杏李新品种‘风味玫瑰’小孢子发生及雄配子体发育的研究

利用常规石蜡切片技术,对杏李的小孢子发生及雄配子体发育过程进行解剖学研究。结果表明:(1)花药壁由外到内分别为表皮、药室内壁、中层和绒毡层。绒毡层发育类型为腺质绒毡层;(2)小孢子母细胞减数分裂过程中的胞质分裂类型为连续型,小孢子四分体排列方式为正四面体型;(3)成熟花粉粒为2-细胞型;(4)部分花药囊内单核居中期的小孢子存在胞质不规则过度收缩、绒毡层离散脱落的异常现象,部分二核花粉粒细胞质稀薄,该现象可能会导致花粉活力降低。     

马铃薯花药与花粉粒发育的细胞形态学研究

为了更有效地通过有性杂交选育优良品种,本文对马铃薯的雄性器官进行了系统的形态学观察:1.马铃薯花药的孢原组织为新月形排列,成熟花药药室呈马蹄形。花药壁厚薄不均,药室内壁与中层细胞无明显区分;绒毡层为腺质型,其来源有二;外侧的来源于壁细胞,内侧的来源于药隔组织,并常有二型性。2.马铃薯花药中的造孢细胞产生3～4层时,进而变成小孢子母细胞。小孢子母细胞的减数分裂为同时型,四分体多呈四面体型排列,成熟花粉为2-细胞型。花粉圆球状,具3孔沟,花粉较小,花粉量较大。3.马铃薯花药的开裂,以孔裂为主兼部分纵裂。孔口边缘表皮下有纤维层状(即具条纹状加厚的细胞壁)细胞。部分纵裂部位有裂口异形细胞。花药开裂前,同侧两药室彼此勾通,有利于散粉。     

黄花蒿小孢子的发生和雄配子体的形成

黄花蒿是当今优良抗疟药青蒿素的药源植物。采用石蜡切片法观察了黄花蒿小孢子发生及雄配子体发育的细胞学过程。黄花蒿花药为4室结构;横切面呈蝴蝶状排列;花药壁发育为典型单子叶型;花药壁中层在花药发育的较早期解体,其绒毡层由腺质型绒毡细胞组成,在花粉成熟前绒毡层细胞原位解体;花粉母细胞在减数分裂过程中,细胞分裂同步相差1～2个细胞周期,其细胞质分裂则为同时型;经2次分裂后形成的四分体为正四面体型;花药开裂前的成熟花粉粒为2细胞型,含1个营养细胞和1个具2个细胞核的生殖细胞。     

亚麻大小孢子与雌雄配子体发育

１．亚麻花药由４个药室构成。腺质绒毡层发达，常具双核，成熟时药壁仅有表皮和纤维层两层细胞。小孢子母细胞常为一纵列，减数分裂为同时型，四分体为四面体型排列。成熟花粉粒为３细胞型，圆球状，具３萌发孔；２．胚珠倒生，具双珠被，内珠被后期继续分裂增厚，并具珠被绒毡层。珠心组织不发达，孢原细胞有时多个，胚囊发良属单孢子蓼型。合点端的珠心组织常形成带状的吸器结构；３．雌雄配子体发育时序性有差异，一般雄配子体先     

毛叶茶大小孢子的发生和雌雄配子体的发育

毛叶茶小孢子母细胞减数分裂中胞质分裂为同时型,四分体的排列为四面体型,成熟花粉为2-细胞型;花药壁的发育属于基本型,绒毡层为腺质型;倒生胚珠,双珠被,薄珠心,胚囊发育属葱型。     

茉莉花胚胎学研究Ⅰ.小孢子发生与雄配子体发育

系统研究了茉莉花双瓣品种的小孢子发生与雄配子体发育过程。观察结果表明 :茉莉花双瓣品种药壁发育为基本型 ,中层在小孢子减数分裂时期逐渐解体 ,绒毡层是异型细胞绒毡层 ,解体迟 ,不利于小孢子发育 ,药室内壁纤维层加厚不明显。小孢子从减数分裂中期 开始走向败育 ,胞质分裂为同时型 ,正常四分体为正四面体形。雄配子体发育大多不正常 ,其发育早期有花粉管萌发的异常现象。空瘪、异形花粉多 ,正常与不正常比例为 10 0∶ 32 4。成熟花粉粒为 2 -细胞型 ,具三个萌发孔。     

亚麻大小孢子与雌雄配子体发育

１．亚麻花药由４个药室构成。腺质绒毡层发达。常具双核，成熟时药壁仅有表皮和纤维层两层细胞。小孢子母细胞常为一纵列，减数分裂为同时型，四分体为四面体型排列。成熟花粉粒为３细胞型，圆球状，具３萌发孔；２．胚珠倒生，具双珠被，内珠被后期继续分裂增厚，并具珠被绒毡层。珠心组织不发达，孢原细胞有时多个，胚囊发育属单孢子蓼型。合点端的珠心组织常形成带状的吸器结构；３．雌雄配子体发育时序性有差异，一般雄配子体先于雌配子体，但两者近同步成熟。     

茉莉花胚胎学研究 I．小孢子发生与雄配子体发育

系统研究了茉莉花双瓣品的小孢子发生与雄配子体发育过程。观察结果表明：茉莉花双瓣品种药壁发育为基本型，中层在小孢子减数分裂时期逐渐解体，绒毡层是异常细胞绒毡层，解体迟，不利于小孢子发育，药室内壁纤维层加厚不明显。小孢子从减数分裂中期1开始走向败育，胞质分裂为同时型，正常四分体为正四面体形。雄配子体发育大多为不正常，其发育早期有花粉管萌发的异常现象。空瘪、异形花粉多，正常与不正常比例为100：324。成熟花粉粒为2－细胞型，具三个萌发孔。     

栽培大豆(Glycine max)与野生大豆(G.soja)解剖学的比较研究——Ⅰ.雄配子体的发育

本文对栽培大豆(Glycine max)和野生大豆(G.soja)雄配子体的发育和同步性及精子发生进行了比较研究。大豆和野生大豆花粉母细胞的减数分裂是属于同时型的,小孢子的发育过程基本相同。花粉粒的发育在同一花药中基本上是同步的,在同花中九个连体花药的花粉粒的发育也基本上是同步的,而单个花药中花药粉粒的发育要稍落后于九个连体花药中的花粉粒。大豆的两个精子是在花粉管和花粉粒中形成的,即二、三细胞型;野生大豆的两个精子是在花粉管中形成的即二细胞型。本文讨论了这两种植物精子发生途径的类型及分类学上的意义。     

新型玉米细胞质雄性不育材料泰玉D2花粉败育的细胞学研究

通过光学显微镜观察泰玉D2不育系的花药发育进程,探明新型细胞质雄性不育材料泰玉D2花粉败育的细胞学机理。研究发现,花药绒粘层在二分体时期发生异常,小孢子在单核前期开始败育,至单核后期完全解体,花药发育后期不育系药腔中只观察到少量的小孢子残体,花药壁的4层细胞依然存在,绒粘层细胞已经彻底液泡化, 占据了药腔的整个空间,花粉成熟期不育系花药维管束消失。泰玉D2不育系花药绒粘层在二分体时期成辐射状膨大,小孢子在单核期败育,花粉败育完全,属无花粉类型。     

Characterization of anatomy, ultrastructure and lignin microdistribution in Forsythia suspensa

Forsythia suspensa, as a traditional Chinese medicinal herb, has been studied extensively. In this work, morphological and anatomical features of F. suspensa stem were examined by light microscopy (LM) and scanning electron microscopy (SEM). The results showed that the slenderness and Runkel ratio is 51 and 0.67, respectively. Anatomical observations indicated that F. suspensa is diffuse-porous wood. Helical thickenings and alternate intervessel pits are present on vessel cell wall. Transmission electron microscopy (TEM) images exhibited that the fiber cell wall is typically differentiated into three layers: middle lamella (ML), primary wall (P) and secondary wall (S₁, S₂ and S₃), and the staining intensities represent differing lignin concentrations. Also, the confocal laser scanning microscopy (CLSM) and scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDXA) were used to investigate the lignin distribution in cell wall qualitatively and semi-quantitatively. Confocal images (488 nm) revealed a high level of lignin autofluorescence in the cell corner middle lamella (CCML), with lower levels of fluorescence in the compound middle lamella (CML) and S₂ region. The results from SEM-EDXA demonstrated that lignin concentration ratio in different regions of fiber wall is 1.3 (CCML):1.1 (CML):1 (S₂).     

Investigation of Host Responses of Different Potato Genotypes at Tissue, Cellular and Subcellular Levels After Infection with Phytophthora infestans

In histological and cytological investigations, the infection process of Phytophthora infestans, the late blight pathogen, was comparatively studied in several potato cultivars and somatic hybrid genotypes and their parents using fluorescence microscopy and electron microscopy methods. The results showed that germination of zoospores of P. infestans and frequency of invading by infection hyphae did not differ among the cultivar-pathogen interactions, but, extension of hyphae in host cells markedly differed among these genotypes. In the susceptible genotypes the pathogen grew rapidly inter- and intracellularly, 12 h after inoculation (hai), and some digital like haustoria were formed and the cytoplasm of the host cells became disorganized. In the resistance genotypes, the pathogen was restricted to the site of initial penetration, although some hyphae could penetrate the epidermal cell, however, the host cells produced resistance responses, such as formed wall appositions when in contact with hyphae, and no haustoria like structures were found. In the somatic hybride genotypes, the host response was different according to their parents as shown by transmission electron microscopy. In the hybrid genotype 1508/2, like in the wild species S. bulbocastanum, no hyphae were found in host cells. In the other genotypes, hyphae of P. infestans spread intercellularly and formed haustoria, but the cytoplasm of hyphae and haustoria was disorganized and host cell resistant responses often appeared, such as, host cells were disorganized and necrotic and cell wall apposition were observed.     

Epidermal Cell Wall Biogenesis with Emphasis on Cuticular Layer Formation during Direct Somatic Embryogenesis in Rice

Abstract

Epidermal cell wall biogenesis with emphasis on cuticular layer formation during direct somatic embryogenesis in rice was examined by transmission electron microscopy. The first phenomenon noticed in the early globular stage of somatic embryos was a high activity of cell wall formation. In this stage, many endoplasmic reticula, Golgi bodies and their vesicles were present and epidermal cells were covered by fibrillar material. Cutin was initially deposited on the epidermal cell wall of late globular or early elongate stage embryos. In the late elongate stage, a lamellated cuticular layer formed, and in the late scutellar stage, a more homogenous continuous cuticular layer formed. The cuticular layer disappeared gradually from the scutellum cell wall as the somatic embryo germinated. The disappearance of the cuticular layer was similar to that of the zygotic embryo. There is no cuticular layer on the scutellar epithelial cell wall of the immature zygotic embryo 5 days after germination. Our observations lead to the conclusion that one of the structural and physiological markers of direct somatic embryogenesis is the transformation of fibrillar material into the cuticular layer.     

Ultrastructural changes in tubers of potato (Solanum tuberosum L.) affected by rust spot

Summary The medullary tissues of potato tubers affected by rust spot were embedded in resin, sectioned and stained for optical and electron microscopy. Under the optical microscope, the damaged zones were seen to have thickened and suberized cell walls, with cells partially or totally lacking starch. These features were confirmed by electron microscopy which revealed in relief the cell wall deformation and the characteristic presence, in the vacuole, of osmiophilic granules with a spongy appearance attached to the tonoplast, probable catabolic products of a disturbed metabolism. Separation and degeneration of the plasmalemma and the death of the cells were observed in tissues in the final stages of damage.     

同源四倍体水稻胚乳发育:糊粉层细胞壁纤维素物质发育、胚乳淀粉积累及胼胝质“套”的形成

 利用荧光显微术观察，发现同源四倍体水稻与其二倍体原种的糊粉层细胞壁纤维素物质都存在一个“充实”的过程。授粉后5～6 d，糊粉层开始分化形成，此时其细胞壁上未观察到纤维素物质；授粉后6～8 d，糊粉层细胞壁上开始积累纤维素物质；授粉后8～9 d，糊粉层细胞壁积累了大量的纤维素物质。胚乳淀粉的积累存在一个变化的过程：初生胚乳核周围可见一些淀粉体，随着胚乳游离核的增多，游离核周围淀粉体的数量逐渐减少，胚乳细胞化后，胚乳细胞内开始大量形成淀粉体。利用苯胺蓝染色连续切片荧光观察，发现同源四倍体水稻及其二倍体原种胚乳发育过程中，在珠心表皮和内珠被之间存在一层胼胝质物质，围绕着胚囊并包裹住珠心呈“套”状。这个结构的形成变化过程为：授粉后30 min在珠孔端珠心表皮细胞与内珠被之间开始积累少量的胼胝质，之后胼胝质逐渐增多并向合点端扩展延伸；授粉后1～2 d包裹着整个胚囊外的珠心而仅在维管束处断开；授粉后9～13 d，胼胝质“套”消失。该结构可能与胚和胚乳在发育期间的水分和养分的调节等有密切关系。同源四倍体水稻还存在糊粉层细胞壁发育不同步、糊粉层细胞壁结构异常以及胼胝质“套”不消失等异常现象。这些现象有可能会影响同源四倍体水稻的结实率。     

Effects of Popping on the Endosperm Cell Walls of Sorghum and Maize

The structure of the vitreous endosperm of raw and popped grains of popcorn maize and sorghum has been examined by light and scanning electron microscopy. In both cereals, popping produces everted grains consisting of expanded endosperm foam attached to the pericarp and embryo tissue. As previously reported, each bubble of the foam is formed from an individual starch granule inflated by internal steam pressure. Large fissures may contribute significantly to the expansion of the endosperm foam. The cell walls of the vitreous endosperm of both cereals are shattered into small fragments, which separate slightly as the cell contents expand during popping. Despite this, the endosperm cells retain their polygonal outline. Intact cell walls of raw endosperm, wall fragments from popped endosperm foam, and fragments isolated after treatment of the foam withalpha -amylase, were visualised through the autofluorescence of their ferulic acid content. The in vitro digestibility of popped sorghum was unchanged compared to raw sorghum, whereas that of wet-cooked sorghum was greatly reduced. It is suggested that popping-induced wall fragmentation improves the accessibility of the protein and starch reserves of the endosperm to digestive enzymes.     

不同类型烟草花粉自发荧光强度比较研究

应用激光扫描共聚焦显微镜（LSCM）定量测定了6个不同类型的烟草花粉粒自发荧光强度,发现品种之间花粉粒自发荧光强度存在显著差异。结果表明应用LSCM检测烟草花粉自发荧光强度可作为烟草品种鉴别的重要指标。      

海南普通野生稻的花粉育性观察及杂交亲和性

对海南3个不同居群的普通野生稻(O.rufipogon Griff.)的花粉育性进行了观察研究,并采用荧光显微镜技术观察了转基因水稻花粉在不同居群的普通野生稻柱头上的萌发和在花柱内的生长过程。结果表明,以转基因水稻为对照,3个不同居群的野生稻相互之间花粉可育率在1%水平上差异极显著。用荧光显微镜观察时发现,转基因水稻花粉能在3个居群的普通野生稻的柱头上萌发并能到达胚珠,二者杂交亲和,同时发现,花粉管进入三亚居群胚珠的数目比儋州、万宁居群的数目多,说明相对于儋州、万宁居群来说,三亚居群与转基因水稻的杂交亲和性更高。     

甘蓝型油菜双显性细胞核雄性不育系Shaan-GMS雄配子发育观察

采用常规压片与冰冻切片两种方法,观察甘蓝型油菜不育系Shaan-GMS的不育株与可育株小孢子母细胞减数分裂和小孢子发育过程,以阐明小孢子败育时期和细胞学特征。植株表型上,花期可育株与不育株花器官差异较大:不育株花丝较短,花药小且干瘪,微粉或无粉,淡黄色;细胞学观察结果显示不育株的花粉母细胞能够进行正常的减数分裂,形成四分体,但在单核期开始发生异常。主要表现为小孢子从四分体中释放后无法形成正常的小孢子外壁,随后小孢子外壁、内容物和绒毡层均提早降解,只剩下空壳与残渣,药室也随之萎缩变形,最终导致花粉败育。上述结果说明Shaan-GMS为单核败育类型,可能是一个细胞核雄性不育新材料。     

同源四倍体水稻胚乳发育:极核融合和胚乳细胞化

利用激光扫描共聚焦显微术和塑料包埋半薄切片技术观察同源四倍体水稻极核融合及游离核进一步发育的过程,发现同源四倍体水稻约有1/3子房极核融合过程和游离核进一步发育与其二倍体原种的基本一致;2/3子房出现各种异常现象,如极核未受精、受精异常和胚乳游离核发育滞后等。应用荧光增白剂染色对胚乳细胞化过程进行观察,直接观察到胚乳初生壁的出现和形成过程以及不同部位的胚乳细胞壁的形成机理。表明同源四倍体水稻与二倍体水稻胚乳的细胞化过程基本一致,胚乳细胞初始垂周壁来源于珠孔端胚囊壁内突向心游离生长,初始平周壁来源于游离核有丝分裂产生的成膜体,而中间胚乳细胞壁则有些来源于游离核有丝分裂产生的成膜体,有些是自由生长而来。同源四倍体水稻胚乳细胞化过程也出现相当比例的异常现象,如无细胞壁形成、细胞化不同步和产生分枝状的细胞壁等。同源四倍体水稻胚乳发育过程中出现的极核融合、游离核发育和细胞化过程等异常都可能导致同源四倍体水稻的结实率降低。