澳洲坚果花芽分化的形态学观察

据对澳洲坚果的花芽分化形态学观察结果:花芽分化初期正常,小花分化是从外往内。其生殖器官属于适于异花传粉的雌雄蕊异长型;花芽分化过程中在花托中部、花被、药隔周围等均出现了大量的后含物;花序发育过程中出现了大量脱落的小花;花粉囊结构正常,花粉母细胞为连续性减数分裂;四分体解体后绝大多数单核花粉粒异常,花粉囊内仅约1/9花粉粒正常发育,另有约1/9花粉粒死亡;剩余的7/9花粉粒均为残片,残片周围均环有胼胝质壁。后期花粉囊有大量中空败育的花粉粒,从形态解剖学的角度来看,这是澳洲坚果结实率低的最重要的原因之一。     

麻疯树花的形态和解剖结构

对麻疯树花序、雌花及雄花连续石蜡切片进行观察,结果表明:同一花序不同分枝上花的发育下部枝早于上部枝。同一花序分枝上位于二歧聚伞花序的中央的花发育早期早于两边的花。雌花在发育上经过两性时期,但雄蕊后来停止发育,形成功能上的单性花;雄花的发育则不经过两性时期,即在结构和功能上均为单性花。胚珠原基在发育过程中生长方向发生约90°改变,最终形成倒生胚珠。     

钝叶柃花器官性别分化的形态学研究

【目的】柃木属植物为热带和亚热带常绿阔叶林灌木层优势种,传统认为是严格的雌雄异株,但在重庆缙云山钝叶柃却存在性别变异现象,即除了典型的雌株、雄株还有两性变异株。通过对不同分化时期的花芽进行形态和结构观察,比较两性变异花芽与典型的雌花芽、雄花芽分化过程的异同,旨在掌握钝叶柃不同性别花芽分化的整体进程及各分化时期的形态特征,明确花芽性别分化的关键时期,进而为探讨性别分化的相关机理提供重要的形态学证据。【方法】以钝叶柃典型的雌株、雄株、两性变异株的花芽为试验材料,采用常规石蜡切片法对花芽分化过程中的外部形态变化和组织结构进行观察分析。【结果】1)钝叶柃1～4个花芽着生于当年生新枝及2年生枝叶腋处; 2)花芽分化始于8月上旬,12月中下旬基本完成,历时120天左右,之后花芽处于休眠状态,次年2—3月进入始花期,两性变异花花芽分化时间晚于雄花芽、雌花芽; 3)花芽分化大致可以划分为5个时期,即苞片分化期、萼片分化期、花瓣分化期、雌雄蕊分化期、雌雄蕊成熟期; 4)在花芽发育过程中,两性变异花芽和雄花芽的雌雄蕊原基同时出现,雄花中雄蕊原基正常发育而雌蕊原基停止发育,两性变异花中雌雄蕊原基皆正常发育;雌花中只见雌蕊原基,未见雄蕊原基。5)在雌雄蕊分化期,两性变异花中,雌蕊原基发育速度略快于雄蕊原基,雌蕊发育与雌花一致,中央心皮原基基部愈合膨大,中部凹陷形成子房室,顶端愈合向上延伸形成花柱;雄蕊发育与雄花一致,雄蕊原基上端膨大形成花药,下端形成短的花丝。在雌雄蕊成熟期各花器官继续生长,发育日趋成熟。6) 3种不同性别花芽长宽比在分化的整个过程中均呈先上升后下降的趋势,雄花芽在萼片分化期长宽比值达到峰值,而雌花芽、两性变异花芽均在雌雄蕊分化期达到峰值。花芽外部形态特征(形状、色泽)在5个分化时期的动态变化依次为圆锥形(绿色)→椭圆形或近圆形(绿色褪尽,深紫红色)→圆胖(深紫红色)→圆形,雄花芽顶端圆钝,雌花芽、两性变异花芽顶端渐尖(紫红色逐渐褪去,绿色加深)→椭圆形(紫红色完全褪尽,由嫩绿色逐渐变成黄绿色或棕绿色)。【结论】钝叶柃3种不同性别花芽在苞片分化期、萼片分化期、花瓣分化期花芽形态和内部组织结构保持一致,而在雌雄蕊分化期出现较大差异,两性变异花芽与雄花芽的分化较为相似,均出现雌蕊、雄蕊原基,明确性别分化的关键期为雌雄蕊分化期,随着分化时期不断推进,花芽外部形态也发生相应的变化。     

虎眼万年青小孢子发生与雄配子体发育研究

该文对虎眼万年青的小孢子发生和雄配子体形成进行研究。结果表明:每朵花有6枚雄蕊,每个花药具4个花粉囊,花药壁由表皮、药室内壁、中层和绒毡层组成。小孢子母细胞在减数分裂过程中胞质分裂属连续型,四分体为四面体型与左右对称型两种类型,以四面体型为主。绒毡层发育类型属分泌型,成熟花粉粒属2-细胞型,有1个萌发沟。     

华中五味子雄花生长发育特征研究

通过对华中五味子雄花发育特征的研究,旨在为遗传育种和栽培管理提供参考。采用SMZ—168体视显微镜对华中五味子不同发育时期雄花形态特征进行观察,采用石蜡切片法对其细胞结构特征进行研究,采用蒽酮乙酸乙酯比色法测量其花部可溶性糖的含量,采用考马斯亮蓝法测量其花部可溶性蛋白的含量。不同发育时期花柄细胞结构无明显差异,由内至外分别为维管柱、皮层和表皮;不同发育时期花瓣细胞结构无差异,随着花的发育,薄壁细胞不断分裂,花瓣增厚,花瓣上存在气孔;花药及花粉在Ⅴ(花冠展开期)发育成熟,外部形态表现为内侧花瓣全部变红,外侧花瓣绿色,花蕾顶部露出红色,花瓣逐渐展开。不同发育时期,雄花花柄、花瓣、雄蕊中可溶性糖含量均在Ⅵ(盛开期)时期达到最大值;华中五味子同一发育时期不同部位中,雄花花瓣中可溶性糖含量最高。华中五味子不同发育时期,雄花花柄、花瓣、雄蕊中可溶性蛋白质含量先降低后升高;同一发育时期不同花部,雄花花柄、雄蕊中可溶性蛋白质含量相对较高。花药及花粉在Ⅴ(花冠展开期)发育成熟,外部形态表现为内侧花瓣全部变红,外侧花瓣绿色,花蕾顶部露出红色,花瓣逐渐展开;发育时期、花部位对其可溶性糖、可溶性蛋白质含量存在极显著影响。     

棉团铁线莲小孢子发生和雄配子体的形成

采用石蜡切片技术,观察棉团铁线莲小孢子发生和雄配子体的形成过程。结果表明:棉团铁线莲每个花药横切面呈蝶形,具4个花粉囊;小孢子在四分体中的排列以四面体型为主;成熟花粉粒近球形,属2-细胞型,具有3条萌发沟;花粉囊壁由4层细胞构成,即表皮(1层)、药室内壁(1层)、中层(数层)、绒毡层(1层);绒毡层发育属分泌型。     

荷兰水仙不同花型花芽分化研究初报

以重瓣型水仙Dick Wilden、喇叭形水仙Barrett Browning、多花型水仙Martinette3个花型的荷兰水仙为试验材料,采用了石蜡切片的方法对这3种荷兰水仙花芽分化过程进行形态学观察,研究花芽发生、发育进程.结果表明 :荷兰水仙的花芽分化过程可分为叶芽时期、花序原基形成期、佛焰总苞形成期、花原基形成期、花被形成期、雄蕊形成期、雌蕊形成期.其中多花型与喇叭形水仙在各个分化时期基本一致,而重瓣型则在雌雄蕊分化时期出现明显的差异,并未分化出雌雄蕊.     

毛白杨胚胎学观察Ⅰ．花药的结构及花粉的发育

本研究所用植物材料于1980－1982年分期分批取自河南郑州和北京等地的毛白杨Populus tomentosa Carr雄株。小孢子发生属同时型，四分体排列有三种形式：四面体形，左右对称形和交叉型。单核小孢子有丝分裂多不均等，少为均为分裂，形成大小一致的两个细胞，以致营养细胞和生殖细胞无法区别，这部分小孢子可能已在体内即走上Vasil(1980)所归纳的组织培养过程中孢子体发育的B途径。对毛白杨雄性不育的形态解剖特征着重予以描述，不散粉的花药皱缩；花粉囊壁层表皮细胞的胞壁呈犬牙状，败育花粉形态多样，大小不一，无核或核极小；无色或染色极深，从发育过程来看，花粉的败育主要是由于减数分裂II末期产生不正常四分体的缘故。同时，绒毡层在减数分裂期间发育极不正常，可能与花粉的败育有密切的关系。     

杉木授粉生物学特性的初步观察

国内外对裸子植物中松柏目植物的受精过程和胚胎发育研究不少,研究材料证明从传粉开始到受精,中间需要一个时期,不同树种长短不一,如松属需13个月,金钱松属2个月,南洋杉6个月,落羽松3个月,紫杉1个月,水杉约3个半月。传粉至受精作用之间为期如此之长,在这期间,环境条件的突然变化或者雌、雄配子体发育不健全,停止在发育的某阶段,都会影响胚珠的正常发育,不能受精,不能形成胚。有些树种如水杉,在受精以后,形成发育完全的种子很少,多数胚珠在胚胎发育过程中会发生败育现象而导致瘪籽。杉木Cunninghamia lanceolata(La-mb)Hook授粉生物学特性研究方面的材     

云南蓝果树两性花的花药发育机制

利用石蜡切片法观察极小种群植物—云南蓝果树两性花的小孢子发育过程,以明确小孢子败育的原因和败育时期,为进一步拯救保护和研究云南蓝果树奠定基础。结果表明:(1)云南蓝果树有一部分两性花小孢子正常发育,经过小孢子母细胞、减数分裂和四分体等时期,最后发育为成熟花粉粒;(2)败育的云南蓝果树两性花在形成四面体型四分体之前都能正常发育,在四分体时期不能分离或分离后不能正常发育,从而败育。研究认为,绒毡层细胞发育异常是云南蓝果树两性花小孢子败育的主要原因,败育的时期是四分体时期和单个小孢子时期。     

Comparative microsporogenesis and flower development in Eucalyptus urophylla × E. grandis

Microsporogenesis and flower development in Eucalyptus urophylla 9 E. grandis were examined using chromosome tableting to provide a method to predict the meiotic stages in this species. Although microsporogenesis was normal, cytokinesis during meiosis of pollen mother cells occurred simultaneously, with strong asynchronism observed in the two different lengths of stamens in a flower bud. In a single flower, the developmental period of microsporogenesis in anthers on the longer stamens was always ahead of those on the shorter stamens. Flower development was also asynchronous at different locations on a branch. Flower buds on the upper side of the branch were larger in diameter than those on the lower side. In addition,a correlation was observed between microsporogenesisdevelopment and flower bud diameter growth. The pachytene stage was first observed when the diameter of the flower buds increased to 3.0 mm, and the majority of the meiotic stages were observed when bud diameters ranged from 3.5 to5.0 mm. This study showed that the developmental stages of microsporogenesis in Eucalyptus urophylla 9 E. grandis could be distinguished readily, which may be applicable to future breeding studies.     

Comparative microsporogenesis and flower development in <Emphasis Type="Italic">Eucalyptus urophylla</Emphasis> × <Emphasis Type="Italic">E. grandis</Emphasis>

Microsporogenesis and flower development in Eucalyptus urophylla × E. grandis were examined using chromosome tableting to provide a method to predict the meiotic stages in this species. Although microsporogenesis was normal, cytokinesis during meiosis of pollen mother cells occurred simultaneously, with strong asynchronism observed in the two different lengths of stamens in a flower bud. In a single flower, the developmental period of microsporogenesis in anthers on the longer stamens was always ahead of those on the shorter stamens. Flower development was also asynchronous at different locations on a branch. Flower buds on the upper side of the branch were larger in diameter than those on the lower side. In addition, a correlation was observed between microsporogenesis development and flower bud diameter growth. The pachytene stage was first observed when the diameter of the flower buds increased to 3.0 mm, and the majority of the meiotic stages were observed when bud diameters ranged from 3.5 to 5.0 mm. This study showed that the developmental stages of microsporogenesis in Eucalyptus urophylla × E. grandis could be distinguished readily, which may be applicable to future breeding studies.     

Overexpression of a fungal laccase gene induces nondehiscent anthers and morphological changes in flowers of transgenic tobacco

Laccases play important roles in the development of fruiting bodies and in lignin degradation by basidiomycetes. In this study, we present novel phenotypes of transgenic tobacco plants with a chimeric gene for fungal laccase under the control of the cauliflower mosaic virus 35S promoter. At the flowering stage, the transgenic plants that produced recombinant laccase had brownish anthers instead of the greenish anthers of wild-type plants. The brownish anthers exhibited male sterility with a nondehiscent phenotype at varying frequencies. The frequency of nondehiscence depended on the temperature at which plants were cultivated and it was higher at 24°C than at 29°C. The cell wall structures of transgenic anther tissues were almost the same as in the wild type, but the stomium was severely deformed, and abnormal components were apparent in cells of the endothecium and epidermis. Furthermore, the pattern of deposition of flavonoids in the transgenic anther epidermis differed from the wild-type pattern. The expression of laccase also induced other phenotypic changes in the flowers of transgenic plants, namely, increased petal number, fused and petaloid stamens, and doubling of floral organs. These results indicate that the ectopic expression of laccase influences various aspects of flower development.     

硬头黄竹花的形态与结构研究

[目的]研究硬头黄竹花(Bambusarigidd)的基本形态结构及胚胎发育规律,为其胚胎学积累原始资料,为育种工作打下基础。[方法]通过解剖与形态观察的方法,对硬头黄竹生殖器官、抱子发生及雌雄配子体的发育过程进行解剖观察。[结果]硬头黄竹小穗为假小穗,簇生,基部具潜伏芽,平均长度为3.75 cm,有3~7朵小花。小花内外稈各1片,浆片3枚,雌蕊1枚,雄蕊6枚。雌蕊为三分枝羽毛状柱头。子房长卵圆形,具明显纵向三棱。子房单室,侧膜胎座、倒生胚珠。正常发育的花粉粒为二细胞花粉,花药壁造抱细胞时期为四层药壁,花药成熟时只剩两层药壁。绒毡层为分泌型,花药成熟时,绒毡层完全退化。花药易见发育异常现象,形成不同的败育类型。[结论]硬头黄竹小穗基本结构发育正常,但花药发育后期会大量出现异常现象,这是导致硬头黄竹结实率低的主要原因。     

色木槭开花习性与幼果发育的观察与研究

通过对色木槭开花习性与幼果发育的观察与研究,结果表明：在相同小气候条件下,株闯花期物候特征相差4～6d,所需要的≥10℃的有效积温存在明显差异,是遗传差异作用的结果;然而花期差异不大,为15-16d。花的形态构造有2种类型、3个开放时间。即第1批花为雄蕊伸长型,第2批花为雌蕊伸长型,第3批既有雄蕊伸长型,亦有雌蕊伸长型;雌蕊伸长型最终发育成小幼果,存在部分花果同期现象。     

毛白杨花粉败育机制的研究

从细胞遗传学角度较为系统地揭示了毛白杨花粉败育的机制，即主要是毛白杨异质性遗传基础与环境相互作用的结果。（1）在减数分裂中有数目不等的联合程度较差的单价体以及落后染色体出现，这种与异质性相关的染色体行为异常，导致同源染色体向子细胞的不均衡，造成且功能染色体的缺失，从而引起毛白杨一定比率的败育花粉的产生；（2）遗传上的不平衡与温度等环境因子相互作用，进一步引发毛白杨生理乃至结构上的不平衡，花粉母细胞（或孢原细胞）和绒毡层细胞发育异常，从而造成不产粉或产粉较少；环境与基因型互作的差异性导致了花粉败育的年度不稳定性。（3）易位、倒位等染色体结构变异和天然三倍体株系的存在也是造成毛白杨花粉败育的原因。     

Isolation and functional analysis of the CjNdly gene, a homolog in Cryptomeria japonica of FLORICAULA/LEAFY genes

We report the isolation and characterization of CjNdly, a homolog in Japanese cedar (Cryptomeria japonica D. Don) of the FLORICAULA/LEAFY (FLO/LFY) genes. We determined the entire nucleotide sequence of CjNdly, including short 5'- and 3'-untranslated regions. The deduced amino acid sequence was similar to those of the products of the FLO/LFY genes from other species. The nucleotide sequence showed the closest homology to that of the NEEDLY gene in Pinus radiata D. Don. Although no proline-rich region has been reported previously in homologous gene products from gymnosperms, we found such a region at the amino-terminal end of the deduced amino acid sequence encoded by CjNdly. We detected the expression of CjNdly in both reproductive and vegetative tissues and organs of C. japonica. Heterologous expression of CjNdly in transgenic tobacco plants induced precocious flowering of regenerating shoots on agar-solidified medium and flowers with an abnormal phenotype, namely, petal-like stamens. Our findings suggest that the CjNdly gene may have important roles in flower development in Japanese cedar, resembling those of its angiosperm homologs.     

日本栗引种栽培试验初报

报道日本栗在河南引种栽培研究结果。筑波、银寄等6个优良品种种植表现出生长快、长势好、早实、早熟、丰产、粒大、质优等优良性状,是值得大力推广的优良品种。适当密植、幼树整形修剪、合理配植授粉树、加强肥水管理及适时除雄是日本栗获得早实丰产的关健技术措施。     

遮荫和光照对缺苞箭竹发育的影响

据观察,缺苞箭竹通常在迹地和疏林地比郁闭度大的林地衰老快、开花多,说明缺苞箭竹发育与林地遮荫度有关,为了证实这一现象,在全光照(sun)、林地部分遮荫(约为全光照下光量的50％)和深度遮荫(约为全光照下光量的2％)的条件下,分植零星开花竹丛,观察其发育变化。结果表明:在深度遮荫的条件下,原有的花穗不开放,花芽不继续发育,未花枝也不继续发育成花枝,竹丛中也不再出现新的开花植株,而未花竹和发笋量则逐年增加;在全光照和部分遮荫的条件下,原有的花穗很快开放,特别是全光照条件下,花茅和未花枝继续发育成花穗和花芽的速度更快,而且新的开花植株逐年增加,未花植株和发笋量逐年减少。结果也表明:光照时间和光照强度是控制缺苞箭竹开花的最明显的气象因子。     

竹材的微观结构及其与力学性能的关系

采用宏观与微观相结合的方法,研究了不同种类不同部位的沿壁厚分层竹材的力学性能与生物组织微结构的关系。在扫描电镜内进行试验动态测试,并分析其形态。竹材主要由承力的纤维厚壁细胞和起速接作用并传递载荷的薄壁细胞基体所组成。竹材具有良好的比强度,比刚度,是其厚壁细胞竹纤维排列整齐的结果。在宏观力学性能方面;毛竹高于蒿竹,靠上部大于基部,竹壁外层优于内层,这都是与纤维组织细密、纤维层厚、纤维密度大等因素有关。对竹材生物组织微观结构合理分布和独突优越性的了解,不仅对竹材细胞组织的真实形态有进一步的科学认识,而且对研制竹/塑及其它复合材料增强的有效性和纤维铺层设计都有实际意义,并有助于对不同部位竹材的充分利用。