夜间开花的睡莲

说到“睡莲”、人们往往把它们与“睡”字联系在一起,以为睡莲是白天丹花,晚上花朵闭合（睡眠）的植物。其实不尽然。睡莲属植物中的热带睡莲,有一些品种的花朵是夜间开放,白昼闭合的。此类睡莲,它们的花朵通常在晚上8点左右开始展放,10点钟左右花瓣完全开放,次日上午8点,其花瓣开始回拢,到中午间点左右完全闭合。更奇妙的是,它们这种“值夜班”的习性,并不因地域的改变而变化。例如,在美国夜间开花的睡莲品种,被引种到中国后,并不困昼夜的倒置而表现为白天开花,依然夜开,昼六夜间开花的睡莲,卜分适宜家庭居室观赏,因而倍…     

睡莲属植物花粉形态研究

为明确睡莲属植物花粉形态特征,研究利用扫描电镜对18种或品种睡莲属植物的花粉形态特征进行观察,并对花粉形态及其种间亲缘关系进行分析,同时利用离体萌发法对睡莲品种‘彼得’的花粉活力进行测定,为睡莲杂交育种亲本的选择提供依据。结果表明:(1)18种或品种睡莲属植物的花粉均为单粒花粉,形态均为近球体或扁球体,其中巨花睡莲花粉粒最大,体积指数为30.3;埃及白睡莲花粉粒最小,体积指数为19.2。(2)花粉外壁纹饰类型繁多,包括网纹状、小颗粒状、瘤状、小柱状、长条状、微波纹起伏状。(3)根据聚类分析可将18种或品种睡莲属植物分为4个类群,其中Nymphaea亚属与Brachyceras亚属间亲缘关系最近。(4)‘彼得’的花粉离体萌发率高,可达95%以上。研究认为,睡莲属植物的花粉形态特征,特别是花粉萌发沟类型、外壁纹饰等特征可作为睡莲属植物种间分类、亚属间以及种间亲缘关系、系统进化规律的关键证据。     

碧波仙子——睡莲

一、分布与学名来源睡莲,是睡莲科睡莲属（Nymphaea）植物的泛称。全世界睡莲属植物有40－50种,我国有5种。按其生态学特征,睡莲可分为耐寒、不耐寒两大类,前者分布于亚热带和温带地区,后者分布于热带地区。睡莲属植物的学名Nymphaea源于拉丁语Nymph,意为居住在水乡泽国的仙女,在古希腊、古罗马、古埃及,睡莲与中国的荷花一样,被视为圣洁、美丽的化身,常被用作供奉女神的祭品。在新约圣经中,也有“圣洁之物,出淤泥而不染”之说。二、国内外发展动态我国植物学家对睡莲的关注程度远不如荷花。而国外的植物学家则对此颇为关注,…     

睡莲无性繁殖栽培技术初探

本文介绍了睡莲属(Nymphaea L.)3个种(延药睡莲N.stellata,黄睡莲N.mexicana,白睡莲N.alba[1])的无性繁殖栽培试验结果,探讨了睡莲无性繁殖栽培技术,为睡莲属植物的快速繁殖奠定了良好的基础。     

世界上最小的睡莲——侏儒卢旺达睡莲

正通常说到睡莲,基本上是睡莲科睡莲属(Nymphaea)植物的泛称,根据Flora of China记载,世界睡莲属植物约50种,分布在全球的温带及热带地区,目前主要作为观赏植物而广泛栽培于池沼或庭园水景中。从花色上讲,睡莲属植物可能是水生植物中颜色最为丰富的一类植物,雪白、粉色、黄色、粉红色、玫瑰红色、橙色、蓝色、蓝紫色等等,妖娆万分,让人眼花     

睡莲微型化栽培试验

睡莲属(Nymphaea)是水生植物睡莲科(Nymphaeaceae)的一个重要属。自古以来成为我国湖、塘、庭园水池中点缀水景的名花。它与荷花一样出污泥而不染,花型秀美,色彩艳丽,花期长,因而赢得了人们的喜爱。为了培育适合城市居民家庭养花的小型睡莲品种,我们从1988年开始进行睡蓬微型化栽培试验,取得了较明显的效果。获得了一个适合家庭阳台种植的盆栽睡莲品     

克鲁兹王莲(睡莲科)的开花生物学研究

分别于2003和2004年8月在北京地区观察了户外种植的克鲁兹王莲(Victoria cruziana)花的生物学.结果显示:(1)克鲁兹王莲的花在连续2 d内开放和关闭,第1天花开放的时间为19:20;第2天于12:00~13:00完成关闭过程,第2天15:00~16:00花第2次开放,第3天早晨花关闭后沉入水下.(2)开花第1天晚上花内温度高出环境温度最高达11°C,开花的第2天以后,花内温度与水表面温度相近.(3)克鲁兹王莲的花第1次和第2次开放以及关闭过程中花器官呈现有规律的运动,第1天晚上花的开放过程可划分为4个时期,花的第1次关闭与第1次开放过程中花器官的运动不是简单的相反过程,第2次开放与第1次开放的过程也不相同.(4)首次描述了拟雄蕊、雄蕊以及伴生心皮(paracarpels)在开花和关闭过程中的活动规律;开花第1天晚上的柱头是湿润的,但并不像睡莲属(Nymphaea)植物那样积累1池粘液.(5)在北京地区,克鲁兹王莲自花受精能够产生种子.研究结果认为王莲属植物的花具有很多高度特化的特征以适应昆虫传粉.     

睡莲微型化栽培试验

睡莲属(Nymphaea)是水生植物睡莲科(Nymphaeaceae)的一个重要属。自古以来成为我国湖、塘、庭园水池中点缀水景的名花。它与荷花一样出污泥而不染,花型秀美,色彩艳丽,花期长,因而赢得了人们的喜爱。为了培育适合城市居民家庭养花的小型睡莲品种,我们从1988年开始进行睡蓬微型化栽培试验,取得了较明显的效果。     

薄壳山核桃在南京的开花物候期观察和比较

对种植于南京的薄壳山核桃[Carya illinoensis (Wangench.)K.Koch] 18个品种(系)的开花物候期(包括雌花和雄花的单花开花过程和花期以及雄花散粉期和雌花可授期)进行了观察和比较.结果表明:供试的18个品种(系)雄花单花的开放过程包括花被裂开、雄花变黄、花药散粉、花药变黑和小花脱落5个时期,其开放过程持续天数为13～22 d;各品种(系)雄花集中在4月下旬进入初花期,5月中下旬进入落花末期,雄花的整个花期持续天数为16～24 d.雌花单花的开放过程包括子房显露、柱头裂开、柱头倒“八”字形、柱头枯萎和子房膨大5个时期,其开放过程持续14 ～ 22 d;雌花集中在4月下旬进入初花期,末花期集中在5月中旬,雌花的整个花期持续天数为12 ～23 d.18个品种(系)的雌花可授期天数为3～10d、雄花散粉期天数为4～9d,多数品种(系)的雄花散粉期与雌花可授期天数为7d.依据雌花和雄花开放的先后顺序可以确定其中的12个品种(系)为雌先型,5个品种为雄先型,仅1个品种为同时型;并根据观察结果确定了22个可行的授粉组合.适宜的品种配置方案为‘马罕’(‘Mahan’)、‘西奥克斯’(‘Sioux’)、‘金华’(‘Jinhua’)、‘卡多’(‘Caddo’)和‘波尼’(‘Pawnee’).     

睡莲

睡莲是睡莲科（Nymphaeaceae）睡莲属（Nym—phaea）植物的统称,多年生水生草本植物,主产于温带与热带地区。有热带睡莲（tropicalwaterlily）与耐寒睡莲（hardywaterlily）2种生态型。茎是根状或球状块茎。叶圆形或心形。热带睡莲的叶缘有波状、锯齿状或重锯齿状的不规则缺刻,而耐寒睡莲叶片全缘。     

耐寒睡莲花瓣中花青素苷组成及其与花色的关系

睡莲(Nymphaea spp.)为多年生水生观赏花卉。以耐寒睡莲不同花色的119个栽培品种为材料, 利用高效液相色谱(HPLC-DAD)和液质联用技术(HPLC-ESI-MSⁿ)测定了其花瓣中的花青素苷成分。采用英国皇家园艺学会比色卡(RHSCC)和国际照明委员会(CIE)制定的CIEL^*a^*b^*表色系统测量了57个品种的花色, 运用多元线性回归方法分析花色与花青素苷组成之间的关系。结果表明: 耐寒睡莲花瓣中含有14种花青素苷, 其中飞燕草素-3-半乳糖-5-乙酰-半乳糖苷(Dp3Ga5acetylGa)、飞燕草素-3-鼠李糖-(1→2)-半乳糖苷(Dp3Rh(1→2)Ga)、矢车菊素-3-半乳糖-(1→2)-半乳糖苷(Cy3Ga(1→2)Ga)、矢车菊素-3-乙酰-半乳糖-(1→2)-半乳糖苷(Cy3acetylGa(1→2)Ga)、矢车菊素-3-没食子酰-半乳糖苷(Cy3galloylGa)、飞燕草素-3-乙酰-葡萄糖苷(Dp3acetylG)、飞燕草素-3-葡萄糖苷(Dp3G)和矢车菊素-3-半乳糖-半乳糖-半乳糖苷(Cy3GaGaGa)8个组分在耐寒睡莲中为首次报道。Dp3Ga、Dp3galloylGa、Cy3Ga(1→2)Ga和Cy3galloylGa是决定耐寒睡莲呈色的关键花青素苷。     

The effect of aquatic plant abundance on shell crushing resistance in a freshwater snail

Most of the shell material in snails is composed of calcium carbonate but the organic shell matrix determines the properties of calcium carbonate crystals. It has been shown that the deposition of calcium carbonate is affected by the ingestion of organic compounds. We hypothesize that organic compounds not synthesized by the snails are important for shell strength and must be obtained from the diet. We tested this idea indirectly by evaluating whether the abundance of the organic matter that snails eat is related to the strength of their shells. We measured shell crushing resistance in the snail Mexipyrgus churinceanus and the abundance of the most common aquatic macrophyte, the water lily Nymphaea ampla, in ten bodies of water in the valley of Cuatro Ciénegas, Mexico. We used stable isotopes to test the assumption that these snails feed on water lily organic matter. We also measured other factors that can affect crushing resistance, such as the density of crushing predators, snail density, water pH, and the concentration of calcium and phosphorus in the water. The isotope analysis suggested that snails assimilate water lily organic matter that is metabolized by sediment bacteria. The variable that best explained the variation in crushing resistance found among sites was the local abundance of water lilies. We propose that the local amount of water lily organic matter provides organic compounds important in shell biomineralization, thus determining crushing resistance. Hence, we propose that a third trophic level could be important in the coevolution of snail defensive traits and predatory structures.     

Water lilies and scarabs: faithful partners for 100 million years?

Night-flowering water lilies (Nymphaeaceae) in South America are pollinated by Cyclocephala scarab beetles (Scarabaeidae: Cyclocephalini) in a specialized relationship involving synchronized flowering movements, strong floral scent, food tissues, and heat-producing flowers. We report that a similar and closely related association exists in West Africa between Nymphaea lotus L. and Ruteloryctes morio Fabricius (Cyclocephalini). This finding strongly supports a late Early Cretaceous origin of a symbiosis between the night-flowering water lilies and pollinating Cyclocephalini beetles. We believe that this is the first unambiguous evidence of a plant-pollinator relationship of this age.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 80 , 539–543.     

Fortnightly light and temperature variability in estuarine intertidal sediments and implications for microphytobenthos primary productivity

Photosynthetically active radiation (PAR) and temperature were measured continuously at the surface of estuarine intertidal sediments in the Tagus estuary, Portugal, along two spring-neap tidal cycles. PAR and temperature were strongly conditioned by the periodic tidal inundation, with large and abrupt variations occurring during flooding and ebbing. PAR levels reaching the sediment surface decreased very rapidly to zero or very low values during most of the daytime immersion. Inundation during high tide had the general effect of attenuating the amplitude of daily temperature fluctuation, with the incoming water usually warmer than the sediment during the night or early morning and cooler during the day. The daily progression of tidal emersion resulted in a clear fortnightly variation in total daily PAR reaching the sediment surface, while both daily mean temperature and mean temperature of diurnal low tide periods failed to exhibit a well-defined fortnightly periodicity. The obtained results indicate that the estuarine intertidal environment is dominated, at sub-seasonal time scales, by fortnightly periodicity in irradiance and temperature conditions favourable for benthic photosynthesis.     

结实期土壤水分亏缺影响水稻籽粒灌浆的生理原因

通过分析结实期土壤水分亏缺对水稻(Oryza sativa)籽粒中蔗糖向淀粉合成的生理代谢中关键酶活性及籽粒灌浆的调节作用, 探讨土壤水分亏缺影响水稻籽粒灌浆的生理机制。结果表明, 适度土壤水分亏缺诱导了灌浆高峰期(花后15-20天)水稻籽粒中蔗糖合成酶、腺苷二磷酶葡萄糖焦磷酸化酶、可溶性淀粉合成酶及淀粉分支酶活性的增加, 提高了籽粒灌浆中前期(花后10-20天)籽粒中淀粉积累速率和籽粒灌浆速率。但在灌浆后期(花后20-30天)籽粒中, 上述关键酶活性下降较快, 籽粒活跃灌浆期明显缩短, 灌浆前中期灌浆速率的增加不能完全补偿灌浆期缩短带来的同化物积累损失, 导致水分亏缺处理水稻籽粒充实不良, 结实率、籽粒重和产量显著降低。研究认为, 灌浆期土壤水分亏缺引起的灌浆后期籽粒中蔗糖向淀粉合成代谢中一些关键酶活性快速下降和籽粒内容物的供应不足是籽粒淀粉积累总量减少、粒重降低的主要生理原因。     

Influence of macrophyte decomposition on growth rate and community structure of okefenokee swamp bacterioplankton

Dissolved substances released during decomposition of the white water lily (Nymphaea odorata) can alter the growth rate of Okefenokee Swamp bacterioplankton. In microcosm experiments dissolved compounds released from senescent Nymphaea leaves caused a transient reduction in the abundance and activity of water column bacterioplankton, followed by a period of intense bacterial growth. Rates of [H]thymidine incorporation and turnover of dissolved d-glucose were depressed by over 85%, 3 h after the addition of Nymphaea leachates to microcosms containing Okefenokee Swamp water. Bacterial activity subsequently recovered; after 20 h [H]thymidine incorporation in leachate-treated microcosms was 10-fold greater than that in control microcosms. The recovery of activity was due to a shift in the composition of the bacterial population toward resistance to the inhibitory compounds present in Nymphaea leachates. Inhibitory compounds released during the decomposition of aquatic macrophytes thus act as selective agents which alter the community structure of the bacterial population with respect to leachate resistance. Soluble compounds derived from macrophyte decomposition influence the rate of bacterial secondary production and the availability of microbial biomass to microconsumers.     

Reduction in seed set upon exposure to high night temperature during flowering in maize

High temperature reduces crop production; however, little is known about the effects of high night temperature (HNT) on the development of male and female reproductive organs, pollination, kernel formation and grain yield in maize (Zea mays L.). Therefore, a temperature-controlled experiment was carried out using heat-sensitive maize hybrid and including three temperature treatments of 32/22°C (day/night; control), 32/26°C and 32/30°C during 14 consecutive days encompassing the flowering stage. When exposed to 30°C night temperature, grain yield and kernel number reduced by 23.8 and 25.1%, respectively, compared with the control. The decrease in grain yield was mainly because of the lower kernel number rather than change in kernel weight under HNT exposure around flowering. No significant differences in grain yield and kernel number were found between 22 and 26°C night temperatures. HNT had no significant effects on the onset of flowering time and anthesis-silking interval but significantly reduced time period of pollen shedding duration and pollen viability, and increased leaf night respiration. Different from high daytime temperature, HNT had no lasting effects on daytime leaf photosynthesis, biomass production and assimilate transportation. From the perspective of source–flow–sink relationship, the unchanged source and flow capacities during daytime are supposed to alleviate the adverse effects on sink strength caused by HNT compared with daytime heat stress. These new findings commendably filled the knowledge gaps concerning heat stress in maize.     

模拟水位变化对杭州湾芦苇湿地夏季温室气体日通量的影响

水位是影响湿地温室气体排放的重要因子。采用静态箱-气相色谱法研究了模拟条件下不同水位(0、5、10 cm和20 cm)对芦苇湿地温室气体(CO_2、CH_4、N_2O)夏季昼夜通量变化的影响。结果表明,1)4种不同水位CO_2通量日变化均表现为昼低夜高,且白天为汇,夜间为源,整体均表现为CO_2的汇;不同水位CH_4通量日变化则均表现为昼高夜低,且整体上均表现为CH_4的源;N_2O通量总体上水淹后均表现为昼高夜低而0cm水位表现为昼低夜高;2)随着水位的增加CH_4和CO_2平均通量呈现先增加后降低的趋势,且10cm水位下CH_4和CO_2平均通量最高,N_2O通量则在5cm水位最高;3)通过相关性和主成分分析表明,气温、水温是土壤CH_4、N_2O通量日变化的主导因子,而土壤温度是CO_2日变化通量的主导因子,同时,土壤p H、Eh及水体p H、Eh是CO_2通量日变化的重要因子之一。     

早春短命植物黑鳞顶冰花的花粉呈现时序及其适应性

花粉的时序呈现是指植物花药按一定次序释放花粉的现象, 被认为是对传粉者访问频率的一种适应。在传粉者充足的环境中, 植物通过限制花粉1次被移出的数量, 使花粉供体能作为多个父本, 从而提高雄性适合度。该文从开花习性、花部特征、传粉者及繁育系统等方面对早春短命植物黑鳞顶冰花(Gagea nigra)的花粉呈现时序及其适应性进行研究, 结果表明, 黑鳞顶冰花单花期约5-7天; 白天开放, 晚上闭合, 花药次序开裂, 呈拉链式散粉, 散粉期4-6天。黑鳞顶冰花以异交为主, 部分自交亲和。蝇类和食蚜蝇为主要传粉者, 访花频率为(0.141±0.078) flower∙h^-1。在雄蕊的时序散粉过程中, 雌蕊持续生长, 经历了从低于雄蕊到等高、再到高于雄蕊阶段。在等高阶段, 单花早晚的开闭, 使得雌雄蕊紧靠在一起, 促成了自动自花授粉。在传粉者缺乏的环境中, 黑鳞顶冰花的花粉时序呈现延长了散粉期, 在等待传粉者和分摊风险方面具重要作用。这种花粉渐次呈现的策略, 在新疆的早春开花植物中可能广泛存在。