Degree of style coiling is associated with corolla-tube length in the nectarless flowers of Roscoea schneideriana

The plant-pollinator‘arms race’model posits that a major driver of the evolution of elongated corollas in flowers is reciprocal selection for‘morphological fit’between pollinator-tongue length and access distance to nectar(usually corolla-tube length).Evidence for the pollinator-mediated selection on tube length and evolution of multiple,correlated floral traits remains inconclusive.To gain possible insights into the strength of stabilizing selection by assessing standing phenotypic variation,we measured a series of functionally important floral traits,including corolla tube length and‘effective’tube depth and degree of style coiling.We then calculated coefficients of variation(CV)for these traits in three field populations of R.schneideriana.Unlike in most long-tubed flowers,the bottom part of the corolla tube is completely occupied by the style,with no room for nectar.The length of this portion of the corolla tube was more variable(higher CV)than the upper part of the corolla tube,suggesting that functional tube depth was under stronger stabilizing selection.The degree of style coiling was negatively related to the corolla-tube length in all three populations of R.schneideriana,suggesting that there may be conflicting selection acting on style length and corolla-tube length,which are otherwise usually tightly correlated.Given the lack of nectar in the flowers of this species,the long corolla tubes and long styles may represent morphological holdovers from ancestors that were pollinated by long-tongued pollinators,as is still seen in related species in the western Himalayas.

Comparisons of Nectar Quantity and Sugar Concentration of Pomegranate Blossom in a Day

[Objective] The aim was to research the rules of nectar quantity and sugar concentration of perfect and staminate flowers in a day. [Method] Based on nine Tianguang Yan pomegranate trees, nectar quantity and sugar concentration of per- fect and staminate flowers were measured and analyzed in morning and afternoon. [Result] Average nectar quantity and sugar concentration differed insignificantly in morning and afternoon of perfect flowers, which could also be applied to staminate flowers. However, average nectar quantity of perfect flower was 64.09 μI and of staminate flower was 44.07 μl. It is obvious that the two were of extremely signifi- cant differences （t=4.642, P〈0.01）, and the former was significantly higher by 45,43%. On the other hand, average sugar concentration of perfect flower was 48.44% and of staminate flower was 37.16%. The two were of extremely significant differences and the former is higher by 30.36%, compared with the latter. These suggested that nectar quantity and sugar concentration would maintain unchanged in different periods for a day, if nectars are not consumed by pollinators, such as bees and butterflies. In the same period, nectar quantity and sugar concentration of per- fect flowers were higher than those of staminate flowers. [Conclusion] The research provides references for benefits increase of bee farmers and fruit farmers, as well as exploration of bee pollination.

Broad bean cultivars increase extrafloral nectary numbers, but not extrafloral nectar, in response to leaf damage

Phenotypic plasticity allows organisms to maximize fitness, by optimizing the expression of costly defensive traits. Broad bean, Vicia faba L. “Broad Windsor”, produces increased numbers of extrafloral nectaries (EFNs) in response to leaf damage to attract mutualistic partners and reduce herbivory. It is currently unknown, however, whether EFN induction is cultivar-specific or is a more general phenomenon. It has also not been determined whether broad beans increase nectar secretion rates in conjunction with EFN induction. We hypothesized that: a) as all broad beans have conspicuous EFNs, all cultivars should produce additional EFNs in response to leaf damage, and b) overall nectar secretion rates should increase with EFN numbers, to attract additional mutualists. We tested our hypothesis by subjecting three broad bean cultivars, Vicia faba L. “Broad Windsor”, “Stereo”, and “Witkiem” to mechanical leaf damage. The degree of change in plant traits associated with growth, in addition to EFN induction, was assessed 1 week after leaf damage. Extrafloral nectar volumes were also assessed, every 24 hours, pre- and post-leaf damage. We confirmed our first, but rejected our second, hypothesis. All cultivars produced additional EFNs, but none increased extrafloral nectar volumes, when experiencing leaf damage. Further experimentation is required to determine if energetic tradeoffs limit multiple forms of defense (i.e., EFN vs. nectar induction), or if this alternative strategy is adaptive for attracting and retaining mutualists. Understanding the costs and benefits of EFN vs. nectar induction will provide insight into the evolution of defensive mutualisms between plants and predatory arthropods.

Differential volatile organic compounds in royal jelly associated with different nectar plants

The aim of this work was to distinguish volatile organic compound（VOC） profiles of royal jelly（RJ） from different nectar plants. Headspace solid-phase microextraction（HS-SPME） was used to extract VOCs from raw RJ harvested from 10 nectar plants in flowering seasons. Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry（GC-MS）. Results showed that VOC profiles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exemplified by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid. As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.

Identification of summer nectar plants contributing to outbreaks of Mythimna separata(Walker)(Lepidoptera: Noctuidae) in North China

The presence of adequate nectar sources along the migratory pathway is a prerequisite for moths of oriental armyworm, Mythimna separata, to reach target habitats and lay eggs. Identification of plant species and assessment of their suitability as wild nectar sources along the summer migration pathway of adult M. separata are critical steps in making effective forecasts of second-and third-generation armyworm outbreaks in North China. We explored five aspects of moth-nectar source relationships：（1） Field investigations in 2014 and 2015 showed that the florescence of chaste tree, Vitex negundo var. heterophylla, a primary nectar plant in apiculture, coincided with the summer migration of oriental armyworm moths. The flowers of chaste tree opened day and night and M. separata moths were found actively flying around and resting on tree.（2） Identification of moth-borne pollen by scanning electronic microscopy（SEM） micrographs in 2015 and 2016 revealed that 15.4% of 369 moths trapped by blacklight traps, 17.1% of 557 moths captured by vertical-pointing searchlight traps and 24.4% of 311 moths caught by pheromone traps were found with pollen attached to their proboscis. A total of 228 pollen-carrying individuals out of 1237 armyworm moths were captured by the three types of traps. The three highest percentages of pollen-bearing armyworm moths were carrying pollen of Toona sp.（59.65%）, Ligustrum sp.（27.19%） and Syringa sp.（4.39%）. In total, 14 types of pollen were detected where three were identified to species, 10 to genus and one as an unknown species.（3） Analysis of geographical distribution, flowering periods and relative abundances of candidate nectar plants suggested that Chinese toon, Toona sinensis, and privet, Ligustrum lucidum, were two important nectar plant species.（4） Analysis on relationship between pollen and ovarian development showed that 14, 15 and 10 females carrying pollen of T. sinensis had ovaries at developmental stages Ⅰ, Ⅱ and Ⅲ, respectively. Many T. sinensis pollen grains were present on the proboscises of female moths.（5） Comparison of trap effectiveness between blacklight and vertical-pointing searchlight traps indicated blacklight traps caught the highest proportion（35.2%） of female in ovarian stage Ⅴ, whereas vertical-pointing searchlight traps caught the highest proportion（43.5%） of female in ovarian stage I with additional proportions of decreasing percentages for stages Ⅱ, Ⅲ and Ⅳ. Integrated analysis on these five aspects suggests that T. sinensis is an important, suitable summer nectar source that potentially influences migration and reproduction of M. separata moths andthus contributes to outbreaks of this pest. The vertical-pointing searchlight trap was the most effective tool for monitoring the migratory flight of adult M. separata. Privet, Ligustrum lucidum, and clove, Syringa sp., are possible suitable summer nectar plants that need further study to elucidate their importance. The reason why field investigation results on chaste tree differed from the results of moth-borne pollen analyses was discussed.

Nectar secretion of RN-type cytoplasmic male sterility three lines in soybean [Glycine max(L.) Merr.]

Significant progress has been achieved in the use of heterosis in soybean and several soybean hybrids have been released in China. However, broad use of hybrid soybean seed is limited due to low seed setting of female parents. Breeding cytoplasmic male sterile（CMS） lines with high out-crossing rate is necessary to solve the problem. The objective of this study was to determine the relationship between out-crossing rate of CMS lines and their nectar secretion. The daily nectar secretion rhythm, meteorological effect on nectar secretion, and differences in nectar secretion among genotypes and years were investigated in 27 soybean CMS lines（A-lines） with their maintainers（B-lines） and restorers（R-lines）. The correlation between out-crossing rate of CMS lines and nectar production was also evaluated. Nectar secretion had diurnal variation. Secretion initiated at about 06：00 for most materials and reached a peak at 07：00–08：30 after flower opened, then the nectar secretion decreased gradually. A sub-peak appeared at about 13：00, while the nectar could not be detected at 17：00. Nectar secretion was greatly influenced by the weather conditions. The amount of nectar secretion increased gradually over time during periods of high temperature and no rainfall for several days. Rainy weather and low temperatures inhibited nectar secretion. There were obvious variations of nectar amount among different genotypes tested. Significant nectar variation within a genotype among years was also observed, and the highest nectar secretion was 3-fold higher than the lowest. The amount of nectar secretion from R-lines was significantly higher than that of A-and B-lines. There was no significant difference in nectar secretion between A-and B-lines. A-and B-lines with higher out-crossing rates secreted more nectar. The amount of nectar secretion of A-and B-lines were significantly positively correlated with the out-crossing rate of A-lines.

Nutritional, Chemical and Organoleptical Characteristics of Low-Calorie Fruit Nectars Incorporating Stevioside as a Natural Sweetener

The study is aiming at preparation of low-calorie fruit nectars for diabetes and weight maintaining approaches as well as consumer satisfaction. Therefore, twenty low-calorie fruit-based formulated nectars were prepared mainly from orange, pomegranate, guava and mango pulps which sweetened with sucrose or sucrose— replaced at 25%, 50%, 75% and 100% using stevioside. Primitively, the yield of fresh fruits had been calculated. Consequently, nutritional, chemical and organoleptical characteristics of prepared fruit nectars have been determined. Results indicated that total solids content was in range of 5.57% - 13.20%, 9.90% - 14.37%, 8.25% - 13.27% and 8.25% - 16.50% for orange, pomegranate, guava and mango nectars, respectively. Dependently, caloric value resulted 21.57 to 51.08, 38.31 to 55.62, 31.93 to 51.37 and 31.93 to 63.86 kcal 100 g-1 fw for orange, pomegranate, guava and mango nectars, respectively. Total phenols content [TPC, mg GAE 100 g-1 dw] ranged from 665.12 to 747.41, 1180.42 to 1319.47, 742.54 to 848.27 and 418.01 to 472.42 for orange, pomegranate, guava and mango nectars, respectively. The antioxidant capacity by DPPH method [μmol TE g-1 dw] ranged from (20.79 to 26.51), (47.13 to 56.56), (60.68 to 69.25) and (8.39 to 13.32) for orange, pomegranate, guava and mango nectars, respectively. Total carotenoids [mg 100 g-1 dw] were the highest in mango nectars ranged from (102.99 to 110.52) in mango nectar with 100% sugar and mango nectar with 100% stevioside, respectively. Anthocyanins content recorded 6.14 mg 100 g-1 dw in pomegranate nectar with 100% sugar, while increased to be 9.01 mg 00 g-1 dw in pomegranate nectar with 100% stevioside. Ascorbic acid [mg 100 g fw] ranged from 23.41 to 27.53, 15.73 to 18.32, 25.72 to 30.87 and 18.07 to 20.98 for orange, pomegranate, guava and mango nectars, respectively. The results of organoleptical attributes showed no effect of sugar substituting by stevioside on color, odor and mouth feel. The most dramatic effect of sugar substituting had been observed on taste, bitter after taste and the overall acceptability of prepared nectars with high substitution levels. Practically, using stevioside to produce low-calorie nectars was shown to be satisfactory up to 50% - 75% substituting level, resulting low-calorie nectars and could be applied commercially.

Characterization of sugar diversity in floral and extra-floral nectar from the Coastal Coral Tree(Erythrina caffra Thunb.)in Southern California

The Coastal Coral Tree (Erythrina caffra Thunb.) produces floral nectar (FN) that serves to attract pollinating insects, but also secretes nectar from extra-floral (EFN) glands that serves to attract predatory insects, such as ants. While studies on myrmecophytes (i.e. specialized plants that attract and interact with ants) have primarily focused on interspecific evaluations of EFN chemistry, the Coastal Coral tree offers an opportunity to contrast intraspecific nectar chemistry with differing evolutionary and ecological functions. We hypothesized that the richness of (molecular) sugar species, relative concentrations, and diversity of sugars in FN and foliar EFN would diverge due to differences in the ecological role of the two types of nectar. High performance liquid chromatography with refractive index detection was used to identify the richness of sugar species (based on retention time), measure the relative concentrations, and evaluate the diversity of sugars in FN and foliar EFN secretions. We detected sugar species unique to each gland type and reported significant differences in the relative concentration of one sugar species common to both gland types. While the mean diversity index of sugars was similar for both gland types, the diversity of foliar EFN sugars was significantly more variable than that of FN sugars. The composition of FN showed little variation, and was reflective of its fundamental role in plant reproduction. Foliar EFN, however, demonstrated the variability expected of a context-dependent myrmecophyte that interacts with a facultative ant species assemblage across a mosaic of abiotic and biotic conditions.

寄主植物及猎物对杂食性天敌烟盲蝽若虫存活和发育的影响

杂食性昆虫烟盲蝽是多种害虫的重要捕食性天敌,它在猎物缺乏时可通过取食一些植物维持生存。因此,了解烟盲蝽在不同植物上的生物学特性以及有无猎物对其生物学特性的影响,是利用烟盲蝽创建储蓄植物系统开展害虫生物防治的基础。本研究通过室内离体叶片添加或不添加猎物烟粉虱、以及整株植物饲喂若虫的方法,测试了烟盲蝽在芝麻、香雪球和荞麦3种蜜源植物以及棉花和小白菜两种作物上的存活、发育及性比。结果表明,无猎物时,烟盲蝽若虫在芝麻和小白菜离体叶片上能发育至成虫,成虫获得率分别是85.2%和80.0%,若虫发育历期分别为15.0d和19.2d,但在荞麦、香雪球、棉花离体叶片和清水对照上分别只发育至4龄、3龄、3龄和2龄。添加猎物时,烟盲蝽若虫在5种植物离体叶片上都能发育至成虫,其中在芝麻上的若虫期最短,为11.8d,成虫获得率最高,为83.3%。烟盲蝽若虫在几种整株植物上的存活和发育与离体叶片上的结果相似,即只能在芝麻和小白菜上发育至成虫,成虫获得率分别为93.3%和66.7%。所有测试条件下饲养的烟盲蝽雌性比都在0.6左右,且雌、雄虫的若虫发育历期差异不显著。最后讨论了利用烟盲蝽这一重要杂食性天敌创建储蓄植物系统实施害虫生物防治的可行性。

基于北京休闲农业发展需求的唇形科蜜源植物筛选研究

基于北京市休闲农业发展需求,通过引进6种唇形科蜜源植物,结合观赏期、生长情况及访花昆虫等方面的观测,筛选适合北京休闲农业领域推广种植的蜜源植物种类。结果表明:荆芥和密叶牛至综合景观效果好,可以提供更长的持续花期,同时在吸引访花昆虫的总数和昆虫多样性方面理想,可以为自然观察、科普研学等需求提供更好的支撑。因此,推荐这2种植物应用于北京地区休闲农业园区、乡村民宿及城市农园的美化和科普性种植。

广西不同油茶物种花蕊花蜜糖含量分析

油茶(Camellia)为异花虫媒授粉树种,自花授粉基本不育,结果依赖传粉者。为探讨油茶花蕊花蜜中的糖含量与蜜蜂访花的关系,以陆川油茶(C.vietnamensis)、广宁红花油茶(C.semiserrata)、普通油茶(C.oleifera)和香花油茶(C.osmantha)盛开期的花朵为研究对象,采用离子色谱法分析不同油茶物种花蕊花蜜中的糖类(半乳糖、葡萄糖、蔗糖、麦芽糖、果糖和阿拉伯糖)含量。结果表明,离子色谱法可有效、准确地对油茶花蕊花蜜中的糖含量进行分析;不同油茶物种花蕊花蜜中的糖含量存在明显差异,但均以果糖、蔗糖、葡萄糖、半乳糖和麦芽糖为主,均未检出阿拉伯糖;果糖在各油茶物种花蕊花蜜中的含量均最高。香花油茶花蕊花蜜中的果糖、蔗糖、葡萄糖、半乳糖和麦芽糖含量均明显高于其他3个油茶物种,分别为19.62、8.39、14.79、0.25和0.18 mg/g。香花油茶花蕊花蜜中的果糖、蔗糖和葡萄糖含量高是其吸引中华蜜蜂(Apis cerana)访花的因素之一。

Floral nectary, nectar production dynamics, and floral reproductive isolation among closely related species of Pedicularis

Floral nectar is thought to be one of the most important rewards that attract pollinators in Pedicularis; however, few studies have examined variation of nectary structure and/or nectar secretion in the genus, particularly among closely related species. Here we investigated nectary morphology, nectar quality, and nectar production dynamics in flowers of Pedicularis section Cyathophora. We found a conical floral nectary at the base of the ovary in species of the rex-thamnophila clade. Stomata were found on the sudace of the nectary, and copious starch grains were detected in the nectary tissues. In contrast, a semi-annular nectary was found in flowers of the species of the superba clade. Only a few starch grains were observed in tissues of the semi-annular nectary, and the nectar sugar concentration in these flowers was much lower than that in the flowers of the rexthamnophila clade. Our results indicate that the floral nectary has experienced considerable morphological, structural, and functional differentiation among closely related species of Pedicularis. This could have affected nectar production, leading to a shift of the pollination mode. Our results also imply that variation of the nectary morphology and nectar production may have played an important role in the speciation of sect. Cyathophora.

东北地区早春蜜源植物传粉昆虫多样性研究

为了揭示蜜源植物与传粉昆虫的关系,科学的保护和利用传粉昆虫资源,本研究选取东北地区早春常见蜜源植物柳树Salix、延胡索Corydalis和银莲花Anemone为研究对象,对其传粉昆虫种类和访花行为进行调查,分析不同蜜源植物的传粉昆虫种类、优势类群、多样性和访花行为。结果表明:东北地区早春蜜源植物传粉昆虫共采集726头,隶属于5目14科53种,其中膜翅目4科35种,双翅目5科13种,鳞翅目3科3种,同翅目1科1种,鞘翅目1科1种。柳树的优势传粉昆虫为蜂类,延胡索的优势传粉昆虫为熊蜂类,银莲花的优势传粉昆虫为蝇类。延胡索的传粉昆虫多样性、均匀度和丰富度均最高。蜜蜂对柳树单位时间内访花次数和单花停留时间最高,为94.33次和18.90 s。熊蜂对延胡索单位时间内访花次数和单花停留时间最高,为76.42次和15.37 s,熊蜂在采集延胡索花时有明显的盗蜜行为,该行为有利于其它传粉昆虫生存。东北地区保护生物多样性和传粉昆虫资源,应结合蜜源植物保护,可在早春时期补种柳树、延胡索和银莲花,并合理搭配,为传粉昆虫提供良好食物源和栖息地。

滇水金凤花蜜相关SWEET7和SWEET16的克隆及表达分析

植物SWEET(Sugars will eventually be exported transporter)基因家族是一类重要的糖转运蛋白,参与开花植物的花蜜合成。本研究以野生型和突变型滇水金凤(Impatiens uliginosa)为材料,基于课题组前期的花距转录组数据,通过筛选和RT-PCR技术克隆得到花蜜相关基因SWEET7和SWEET16,分别命名为IuSWEET7和IuSWEET16,其cDNA分别为741 bp和903 bp,分别编码246和300个氨基酸。生物信息学分析表明:IuSWEET7为疏水性不稳定蛋白,IuSWEET16为疏水性稳定蛋白,二者均含有2个典型的MtN3/saliv保守结构域;IuSWEET7和IuSWEET16基因的氨基酸序列与杜鹃花(KAG5539487.1)、一串红(XP_042052415.1)等植物同源序列的相似性均在54.15%~71.48%;系统进化分析表明,IuSWEET7和IuSWEET16处于两个不同分支。qRT-PCR分析表明两个基因在野生型和突变型滇水金凤花距的3个时期中均有表达,且在不同部位中表达模式不同。其中IuSWEET7基因在野生型滇水金凤中其表达量从花苞期至盛花期逐渐上升;在突变型2距和3距中其表达量从花苞期至盛花期先上升后下降,且在始花期表达量最高;而IuSWEET16基因在野生型和突变型3距中其表达量从花苞期至盛花期均逐渐上升,但在突变型2距中其表达量从花苞期至盛花期先上升后下降,也在始花期时达到最高。

贵州蓝莓蜜TaqMan探针实时荧光PCR检测方法的建立与应用

该研究利用TaqMan特异性探针实时荧光PCR检测手段,建立了高效、精准鉴别贵州特色(中蜂)蓝莓蜜的方法。对贵州白竹林、麻卡和乌卡坪三个地域的蓝莓种植区蓝莓蜜进行采集(包括意蜂蓝莓蜜),同时购买市售蜂蜜及加拿大蓝莓蜜,该方法通过采集贵州麻江县白竹林地区蓝莓种植园及蜂场周围蓝莓同花期26种植物样本,基于植物基因组中trnL基因序列的多序列比对,设计蓝莓trnL基因特异性引物,并进行TaqMan探针验证。结果表明,本研究设计的TaqMan探针特异性强,建立的TaqMan探针实时荧光PCR检测方法能检测到蓝莓花粉DNA最低浓度为0.3 ng/μL;利用建立的方法对11种市售蜂蜜和贵州蓝莓蜜样本进行检测,发现贵州蓝莓蜜的Ct值为24~26,蓝莓花粉数在800~1700颗,其余蜂蜜Ct值在30以上,表明该方法能够有效实现贵州蓝莓蜜和其他蜂蜜的区分,具有良好的应用前景。

枸杞开花生物学及传粉特征研究

授粉不足是导致枸杞落花落果的直接原因之一,为了解枸杞的生殖生物学特点,以‘宁杞10号’为研究材料,测定其花期不同阶段的花部色态、柱头可授性和花粉活力等开花特性及泌蜜规律,并对其常见传粉昆虫的单次访花时长、柱头花粉沉降数等传粉特征进行分析。结果表明,在开花后12~24 h,花瓣颜色变为浅紫色和白紫色时,柱头可授性、花粉活力和泌蜜量均最高,相比其他几个阶段差异显著(P<0.05)。常见传粉昆虫单次访花后的柱头花粉沉降数(螟蛾>蜜蜂>无垫蜂)与自然传粉相比差异显著,蜜蜂对紫色花的访花时长均值为4.1 s,与对黄色花的访花时长(均值为1.7 s)相比差异极显著(P<0.01);从整体效率和传粉昆虫访问数量而言,建议引入传粉昆虫(如蜜蜂)以加强枸杞辅助授粉,提高枸杞的坐果结实率。研究结果为制定枸杞辅助授粉措施提供科学依据。

Corrections on energy spectrum and scatterings for fast neutron radiography at NECTAR facility

Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM-II in Technische Universit/it Mfinchen （TUM）, Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function （PSeF） simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections.

Floral biology of Salvia stachydifolia,a species visited by bees and birds:connecting sexual phases,nectar dynamics and breeding system to visitors’behaviour

Aims Adaptive convergence in floral phenotype among plants sharing a pollinator guild has been acknowledged in the concept of pollination syndrome.However,many plants display traits associated with a given syndrome,but are visited by multiple pollinators.This situation may indicate the beginning of a pollinator shift or may result in a stable situation with adaptations to different pollinators.In Salvia stachydifolia,a previous study suggested that flower shape is optimized to maximize the contribution to pollination of bees and hummingbirds.Here,we studied three additional aspects of its floral biology:sexual phases,nectar dynamics and breeding system,and examined their connection with pollinators’behaviour to explore the presence of adaptations to bee and/or hummingbird pollination.Methods Using a greenhouse population,we applied five pollination treatments to characterize breeding system.To determine sexual phases,we recorded flower opening,anther dehiscence,corolla fall and stigma receptivity.Additionally,we characterized nectar volume and concentration dynamics along the day.Finally,to determine pollinator assemblage and visitation patterns,we performed field observations and recorded pollinators’behaviour.Important Findings Salvia stachydifolia was partially protandrous and self-compatible,but open-pollinated plants attained the highest reproductive success,suggesting that reproduction is mainly dependent on pollinator activity.Bombus opifex bumblebees were the most frequent visitors,but Sappho sparganura hummingbirds dominated visits early in the morning and at dusk.Nectar was typical of bumblebee pollination.We suggest that the bee–hummingbird mixed visitation constitutes an unstable evolutionary situation,making S.stachydifolia an ideal system to understand the ecological circumstances in which pollination shifts occur.

Variation of nectar production in relation to plant characteristics in protandrous Aconitum gymnandrum

Aims Floral nectar plays a vital role in plant reproductive success by attracting pollinators.Nectar traits of a flower can depend directly on plant characteristics other than environmental factors and exhibit extensive flower-and plant-level variations.studies on nectar traits frequently focused on intraplant variation for dichogamous plants,but few have paid attention to both intra-and interplant nectar variations in relation to plant characteristics.revealing within-and among-plant variation and its relative magnitude is important for our understanding of how pollinator-mediated selection can act on nectar traits and evolution of nectar traits.Methods Through investigating protandrous Aconitum gymnandrum populations at the alpine meadows and Wetland Ecosystems research station of lanzhou university,we examined the relationships between nectar production per flower and plant characteristics(e.g.flower position within inflorescences,flo-ral sexual phases,flowering time,inflorescence size and floral attractive traits).Important Findings A.gymnandrum exhibited a declining gradient in the nectar volume along inflorescences,with more nectar in basal flowers than distal ones.Protandrous flowers of A.gymnandrum did not show gender-biased nectar production while the nectar volume varied with differ-ent stages of floral sexual phases.The significant correlation between the first flowering date of individuals and the mean nectar volume per flower was positive in 2013,but became negative in 2014,sug-gesting complex effects of biotic and abiotic factors.The mean nectar volume per flower was not related to inflorescence size(the num-ber of total flowers per plant).Furthermore,nectar production was weakly associated with floral attractive traits(the petal width and the galea height),even if the effect of flowering time of individuals was removed,suggesting that the honesty of floral traits as signals of nec-tar reward for pollinators is not stable in this species.

Nectar and Pollen Sources for Honeybee （Apis cerana cerana Fabr.） in Qinglan Mangrove Area, Hainan Island, China

In the present study, nectar and pollen sources for honeybee （Apls cerana cerana Fabr.） were studied in Qlnglan mangrove area, Hainan Island, China, based on microscopic analysis of honey and pollen load （corblcular and gut contents） from honeybees collected In October and November 2004. Qualitative and quantitative melittopalynologlcal analysis of the natural honey sample showed that the honey is of unlfloral type with Mimosa pudlca L. （Mlmosaceae） as the predominant （89.14%） source of nectar and pollen for A. cerana cerana In October. Members of Araceae are an Important minor （3%-15%） pollen type, whereas those of Arecaceae are a minor （〈3%） pollen type. Pollen grains of Nypa fruticans Wurmb., Rhlzophora spp., Excoecarla agallocha L., Lumnitzera spp., Brugulera spp., Kandella candel Druce, and Ceriops tagal （Perr.） C. B. Rob. are among the notable mangrove texa growing In Qinglan mangrove area recorded as minor taxa In the honey. The absolute pollen count （I.e. the number of pollen grains/10 g honey sample） suggests that the honey belongs to Group V （〉1 000 000）. Pollen analysis from the corblcular and gut contents of A. cerana cerana revealed the highest representation （95.60%） of members of Sonneratia spp. （Sonneratlaceae）, followed by Bruguiera spp. （Rhizophoraceae）, Euphorblaceae, Poaceae, Fabaceae, Arecaceae, Araceae, Anacardlaceae, and Rublaceae. Of these plants, those belonging to Sonneratla plants are the most Important nectar and pollen sources for A. cerana cerana and are frequently foraged and pollinated by these bees in November.