龙牙花不同花器官的表皮形态

花的光合作用与气孔密度密切相关,但关于在花生长过程中气孔密度如何改变尚未见报道。以龙牙花（Erythrina corallodendron）花为实验材料,将花的生长期分为6个阶段,采用光学显微镜对不同阶段的花萼、旗瓣、翼瓣、龙骨瓣、雌蕊托、子房、花柱、花丝和花药表皮的形态特征、表皮细胞密度、气孔密度、保卫细胞长度及宽度进行研究,并对其光合作用的能力进行测定。结果发现：除了翼瓣和花丝表皮以外,气孔均分布在花朵的其它器官表皮上,如花萼、旗瓣、龙骨瓣、雌蕊托、子房、花柱和花药。气孔复合体主要有无规则型、平列型以及辐射型,但不同花器官存在的气孔类型具有差异。在花萼、旗瓣、龙骨瓣、翼瓣以及花丝生长过程中表皮细胞密度逐步下降,表明其生长主要由表皮细胞扩大引起;大部分花器官如花萼、旗瓣、龙骨瓣、雌蕊托和子房表皮的气孔密度在其生长中后期趋于稳定,然而其保卫细胞长度和宽度的变化规律具有多样性。旗瓣不进行光合作用。     

花生的有性杂交方法

花生为自花受粉植物,蝶形花冠,由一片旗瓣、两片翼瓣和两片龙骨瓣组成.花冠为黄色,在旗瓣的基部,有作放射状排列的紫红色线条(下图).开花时,旗瓣和翼瓣张开,龙骨瓣紧紧地包住雄蕊和雌蕊,因此,异花受粉的可能性很小. 萼片有五,花萼基部延长而成萼管.雌蕊一枚,有子房、花柱和柱头三部分.子房柄很短,受精后5-7天,开始生长并向地弯曲,子房柄达到地面后深入土层2-8厘米处结实.雄蕊10枚,8个发育、两个退化无花药.     

扶桑花展开过程中气孔密度和气孔指数的动态变化

以扶桑花为实验材料, 研究了蕾期(Ⅰ)、花瓣露出(Ⅱ)、花冠微展(Ⅲ)和花冠完全展开(Ⅳ)4 个阶段花冠和花萼等部位的气孔分布特点及其动态变化。结果发现: 花瓣上、下表皮, 萼片的下表皮及花柱上有气孔分布。随着花的展开, 花柱和花萼下表皮的气孔密度和气孔指数呈出先下降后上升的趋势; 花瓣上表皮的气孔密度和气孔指数呈现出逐渐增加的趋势; 而花瓣下表皮的气孔密度和气孔指数则呈现出下降-上升-下降的趋势。     

大花美人蕉花发育过程中气孔密度和气孔指数的动态变化

对大花美人蕉(Canna generalis Bailey)不同发育时期花瓣、苞片和花萼上气孔的分布情况、气孔密度和气孔指数的变化进行了研究。结果表明,花瓣、苞片和花萼上、下表皮均有气孔分布。花瓣、苞片和花萼上表皮的气孔密度和气孔指数均小于下表皮的。随着花的发育,花瓣、苞片和花萼上的气孔密度和气孔指数一般呈现先上升后下降的变化趋势。     

大豆花和鲫鱼模型的制作

1　大豆花模型1.1　材料　布、胶合衬、铁丝 (或铜丝 )、海绵和毛线等。1.2　制作方法　用 3～ 4层布贴合 ,最上层贴胶合衬 ,剪出旗瓣、翼瓣、龙骨瓣 (放大倍数自定 ) ,并根据大豆花实物塑型 ;用铁丝与海绵做出雌蕊 ,外面用毛线缠绕 ,用细铁丝做花丝并与毛线织成二体雄蕊 ,花丝顶端固定海绵粒当花药。用吹塑纸制成花萼 ,外贴与实物相同颜色的布 (淡绿色 ) ,最后根据实物染上颜色 ,一枚鲜艳逼真的大豆花放大模型做好了 (做个底座安装 )。1.3　使用　模型可以灵活拆卸、组合。在课堂上 ,任课教师边讲解 ,边把旗瓣、翼瓣、龙骨瓣一个个卸开 ,分…     

鸡蛋花(夹竹桃科)花表皮气孔的初步研究

对鸡蛋花花表皮的气孔进行初步研究,结果发现:花冠裂片的上表皮没有气孔的分布;花冠裂片的下表皮则有气孔的分布。当花冠裂片长度1.5cm时,气孔密度最大,且极显著地高于花冠裂片长度为2.0、2.5、3.5cm和4.0cm时的气孔密度。长度为3.0cm的花冠裂片的气孔指数最大,与花冠裂片长度为1.0、2.0、3.5cm和4.0cm时的气孔指数的差异均达极显著水平。在花冠筒长度为0.3cm和0.4cm时,没发现气孔;当花冠筒生长到0.5cm时开始出现气孔。花冠筒长度为0.6cm时,气孔密度最大,且极显著地高于其它长度花冠筒的气孔密度。花冠筒长为0.6、1.1cm和1.3cm时的气孔指数均极显著地大于长度为0.5cm花冠筒的气孔指数。花冠裂片和花冠筒下表皮的普通表皮细胞都呈不规则的多边形,保卫细胞呈半月形。     

气孔在四季秋海棠营养器官和繁殖器官上的发育及相关性分析

主要观察了气孔在四季秋海棠营养器官和繁殖器官上的分布和发育情况,并分别对叶片和翅上气孔簇大小、气孔簇密度等指标的相关性进行了研究、结果表明:在叶片的下表皮、雌花和雄花的花被片、苞片、小苞片和翅上有气孔分布,而在茎、花梗上却未见气孔分布.叶片下表皮和翅上气孔通常成簇分布.在叶片的下表皮,气孔簇大小与气孔簇密度呈显著的负相关(P<0.05);气孔簇密度与叶片长度呈极显著的负相关(P<0.01).而翅上的气孔簇密度、气孔簇大小与子房长度无显著相关性(P>0.05).在四季秋海棠中,不同器官表皮的气孔簇大小是不同的,这可能与生理功能的不同有关.     

白刺叶片气孔特征对人工模拟降雨的响应

以荒漠生态系统典型植物白刺(Nitraria tangutorum Bobr)叶片为研究对象,利用数码图像显微镜处理系统,研究了不同人工模拟增雨处理下的白刺叶片气孔密度及形态特征的变化情况。结果表明,荒漠植物固有特征决定了白刺叶片下表皮气孔密度大于上表皮,上表皮、下表皮气孔密度对增雨响应差异不显著(P0.05)。增雨处理上表皮、下表皮气孔密度与对照差异显著(P0.05)。相同增雨季节,50%处理下叶片气孔密度高于100%处理;不同增雨季节,气孔密度对生长季后期增雨响应更明显。白刺叶表皮气孔分布遵循"一细胞间隔(one cell spacing rule)"法则。增雨后叶片上表皮和下表皮气孔长度、宽度均有不同程度的增加,气孔形态特征对100%处理的响应较50%处理更为明显,且生长季后期增雨对叶片气孔形态特征的影响更大。     

叶子花表皮特征的研究及意义

对叶子花（Bougainvillea spectabilis）正常叶和变态叶上气孔密度、气孔指数和保卫细胞大小进行了研究。结果表明：正常叶上表皮的表皮细胞为多边形,垂周壁平直;下表皮的表皮细胞为不规则型,垂周壁浅波状;气孔类型为不规则型。变态叶上表皮没有发现气孔,变态叶下表皮的表皮细胞垂周壁则由浅波形逐渐变为深波形,气孔类型为不规则型和轮列型。随着变态叶的发育,变态叶下表皮的气孔密度降低,气孔指数升高;变态叶保卫细胞的长增大,宽减小。变态叶的平均气孔密度和平均气孔指数明显低于正常叶。正常叶和变态叶的保卫细胞均呈肾形。     

臭椿花器官分化的初步研究

利用扫描电镜(SEM)和光镜(LM)对臭椿花序及花器官的分化和发育进行了初步研究,表明:1)臭椿花器官分化于当年的4月初,为圆锥花序;2)分化顺序为花萼原基、花冠原基、雄蕊原基和雌蕊原基。5个萼片原基的发生不同步,并且呈螺旋状发生;5个花瓣原基几乎同步发生且其生长要比雄蕊原基缓慢;雄蕊10枚,两轮排列,每轮5个原基的分化基本是同步的;雌蕊5,其分化速度较快;3)在两性花植株中,5个心皮顶端粘合形成柱头和花柱,而在雄株中,5个心皮退化,只有雄蕊原基分化出花药和花丝。本研究着重观察了臭椿中雄花及两性花发育的过程中两性花向单性花的转变。结果表明,臭椿两性花及单性花的形成在花器官的各原基上是一致的(尽管时间上有差异),雌雄蕊原基同时出现在每一个花器官分化过程中,但是,可育性结构部分的形成取决于其原基是否分化成所应有的结构:雄蕊原基分化形成花药与花丝,雌蕊原基分化形成花柱、柱头和子房。臭椿单性花的形成是由于两性花中雌蕊原基的退化所造成,其机理有待于进一步研究。     

GFP-mTn融合蛋白对蓝猪耳生活细胞微丝骨架的标记

用农杆菌介导法将嵌合基因GFP-mTn(mTn是微丝结合蛋白Talin的微丝结合域,可以显示活体细胞中微丝的结构)导入蓝猪耳。经激光共聚焦显微镜观察了转基因植株的各种不同组织中融合蛋白的表达和分布情况。在叶片的表皮细胞、保卫细胞、根部的皮层细胞中有融合蛋白的不同程度表达。但仅在保卫细胞中微丝标记状况良好,显示基因表达的组织特异性。经光诱导处于开放态的气孔的保卫细胞微丝呈网状结构,在细胞内无规则分布;经黑暗诱导处于关闭态的气孔保卫细胞中微丝束沿保卫细胞纵轴排列,呈卷曲状分布,并观察到螺旋和环状的微丝结构。在转基因植株的其他部位,例如茎表皮细胞、根毛细胞和花粉粒中,未检测到目的基因的表达。本研究获得的转基因植株为研究气孔运动过程中微丝动态变化提供了有用的材料。     

GFP-mTn融合蛋白对蓝猪耳生活细胞微丝骨架的标记

用农杆菌介导法将嵌合基因GFP-mTn(mTn是微丝结合蛋白Talin的微丝结合域,可以显示活体细胞中微丝的结构)导入蓝猪耳.经激光共聚焦显微镜观察了转基因植株的各种不同组织中融合蛋白的表达和分布情况.在叶片的表皮细胞、保卫细胞、根部的皮层细胞中有融合蛋白的不同程度表达.但仅在保卫细胞中微丝标记状况良好,显示基因表达的组织特异性.经光诱导处于开放态的气孔的保卫细胞微丝呈网状结构,在细胞内无规则分布;经黑暗诱导处于关闭态的气孔保卫细胞中微丝束沿保卫细胞纵轴排列,呈卷曲状分布,并观察到螺旋和环状的微丝结构.在转基因植株的其他部位,例如茎表皮细胞、根毛细胞和花粉粒中,未检测到目的基因的表达.本研究获得的转基因植株为研究气孔运动过程中微丝动态变化提供了有用的材料.     

NORMAL FLORAL ONTOGENY AND COOL TEMPERATURE-INDUCED ABERRANT FLORAL DEVELOPMENT IN GLYCINE MAX (FABACEAE)

Floral onset in soybean (Glycine max cv. Ransom) is characterized by precocious initiation of axillary meristems in the axils of the most recently initiated leaf primordium. During floral transition, leaf morphology changes from trifoliolate leaf with stipules, to a three-lobed bract, to an unlobed bract. Soybean flowers initiated at 26/22 C day/night temperatures are normal, papilionaceous, and pentamerous. Sepal, petal, and stamen whorls are initiated unidirectionally from the abaxial to adaxial side of the floral apex. The median sepal is located abaxially and the median petal adaxially on the meristem. The organogeny of ‘Ransom’ flowers was found to be: sepals, petals, outer stamens plus carpel, inner stamens; or, sepals, petals, carpel, outer stamens, inner stamens. The outer stamen whorl and the carpel show possible overlap in time of initiation. Equalization of organ size occurs only within the stamen whorls. The sepals retain distinction in size, and the petals exhibit an inverse size to age relationship. The keel petals postgenitally fuse along part of their abaxial margins; their bases, however, remain free. Soybean flowers initiated at cool day/night temperatures of 18/14 C exhibited abnormalities and intermediate organs in all whorls. The gynoecium consisted of one to ten carpels (usually three or four), and carpel connation varied. Fusion of keel petals was often lacking, and stamen filaments fused erratically. Multiple carpellate flowers developed into multiple pods that were separate or variously connate. Intermediate type organs had characteristics only of organs in adjacent whorls. These aberrant flowers demonstrate that the floral meristem of soybean is not fixed or limited in its developmental capabilities and that it has the potential to produce alternate morphological patterns.     

Investigating the independent evolution of the size of floral organs via G-matrix estimation and artificial selection

The attractiveness of a plant to pollinators is dependent on both the number of flowers produced and the size of the petals. However, limiting resources often result in a size/number trade-off, whereby the plant can make either more flowers or larger flowers, but not both. If developmental genes underlying sepal and petal identity (some of which overlap) also influence size, then this shared genetic basis could constrain the independent evolution of floral size and attractiveness. Here, we determined whether the size of sepals and petals in the dioecious perennial, Silene latifolia, are developmentally independent by performing two experiments: a genetic variance-covariance experiment to estimate genetic correlations between calyx width, petal-limb length, flower mass, and number and a four-bout artificial-selection experiment to alter calyx width and estimate the correlated response in petal-limb length. In addition, we determined whether variation in petal-limb length is the result of cell expansion or cell proliferation. The first experiment revealed that petal-limb length is not genetically correlated with calyx width, and the second experiment confirmed this; selection on calyx width did not result in a predictable or significant change in petal-limb length. Flower number was negatively correlated with all the floral traits measured, indicating a flower size/number trade-off. Cell number, but not size, explained a significant amount of the variation in petal-limb length. We conclude that the size of the two outer floral organs can evolve independently. This species can therefore increase the number of flowers produced by decreasing investment in the calyx without simultaneously decreasing petal size and the attractiveness of each individual flower to pollinators.     

Natural variation in stomatal abundance of Arabidopsis thaliana includes cryptic diversity for different developmental processes

Background and Aims

Current understanding of stomatal development in Arabidopsis thaliana is based on mutations producing aberrant, often lethal phenotypes. The aim was to discover if naturally occurring viable phenotypes would be useful for studying stomatal development in a species that enables further molecular analysis.

Methods

Natural variation in stomatal abundance of A. thaliana was explored in two collections comprising 62 wild accessions by surveying adaxial epidermal cell-type proportion (stomatal index) and density (stomatal and pavement cell density) traits in cotyledons and first leaves. Organ size variation was studied in a subset of accessions. For all traits, maternal effects derived from different laboratory environments were evaluated. In four selected accessions, distinct stomatal initiation processes were quantitatively analysed.

Key Results and Conclusions

Substantial genetic variation was found for all six stomatal abundance-related traits, which were weakly or not affected by laboratory maternal environments. Correlation analyses revealed overall relationships among all traits. Within each organ, stomatal density highly correlated with the other traits, suggesting common genetic bases. Each trait correlated between organs, supporting supra-organ control of stomatal abundance. Clustering analyses identified accessions with uncommon phenotypic patterns, suggesting differences among genetic programmes controlling the various traits. Variation was also found in organ size, which negatively correlated with cell densities in both organs and with stomatal index in the cotyledon. Relative proportions of primary and satellite lineages varied among the accessions analysed, indicating that distinct developmental components contribute to natural diversity in stomatal abundance. Accessions with similar stomatal indices showed different lineage class ratios, revealing hidden developmental phenotypes and showing that genetic determinants of primary and satellite lineage initiation combine in several ways. This first systematic, comprehensive natural variation survey for stomatal abundance in A. thaliana reveals cryptic developmental genetic variation, and provides relevant relationships amongst stomatal traits and extreme or uncommon accessions as resources for the genetic dissection of stomatal development.     

Effect of Elevated Carbon Dioxide Concentration on the Stomatal Parameters of Rice Cultivars

The response of stomatal parameters of four rice cultivars to atmospheric elevated CO₂ concentration (EC) was studied using open top chambers. EC brought about reduction in stomatal conductance and increase in stomatal index, size of stomatal guard cells, stroma, and epidermal cells. Such acclimation helped the regulation of photosynthesis to EC. These changes in stomatal characters made rice cultivars adjustable to EC environment.     

Roles of CONSTITUTIVE PHOTOMORPHOGENIC 10 in Arabidopsis stomata development

Stomata are epidermal bi-celled structures that differentiate within special cell lineages initiated by a subset of protodermal cells. Recently, we showed that the Arabidopsis photomorphogenic repressor COP10 controls specific cell-lineage and cell-signaling developmental mechanisms in stomatal lineages. Loss-of-function cop10-1 mutant cotyledons and leaves produced (in the light and in the dark) abundant stomatal clusters, but nonlineage epidermal cells were not affected. Here we examine COP10 role in hypocotyls, cylindrical organs displaying a distinct epidermal organization with alternate files of protruding and non-protruding cells, with the latter producing a limited number of stomata. COP10 prevents stomatal clusters and restricts stomata production in hypocotyls; these roles are specific to lineage cells as in cotyledons, since COP10 loss of function does not elicit stomatal fate in nonlineage cells; COP10 also sustains the directional cell expansion of all hypocotyl epidermal cell types, and seems necessary for the differentiation between protruding and non-protruding cell files.     

‘红露珍’山茶花花器官上气孔的动态变化与花瓣展开的关系

本试验以‘红露珍’山茶为实验材料,分别研究了蕾期（I）、花瓣露出（II）、花冠微展（III）、花冠完全展开（IV）和落地花冠（V）等5个阶段花瓣和雄蕊等部位气孔的分布特点及其动态变化。结果发现,花瓣基部的上下表皮、雄蕊管的内外表皮均有气孔分布。在每个阶段,花瓣基部上表皮的气孔器长度极显著大于下表皮的气孔器长度（P〈0.01）。当山茶花冠微展时,下表皮的气孔开度为（2.5±0.3）μm,而当花冠展开时,下表皮的气孔开度却为（0.9±0.3）μm;上表皮的气孔开度在整个发育过程中未发生显著性的改变,其平均开度为（4.3±0.3）μm。在每个阶段,花瓣下表皮的表皮细胞密度大于上表皮的表皮细胞密度。雄蕊管内外表皮上的气孔在各阶段均维持较大的气孔开度。气孔的不均等分布、气孔开度的变化、表皮细胞的差速生长都可能与花瓣的展开有关。     

Depolymerization of actin cytoskeleton is involved in stomatal closure-induced by extracellular calmodulin in Arabidopsis

CaM ubiquitously presents inside eukaryotic cells. CaM抯 gene expression and its subcellular localization are regulated by light, osmotic stress, pathogens, plant hormones, etc.[1]. Intracellular CaM of plant displays important functions in pathogenesis and wounding reaction[2] and hypersensitive response[3]. CaM has been found extracellular spaces in many plant species, such as soluble extracts of oat coleoptile cell walls[4], the wheat coleoptile cell walls[5], maize root tips cell walls[6…