新西兰岩石百合中两种共存的繁育策略：延迟自动自交和欺骗传粉吸引

延迟自动自交和欺骗传粉吸引在被子植物多数类群中有相关报道,但是至今没有发现两种繁育策略在同一物种中共存现象。本研究通过对照试验检测新西兰岩石百合雄蕊附属物和花冠闭合运动是否分别具有欺骗吸引和延迟自交功能。研究结果表明,新西兰岩石百合黄色的雄蕊附属物拟态花粉（或花药）,约93%的昆虫访花行为源自黄色花药附属物的欺骗吸引,雄蕊附属物的报酬拟态功能有效提高昆虫拜访频率并促进异交。同时,研究发现新西兰岩石百合花期结束时花瓣闭合促使雌雄隔离距离的缩小,花瓣自然闭合的花朵平均结籽数（20.62）显著高于闭合前去雄处理花朵（11.79）。我们的结果表明延迟自动自交与欺骗传粉吸引两种繁育策略在新西兰岩石百合中共存。     

新西兰岩石百合中两种共存的繁育策略：延迟自动自交和欺骗传粉吸引

延迟自动自交和欺骗传粉吸引在被子植物多数类群中有相关报道,但是至今没有发现两种繁育策略在同一物种中共存现象。本研究通过对照试验检测新西兰岩石百合雄蕊附属物和花冠闭合运动是否分别具有欺骗吸引和延迟自交功能。研究结果表明,新西兰岩石百合黄色的雄蕊附属物拟态花粉（或花药）,约93%的昆虫访花行为源自黄色花药附属物的欺骗吸引,雄蕊附属物的报酬拟态功能有效提高昆虫拜访频率并促进异交。同时,研究发现新西兰岩石百合花期结束时花瓣闭合促使雌雄隔离距离的缩小,花瓣自然闭合的花朵平均结籽数（20.62）显著高于闭合前去雄处理花朵（11.79）。我们的结果表明延迟自动自交与欺骗传粉吸引两种繁育策略在新西兰岩石百合中共存。     

Autonomous Self pollination under Dominant Flexistylous Outcorssing Mechanism in Alpinia galanga (Zingiberaceae)

Autonomous self pollination is considered to be a reproductive assurance mechanism for plants when facing extreme environments that scarce in pollinators, and it also has disadvantages like inbreeding depression and pollen/ovule discounting. In several genera of Zingiberaceae like Alpinia and Amomum, a specialized mechanism named flexistyly exists, precedent studies consider its significance as preventing unnecessary self pollination and sexual interference. However according to our field observation, if pollen grains on cataflexistylous (CATA) flowers remain on the anther when the style curves downwardly, potential exists that the stigma contacts the pollen, thus autonomous self pollination occurs. Here, we studied the breeding system of Alpinia galanga, the results show that (1) Alpinia galanga is self compatible in which inbreeding depression occurs to some degree; (2) The anaflexistylous (ANA) morph of Alpinia galanga allocates more resource into outcrossing than the CATA morph; (3) The P/O ratio of the ANA morph is significantly lower than that of the CATA morph, as Alpinia galanga has constant six ovules in each ovary, the significant difference in P/O value reflects the contrast in pollen production. This phenomenon may be interpreted as the ANA morph provides pollen exclusively for the CATA morph. But the CATA morph, despite delivers pollen to the ANA morph, also need its own pollen for potential autonomous self pollination. In summary, autonomous self pollination exists in Alpinia galanga, and while flexistyly functions to avoid unnecessary self pollination and sexual interference, it also provides advantages for delayed autonomous self pollination as a necessary reproductive assurance and preventing conflict among these three major features by controlling the time of autonomous self pollination. This peculiar mechanism in Alpinia galanga thoroughly demonstrates its adaptation to unfavorable surrounding during the evolutionary process.     

Pollination biology of the Galápagos endemic, Tournefortia rufo-sericea (Boraginaceae)

Tournefortia rufo-sericea is an endemic member of the Galápagos angiosperm flora. Although not uncommon within the archipelago, its status is presently listed as vulnerable and, as such, a complete knowledge of its pollination biology may prove useful in preventing its decline. Pollination experiments, flower-visitor observations, nectar and fluorescence studies, as well as pollen : ovule ratio and pollen size studies were included in this investigation. The small, white flowers of this species set fruit via open pollination (81%), autonomous self-pollination (80%), diurnal pollination (80%), and nocturnal pollination (85%). Ants are the most common visitor to the flowers of this species, primarily during the day, whereas beetles and moths make visits at night. A small amount of nectar is presumably produced, as moths are often seen probing the corollas. Experiments with fluorescent dust did not support interflower pollen movement. The pollen : ovule ratio was 4972 : 1, which suggests xenogamy, and the mean pollen size was 21 µm. Despite the pollen : ovule ratio, it appears that this species exhibits a breeding strategy of facultative autogamy, in which the majority of flowers set fruit via autonomous self-pollination, but limited outcrossing may occur when pollinators are available. Conservation efforts for T. rufo-sericea should focus on the control or eradication of exotic species.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 21–31.     

Evidence of a Strong Domestication Bottleneck in the Recently Cultivated New Zealand Endemic Root Crop,Arthropodium cirratum (Asparagaceae)

We use chloroplast DNA sequencing to examine aspects of the pre-European Māori cultivation of an endemic New Zealand root crop, Arthropodium cirratum (rengarenga). Researching the early stages of domestication is not possible for the majority of crops, because their cultivation began many thousands of years ago and/or they have been substantially altered by modern breeding methods. We found high levels of genetic variation and structuring characterised the natural distribution of A. cirratum, while the translocated populations only retained low levels of this diversity, indicating a strong bottleneck even at the early stages of this species’ cultivation. The high structuring detected at four chloroplast loci within the natural A. cirratum range enabled the putative source(s) of the translocated populations to be identified as most likely located in the eastern Bay of Plenty/East Cape region. The high structuring within A. cirratum also has implications for the conservation of genetic diversity within this species, which has undergone recent declines in both its natural and translocated ranges.     

Pollination ecology and pollination system of Impatiens reptans (Balsaminaceae) endemic to China

BACKGROUND AND AIMS: China is one of the centres of geographical distribution of Impatiens L. Studies of the pollination ecology of this genus in China have, until now, been unreported. Impatiens reptans, a species endemic to China, was studied. The aims were to examine the pollination ecology and pollination system of this species, to compare its pollination ecology with other Impatiens species growing in Sumatra and Japan, and to discuss possible reasons for its limited distribution. METHODS: The pollination ecology of I. reptans was studied by carrying out continuous observations within three naturally growing populations. Its pollination system was studied using different pollination methods, marking and counting pollen grains, assessing pollen viability and observing pollinator behaviour. KEY RESULTS: The flowering phase of the protandrous I. reptans lasted for 89 d. The life span of an individual flower was 3.6 d. Primary pollinators were honey-bees and bumble-bees. Secondary pollinators were diurnal hawk moths and butterflies. Bombus briviceps and Bombus sp. were nectar gatherers. The mean nectar sugar concentration was 29.5 %, and the mean value of sucrose/glucose + fructose was 0.82. The proportion of seed set ranged from 0.857 to 0.873. Distances that seeds were ejected ranged from 0.58 to 1.17 m. Percentage seed germination under controlled conditions was 23.1. Pollen viability was highest on the day of anthesis and thereafter decreased. Ratios of pollen : ovules ranged from 958.8 to 970.6. CONCLUSIONS: Impatiens reptans reproduces by means of cross-pollination. Its dependence on a specialized habitat, a narrow environmental niche, a low percentage of seed germination, and habitat loss could be reasons for its limited distribution and endemism.     

Isolation and characterization of polymorphic microsatellite loci in nurse shark (Ginglymostoma cirratum)

We report on the development of nine polymorphic microsatellite loci in nurse shark (Ginglymostoma cirratum) using a combination of enriched and unenriched subgenomic libraries. Based on the small percentage of positive clones in the unenriched library (0.4%) it appears that microsatellites are very scarce in nurse shark genomes. Numbers of alleles at polymorphic loci ranged from two to 15; observed heterozygosity ranged from 0.17 to 0.90. We expect these loci to be useful for studies of breeding structure and paternity.     

聚果榕传粉榕小蜂传粉与产卵之间的权衡

【目的】榕树(Ficus)依赖专性榕小蜂(Agaonidae)传粉,同时为传粉榕小蜂提供繁衍后代的场所,两者形成动植物间经典的协同进化关系。在雌花期果内,榕小蜂需在有限的存活时间内完成传粉和产卵,而传粉榕小蜂如何在传粉与产卵之间进行权衡仍然是悬而未解的问题。本研究旨在明确传粉榕小蜂——一种栉颚榕小蜂Ceratosolen sp.在雌雄同株的聚果榕Ficus racemosa雌花期果内的行为活动及繁殖模式。【方法】借助测微尺测量聚果榕榕果雌花花柱长度与传粉榕小蜂(Ceratosolen sp.)产卵器长度,通过显微视频记录传粉榕小蜂在雌花期果内搜索、传粉及产卵行为;结合单果控制性引蜂试验,测定不同阶段榕小蜂个体大小、孕卵量、携粉量,以及雄花期最终繁殖的榕小蜂后代和榕果种子数量。【结果】聚果榕雌花花柱长度存在树间变异,榕小蜂产卵器长度比绝大多数的雌花花柱长,说明该小蜂可以产卵于大部分的雌花子房里。通常个体大的榕小蜂孕卵量更多,但个体大小与携粉量之间相关性不显著。观察发现,榕小蜂进入雌花期榕果内,前6 h集中产卵,可产下孕卵量的95%,平均搜索用时27 s,产卵用时46 s,此期间传粉行为少见,花粉筐中携带花粉量亦无明显变化;榕小蜂进果后6-24 h,主要执行传粉,其行为主动,连贯高效,单次传粉用时平均为2 s,最终可传完携粉量的80%。控制引蜂试验也证实榕小蜂进入榕果内前6 h主要执行产卵繁殖后代,之后6-24 h主要执行传粉以繁殖榕树种子。【结论】在雌雄同株的聚果榕雌花期榕果内,榕小蜂先产卵、后传粉。本研究首次展示了传粉榕小蜂在聚果榕雌花期榕果内的产卵和传粉行为,并获得与行为相匹配的产卵量和传粉繁殖量,反映了具主动传粉行为的榕小蜂在传粉和产卵之间存在时间和数量上的权衡。     

Flowering biology of Aspidistra (Asparagaceae): new data on pollination by dipteran insects

The genus Aspidistra comprises about 160 species of herbaceous plants. In previous investigations, different authors suggested that Aspidistra is pollinated by flies, fungus gnats, slugs, amphipods and even collembolans. The vast majority of data was based on only one species, A. elatior, and was not confirmed by direct observations. Recent field observations of anthetic plants confirm the idea of pollination by flies for two other species of the genus. The present study summarizes direct observations of flowering phenology and pollination of five previously unstudied species of Aspidistra. Flowering biology was studied using visual observations as well as video and photo monitoring. Flowers and captured pollinators were investigated using scanning electron microscopy. As a result, knowledge of the flowering biology of Aspidistra has been increased. The absence of heat production and an ultraviolet pattern were verified. The present data show that flowers of Aspidistra can serve as a food resource for animals. The investigated species of Aspidistra are pollinated by dipteran insects: A. formosa, A. marasmioides and A. subrotata are pollinated by fungus gnats; A. multiflora and A. oviflora are pollinated by flies. The occurrence of fungus‐gnat pollination was directly demonstrated for the first time in the genus Aspidistra. The present study confirmed the idea of myiophily in the genus Aspidistra. Apparently, myiophily is common and diverse in Aspidistra. More likely, pollinators are attracted by scent, which is undetectable by humans, but the attraction mechanism is still not completely clear.     

Deceptive pollination in two subspecies of Disa spathulata (Orchidaceae) differing in morphology and floral fragrance

The non-rewarding flowers of Disa spathulata (L.f) Sw. have a highly elongated scent-producing lip that varies in size and form between the two subspecies of this orchid. We investigated whether this unusual morphology is associated with the evolution of a specialized scent-based pollination system. Field observations carried out in South Africa showed that flowers of D. spathulata are pollinated solely by bees belonging to the genus Tetraloniella (Anthophoridae). Flowers of D. spathulata subsp. spathulata were visited by Tetraloniella brevikeraia, while flowers of D. spathulata subsp. tripartita (Lindl.). H. P. Linder were visited by Tetraloniella junodi. The floral fragrance of D. spathulata is emitted by the lip blade and differs markedly between the two subspecies (only 24 [42.1] of the 57 compounds identified were shared). Fragrance of D. spathulata subsp spathulata is dominated by the fatty acid derivatives decyl actetate, octanol, and decanol, while that of D. spathulata subsp. tripartita is dominated by the terpenoids (E) - ocimene, caryophyllene, and (E) nerolidol. Both male and female Tetraloniella bees were strongly attracted to cut flowers of D. spathulata subsp spathulata, even at sites where the orchid does not naturally occur. Bees visit the orchids repeatedly despite the lack of rewards in their flowers. Sexual deception in D. spathulata can be excluded by the attraction of both male and female bees, and yet the manner in which bees are attracted seems too intense and species-specific to be characterized as food-deception. This implies the existence in D. spathulata of a system of scent-based deception of insects that has not been described previously in plants.     

Pollination syndromes predict brood-site deceptive pollination by female hoverflies in Paphiopedilum dianthum (Orchidaceae)

In order to explore the relationship between the pollinator and pollination syndromes, and to evaluate the possibility of predicting likely pollinators based on pollination syndromes, the pollination biology of Paphiopedilum dianthum was examined. This species shares a close phylogenetic relationship, similar habit, and a recognizable syndrome of floral features (including helmet-shaped labellum, big dorsal sepal, and black warts or hairs on petals) with other brood-site deceptive Paphiopedilum species. According to the pollination syndrome concept, P. dianthum would be pollinated by hoverflies and attract pollinators with brood-site deception. Results were consistent with this prediction. Paphiopedilum dianthum was mainly pollinated by female hoverflies (Episyrphus balteatus), and these flies were indeed lured by the false brood-site on the orchid flower. It is suggested that the pollination syndrome may be correlated with pollination selective pressure, but not simply with pollinator species, and that accurate prediction requires consideration of all factors influencing floral characters, including habit and evolutionary history.     

Floral rewards and pollination in Cytiseae (Fabaceae)

 Cytiseae have been reported to be mostly nectar-lacking, yet some taxa secrete nectar from extrastaminal nectaries. We studied the pollination biology of four shrubby species of Cytiseae (Cytisophyllum sessilifolium (L.) Lang, Spartium junceum L., Genista radiata (L.) Scop., Genista cilentina Valsecchi) which differ for ecology, distribution and population size. All species resulted obliged xenogamous, insect visits being necessary for successful pollination. Bumblebees and solitary bees are the principal pollinators, but also many beetles, some hover-flies, and few bugs visit flowers. Pollinator specificity is low, and this may be the reason of the scarce seed set compared to the number of ovules. Pollen is the main reward, but traces of glucose were detected in all species, at the base of vexillum or on the reproductive column. Nectar production is irregular in time, and apparently unpredictable. We suppose that nectar may play a role in attracting pollinators determining their right position for a successful pollination. Received August 12, 2002; accepted November 25, 2002 Published online: June 2, 2003     

利用传粉综合征预测:长瓣兜兰模拟繁殖地欺骗雌性食蚜蝇传粉

在花部进化受传粉者主导这一经典理论影响下,传粉综合征一直被认为是被子植物对应于某些特定传粉者的标志,因此,可以利用传粉综合征来预测传粉者。近年来,这种对应和预测受到多因素影响,以及花部进化理论和传粉者泛化理论的冲击。在本研究中,我们选择长瓣兜兰Paphiopedilum dianthum作为实验材料,来探讨传粉综合征与传粉者的关系以及利用前者预测后者的有效范围。长瓣兜兰具有的一系列特征,同其他依靠假繁殖地欺骗食蚜蝇传粉的兜兰种类相似,包括倒盔状唇瓣,较大的中萼片以及花瓣上的黑色突起和睫状毛,而且长瓣兜兰同这些种类有很近的亲缘关系和相似的生境。根据传粉综合征概念,长瓣兜兰应该是由食蚜蝇传粉,通过模拟繁殖地来欺骗传粉者。为了检验这些预测,我们对长瓣兜兰进行了传粉生物学研究。长瓣兜兰是自交可亲和的物种,不存在自动自交授粉现象,必须依靠昆虫传粉才能结实。结果表明,雌性黑带食蚜蝇Episyrphus balteatus是长瓣兜兰的主要传粉者,并且这种兜兰是通过模拟繁殖地来欺骗食蚜蝇传粉的。根据本实验结果,我们认为传粉综合征只是对应于不同的传粉选择压力而不是简单对应于传粉者种类,而使用传粉综合征预测时还需要考虑生境和演化历史等因素对花部形态的影响,这样才可能得到有效的结果。     

Phenology and pollination biology of eight Peperomia species (Piperaceae) in semideciduous forests in southeastern Brazil

Data on flowering phenology and pollination of Peperomia species are virtually non-existent. This study presents data on the pollination biology of eight Peperomia species from south-eastern Brazil, including the flowering phenology, pollination system, and reproductive success. Data on flowering phenology were recorded weekly and exclusion experiments on inflorescences provided data on autonomous self- and wind pollination. Direct visual observations were made and insect visits were recorded. Four Peperomia species showed continuous flowering, while the others were seasonal and flowered in the wet season. Pollination by wind and Syrphidae was confirmed for two self-incompatible Peperomia species. The remaining species are self-compatible and their high fruit set may be accounted for by autonomous self-pollination and perhaps agamospermy. Although the floral morphology of Peperomia species suggests wind- and/or insect pollination, most of the species studied exhibit autogamy and perhaps agamospermy as the main method of reproduction.     

Pollination specialization and time of pollination on a tropical Venezuelan plain: variations in time and space

Levels of specialization of the pollination systems were evaluated in 155 plant species from the Venezuelan Central Plain. In all, 29 pollination systems were found, resulting from various combinations of nine pollen‐vector types or pollinating agent classes. The number of pollen‐vector types composing a pollination system ranged from one to five. Ninety‐one species were pollinated by only a single pollen‐vector type; the frequency of pollination systems fell monotonically with increasing number of constituent pollen‐vector types. Some 30–40 per cent of bee‐, moth‐, beetle‐ and bat‐pollinated species were pollinated by that group of vectors alone. The highest incidence of co‐occurrence between pollen‐vector types was found for the combinations fly–wasp, butterfly–wasp, butterfly–fly, and to a lesser extent bird–butterfly, bat–bird, bat–moth and butterfly–moth. The average number of pollen‐vector types per plant species was significantly higher for trees and shrubs than for lianas and perennial herbs. The distribution of polyphily, oligophily, monophily and anemophily was significantly associated with life form and habitat. The relative frequencies of these types varied least through the year in the forest‐savannah ecotone and in the vegetation as a whole, reflecting the combination of life forms. There were significantly fewer night‐pollinated than day‐pollinated species. Day‐pollinated species tended to be polyphilous, and most of the night‐pollinated species were monophilous or oligophilous. Time of pollination activity was related to habitat. The relative importance of night pollination among life forms decreased from trees to perennial herbs. Plant species exclusively pollinated during the night reached a peak during the rainy season (May to November) for trees, lianas and perennial herbs. The data as a whole show that the relative frequency of polyphily, oligophily, monophily and anemophily, and the time of pollination activity are influenced by community structure and plant species richness, and may change from season to season. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society, 2004, 145 , 1–16.     

Evolution and homology of bird pollination syndromes in Erythrina (Leguminosae)

Erythrina L. (Leguminosae: Phaseoleae) is a pantropical genus of over 100 species, all of which are either hummingbird or passerine pollinated. Phylogenetic hypotheses based on morphological and chloroplast DNA restriction site characters suggest that shifts from passerine to hummingbird pollination have occurred a minimum of four times in the genus. In hummingbird-pollinated species the inflorescences are held upright, the flowers are arranged radially along the axis, and the narrow standard petal is conduplicately folded to form a pseudotube. In most of the passerine-pollinated species, the inflorescences are held horizontally, the flowers are secund, and the standard petal is open so that the nectar and androecium are easily visible and accessible. Nectar amino acid concentrations and sucrose to hexose ratios are closely associated with pollination mode. Despite the general resemblance in flower and inflorescence morphology among species with the same pollination type, homology assessment reveals that petal morphology and size, and calyx and pollen morphology differ. Morphological characters, even if comprising modifications associated with adaptive pollination systems, therefore provide useful phylogenetic information.     

Delayed pollination,stigma length,sex expression,and progeny sex ratio in spinach,Spinacea oleracea (Chenopodiaceae)

Delayed outcrossed pollination of female spinach plants (Spinacea oleracea L.) resulted in increased stigma length and a male-biased progeny sex ratio. One group of females was outcrossed 10–14 d after anthesis, a second group was never outcrossed, and a third group, the control, consisted of females that were outcrossed as soon as stigmas appeared. Stigma length was significantly greater for plants in the delayed and never outcrossed groups compared to the control. Furthermore, stigmas of virgin flowers grew until they were either pollinated or the plants produced anthers. Plants that were never outcrossed produced their own anthers and self pollinated. The resulting progeny were all female. The sons of the delayed outcrossed group produced more stamens, on average, than sons of the control group. The observed male-biased sex ratio among the progeny of delayed outcrossed plants could be due to gametic selection. To test for this, plants were held virgin until their stigmas reached a length of at least 3 mm. These stigmas were then pollinated either distally or proximally. No significant difference was found between the progeny sex ratios of these two treatments. However, both sex ratios were more male biased than progeny of plants pollinated the day of anthesis (control group of the first experiment). We conclude that maternal factors, rather than gametophytic selection, may be responsible for the male-biased sex ratio observed in the first experiment.     

The predictive power of pollination syndromes: Passerine pollination in heterantherous Meriania macrophylla (Benth.) Triana (Melastomataceae)

The cloud forest species Meriania macrophylla (Benth.) Triana has pseudocampanulate flowers with bulbous stamen appendages, typical for the passerine pollination syndrome found in the Melastomataceae tribe Merianieae. The species is further characterized by strong stamen dimorphism (heteranthery), a condition otherwise associated with pollen‐rewarding bee‐pollinated species (both in Melastomataceae and beyond). In passerine‐pollinated Merianieae, however, flowers usually only show weak stamen dimorphism. Here, we conducted field and laboratory investigations to determine the pollinators of M. macrophylla and assess the potential role of strong heteranthery in this species. Our field observations in Costa Rica confirmed syndrome predictions and indeed proved pollination by passerine birds in M. macrophylla. The large bulbous set of stamens functions as a food‐body reward to the pollinating birds, and as trigger for pollen release (bellows mechanism) as typical for the passerine syndrome in Merianieae. In contrast to other passerine‐pollinated Merianieae, the second set of stamens has seemingly lost its rewarding and pollination function, however. Our results demonstrate the utility of the pollination syndrome concept even in light of potentially misleading traits such as strong heteranthery.