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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。 相似文献
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在2007和2008年对大花百子莲(Agapanthus praecox subsp.orientalis‘Big Blue’)在群体、果序和单果水平上的结实和结籽格局进行了观测,并依据每花序单花数、单花胚珠数和单粒种子质量推算其单株潜在种子产量;此外,采用人工补充授粉方法研究了不同授粉方式对大花百子莲结实和结籽的影响,并对其种子产量的影响因素进行了分析。结果表明:从始花期、盛花期至末花期,随开花时间的延迟,大花百子莲植株的每花序单花数和座果率均逐渐降低,其中始花期开花的植株每花序单花数和座果率均最高。从果序基部、中部至顶端,座果率和结籽率均逐渐减小且差异显著。在果序基部和中部,果实内种子败育率沿果实基部至顶端依次降低,而单粒种子质量则依次增加;且果序基部的果实各部位的种子败育率均低于果序中部的果实,而单粒种子质量则差异不大。大花百子莲的单株潜在种子产量约为43.18 g,而其单株实际种子产量约为2.87 g,远低于其潜在种子产量。自然授粉的大花百子莲每柱头花粉数为27.5粒,而自花授粉、同株异花授粉和异株授粉的每柱头花粉数均超过100粒;与自然授粉、自花授粉和同株异花授粉植株相比,异株授粉植株的座果率和结籽率均显著增加。研究结果显示:大花百子莲的结实和结籽格局呈现非随机分布规律,在引种地存在有性繁殖障碍;养分和授粉状况是制约大花百子莲种子产量的重要因素。 相似文献
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《环境昆虫学报》2015,37(4):715-719
红火蚁Solenopsis invicta Buren是一种重要的入侵物种,它对农业生产的影响是其危害的表现之一。为了揭示红火蚁入侵及其与蚜虫互作对绿豆Vigna radiata植株上访花昆虫的影响,本研究采用田间试验调查了红火蚁的入侵及其与蚜虫互作对绿豆植株上访花昆虫的影响。结果表明:当无蚜虫存在时,在红火蚁入侵区与对照区内,绿豆植株上的主要访花昆虫种类数差异不显著,在入侵区内,小黑蝇日观察数量降低了68.1%;当有蚜虫存在时,与对照区相比,绿豆植株的访花昆虫种类数显著降低了20.4%;小黑蝇日观察数量降低了60.2%,爪哇摇蚊的日观察量比对照区减少了61.5%。因此,研究结果明确了红火蚁与蚜虫互惠对绿豆植株上访花昆虫产生一定的影响。 相似文献
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全球气候变化对生态系统的影响是人类社会面临的紧迫而又严峻的挑战。气候变化带来的极端气候事件的增多, 直接影响到生态系统生产力和服务功能。本文总结了气候变化对植物-传粉昆虫互作的研究进展, 强调植物-传粉昆虫互作网络结构和其时空演变的解析, 以及互作关系和功能性状重组研究的重要性。近年来在气温持续上升背景下对植物-传粉昆虫互作关系影响的研究也受到了更多关注, 这些研究主要集中在两方面: 一是植物和传粉昆虫分布区的变化, 包括部分种群可能灭绝; 二是物候的变化, 即植物花期和传粉昆虫活动期的改变。植物与传粉昆虫任何一方在空间或时间上的改变, 都会导致传粉关系的错配或丢失。此外, 也可能导致植物-传粉昆虫双方的功能性状及其耦合的改变, 从而影响其互作关系的稳定。建议在今后的研究中关注: (1)覆盖生物多样性的多个尺度的研究; (2)对植物-传粉者互作网络的长期监测; (3)重要指示物种繁殖适合度评价; (4)植物-传粉昆虫互作双方功能性状在时间和空间尺度上的变化, 及其互作关系的重组; (5)关键植物和传粉昆虫类群的评估和保护。 相似文献
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为了探讨利用褐脉少花龙葵毛状根来修复重金属镉(Cd)污染的可能性,采用溶液培养法研究了Cd单独及其与钙(Ca)组合对褐脉少花龙葵毛状根生长、抗氧化酶超氧化物歧化酶(SOD)和过氧化物酶(POD)活性及对Cd吸收的影响。结果表明,Cd≤50μmol/L时能促进毛状根生长,而高于100μmol/LCd则抑制毛状根生长,使其侧根根尖变褐和变短,数目减少。与对照相比,不同浓度Cd培养的毛状根可溶性蛋白含量和SOD活性先升高后逐渐下降;其丙二醛(MDA)含量显著提高;100μmol/LCd使毛状根POD活性逐渐升高,但300μmol/LCd则使毛状根POD活性逐渐降低。与对照(仅添加100μmol/L或300μmol/LCd的毛状根)相比,Cd和10~30mmol/LCaCl2组合培养使毛状根可溶性蛋白含量和MDA含量降低;但提高其SOD活性;而100μmol/LCd和10~30mmol/LCaCl2结合培养的毛状根POD活性均比对照低;而300μmol/LCd和10~30mmol/LCaCl2结合培养的毛状根POD活性则均比对照提高。原子吸收分光光度法测定结果表明,毛状根吸收和吸附的重金属Cd含量随着培养基中Cd浓度的升高而增加。但外源加入10~30mmol/LCaCl2能减少毛状根对Cd的吸收,并调节其抗氧化酶SOD和POD活性,降低其膜脂过氧化水平而解除重金属Cd对毛状根生长的抑制或毒害。 相似文献
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The effect of nectar robbing on plant fitness is poorly understood and restricted to a few plant species. Furthermore, the
available studies generally evaluate the effects of nectar robbing on female fitness, disregarding the male component. Here
we measured the effects of the nectar-robbing bumblebees on male (measured as pollen analogue flow distance) and female (measured
as seed production) reproductive success in the insect-dependent Polygala vayredae, a narrow endemic species from the pre-Pyrenees (Spain). Intense nectar robbing by bumblebees significantly reduced the nectar
available to legitimate pollinators in the studied population, and this reduction affected both male and female fitness. Significant
differences were observed in fluorescent dye dispersion between robbed and non-robbed flowers within the population. Fluorescent
dyes from non-robbed flowers were dispersed to larger distances and over a larger number of flowers when compared with robbed
ones. Moreover, significant differences were observed in both fruit set and seed ovule ratios between the two groups, with
non-robbed flowers presenting higher reproductive outcomes. However, no effect on seed weight was detected among treatments.
The data obtained suggest that in this species, nectar robbing has important indirect and negative effects on plant fecundity,
through both male and female functions, due to a modification in the foraging behaviour of legitimate visitors. 相似文献
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Nectar robbing by squirrels is reported for the first time in the striped squirrel (Tamiops swinhoei hainanus), which was found robbing nectar from ginger plants (Alpinia kwangsiensis) in tropical forests of south Yunnan, China. We describe the behavior of squirrels visiting inflorescences, and we compare the fruit set of inflorescences visited by squirrels with that of inflorescences not subject to nectar robbing by squirrels. Most of the styles of robbed flowers were damaged and the affected plants exhibited reduced fruit set. 相似文献
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Exotic entomophilous plants need to establish effective pollinator interactions in order to succeed after being introduced into a new community, particularly if they are obligatory outbreeders. By establishing these novel interactions in the new non-native range, invasive plants are hypothesised to drive changes in the composition and functioning of the native pollinator community, with potential impacts on the pollination biology of native co-flowering plants. We used two different sites in Portugal, each invaded by a different acacia species, to assess whether two native Australian trees, Acacia dealbata and Acacia longifolia, were able to recruit pollinators in Portugal, and whether the pollinator community visiting acacia trees differed from the pollinator communities interacting with native co-flowering plants. Our results indicate that in the invaded range of Portugal both acacia species were able to establish novel mutualistic interactions, predominantly with generalist pollinators. For each of the two studied sites, only two other co-occurring native plant species presented partially overlapping phenologies. We observed significant differences in pollinator richness and visitation rates among native and non-native plant species, although the study of β diversity indicated that only the native plant Lithodora fruticosa presented a differentiated set of pollinator species. Acacias experienced a large number of visits by numerous pollinator species, but massive acacia flowering resulted in flower visitation rates frequently lower than those of the native co-flowering species. We conclude that the establishment of mutualisms in Portugal likely contributes to the effective and profuse production of acacia seeds in Portugal. Despite the massive flowering of A. dealbata and A. longifolia, native plant species attained similar or higher visitation rates than acacias. 相似文献
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《Fungal Ecology》2015
Microorganisms colonize the nectar of many angiosperms. Variable diversity and spatio-temporal dynamics of nectar-inhabiting microorganisms (e.g., yeasts) may drive variation in nectar sugar composition and subsequent plant–pollinator interactions. We assessed yeast frequency of occurrence and density in the nectar of the perennial herb, Delphinium nuttallianum, across multiple spatio-temporal scales, including flower lifetime and sex-phase transition, flowering season, populations, and years. We tested the hypothesis that pollinators vector yeasts by comparing densities between virgin flowers and those open to visitation. Finally, we identified yeasts using molecular methods and tested for an association between yeast density and nectar composition using ultra-performance liquid chromatography. Yeasts were frequent colonists of Delphinium nectar, occurring in all populations and years sampled. Yeast frequency of occurrence and density varied across most spatio-temporal scales examined. Pollinators were vectors of yeast: virgin flowers remained yeast-free, while those open to visitation became inoculated. Nectar samples were species-poor, with a majority colonized by Metschnikowia reukaufii. Finally, increasing yeast density was correlated with a decrease in sucrose and an increase in monosaccharides. Our results document that yeasts form species-poor communities in populations of this hermaphroditic perennial, in addition to highlighting their spatio-temporal dynamics and effects on nectar quality. Spatio-temporal variation in frequency of occurrence, density, and changes in nectar may have important implications for the nature and strength of interactions between Delphinium and its pollinators. 相似文献
11.
《Plant Diversity》2025,47(01)
Plants and their interaction partners offer unparalleled views of evolutionary ecology. Nectar larceny, entailing nectar extraction without pollinating, is thought to be an example of a harmful, antagonistic behavior, but the precise consequences of floral larceny on plant reproductive success remain contentious. We conducted a comprehensive meta-analysis of 153 studies across 120 plant species, using 14 moderators to assess the effects of floral larceny on plant reproductive success and examine the key moderators. We found that floral larceny negatively impacts flower traits, pollinator visitation, pollen deposition, and fruit set, while having a neutral effect on critical female fitness indicators, such as seed set and seed quality, as well as on male fitness. By altering pollinator behavior, floral larceny may reduce geitonogamy, potentially enhancing genetic diversity. Additionally, factors such as pollinator type, plant mating system, and pollen limitation were identified as key moderators of these effects. Our analysis reveals an ultimately neutral effect of floral larceny on plant reproductive success, with potential benefits in certain contexts. These findings suggest that floral larceny plays a complex and multifaceted role within plant-pollinator interactions, facilitating the evolutionary stability and coexistence of floral larcenists and host plants. 相似文献
12.
Animals that consume plant parts or rewards but provide no services in return are likely to have significant impacts on the
reproductive success of their host plants. The effects of multiple antagonists to plant reproduction may not be predictable
from studying their individual effects in isolation. If consumer behaviors are contingent on each other, such interactions
may limit the ability of the host to evolve in response to any one enemy. Here, we asked whether nectar robbing by a bumblebee
(Bombus occidentalis) altered the likelihood of pre-dispersal seed predation by a fly (Hylemya sp.) on a shared host plant, Ipomopsis aggregata (Polemoniaceae). We estimated the fitness consequences of the combined interactions using experimental manipulations of nectar
robbing within and among sites. Within sites, nectar robbing reduced the percentage of fruits destroyed by Hylemya. However, the negative effects of robbing on seed production outweighed any advantages associated with decreased seed predation
in robbed plants. We found similar trends among sites when we manipulated robbing to all plants within a local population,
although the results were not statistically significant. Taken together, our results suggest that seed predation is not independent
of nectar robbing. Thus, accounting for the interactions among species is crucial to predicting their ecological effects and
plant evolutionary response. 相似文献
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The floral biology and pollination process of Glechoma longituba (Nakai) Kuprian, a clonal gynodioecious, perennial herb that is widely distributed in China was investigated in natural populations. During visits to the flowers of G. longituba, the carpenter bee—Xylocopa sinensis mainly displayed nectar-robbing behavior with minimal pollination. Nectar robbing behavior began at the onset of flowering and continued for about 3 weeks ending at about the middle of the flowering period. A total of 18.6% floral visits in this period were by nectar robbers, with about 90% of the flowers in the study populations being subjected to two or two nectar-robbing episodes. During controlled experiments, lower pollination efficiency was recorded for X. sinensis compared to legitimate pollinators. Pollination by the robber-like pollinator X. sinensis during the early-mid phase of the flowering season yielded seeds of 16.16%. Although nectar robbing by the carpenter bee seemed to have a slight enhancing effect on seed set in G. longituba, this effect was effectively masked by the more pronounced detrimental effect of nectar robbing. Experiments indicated that nectar robbing by the carpenter bee reduced seed production by more than 26%, largely owing to the consequent shortening of the life span of robbed flowers. Furthermore, 10.43% of the ovules and 13.04% of the nectaries in the robbed flowers were damaged, thus causing a decrease or entire loss of reproductive opportunity in the robbed flowers. In addition, a higher number of pollen grains remained on the androecia of robbed flowers indicating that nectar robbing may have a lowering effect on male fitness in G. longituba. 相似文献
14.
Summary The widespread occurrence of nonorchid, heterospecific pollen grains on the stigmatic surfaces of a range of nectariferous and nectarless European orchids (Dactylorhiza. Orchis, Goodyera, andGymnadenia species) is reported for the first time, and the impact of heterospecific pollination on orchid reproductive success is experimentally investigated. There are three main components of stigmatic contamination by heterospecific pollen: the frequency of contamination, the diversity of foreign species present on the stigma, and the amount of pollen deposited. Six out of seven of the species examined have greater than 85% of stigmas contaminated with wind and insect-dispersed pollen. From one to nine insect-dispersed foreign pollen species are present per stigma, including pollen of members of the families Apiaceae, Asteraceae, Caryohpyllaceae, Ericaceae, and Primulaceae. Average loads per stigma vary from 13 to 176 grains, with individual stigma loads ranging from one to 909. Whether or not the orchid provides nectar has a major impact on these three components. Nectarless orchids have the greatest frequencies of contamination, diversity of species, and average load per stigma. Insect-dispersed pollen is deposited both by pollinators and visitors but, in spite of low levels of pollination, nectarless orchids still exhibit higher frequencies of heterospecific pollen contamination. The effect of the presence of heterospecific pollen on the reproductive success of orchids is tested in this study for the first time. Average-to-high, naturally occurring loads of heterospecific pollen derived from a mixture ofArmeria maritima,Caltha palustris,Cochlearia officinalis,Cytisus scoparius, andPrimula vulgaris and consisting of 50–250 grains per load are placed onto stigmas ofDactylorhiza purpurella which are subsequently self-pollinated with half of a pollinium. All pollinations produce capsules indicating that heterospecific pollen does not affect fruit set. Although experimental and control fruits are similar in size, they differ in total seed weight and composition. Total seed weight is reduced and the proportion of seeds with normal embryos decreased while the proportion of unfertilised ovules increased following pollination with heterospecific pollen, indicating a detrimental effect on fertilisation. Lower reproductive success caused by fertilisation failure is likely to be most severe in nectarless species because of their generally higher levels of contaminated stigmas. As nectarless orchids are known to have lower fruit set compared with nectariferous ones, this finding suggests that the reproductive success of nectarless orchids may be even lower than previously realised.Abbreviations RS
reproductive success 相似文献
15.
The present study provides new information about the reproductive biology of Boswellia sacra (Burseraceae), focusing on the nectary and its attractiveness for pollinators. The nectary disc changes its color from yellow to orange and red during the flower development. The colors are related to the main period of the stigmatic receptivity, to the dehiscence of anthers with pollen presentation and the nectar secretion. Pollinators preferentially visit the flowers in the “yellow” phase and neglect the “red phase”. This suggests a sophisticated dialogue between the plant and its pollinators. The color change from yellow to red occurs in a very short time (less than 24 h) and it is due to the accumulation of anthocyanins. Despite this dialogue between plant and pollinators, the number of fruits is often scanty. 相似文献
16.
Pollinator behavior influences plant reproduction in many ways. A traditional measure of pollination, the number of visits
received, may be a poor predictor of plant reproductive success, particularly when there are trade-offs between visit quantity
and components of visit quality. For example, the duration of pollinator visits may be negatively correlated with the number
of visits received by a flower. We tested for a trade-off between the number of bumblebee visits and the duration of those
visits in an experimental population of snapdragons (Antirrhinummajus: Scrophulariaceae). The duration of a bumblebee visit to a flower increased significantly with the time interval since the
flower had last been visited. Over the lifetime of a flower the correlation between the total number and average duration
of visits received by a flower was weakly negative. However, at the whole-plant level the correlation was positive: plants
whose flowers received more visits also received visits of longer duration. Factors affecting the relationship between quantity
and duration of pollinator visits to flowers also were investigated. Two factors weakened the negative dependence of average
visit duration on number of visits received by individual snapdragon flowers: (1) the correlation between the total number
of visits to a flower and the average interval between visits was only −0.53, as visits to individual flowers were not very
evenly spaced over time, and (2) newly opened flowers received fewer and shorter visits than older flowers. Comparing whole
plants, nectar production per flower varied dramatically across individuals, a probable explanation for the positive correlation
between visit number and average duration per flower observed at the plant level. The potential for a trade-off between these
two components of pollinator service exists when visit duration depends on reward quantity; whether the trade-off is realized
will depend on variation in nectar production and on whether pollinators forage systematically.
Received: 3 October 1997 / Accepted: 16 June 1998 相似文献