道地产区阳春砂仁中华蜜蜂访花行为及携粉特征研究

作为我国四大南药之一,阳春砂仁Amomum villosum Lour.具有多重功效和悠久的应用历史。阳春砂仁的道地产区为广东省阳春市及周边地区。长久以来,受制于野生优势传粉昆虫资源匮乏,道地产区阳春砂仁自然结实率低、产量低,已严重影响到当地相关产业可持续发展。本研究观察道地产区阳春砂仁的开花过程及花朵形态,记录访花昆虫种类,并着重分析了中华蜜蜂的访花行为特点和传粉潜能。观察发现,阳春砂仁花朵形态特征不利于自花传粉及一般昆虫传粉,但其花朵散粉量和泌蜜量均较大而有利于吸引昆虫传粉。本研究共调查到4种访花昆虫,分别为中华蜜蜂Apis cerana cerana Fabr.、黑头酸臭蚁Tapinoma melanocephalum Fabr.、果蝇1种Drosophila sp.和欧洲球螋Forficula auricularia L.,其中,中华蜜蜂是主要访花昆虫。中华蜜蜂存在采粉和采蜜两种采集行为,且存在显著偏好性,其更频繁采集砂仁花蜜(平均占比77.4%),而不是花粉(平均占比22.6%),采粉行为具有潜在传粉功能,而采蜜行为则不具有传粉作用。另外,中华蜜蜂虫体各部位在采集过程中都可能...     

中华蜜蜂在滇山茶上的访花行为研究

对中华蜜蜂在滇山茶上的访花行为的研究表明,中华蜜蜂全天在滇山茶上的访花过程呈现出单峰型的节律,高峰在13:00～14:00.在31朵观察的样花上,中华蜜蜂全天共到访613次,访花627次,对花的连续访问率为2.23％,每朵花平均被访20.23次,每次到访花停留时间均值为10.23 s,全天在样花上总的累计停留时间为6 270 s,单花累计访问时间达到202.26 s.蜜蜂全天访花累计时间占全部访花昆虫总访花的累计停留时间的比例达到97.80％.在滇山茶访花昆虫中,中华蜜蜂具有明显的优势度,是绝对的优势种.对滇山茶花蜜的研究表明,其单花1天的花蜜分泌量平均为69.5 μL(n=100);花蜜含糖量(124.95～200.64) mg/mL.花蜜成分以多糖为主,占66％以上,此外还含有单糖,占1.9％～33％,其他未知名的组分占16％～22％,部分花蜜中含有山梨醇,占11％.对滇山茶花的挥发物分析结果表明,总的挥发物有59种,萜烯类、酯类和醇类是滇山茶花的主要挥发物成分,分别占46.468％、27.035％和21.609％.     

多叶斑叶兰花蜜特征和分泌规律及其对昆虫访花的影响

为探讨多叶斑叶兰(Goodyera foliosa)花蜜体积和成分的变异性,及其对传粉昆虫的影响,采用毛细管法、折光仪和高效液相-蒸发光法对一天内不同时间段单花花蜜体积、总糖浓度和可溶性糖成分及含量进行检测,用摄像机对其传粉昆虫访花行为进行观察。结果表明,单花花蜜体积在10:00达到最大[(7.19±2.29)μL, n=10],糖浓度在16:00达到最大[(25.85±1.83)%,n=10]。花蜜中的主要可溶性糖为果糖和蔗糖,果糖在上午10:00含量达到最高(78.310 mg/g);蔗糖在下午16:00含量达到最高(247.600 mg/g)。中华蜜蜂(Apis cerana)访花时间为每天9:00-15:00,访花高峰期在10:00-14:00;橘尾熊蜂(Bombus friseanus)访花时间为每天8:00-16:00,访花高峰期在10:00-12:00和16:00-18:00。因此,这两种传粉昆虫访花频率与多叶斑叶兰单花花蜜体积及糖浓度的变化有一定的相关性,它们更倾向于访问较高花蜜体积及糖浓度的花朵。多叶斑叶兰花蜜成分中蔗糖占优势,能有效吸引各种蜂类、蝶类和蚁类访花,且访问频率较高,中华蜜蜂和橘尾熊蜂能携带其花粉块,是主要的有效传粉昆虫。花形态和访花昆虫的体型大小的匹配,决定了是否成为有效传粉昆虫。     

春砂仁的访花昆虫种类及其访花和筑巢行为

阳春砂仁(Amomum villosumLour.)是我国四大南药之一,但花的形态结构较特殊,不易自然授粉。通过野外调查,在3个砂仁种植场共采集到砂仁的访花昆虫21种,其中蜜蜂类11种,蚂蚁类10种。蜜蜂类中,以黄绿彩带蜂Nomia strigataSmith和东方蜜蜂中华亚种Apis(Siamatapis)cerana ceranaFabricius较常见;蚂蚁类中,以细纹小家蚁Monomorium destructor(Jerdon)和黑头酸臭蚁Tapinomamelanocephalum(Fabricius)较常见。此外,还观察记录了黄绿彩带蜂、东方蜜蜂和蚂蚁的访花行为,以及黄绿彩带蜂的筑巢行为。     

草果两型植株的繁育差异研究

草果(Amomum tsaoko)是具有柱头卷曲机制的姜科植物,该研究通过观察和分析传粉者的访花行为、草果的花蜜分泌和最终的结实率,探索其花蜜分泌模式与传粉行为的相互关系,以及对其两型植株繁殖的影响。结果表明:草果两型植株的花蜜分泌在1 d花期的16:40—19:00期间达到高峰;上举型花比下垂型花能够提供更多的花蜜,下垂型花的花蜜分泌受环境温度、光照、湿度的显著影响,其结实率也显著低于上举型花。中华蜜蜂(Apis cerean cerana)是观察点频率最高的有效传粉者,在1 d花期里访花频率呈现双峰模式,访花行为受到温度和湿度的显著影响,78%或18℃较适宜访花。1 d花期中温度、湿度的变化,以及花蜜的动态分泌模式共同促进这一双峰访花模式的形成。草果花蜜分泌模式和双峰访花模式均与草果的柱头卷曲运动匹配,对吸引昆虫精确传粉、维持柱头卷曲机制有重要意义。草果两型植株之间,环境因素对它们花蜜分泌的影响显著不同,导致传粉者不同的访花行为反应和繁殖结果。适当增加居群中上举型植株数量,可能是提高产量的一个有效方法。     

足茎毛兰的欺骗性传粉研究

一些兰科植物常常利用多种多样的欺骗性传粉机制吸引传粉者,唇瓣上的附属物就是其中之一.黄色被认为对昆虫具有吸引作用.在广西雅长兰科植物自治区级保护区内秋季开花的足茎毛兰(Eria coronaria)唇瓣上具有鲜明的黄色斑块,这种花部信号很可能与吸引昆虫有关系.为验证这一假设,我们在广西雅长保护区内对足茎毛兰的传粉过程进行了观察.研究发现,足茎毛兰的唯一传粉者是中华蜜蜂(Apis cerana cerana).与足茎毛兰同在秋季开花的植物主要有光叶海桐(pittosporum glabratum).光叶海桐的花中有丰富的花蜜和花粉,吸引大量中华蜜蜂访问.足茎毛兰虽然不为中华蜜蜂提供任何报酬,但其唇瓣上的黄色斑块的颜色和形态大小与光叶海桐的黄色花相似.根据中华蜜蜂在足茎毛兰和光叶海桐花上的活动情况,我们认为足茎毛兰唇瓣上鲜明的黄色斑块对中华蜜蜂有吸引作用.中华蜜蜂访花时,通常降落在唇瓣的黄色斑块上,调整身体姿势后进入花内,在退出的过程中将花粉块带出或将所携带的花粉块授到柱头上,而药帽留在原来的位置.足茎毛兰的花部构造,特别是药帽的形状与中华蜜蜂的形态以及在花上的行为十分吻合,因此中华蜜蜂的传粉效率较高.人工授粉实验表明足茎毛兰需要依赖传粉者才能完成传粉过程.足茎毛兰在研究样地的自然结实率为20.72%,接近于食源欺骗性传粉兰科植物的平均结实率(20.7%).     

春兰(兰科)传粉生物学的研究

为探讨兰属Cymbidium建兰亚属subgen.Jensoa植物与传粉者之间的关系,对湖南省西南部野生春兰Cymbidiumgoeringii的传粉生物学进行了研究.结果表明春兰花期近40天,多数花(60%左右)在30天内开放.春兰的花开放与气温有直接的关系,当温度明显升高时,春兰的花会大量开放;春兰的花唇瓣3裂,中裂片强烈外弯成90°至180°不等,且少数花的中裂片上有紫褐色斑点;花能够散发出浓郁的香气,距离花1m左右就可以闻到香气.春兰唯一的传粉者为中华蜜蜂Apis cerana cerana,主要在晴天1000-1700气温较高的时间段活动.中华蜜蜂访花时,直接落在唇盘上,后腿蹬在唇瓣中裂片上.头部直接进入花内.当中华蜜蜂头部接近合蕊柱基部时便不能继续进入,开始挣扎退出.退出过程中有时中胸会随着挣扎而拱起,接触到合蕊柱上部,蹭到粘盘(viscidium).当中华蜜蜂中胸背部蹭到粘盘后,花粉块连同药帽就粘到蜜蜂的背部被一起带出.中华蜜蜂访花后,如果没有带出花粉块,则继续访花或者飞离居群;访花后若带出花粉块,则会立即飞离该居群.黑颚条蜂Anthophora melanognatha只是春兰的访问者.春兰不会为传粉者提供花蜜、花粉等报酬,也没有模仿同期开花植物花的形态特征,因而可能是通过其强烈的香味来吸引传粉者.自然条件下,春兰的结实率仅为6.67%.人工异花授粉、自花授粉、同克隆内授粉的结实率分别为100%、90%和100%,表明春兰是高度自交亲和的.而套袋后不采取措施、去雄的花均不结实,表明春兰不存在自动的自花授粉、无融合生殖,因而,春兰必须通过一定的媒介传粉才能繁衍后代.     

谁是腊梅的主要传粉者:昆虫行为与传粉作用

访花昆虫不同的访花与飞行行为导致其访花频率小同,进而对植物传粉产生不同的影响.意大利蜜蜂(Apis mellifera ligustica)、苍蝇和食蚜蝇是腊梅(Chimonanthus praecox)最常见的访花类群(或种类),但是它们的访花行为却有很大不同.意大利蜜蜂主要以快速飞行为主,偶见爬行,苍蝇访花时主要以快速飞行、爬行和跳跃为主,而食蚜蝇以长时间单花访问和悬空飞行以及间歇性休息为主.根据访花类群(或种类)在一朵花上的访花时间和花间飞行时间进行推算,每只意大利蜜蜂、苍蝇和食蚜蝇每分钟分别可以访问4.57、2.65和0.53朵花.结合每种(类)昆虫的访花数量推算出意大利蜜蜂、苍蝇和食蚜蝇每分钟分别可以访问498.19、1,089.74和99.78朵花.传粉效力(相同条件下单位时间内相同数目访花者能够授粉的花朵数)实验结果证明苍蝇和意大利蜜蜂分别是93％、100％(n=30),而食蚜蝇只有13％(n=30).苍蝇和意大利蜜蜂可携带大量花粉且具有很高的传粉效力,因此,访花速度的快慢是二者访花能力强弱的主要限制因素.由此,我们认为苍蝇可能是腊梅最主要的传粉者,意大利蜜蜂次之(数量偏少),食蚜蝇再次(访花与飞行行为的影响以及访花效力较低是限制其访花能力的主要因素).     

中国特有的两种同域分布凤仙花属植物的传粉生物学研究

中国是凤仙花属物种多样性分布中心之一,存在着大量的特有和同域分布现象。为更好地理解同域分布近缘种的传粉综合征分化以及传粉昆虫资源分配问题,该文以中国特有种黄麻叶凤仙花(Impatiens corchorifolia)和金凤花(I.cyathiflora)为研究对象,通过野外调查和实验完成传粉生物学的相关研究,比较分析了这两个种的开花物候、花形态结构、传粉昆虫的种类及访花行为和人工授粉实验等方面的异同。结果表明：(1)两种凤仙花的花距不同,花距的长度与花蜜量呈正比,但与花蜜含糖量无关。花距类型决定了两种植物的传粉昆虫种类的分化。具短花距的黄麻叶凤仙花的花蜜含量为(4.57±1.43)μL,花蜜糖含量为(45.48±2.28)%,由蜜蜂和胡蜂为其传粉。拥有长花距的金凤花的花蜜含量为(10.15±3.28)μL,花蜜糖含量为(46.12±1.48)%,除蜜蜂和胡蜂传粉外,天蛾和熊蜂也为其传粉昆虫。(2)两种植物虽然共享3种传粉者,但表现为明显的错峰访花,传粉行为和花通道的差异决定了传粉者携带花粉的部位不一致。(3)繁育系统实验表明,两种植物均表现出明显的种间杂交障碍和异花授粉偏好性。因此,花...     

白花野牡丹的开花进程、花部形态特征及访花昆虫观察

为了解白花野牡丹( Melastoma candidum f. albiflorum J. C. Ou)的开花进程、花部形态特征及访花昆虫的种类和访花行为,分别于2011年和2012年对栽培于深圳市中国科学院仙湖植物园的白花野牡丹花期进行观察和统计分析。结果表明：白花野牡丹的单花花期约12 h,7：00雌蕊柱头从即将开放的花蕾中伸出、8：00左右花朵半开放、8：30左右花瓣完全展开、16：00左右花瓣开始闭合、19：00左右花瓣完全闭合,翌日花瓣不再开放并逐渐萎蔫,至第4天花部完全脱落。白花野牡丹的花序为近头状的伞房花序,每个花序有3~8朵花;雌蕊1枚;雄蕊2轮(5+5,6+6),内轮雄蕊较短、而外轮雄蕊较长;不分泌花蜜。白花野牡丹花期的访花昆虫有2目5科13种,其中传粉昆虫有2科6种,包括领木蜂( Xylocopa collaris Lepeletier)、东亚无垫蜂〔Amegilla ( Zonamegilla) parhypate Lieftinck〕、蓝彩带蜂(Nomia chalybeata Smith)、彩带蜂(Nomia sp.)、中华蜜蜂(Apis cerana cerana Fabricius)和绿芦蜂(Pithitis smaragdula Smith)。这6种传粉昆虫的访花行为、访花规律及传粉效率各异,其中,领木蜂、东亚无垫蜂、中华蜜蜂和绿芦蜂的日活动规律为单峰型,访花高峰期均在10：00或11：00;而蓝彩带蜂和彩带蜂的日活动规律为双峰型,2个访花高峰期分别在10：00和15：00。花瓣开始松动时,小体型的中华蜜蜂和绿芦蜂开始传粉;随着花瓣继续开放,中等体型的蓝彩带蜂和彩带蜂成为主要传粉者;花瓣完全开放后,大体型的领木蜂和东亚无垫蜂成为主要传粉者。研究结果显示：白花野牡丹花粉是传粉昆虫的惟一报酬;各传粉昆虫的访花行为与白花野牡丹的开花进程密切相关,因此,可以有效保证白花野牡丹的繁殖。     

基于蜂蜜孢粉学鉴定秦岭中华蜜蜂的蜜源木本植物

蜜源木本植物的鉴定能为中华蜜蜂Apis cerana cerana保护和利用提供依据.本研究从在秦岭地区收集的4份中华蜜蜂蜂蜜中分离出植物花粉,然后在扫描电镜下观察花粉形态,根据花粉大小、赤道面观、极面观、表面纹饰对花粉所属植物的种类进行鉴定.共鉴定出中华蜜蜂利用的蜜源木本植物13科,19属,20种.其中以壳斗科Fagaceae、忍冬科Caprifoliaceae最多,卫矛科Celastraceae、桦木科Betulaceae、蔷薇科Rosaceae次之.这些蜜源木本植物中有13种是药用植物.秦岭地区丰富的蜜源木本植物为中华蜜蜂的生存提供了食物资源;同时中华蜜蜂作为传粉昆虫,对维持秦岭地区蜜源植物的生存和生态系统稳定起着重要的作用.     

Spatial and temporal patterns of floral scent emission in Dianthus inoxianus and electroantennographic responses of its hawkmoth pollinator

Scent emission is important in nocturnal pollination systems, and plant species pollinated by nocturnal insects often present characteristic odor compositions and temporal patterns of emission. We investigated the temporal (day/night; flower lifetime) and spatial (different flower parts, nectar) pattern of flower scent emission in nocturnally pollinated Dianthusinoxianus, and determined which compounds elicit physiological responses on the antennae of the sphingid pollinator Hyles livornica.The scent of D.inoxianus comprises 68 volatile compounds, but is dominated by aliphatic 2-ketones and sesquiterpenoids, which altogether make up 82% of collected volatiles. Several major and minor compounds elicit electrophysiological responses in the antennae of H. livornica. Total odor emission does not vary along day and night hours, and neither does along the life of the flower. However, the proportion of compounds eliciting physiological responses varies between day and night. All flower parts as well as nectar release volatiles. The scent of isolated flower parts is dominated by fatty acid derivatives, whereas nectar is dominated by benzenoids. Dissection (= damage) of flowers induced a ca. 20-fold increase in the rate of emission of EAD-active volatiles, especially aliphatic 2-ketones.We suggest that aliphatic 2-ketones might contribute to pollinator attraction in D. inoxianus, even though they have been attributed an insect repellent function in other plant species. We also hypothesize that the benzenoids in nectar may act as an honest signal (‘nectar guide’) for pollinators.     

中华蜜蜂气味结合蛋白AcerOBP14的表达及配体结合特性分析

[目的]气味结合蛋白(odorant binding proteins,OBPs)在昆虫寄主定位、产卵地选择等行为中发挥着重要作用,明确中华蜜蜂Apis cerana cerana AcerOBP14与配体的结合特性有助于阐明中华蜜蜂嗅觉识别的分子机制.[方法]通过qRT-PCR测定OBP14在20日龄中华蜜蜂成年工蜂...     

Population dynamics of Dremomys pernyi and Callosciurus erythraeus in protective and non-protective pine forests at different ages

Four pine forests (6-10,11-15,16-20,and 31-40 year-old)located in the Cangshan Mountain and Erhai Lake National Reserve and 7 pine forests (1-5,6-10,11-15,16-20,21-30,31-40,and more than 50 year-old)located in the non-protective area near the national reserve were selected.Three replications of each forest was set and a total of 33 sites were investigated.At each site,we quantified 6 habitat variables (species richness,abundance,and percentage of grasses and shrubs coverage respectively at the bottom layer of forests)within randomly determined 5 m×5 m areas.One hundred cages were set in five lines at each site to trap small mammals,whose species and numbers were recorded.Dominance of Dremomys pernyi and Callosciurus erythraeus in small mammal communities,time niche breadth,and time niche overlap between the two small mammals were calculated,respectively.Step-wise regression was used to analyze the relationship between small mammals and habitat factors.Our results indicated that D.pernyi occurred earlier than C.erythraeus in protective pine forests.D.pernyi was captured in 6-10 year-old forest initially,and C.erythraeus was captured in 16-20 year-old forest initially.D.pernyi and C.erythraeus were captured in the 31-40 and 21-30 year-oldforests initially in the non-protective area,respectively.Populations of D.pernyi and C.erythraeus in the 31-40 year-old protective forests were 3 and 3.75 times of those in the sameaged non-protective forests,respectively.Shrubs significantly influenced the populations of the two small mammals.The population of D.pernyi was positively correlated with the density of shrubs;the population of C.allosciurus erythraeus was positively correlated with the coverage of shrubs,and negatively correlated with the coverage of grasses.D.remomys pernyi and C.allosciurus erythraeus were important for pine forests to scatter pine seeds.Human activities in the nonprotective pine forests decreased the vegetation heterogeneity at the bottom layer of pine forests,postponed the occurrence of D.pernyi and C.erythraeus,and decreased the populations of the two small mammals.     

Ecological context influences pollinator deterrence by alkaloids in floral nectar

Secondary compounds may benefit plants by deterring herbivores, but the presence of these defensive chemicals in floral nectar may also deter beneficial pollinators. This trade-off between sexual reproduction and defense has received minimal study. We determined whether the pollinator-deterring effects of a nectar alkaloid found in the perennial vine Gelsemium sempervirens depend on ecological context (i.e. the availability of alternative nectar sources) by monitoring the behavioural response of captive bumblebees (Bombus impatiens, an important pollinator of G. sempervirens in nature) to nectar alkaloids in several ecologically relevant scenarios. Although alkaloids in floral nectar tended to deter visitation by bumblebees, the magnitude of that effect depended greatly on the availability and nectar properties of alternative flowers. Ecological context should thus be considered when assessing ecological costs of plant defense in terms of pollination services. We consider adaptive strategies that would enable plants to minimize pollinator deterrence because of defensive compounds in flowers.     

The pollination system of the widely distributed mammal‐pollinated Mucuna macrocarpa (Fabaceae) in the tropics

Although the pollinators of some plant species differ across regions, only a few mammal‐pollinated plant species have regional pollinator differences in Asia. Mucuna macrocarpa (Fabaceae) is pollinated by squirrels, flying foxes, and macaques in subtropical and temperate islands. In this study, the pollination system of M. macrocarpa was identified in tropical Asia, where the genus originally diversified. This species requires “explosive opening” of the flower, where the wing petals must be pressed down and the banner petal pushed upward to fully expose the stamens and pistil. A bagging experiment showed that fruits did not develop in inflorescences (n = 66) with unopened flowers, whereas fruits developed in 68.7% of inflorescences (n = 131) with opened flowers. This indicated that the explosive opening is needed for the species to reproduce. Four potential pollinator mammals were identified by a video camera‐trap survey, and 78.3% and 60.1% of monitored inflorescences (n = 138) were opened by gray‐bellied squirrels (Callosciurus caniceps) and Finlayson's squirrels (C. finlaysonii), respectively, even though more than 10 mammal species visited flowers. Nectar was surrounded by the calyx, and the volume and sugar concentration of secreted nectar did not change during the day. This nectar secretion pattern is similar to those reported by previous studies in other regions. These results showed that the main pollinators of M. macrocarpa in the tropics are squirrels. However, the species' nectar secretion pattern is not specifically adapted to this particular pollinator. Pollinators of M. macrocarpa differ throughout the distribution range based on the fauna present, but there might not have been no distinctive changes in the attractive traits that accompanied these changes in pollinators.     

珀氏长吻松鼠和赤腹松鼠在保护区与非保护区各年龄松林内的种群动态

2004年6~7月,在云南省大理白族自治州苍山和洱海国家自然保护区选取4种年龄段(6~10、11~15、16~20、31~40年)的松林和保护区周围的非保护区选取7种年龄段(1~5、6~10、11~15、16~20、21~30、31~40、50年以上)的松林,每种松林设3个重复,共33个样地,在样地内随机选取3个5m×5m的样方,调查并记录样方内草本植物和灌木的种类、数量、覆盖度。在每个样地按5条样线布笼100个捕捉小兽,每天检查捕获的种类和数量。计算珀氏长吻松鼠和赤腹松鼠在小兽群落中物种优势度、时间生态位宽度、两种小兽的时间生态位重叠度;用逐步回归分析两种松鼠与松林栖境因子的关系。上述结果表明,在保护区珀氏长吻松鼠出现的时间早于(6~10年的松林开始捕获到)赤腹松鼠(16~20年的松林内开始捕获到);在非保护区,分别在31~40年和21~30年的松林内才捕到珀氏长吻松鼠和赤腹松鼠。保护区31~40年的松林内珀氏长吻松鼠和赤腹松鼠种群数量分别是同年龄段非保护区松林的3倍和3·75倍。松林底层的灌木对两种小兽的种群数量有重要影响。珀氏长吻松鼠种群数量与灌木密度呈正相关;赤腹松鼠种群数量与灌木覆盖度呈正相关,而与草本植物覆盖度呈负相关。非保护区树底植被的异质性降低,延迟了两种松鼠在松林里建立种群的时间。     

皖南山区不同生态条件下中华蜜蜂形态特征差异性

为了分析皖南山区中华蜜蜂的生态适应性,对皖南山区5个不同采样点的15群中华蜜蜂450只工蜂的8个形态特征进行测定,对测定的性状特征数据进行数学分析和差异显著性检验,结果是,5个釆样点间的喙长、右前翅长、第三节背板宽、第三节背板颜色、第四节背板宽和第四节背板颜色差异显著。皖南山区中华蜜蜂的前翅长与宽均较大,第3+4背板长也较大,说明皖南中蜂飞翔能力强,采集能力强;背板长反映蜜囊的大小,蜜囊越大,贮存花蜜越多,蜂群进蜜就越快,从形态上说明皖南中蜂是较理想的蜜蜂种群。皖南中蜂种群内遗传变异丰富,种群形态性状的多态性、多型性及其生态地理变异式样,具有生态适应意义。     

Reproductive Ecology of Ocimum americanum L. and O. basilicum L. (Lamiaceae) in India

Abstract Ocimum americanum and O. basilicum bloom once a year. They produce flowers over a long period, a few flowers being produced each day. The flowers of both are short-lived (3-4 hours), bisexual, zygomorphic, and chasmogamic with anthers dehiscing in the bud stage. The open flowers offer nectar and pollen as rewards and are visited and sternotribically pollinated by day-flying animals. The blossoms are flag-shaped, and the reproductive organs are close to the lower corolla lip. The stamens and stigma show movements immediately after anthesis and remain for 20–30 minutes and this may cause self-pollination. Both species reproduce primarily through autogamy. Flowers are open during 5:30–13:30 hr in O. americanum and during 7:00–13:00 hr in O. basilicum . Certain bee species like Apis florea, A. cerana indica, Amegilla sp., and Pseudapis oxybeloies , and the butterfly Surandra queretroum are the most frequent and consistent visitors and can be pollinators for both plant species.     

Pollination biology and floral scent chemistry of the Neotropical chiropterophilous Parkia pendula

During the past several decades, the pollination biology of Old World plant species pollinated by flying foxes and of New World plants pollinated by highly specialized nectar-feeding glossophagine bats has been studied in detail. However, little is known about Neotropical plants that are pollinated by less specialized phyllostomid bats. Therefore, we studied the pollination biology of Parkia pendula , a tree pollinated by Phyllostomus . Flowers of P. pendula are arranged in capitula, and a capitulum is composed of approximately 800 hermaphrodite flowers and 260 sterile flowers. The sterile flowers produced a total of 7.4 ml nectar per night, with a sugar concentration of 14.95%, and proline as the dominant amino acid. Nectar production is highest at dusk and ends at 03:00 h. The floral scent is dominated by monoterpenoids (97.9%), with ( E )-β-ocimene being the dominant (84.0%) compound. No sulfur compounds were detected. The capitula are heavily visited by four species of phyllostomid bats, of which Phyllostomus discolor is the most abundant (98.9%). Nectar production per capitulum is within the reported range of nectar produced by this pantropical genus (5.0–8.0 ml). This genus-wide range seems to be optimal for attracting non-specialized nectar-feeding bats and forces them to visit capitula of several trees to satisfy their dietary needs, thus increasing the probability of cross-pollination for this plant.