脂肪组织冰冻切片简易操作技术

组织切片的染色与观察是细胞生物学实验中的重要内容之一,在教学过程中,经常用到冰冻切片技术,也就是借助低温冷冻将组织快速冻结达到一定的硬度进行制片的一种方法。由于冰冻切片机购价昂贵,在高等院校教学单位,一般都安排专人管理与操作,因此在细胞生物学教学中,无法让学生真正亲自操作,获得锻炼。     

杂草果实的冰冻切片技术

介绍一种快速、简便的杂草果实解剖技术。以4种木质化程度高且能够漂浮的杂草果实为材料进行冰冻切片, 经过材料固定、前处理、样品冷台固定、冷冻切片、展片、染色和观察并拍照等操作步骤, 可以获得清晰的果实解剖照片, 直观地揭示杂草果实适应漂浮的显微结构。杂草果实冰冻切片方法的优点是不需要对材料进行长时间的软化处理以及繁琐的脱水和包埋等过程。其关键环节是适宜的甘油浓度、冰冻温度和展片步骤。其中, 15%的甘油浓度进行前处理最合适。     

杂草果实的冰冻切片技术

介绍一种快速、简便的杂草果实解剖技术。以4种木质化程度高且能够漂浮的杂草果实为材料进行冰冻切片,经过材料固定、前处理、样品冷台固定、冷冻切片、展片、染色和观察并拍照等操作步骤,可以获得清晰的果实解剖照片,直观地揭示杂草果实适应漂浮的显微结构。杂草果实冰冻切片方法的优点是不需要对材料进行长时间的软化处理以及繁琐的脱水和包埋等过程。其关键环节是适宜的甘油浓度、冰冻温度和展片步骤。其中,15%的甘油浓度进行前处理最合适。     

高度木质化材料的冰冻切片技术

高度木质化植物材料的切片难度很大,应用常规切片方法不容易取得高质量的图版。本文介绍的冰冻切片方法,不需要进行长时间的软化处理、以及繁琐的脱水、包埋等过程,切片还进行不同的染色或组织化学测定,是一种快速、简捷和有效的制片方法。 其关键步骤是选好甘油浓度, 冰冻温度和展片步骤。     

高度木质化材料的冰冻切片技术

高度木质化植物材料的发片难度大,应用常规切片方法不容易取得高质量的图版。本文介绍了冰切片方法,不需要进行长时间的软化处理、以及繁琐的脱水、包埋等过程,切片还进行不同的染色或组织化学测定,是一种快速、简捷和有效的制片方法。其关键步骤是选好甘油浓度,冰冻温度和展片步骤。     

冰冻切片法制作家兔眼球切片

用Ｓｚｅｎｔ－Ｇｙｏｒｇｙｒｉ液固定,明胶包埋,冰冻切片法制作 家兔眼球切片,获得了完整球壁的理想切片,其中睫状体,睫状突和睫状小带的形态结构更为理想。     

冰冻切片技术在植物显微结构和组织化学中的应用

介绍了冰冻切片法研究植物显微结构和组织化学的一般程序。结果表明,冰冻切片过程简单有效且图版清晰,在1d内可获得高质量图片,解决了利用普通石蜡切片观察植物样品需要进行脱水、浸透、包埋操作且耗时长的问题,在植物显微结构和组织化学研究中具有广阔的应用前景。     

植物冰冻切片条件的优化及其与石蜡切片在组织化学应用中的比较

冰冻切片是植物组织学研究中一项重要的实验技术,冷冻温度和冷冻时间是决定切片质量的关键因素。通过比较15种冰冻切片条件,得出植物组织直接冰冻切片较适宜的冷箱温度、冷台温度和冷冻时间。同时,通过对5种植物的不同组织进行组织化学染色,比较了新鲜材料直接冰冻切片与常规石蜡切片在不同化学成分鉴定上的异同及各自的适用范围。结果表明,对于多糖、蛋白质和角质,两种切片方法的鉴定结果比较一致,但对于脂肪只能采用冰冻切片技术。研究结果对植物组织学实验和研究方法的改进具有一定的参考价值。     

利用冰冻切片机快速制作木质茎显微切片技术

植物的木质茎,因次生维管组织含量多,细胞壁木质化程度高,质地较硬,徒手切片和石蜡切片均难以获得满意的切片效果。冰冻切片机可对一定硬度的组织进行切片,是制件植物木质茎的制片的有效工具之一。【方法】利用冰冻切片机可在不经化学固定,对一些质地均匀,含水量较高的木质茎直接切片;而对木质坚硬、含水量较少的茎,经过FAA等固定剂固定后,OCT包埋,(-30)～(-25)℃切片,用0.1%甲苯胺蓝染色液染色。【结果】木质茎的冰冻切片结构完整,图像清晰、色彩丰富。【结论】冰冻切片机可用于木质茎的显微切片制作,再结合甲苯胺蓝染色,具有简便、高效、易操作的优点。     

冰冻切片制作体会及常见问题

目的:探讨冰冻切片制作过程中的影响因素及改进措施,提高切片质量,确保实验结果科学性、稳定性及可靠性.方法:从标本的取材、制片以及固定等多个环节阐述冰冻切片常见问题.结果:通过调整切片机的相应设置并且在冰冻切片多个环节中采取了相应措施,使切片更完整,厚薄均匀,无脱片和冰晶空洞现象产生,切片质量优良.结论:制作出高质量的冰冻切片需在取材处理、切片、固定等诸多环节上精益求精,这对冰冻切片这一专业性很强的实验技术的质控有着重大意义.     

榛属（桦木科）花序及花的形态发生

在扫描电镜下观察了桦木科榛属榛、毛榛和滇榛的花序和花的形态发生过程。榛属雌花序由多个小聚伞花序螺旋状排列组成;每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化形成2个花原基;每个花原基分化出2个心皮原基,形成二心皮雌蕊;雌蕊基部有2层花被原基,内层花被原基环状,外层花被发生于花原基近轴面和远轴面,近轴面和远轴面的花被不均等分化,外层花被发生早于内层花被。雄花序为柔荑状,由多个小聚伞花序螺旋状排列组成。每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化出2枚次级苞片和4。6个雄蕊原基,形成4—6枚雄蕊,每个雄蕊具4个药囊,在雄蕊原基分化形成4药囊雄蕊过程中．出现雄蕊原基纵裂。并且花丝纵裂至基部。为进一步全面探讨桦木科属间系统演化关系提供了证据。     

榛属 (桦木科) 花序及花的形态发生

在扫描电镜下观察了桦木科榛属榛、毛榛和滇榛的花序和花的形态发生过程。榛属雌花序由多个小聚伞花序螺旋状排列组成;每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化形成2个花原基;每个花原基分化出2个心皮原基,形成二心皮雌蕊;雌蕊基部有2层花被原基,内层花被原基环状,外层花被发生于花原基近轴面和远轴面,近轴面和远轴面的花被不均等分化,外层花被发生早于内层花被。雄花序为柔荑状,由多个小聚伞花序螺旋状排列组成。每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化出2枚次级苞片和4~6个雄蕊原基,形成4~6枚雄蕊,每个雄蕊具4个药囊,在雄蕊原基分化形成4药囊雄蕊过程中,出现雄蕊原基纵裂,并且花丝纵裂至基部。为进一步全面探讨桦木科属间系统演化关系提供了证据。     

棉花变异体(CHV1)的花形态特征分析

棉花体细胞培养再生植株存在大量的生理变异和可遗传变异,从中分离到一个性状稳定的花器变异体(CHV1)。从花器官形态特征和表面显微特征分析,该变异体的所有花器官都变成了苞叶状器官,但中央数片叶状器官的基部有胎座和胚珠着生。变异体每朵花有苞叶3-7片,苞叶状器官19-41片。苞叶状器官在花梗上的排布介于“轮”与“螺旋”状之间。据花器发育理论和变异体花的生长特性推测,该变异体中控制花器发育的A、B和C功能皆失活。对造成该变异的可能机理和棉花花发育模式进行了分析。该变异材料对研究棉花花发育和体细胞无性系变异的机理有一定价值。     

Protein analysis of floral organs of some members of solanaceae

Soluble proteins of the floral organs of some solanaceous species were analysed by SDS-polyacrylamide gel electrophoresis. In general, the protein content of anther and ovary was higher than that of the style which was greater than that of sepal and petal. The polypeptide patterns showed that in different species, each organ-type had many common bands, although they were of varying intensity. Also, proteins unique to an organ-type were not always detected in the various species. Some ‘species-specific’ polypeptides were, nevertheless, identified in one or more floral organs of a species.     

Transformation of floral organs with GFP in Medicago truncatula

 A high frequency of embryogenesis and transformation from all parts of flowers of two lines of Medicago truncatula R-108–1 and Jemalong J5 were obtained. Using this flower system, we obtained transgenic plants expressing promoter-uidA gene fusions as well as the gfp living cell color reporter gene. Moreover, this method allows us to save time and to use a smaller greenhouse surface for the culture of donor plants. Southern hybridization showed that the internal gfp fragment had the expected size and the number of T-DNA copies integrated in the plant genome varied between one and three. These data suggest that the presence of the GFP protein has no toxic effects, since no rearrangement of the gfp reporter gene was detected in the regenerated plants. Received: 25 May 1999 / Revision received: 2 August 1999 / Accepted: 2 August 1999     

Disproportionate carbon and water maintenance costs of large corollas in hot Mediterranean ecosystems

Larger corollas increase the reproductive success of entomophilous plants, but are also associated with increased carbon and water costs, especially under hot and dry conditions. Minimizing floral carbon and water loss by reducing corolla size should be potentially advantageous for plants living in these environments. We quantify maintenance costs of corollas (water and carbon) in large-flowered rockroses (Cistus spp.) in a Mediterranean ecosystem. We performed field studies of two coflowering sympatric Cistus of contrasting corolla size to analyze water costs. Additionally, we used the larger-flowered species (C. ladanifer) to analyze the effects of intraspecific variation in corolla size on floral net carbon exchange and transpiration rates. We also assessed the mean daily percentage of plant water and carbon consumed by corollas by comparing with that of leaves at the time of flowering in C. ladanifer. Temperature and corolla area increased water maintenance costs, following an allometric relationship where transpiration rate per unit of area increased with corolla area. Larger flowers tended to heat less under strong irradiance than smaller ones in both species, especially in C. ladanifer, demonstrating a stronger transpirational cooling effect on larger flowers. In terms of carbon, temperature significantly affected net carbon exchange rates, which were not affected by corolla size. Daily water and carbon expenses of corolla were ca. 50% of those of leaves on an organ surface area basis. Our results suggest that water and carbon maintenance costs of large flowers in the Mediterranean impose significant constraints to corolla size, ecophysiologically favoring smaller-flowered individuals in these ecosystems.     

Pollination biology in a palm swamp community in the Venezuelan Central Plains

RAMIREZ, N. & BRITO, Y., 1992. Pollination biology in a palm swamp community in the Venezuelan central plains. In a palm swamp community that differs strongly from the surrounding savanna in the Venezuelan central plains, the pollination and floral biology of 33 plant species were studied during three years: 1983, 1984 and 1989. The most frequent flower colours were white, pink, yellow, and in a lesser proportion green, brown, purple and red. Floral symmetry was found in roughly equal proportion for actinomorphic and zygomorphic flowers. Most flowers were short-lived (6–12 hours); in monoecious species the female flowers were longer-lived than the male flowers. The most frequent rewards were pollen and nectar (36.4%) and pollen (30.3%). At the community level, bee- and wasp-pollination prevailed in 57.1% of plant species studies, followed by wind- (14.3%), fly- (11.4%), butterfly- (8.6%), bird- (5.7%) and beetle-pollination (2.9%). Between one and five plant species were simultaneously visited by the visitor species. The vast majority of the pollinating species displayed a high degree of load specificity: 26 pollinator species (65.0%) carried pollen from only one plant species, eight (20.0%,) carried pollen from two plant species, three (7.5%) carried pollen from three plant species and one (2.5%) carried pollen from five plant species. Visitor specificity and pollen transportation were similar amongst the visiting agents. Plant pollination-system specificity and pollen transportation were statistically significant among plant species with different pollinator types, but plant pollination system and pollen transportation were not different among floral symmetry, floral longevity, reward type, plant sexuality, breeding system and plant life form. The visitor species/plant species ratio was 1.6, and the pollinator species/ plant species ratio was 1.3. Among different guilds, birds, Coleoptera and Lepidoptera showed the highest pollinator species/plant species ratio, and wind pollination exhibited the lowest.     

马先蒿属花冠无喙类的花器官发生

对花冠无喙类密穗马先蒿(Pedicularis densispica)和大王马先蒿(P．rex)的花器官电镜扫描发现,两种不同花冠型(无齿和具齿)的马先蒿花部器官发生和发育初期十分相似,表现为明显的单轴对称。2个萼片原基首先发生于花顶的近轴侧位,然后沿花顶边缘向远轴端发育形成--马蹄形结构。密穗马先蒿在近轴中部又出现1枚萼片原基,随后马蹄形结构分化出4枚萼片,并与近轴中部的原基愈合后构成5齿萼片;而大王马先蒿的2齿萼片直接由马蹄形结构发育而成。5枚独立的花瓣原基随后发生,但发育相对滞后;除近轴中部位置1枚空缺外,4枚雄蕊原基与花瓣原基位置呈交互发生;2个心皮原基同时在拱形花顶的近轴和远轴端发生,剩余的花顶形成中间的隔膜,并与2个心皮形成中轴胎座。对马先蒿与金鱼草(Antirrhinum majus)和毛地黄(Digitalis purpurea)花器官发生和发育初期的特征进行了比较,讨论了马先蒿属花冠对称性变化的意义。