值出现也出现在花生繁育期(83);均匀度指数在0.1137~0.7613之间,峰值出现在2014年6月(0.7613);优势集中指数在0.0172~0.2134之间,峰值出现在2014年8月(0.2134)。 相似文献
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茴香砂仁种子的解剖学和组织化学研究 总被引:3,自引:1,他引:2
茴香砂仁种子的假种皮膜质,由内、外表皮及其间的数层薄壁细胞构成,种皮黑褐色,由外种皮、中种皮和内种皮组成,外种皮为1层表皮细胞;中种皮由1层细胞的下皮层,1层细胞的半透明细胞层、3-4层薄壁细胞的中种皮薄壁细胞层和1层细胞的色素细胞层组成,内种皮由1层径向延长的细胞构成,内切向壁与部分径向壁非常增厚,种子珠区分化出珠孔领,孔盖和珠孔区薄壁细胞,合点区内种皮出现缺口,缺口间的合点区色素细胞群整体轮廓呈刺叭状,珠孔端的则为1层细胞,细胞内含蛋白质、多糖、脂类物质,胚含量脂类物质,还含有蛋白质与多糖。 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 present paper reports the chromosome numbers and karyotypes of five species in Polygonatum from Anhui of China. The materials used in this work are listed in Table 1, Photomicrographs of somatic metaphase and karyograms of the five species of Polygonatum in Plate 1, 2, 3, the idiograms in
Fig. 1-11 and a comparison of the karyotype of them is provided in Table 2. The results are shown as follows:
1. Polygonatum odoratum (Mill.)Druce
Two materials were examined. One from Mt. Huangshan, Anhui, has 2n= 16 = 10m (3sc)+ 6sm (Plate 1 :A, B). The idiogram is shown in Fig. 1. The chromosomes range in length from 2.85 to 8.85 μm, with the total length 48.63μm and the ratio of the longest to the shortest 3.11, The karyotype belong to Stebbins’(1971) 2B. The two chromosomes of the first pair have arm ratios 1.01 and 1.29 respectively, and The first pair has one chromosome carrying a satellite attached to the short arm, showing heterozyosity .The chromosome num ber of 2n= 16 in P. odoratum and its karyotype are reported for the first time.
The other from Langyashan, Chu - xian, Anhui, is found to have 2n = 18 = 10m (Isc)+2sm+6st(2sc) (Plate 1: C, D). The idiogram is shown in Fig. 2. The chromosomes range in length from 2.43 to 8.29μm, with the total length 46.67µm and the ratio of the longest to the shortest 3.41. The karyotype is also of 2B. In a somatic chromosome complement the 2nd pair have one chromosome carrying a satellite attached to the long arm, showing heterozygosity.
2. Polygonatum filipes Merr.
Two materials were examined. One from the Huangshan, Anhui is found to have two cytotypes: 2n= 16 and 2n=22. This paper reports one of them. The karyotype formula is 2n=22=8m+8sm(2sc)+6st(Plate 3: Q, R). The idiogram is shown in Fig. 3. The chromosomes range in length from 2.55- 5.85μm, with the total length 45.01 μm and the ratio of the longest to the shortest 2.29. The karyotype belongs to 3B.
The other material from the Fangchang, Anhui, is shown to have four cytitypes: 2n= 14, 2n= 16, 2n=20 (Plate 3: W) and 2n=22. This paper reports two of them.
Type I: the karytype formula is 2n=14=10m+4sm (Plate 3: S, T). The idiogram is shown in Fig. 5. The chromosomes range in length from 2.59 to 7.61μm, the total length 37.44μm and the ratio of the longest to the shortest is 2.94. the karyotype belongs to 2B.
Type II :The karyotype formula is 2n=16=8m+4sm+4st (Plate 3: U, V).
The idiogram is shown in Fig. 4. The chromosomes range in length from 2.65 to
8.21 μm, the total length 46.01 μm and the ratio of the longest to the shortest
3.10. The karyotype belongs to 2B.
The chromosome numbers of 2n=20, 2n= 14 and 2n=22, and karyotype of
2n= 14 and 2n=22 in P. filipes are reported for the first time.
3. Polygonatum cytonema Hua
Two materials were examined. One from the Langyashan, Chuxian, anhui, is found to have 2n = 18 = 8m (2sc)+ 6sm+ 4st (Plate 2: K, L). The idiogram is shown in Fig. 7. The chromosomes range in length from 3.41 to 9.21 μm, the total length 56.34μm and the ratio of the longest to the shortest is 2.70. The karyotype belongs to 2B.
The other material from the Huangshan, Anhui, has two cytotypes: 2n=20 and 2n= 22. Type I: The karyotype formula is 2n= 20= 8m+ 6sm+ 6st (Plate 2: M, N). The idiogram is shown in Fig. 8. The chromosomes range in length from 1.75 to 5.03μm, with the total length 32. 91μm and the ratio of the longest to the shortest 2. 87. The karyotype is also of 2B. Type II: The karyotype formula is 2n=22=6m+ 8sm+4st+ 4t (Plate 2: O, P ). The idiogram is Shown in Fig. 10. The chromosomes range in length from 1.75 to 4.95 μm, with total length 35.05μm and the ratio of the longest to the shortest 2.83. The karyotype brlongs to 3B.
4. Polygonatum desoulayi kom.
The material from Xuancheng, Anhui, is found to have karyotype 2n = 22 = 10m (2sc) + 6sm (lsc) + 6st ( Plate 2. I, J). The idiogram is shown in Fig. 6. The chromosomes range in length from 1.86 to 5.61μm, with the total length 41.98μm and the ratio of the longest to the shortest 3.02. The karyotype is also of 3B. The first pair has one chromosome carrying a satellite attached to the long arm, showing heterozygosity. The chromosome number and karyotype of Chinese material are reported for the first time.
5. Polygonatum verticillatum (L.) All. The material from the Langyashan, Chuxian, Anhui is found to have two cytotypes. Type 1: the karyotype formula is 2n = 18 = 2m+ 2sm+ 10st+ 2t+ 2T (Plate 1: G, H). The idiogram is shown in Fig.9. The chromosomes range in length from 1.86 to 4.03μm, with total length 28.28μm and the ratio of the longest to the shortest 2.17. The karyotype classification belongs to 3B. Type II: The karyotype formula is 2n=24=6m+4sm+12st+2T (Plate 1: E, F). The idiogram is shown in Fig. II. The chromosomes range in length from 2.01 to 5.03μm, with total length 41.36μm and the ratio of longest to shortest 2.50. The karyotype is also of 3B. The chromosome numbers and karyotypes of Chinese material are reported for the first time. 相似文献
20.
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