青菜小孢子发生和雄配子体发育的细胞形态学观察

本文主要报道了青菜(Brassica chinensis L.)小孢子发生和雄配子体发育,其观察结果表明:青菜花芽中,小孢子母细胞减数分裂或小孢子以四分体释放等,内轮4枚长雄蕊晚于外轮2枚短雄蕊.同一花药不同花粉囊内,小孢子母细胞处于减数分裂3～4个时期;同一花粉囊中,在减数分裂Ⅱ的前期表现具有一定程度的同步性,而前Ⅰ期可观察到2～3个时期;但单胞期以后发育又表现同步.除此,笔者对花药壁层的发育和变化进行了详细观察,发现有少数小孢子发生过程中具有异常现象.     

褐毛铁线莲花部结构的扫描电镜观察

利用扫描电镜对野生露地栽培的褐毛铁线莲进行花粉、柱头、萼片的扫描电镜观察。结果表明,褐毛铁线莲的雄蕊多数,花丝被毛,花药无毛,且雄蕊群高低相间,对雌蕊呈包围之势,更有利于授粉。雌蕊由多个离生心皮组成,心皮顶端最后发育成指状。顶端柱头为主要受粉面,随着花期的进行,受粉面沿着腹缝线延伸,扩大了整个受粉面,从而增加了更多的受粉机会。花粉为铁线莲属典型的三沟型花粉,呈椭球形,表面分布细密的刺状凸起,较为粗糙,符合虫媒受粉的花粉形式,发育类型较为原始。其散粉方式呈阶段性,与受粉面的发育方式相适应。花萼属于厚萼型,其背腹面差异较大,茸毛和皮孔器仅在背面分布,腹面则较为光滑。花萼背面布满茸毛,增加了其粗糙程度,方便昆虫停留,有利于授粉。     

十字花科植物花旗竿花药发育的细胞形态学观察

采用常规石蜡切片技术,观察研究十字花科植物花旗竿的花药发育过程。研究结果表明:花旗竿每朵花6枚雄蕊,每个花药4个花粉囊;小孢子在四分体中的排列为四面体型;成熟花粉粒近球形,属3-细胞型花粉粒并有3个萌发沟;花粉囊壁由4层细胞构成,即表皮(1层)、药室内壁(1层)、中层(1层～数层)和绒毡层(1层);绒毡层发育属分泌型。     

薄皮甜瓜雄花小孢子发生与雄配子体发育的研究

[目的]研究薄皮甜瓜(Cucumis melo L.)小孢子发生与雄配子体发育的规律。[方法]以薄皮甜瓜(龙甜四号)雄花为研究对象,利用传统石蜡切片技术对薄皮甜瓜雄花花芽分化和小孢子发生以及雄配子体发育进行了形态学观察。[结果]薄皮甜瓜雄蕊5枚,聚药雄蕊,花药折叠,花药壁发育为基本型。花药壁由3～4层细胞构成,药室内壁宿存。绒毡层属腺质绒毡层。花粉母细胞减数分裂为同时型。成熟花粉2-细胞型为主。成熟花粉粒一般呈近圆形和近三角形,花粉表面具3个萌发孔。[结论]该研究可为甜瓜性别分化研究奠定理论基础。     

长白山区狼爪瓦松花器结构初步观察

以长白山区野生狼爪瓦松新鲜花朵为试验材料,采用常规石蜡切片法观察了狼爪瓦松花器的显微结构。结果表明:狼爪瓦松每朵花有5枚花萼与5枚花瓣,其中包含10枚雄蕊和5枚雌蕊;雄蕊的每个花药具有4个花粉囊,成熟花粉粒为2-细胞型,有3个萌发沟,3个萌发孔;雌蕊属离生雌蕊,子房上位,每个子房包含多个胚珠,胎座属侧膜胎座类型。     

广宁红花油茶花器官发生

利用扫描电镜观察了山茶科Theaceae山茶属Camellia红山茶组广宁红花油茶Camellia semiserrata Chi.的花器官发生过程.广宁红花油茶花被片呈螺旋形发生,心皮原基发生于环状分生组织,4～5枚心皮原基同时发生,在后来的发育过程中,心皮原基发育成合心皮雌蕊,心皮原基纵向伸长发育成合生花柱,柱头布满乳凸状细胞,柱头浅裂,一般3～5裂;雄蕊原基分为内轮雄蕊原基和外轮雄蕊原基,内轮雄蕊原基一般15～21枚同时发生于环状分生组织,外轮雄蕊原基也发生于环状分生组织,外轮雄蕊原基分为3～5层,其基部1/3～1/2合生,外轮雄蕊原基中同层的同时发生,不同层的雄蕊原基发生次序不同;广宁红花油茶的花器官发生与山茶科厚皮香亚科Ternstroemi-oideae杨桐属Adinandra Jack的阔叶杨桐Adinandra latifolia L.K.Ling和猪血木Euryodendron excelsun H.T.Chang明显不同.该研究为山茶属甚至于山茶科的系统发育与演化提供了花器官方面的依据.     

青藏高原蕨麻开花进程及花器结构的初步研究

对青海省蕨麻研究中心150盆人工种植的青藏高原蕨麻的开花动态进行定点观察,对蕨麻开花生长及花器解剖结构进行研究。结果表明,蕨麻单花花期为4~5 d,开花进程中,雄蕊向心聚合包围雌蕊,最后雄蕊群高于雌蕊群。花朵平均大小15.66 mm,旗瓣的长度和宽度分别为7.07 mm和5.62 mm,每朵花有20枚雄蕊,单体雄蕊,其高度为2.64 mm,雌蕊30枚,其高度(柱头+花柱+子房)为2.52 mm。花药着生方式为背着药,开裂方式为纵裂,花药对柱头的紧密包围,使雄、雌蕊的空间不分离。     

蓬垒雌雄配子体发育的研究

蓬垒的雄蕊发育早于雌蕊，雄蕊多数，排列成３轮或４轮，各轮之间的花药发育不同步，具有向基性；花粉母细胞减数分裂后产生四面体型四分体；成熟花粉粒为２－细胞型，雌蕊屡离生单雌蕊，着生在凸起的花托上；子房内着生两枚胚珠，后期只有一枚发育成熟，另一枚退化；胚珠倒生，单珠被，厚珠心，蓼型胚囊。     

蓬■（RubushirsutusThunb．）雌雄配子体发育的研究

蓬（ＲｕｂｕｓｈｉｒｓｕｔｕｓＴｈｕｎｂ．）的雄蕊发育早于雌蕊，雄蕊多数，排列成３轮或４轮，各轮之间的花药发育不同步，具有向基性；花粉母细胞减数分裂后产生四面体型四分体；成熟花粉粒为２－细胞型．雌蕊为离生单雌蕊，着生在凸起的花托上；子房内着生两枚胚珠，后期只有一枚发育成熟，另一枚退化；胚珠倒生、单珠被、厚珠心，蓼型胚囊     

盾叶薯蓣小孢子发生及雄配子体发育的研究

观察了盾叶薯蓣小孢子发生以及雄配子体形成过程。结果表明:盾叶薯蓣雄蕊6枚,花药具4个小孢子囊,花药壁发育方式为基本型,由表皮、药室内壁、中层和绒毡层组成,绒毡层为腺质型。小孢子母细胞在减数分裂后胞质分裂为同时型,小孢子四分体排列多为四面体形,偶为交叉型;成熟花粉为2细胞型花粉粒。在盾叶薯蓣小孢子发生、雄配子体形成及花药壁发育过程中未见败育或其他异常现象。     

稻谷腹部、背部微观结构差异性分析

【目的】从微观角度对糙米腹部、背部的结构差异性进行研究,从宏观角度对糙米的三点弯曲破碎力学性能进行研究,以建立微观结构与宏观力学性能之间的相关关系,为稻谷籽粒裂纹起始于腹部建立理论依据。【方法】对两个品种糙米横截面的腹部、背部在淀粉粒和细胞层次以及糊粉层进行扫描电镜观察,采用三点弯曲法测试糙米的破碎力学性能。【结果】糙米腹部、背部微观结构在淀粉粒、细胞层次以及糊粉层均存在差异,籽粒腹部、背部微观结构的差异对其腹部、背部的结构强度产生影响,使籽粒腹部的结构强度小于背部,与力学测试性能一致,并且腹部、背部微观断裂形式亦存在差异。【结论】稻谷籽粒在解吸和吸湿条件下裂纹起始于腹部与其腹部结构强度小于背部有关。     

河南太行山区部分野生花卉调查

介绍了太行山野生花卉特点及连香树、山白树、太行花、矮牡丹、连翘、山杏的生态学特性和生物学习性,为加强该区野生花卉资源保护和开发利用提供科学依据。     

Tbx5 and the retinotectum projection

Dorsal and ventral aspects of the eye are distinct from the early stages of development. The developing eye cup grows dorsally, and the choroidal fissure is formed on its ventral side. Retinal axons from the dorsal and ventral retina project to the ventral and dorsal tectum, respectively. Misexpression of the Tbx5 gene induced dorsalization of the ventral side of the eye and altered projections of retinal ganglion cell axons. Thus, Tbx5 is involved in eye morphogenesis and is a topographic determinant of the visual projections between retina and tectum.     

不同品质籼稻胚乳糊化前后微结构差异的研究

 利用扫描电镜观察品质差异较大的 4个籼稻品种稻米糊化前后的微结构 ,发现同等条件下不同部位的糊化明显不同。背部糊化最好 ,细胞完全崩解为絮状或小块状的蓬松物质 ;腹部糊化次之 ,呈较大块状或细胞结构刚被破坏 ,有的细胞轮廓仍可见 ;中部糊化最差 ,多为完整胚乳细胞。不同品种糊化后差异明显 ,米质好的品种其背、中、腹部的糊化比米质差的品种的相应部位好 ,米质较差品种的中部明显凹陷 ,而较优品种的断面较平 ,该现象同样表现在早、晚稻的对比上。品种间背部糊化的差异小于中、腹部 ,品种内米质较优的稻米背、腹、中部的差异比米质差的小。米质较好的品种的胚乳横断面可见较多断裂的细胞 ,而米质较差的品种几乎见不到断裂的细胞 ,其数目与米质优劣有一定的正相关。米质优劣与糊化时的吸水率和延长率正相关 ,吸水率和延长率高则糊化较好     

Microscopic Structures of Endosperms Before and After Gelatinization in Rice Varieties with Varied Grain Quality

The microscopic structures of the endosperm of indica rice varieties with different quality be-fore and after gelatinization were observed using scanning electron microscope. The results showed that the de-gree of gelatinization varied in different parts of the grain and in different varieties under the same experimen-tal conditions. The gelatinization of dorsal side was the most complete. Its cells were decomposed totally intopuff-like or flocculent materials. The ventral side gelatinized less thoroughly, appearing agglomerate and somecell frames were still visible. The middle part gelatinized most incompletely and the cells were still integrated.Evident differences in gelatinization were observed among different varieties, the dorsal, ventral and middleparts of high quality varieties gelatinized more thoroughly than those of the corresponding parts of low qualityvarieties respectively. An obvious concavity often appeared in the middle of the cross-section of the low qualitygrains while the cross-section of high quality grains was normally flat. The same phenomenon was noted whencomparing the early maturing indica rice and the late maturing indica rice. Varietal difference of gelatiniza-tion in dorsal sides was not as distinct as in middle parts and ventral sides. The difference among dorsal side,middle part and ventral side in gelatinization was greater in low quality grains than that of high quality grains.In addition, a lot of ruptured cells were observed in the cross-section of high quality rice, while few of themcould be found in the low quality rice. Apparently, the number of ruptured cells is positively correlated withrice quality. Quality of rice grain also has positive correlation with the rate of water absorption and extension. Highrates of water absorption and extension lead to better gelatinization of rice grain, and hence indicate good quality.     

The effect of the floor plate on pattern and polarity in the developing central nervous system

The effect of floor plate on cellular differentiation in the neural tube of quail embryos was examined. In the developing neural tube the floor plate, which consists of specialized neuroepithelial cells, is located in the ventral midline of the neural tube. When Hensen's node was extirpated the floor plate and notochord did not develop, and the normal differentiation of the ventral horn motor neurons and dorsal and ventral roots did not occur. When one side of the neural tube was deprived of notochord, the ventro-dorsal differentiation took place on both sides. However, when one side of the neural tube was deprived of the floor plate, the ventral horn motor neurons and dorsal and ventral roots did not develop on that side. These observations suggest that the floor plate influences motor neuron differentiation and acts as an intrinsic organizer to establish pattern and polarity in the developing nervous system.     

Neuronal generation of the leech swimming movement

The swimming movement of the leech is produced by an ensemble of bilaterally symmetric, rhythmically active pairs of motor neurons present in each segmental ganglion of the ventral nerve cord. These motor neurons innervate the longitudinal muscles in dorsal or ventral sectors of the segmental body wall. Their duty cycles are phase-locked in a manner such that the dorsal and ventral body wall sectors of any given segment undergo an antiphasic contractile rhythm and that the contractile rhythms of different segments form a rostrocaudal phase progression. This activity rhythm is imposed on the motor neurons by a central swim oscillator, of which four bilaterally symmetric pairs of interneurons present in each segmental ganglion appear to constitute the major component. These interneurons are linked intra- and intersegmentally via inhibitory connections to form a segmentally iterated and inter-segmentally concatenated cyclic neuronal network. The network appears to owe its oscillatory activity pattern to the mechanism of recurrent cyclic inhibition.     

宁夏襀叉科(襀翅目)二新记录种记述(英文)

文章记述了宁夏襀叉科二新纪录：乳突倍叉襀Amphinemura mamillata和刀突原叉襀Protonemura macrodyctala。乳突倍叉襀的主要特征为第九背板后缘中部形成两个乳状突起，其上着生许多小刺，肛侧突外叶近端部膨大，有刺，并与中叶相连，中叶端半部沿外缘有数列黑刺，中部向上强烈弯曲。刀突原叉襀的主要鉴征为肛上突端部向前延伸形成刀状的刺突，背骨片端部外缘有两簇黑刺，且肛侧突外叶端部有1～3根明显的黑刺。观察标本保存在中国农业大学标本馆。     

鸡、鸭和鹅胰腺的比较解剖

本实验用大体解剖学方法,对鸡、鸭、鹅的胰叶和胰管的形态结构进行观察.3种家禽的胰腺均分为背侧胰叶、腹侧胰叶和脾胰叶,除有背侧胰管和腹侧胰管外,并有一小胰管,鸡、鸭、鹅分别自背侧胰叶腹侧、背侧胰叶尾端和腹侧胰叶尾端发出.背侧胰管和腹侧胰管的入肠形式:鸡为背侧胰管在前,腹侧胰管在后.鸭和鹅有3种:背侧胰管和腹侧胰管左、右并列:背侧胰管在前,腹侧胰管在后;腹侧胰管在前,背侧胰管在后.     

重瓣野迎春花部维管束系统的解剖学观察

运用石蜡制片技术对重瓣野迎春的花部维管束进行解剖学研究,以探索其花部维管束分布与延伸,明确野迎春的花部重瓣来源的解剖学证据。结果表明:野迎春的花梗维管束为外韧型,密集地分布于花梗中央;心皮背束2束,隔膜束1束;子房壁维管束中的外轮维管束和内轮维管束,向上延伸发展为萼片维管束和花瓣维管束;同时,隔膜束和心皮背束继续向内移动,并产生分支;隔膜束延伸成花瓣维管束和雄蕊维管束,心皮背束发展成为雄蕊维管束和花柱维管束。重瓣野迎春的两轮花瓣维管束的来源为隔膜束和子房壁,故其重瓣的演化类型属于重复起源。