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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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《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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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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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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Shoichi Nakakuki 《Primates; journal of primatology》1991,32(3):403-408
The bronchial ramification in one specimen of gorilla lung was examined from the viewpoint of comparative anatomy, on the
basis of the fundamental structure of bronchial ramification in the mammalian lung (Nakakuki, 1975, 1980). The right lung of the gorilla consists of the upper, middle, lower, and accessory lobes. The right lung has
the dorsal, lateral, and ventral bronchiole systems, but the medial bronchiole system is lacking. The upper lobe is formed
by the first branch of the dorsal bronchiole system. The middle lobe is formed by the first branch of the lateral bronchiole
system. The accessory lobe is formed by the first branch of the ventral bronchiole system. The remaining bronchioles constitute
the lower lobe. The left lung consists of the middle and lower lobes; the upper and accessory lobes are lacking. The left
lung has the dorsal and lateral bronchiole systems, but the ventral and medial bronchiole systems are lacking. The middle
lobe is formed by the first branch of the lateral bronchiole system. The remaining bronchioles constitute the lower lobe.
The bronchial ramifications of the gorilla lung are rather similar to those of the human lung. 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
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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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利用石蜡切片技术对瑶山苣苔大小孢子发生、雌雄配子体发育及胚胎发育进行了细胞学观察,结果表明:瑶山苣苔胚珠倒生,单珠被,薄珠心,具珠被绒毡层。大孢子母细胞减数分裂形成的四分体呈直线排列,合点端的大孢子发育为功能大孢子,其余3个大孢子退化,胚囊为单孢子发生的蓼型胚囊发育方式。花药为四囊形,花药壁由外到内依次为表皮、药室内壁、中层和腺质绒毡层,小孢子形成时胞质分裂为修饰性同时型,小孢子四分体排列方式为四面体形,成熟花粉为2核细胞。胚乳发育为细胞型,在胚的发育过程中被吸收耗尽。瑶山苣苔大小孢子发生和雌雄配子体发育基本正常,不是导致其濒危的原因。但瑶山苣苔果实成熟时,胚仅发育至球形胚时期,需要经过一定时间休眠才能完成形态后熟,表明胚未发育完全可能是该物种天然更新困难的原因之一。 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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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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The external features of the developing embryos of the springtail, Tomocerus ishibashii, are described. The clypeolabral anlage arises as a single, unpaired swelling. The entognathy is completed by the ventral growth of the tergal anlagen of mandibular, maxillary, and labial segments. These anlagen also form the posterior part of the cranium. The palpi of maxilla and labium are homologous with the telopodites, and proximal parts of these head appendages are homologous with the coxopodites. The sternal element of the labial segment does not participate in the postmentum formation. The anlagen of abdominal appendages appear in the first to the fourth abdominal segments. The first, third, and fourth appendage anlagen form the ventral tube, tenaculum, and furcula, respectively. The fused proximal parts of the first, third, and fourth appendage anlagen are homologous with the coxopodites, and the distal parts which do not fuse are homologous with the telopodites. The anlagen of the second abdominal appendages become flattened and spread over the ventral side of this segment. The ventral structures of the first four abdominal segments are appendicular in origin. 相似文献
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将城市污泥应用于生态恢复因能避开粮食作物食物链而具有良好前景,但其对地表水环境影响仍不十分清楚.本文将城市污泥与建筑垃圾按1∶1体积比混合为生长基质,覆盖在模拟的煤矸石边坡上,播种8种乡土木本植物,对生长季植物生长情况以及坡面地表水和下渗水的电导率、p H、氮磷钾、重金属、多环芳烃等含量进行分析.结果表明:坡面植物生长良好,平均覆盖度达60%;地表水和下渗水的p H值近中性,变化不大,而电导率、氮磷钾、重金属和多环芳烃含量均较高,其中,氮、磷含量在整个生长季超过国家地表水环境质量Ⅴ类水质标准;7月重金属含量最高,其中,As含量只达地表水环境质量Ⅳ~Ⅴ类标准,其余重金属含量多达Ⅱ~Ⅳ标准;随着夏季雨水淋洗增加以及植物-土壤系统对化学物质的吸收、降解和固着作用,地表水和下渗水的电导率、氮磷钾、重金属和多环芳烃含量均显著下降,生长季后期重金属含量达到地表水环境质量Ⅱ~Ⅲ类标准,多环芳烃含量减少约一半.将城市污泥直接应用在煤矸石边坡生态恢复中有利于植物生长,植物-土壤系统使得生长基质中的有害物含量逐渐降低,对地表水环境的负影响主要表现为氮、磷的富营养化,但总体上其环境安全性可控. 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