Pollination Success Research Articles

Effect of gradual pollen presentation on pollination efficiency and reproduction of Vaccinium corymbosum Berkeley in two habitats

IntroductionGradual pollen presentation is a reproductive strategy for plants to improve the efficiency and accuracy of pollen export and acceptance as well as to promote outcrossing. Vaccinium corymbosum Berkeley has a typical mechanism of gradual pollen presentation.MethodsIn this study, we used indoor and outdoor observations to investigate the floral characteristics, pollination characteristics and breeding system of this species in open ground and greenhouse.ResultsThe results showed that the single white, inverted bell-shaped flower of V. corymbosum was able to effectively avoid the negative effects of rainfall, nectar dilution and pollen removal by wind, and improved pollen viability and the duration of stigma receptivity. The setting rate of ‘Northland’ is higher than open ground by artificial pollination in greenhouse, therefore, greenhouses are more suitable for ‘Northland’ reproduction. The gradual pollen presentation prolongs dispersal time, promotes pollinator participation in the pollination process, increases staminate fitness, and provides for nectar feeding by pollinators as well as pollen export. Bombus spp. and A. m. ligustica were effective pollinators in the open ground and greenhouse, and the pollination efficiency of Bombus spp. was higher than that of A. m. ligustica, and greenhouse pollination is more efficient than open ground. The coincidence of the peak period of pollinator visits with the period of highest pollen viability and optimal pollination of stigmas, as well as the high nectar production, could maximize the frequency of pollinator visits and increase the chances of successful pollination as well as the pollination efficiency.DiscussionTherefore, it is important to study the floral characteristics of V. corymbosum Berkeley and the mechanism of gradual pollen presentation in order to improve the pollination efficiency and promote the success of outcrossing, which can provide a theoretical basis for the breeding of V. corymbosum.

The deceptive pollination of Anacamptis morio: generalised food deception or an initial step towards adaptive mimicry?

ABSTRACT Background To attract their pollinators non-rewarding orchids rely on various deception strategies that range from generalised food deception to floral mimicry of a specific model (Batesian mimicry). Aims We evaluated whether the deceptive orchid Anacamptis morio may represent an initial step in the evolutionary trajectory from generalised food deception to Batesian mimicry by resembling the rewarding Polygala nicaeensis, a species with purple flowers very similar to those of A. morio. Methods We assessed the pollination success of A. morio in relation to co-flowering rewarding species. Then, we estimated male and female reproductive success of A. morio depending on the presence of and similarity to the putative model P. nicaeensis. Results The pollination success of A. morio covaried with that of P. nicaeensis and its pollination efficiency was higher when the two species co-occurred. However, we did not find supporting evidence that A. morio mimicked its potential rewarding model. We also found that the orchids with stronger colour reflectance exhibited greater pollination success, according to a scenario of ecological facilitation rather than adaptive mimicry. Conclusion Co-flowering rewarding species with a colour similar to the orchid may enhance the specific pollinator abundance and condition their foraging preference, hence producing a positive effect on the reproductive success of A. morio.

Impact of growing conditions on vegetation, development and reproductive success of <i>Orchis purpurea</i> Huds. in the South-Eastern Crimea

The individual and population parameters of lady orchis — Orchis purpurea Huds. (Orchidaceae) under different growing conditions are compared. The onthogenetic type of cenopopulations, age, efficiency, recovery indices, vitality of individuals, plasticity index are determined. The largest number of plants is noted in forest communities. Demographical and morphological parameters differ nonsignificantly. Slight fluctuations in the vitality of individuals are noted depending on the habitat and the conditions of the growing season. The pollination success of plants in steppe biotopes is much higher than that in forest biotopes: the average fruit set in steppe biotopes was 39.63 %, in forest biotopes — 4.97—5.84 %. However, it did not affect reproductive success, the main indicator of which is the presence of new generations of plants: in all studied cenopopulations, a high proportion of individuals of the pregenerative period was noted. It is established that O. purpurea has a wide ecological amplitude and high adaptability to various conditions. It can grow in different habitats without changing morphological, demographic and ontogenetic parameters.

Impacts of ramet density and herbivory on floral volatile emissions and seed production in Solidago altissima.

Plants produce an array of floral olfactory and visual cues to attract pollinators, including volatile organic compounds (VOC), which mediate plant-pollinator interactions and may be influenced by herbivory and neighboring plants. Consequently, these factors may affect plant fitness by disrupting pollination. However, most evidence comes from controlled experiments, limiting our understanding of how VOCs function in natural populations. This study investigated how herbivory and conspecific ramet density influence floral VOC profile, pollination, and seed production in a naturally occurring population of Solidago altissima. We recorded leaf herbivory and ramet density surrounding one focal ramet in 1-m2 plots. We collected VOCs from the floral headspace and measured ovary fertilization as a proxy for pollination success and the number of seeds produced by the focal ramet. Our findings revealed interactive effects between ramet density and herbivory on floral VOC emission, richness, and diversity. Specifically, at lower ramet densities, herbivory did not affect floral volatile emissions. However, in highly dense stands, herbivory suppressed floral volatile emissions. Despite these changes, floral volatiles did not affect pollination and the number of seeds in S. altissima. Our field-based findings underscore the importance of understanding the complex responses of floral VOCs to environmental stressors and their contributions to plant reproduction within natural communities. Our results suggest that while herbivory and ramet density influence floral scent, these changes do not affect reproduction in our study. Ultimately, generalist-pollinated plants like S. altissima might not rely heavily on chemical signaling during pollination.

Learning to handle flowers increases pollen collection for bees but does not affect pollination success for plants

Abstract Cooperation and conflict are common in plant–pollinator interactions. Flowering plants often entice pollinators to visit by offering floral food rewards, thereby facilitating pollination. However, pollinators such as bees can learn to improve their collection of floral rewards (such as pollen), changing how they interact with the flower’s reproductive organs, which together could reduce pollination success. Consequently, complex flowers that slow pollinator learning might benefit the plant. Yet how pollinator learning and flower complexity interact to affect pollination success is unknown. We therefore asked how differences in complexity of 4 flower types (Phacelia campanularia, Exacum affine, Solanum elaeagnifolium, and Erythranthe guttata) affected learning by pollen-foraging generalist bumble bees (Bombus impatiens) and how learning affected pollen collection and pollen deposition on these flowers. We found that bees generally learned how to efficiently handle more complex flower types more slowly. Bees that required more visits to become efficient foragers collected less pollen, with no effect on pollen deposition. Except for the simplest flower type, learning also involved development of motor routines unique to each flower type. Experienced bees overall collected more pollen, but individual differences in motor routines did not affect pollen collection. Conversely, individual differences in motor routines affected pollen deposition, but there was no overall effect of experience. Thus, even though learning overall benefits the bee, it does not alter female (and potentially male) fitness benefits for the plant. We discuss potential reasons for these patterns and consequences for bee behavior and flower evolution.

Genotypic variation in blueberry flower morphology and nectar reward content affects pollinator attraction in a diverse breeding population

BackgroundPollination is crucial to obtaining optimal blueberry yield and fruit quality. Despite substantial investments in seasonal beekeeping services, blueberry producers consistently report suboptimal pollinator visitation and fruit set in some cultivars. Flower morphology and floral rewards are among the key factors that have shown to contribute to pollinator attraction, however little is known about their relative importance for improving yield in the context of plant breeding. Clarifying the relationships between flower morphology, nectar reward content, pollinator recruitment, and pollination outcomes, as well as their genetic components, can inform breeding priorities for enhancing blueberry production. In the present study, we measured ten flower and nectar traits and indices of successful pollination, including fruit set, seed count, and fruit weight in 38 southern highbush blueberry genotypes. Additionally, we assessed pollinator visitation frequency and foraging behavior over two growing seasons. Several statistical models were tested to optimize the prediction of pollinator visitation and pollination success, including partial least squares, BayesB, ridge-regression, and random forest.ResultsRandom forest models obtained high predictive abilities for pollinator visitation frequency, with values of 0.54, 0.52, and 0.66 for honey bee, bumble bee, and total pollinator visits, respectively. The BayesB model provided the most consistent prediction of fruit set, fruit weight, and seed set, with predictive abilities of 0.07, -0.08, and 0.42, respectively. Variable importance analysis revealed that genotypic differences in nectar volume had the greatest impact on honey bee and bumble bee visitation, although preferences for flower morphological traits varied depending on the foraging task. Flower density was a major driving factor attracting nectar-foraging honey bees and bumble bees, while pollen-foraging bumble bees were most influenced by flower accessibility, specifically corolla length and the length-to-width ratio.ConclusionsHoney bees comprised the majority of pollinator visits, and were primarily influenced by nectar volume and flower density. Corolla length and the length-to-width ratio were also identified as the main predictors of fruit set, fruit weight, seed count, as well as pollen-foraging bumble bee visits, suggesting that these bees and their foraging preferences may play a pivotal role in fruit production. Moderate to high narrow-sense heritability values (ranging from 0.30 to 0.77) were obtained for all floral traits, indicating that selective breeding efforts may enhance cultivar attractiveness to pollinators.

Nocturnal burst emissions of germacrene D from the open disk florets of pyrethrum flowers induce moths to oviposit on a nonhost and improve pollination success.

Recent studies show that nocturnal pollinators may be more important to ecosystem function and food production than is currently appreciated. Here, we describe an agricultural field study of pyrethrum (Tanacetum cinerariifolium) flower pollination. Pyrethrum is genetically self-incompatible and thus is reliant on pollinators for seed set. Our pollinator exclusion experiment showed that nocturnal insects, particularly moths, significantly contribute to seed set and quality. We discovered that the most abundant floral volatile, the sesquiterpene (-)-germacrene D (GD), is key in attracting the noctuid moths Peridroma saucia and Helicoverpa armigera. Germacrene D synthase (GDS) gene expression regulates the specific GD production and accumulation in flowers, which, in contrast to related species, lose the habit of closing at night. We did observe that female moths also oviposited on pyrethrum leaves and flower peduncles, but found that only a small fraction of those eggs hatched. Larvae were severely stunted in development, most likely due to the presence of pyrethrin defense compounds. This example of exploitative mutualism, which blocks the reproductive success of the moth pollinator and depends on nocturnal interactions, is placed into an ecological context to explain why it may have developed.

Abundance and diversity of the culturable nectar mycobiome in Rhododendron catawbiense varies with elevation

Abstract The nectar microbiome can influence pollinator choice and plant fitness. Previous research has shown that changes in environmental conditions at large spatial scales can influence nectar microbiome composition. However, little is known about how changes in climate with increasing elevation affect nectar microbiome abundance and composition. Here we describe the culturable nectar mycobiome of Rhododendron catawbiense (Ericaceae) by quantifying colony abundance, identity, and richness of fungal genera. We further evaluate how the culturable nectar mycobiome (CNMB) abundance, diversity, and composition (i.e., the fungal species within the nectar microbiome) varies at two different elevations. Nectar samples were collected from R. catawbiense individuals at a high and low elevation and were cultured on yeast agar with 0.01% chloramphenicol media. Fungal colonies were categorized morphologically, quantified, and then identified using DNA barcoding. In total, 2,822 fungal colonies were recorded belonging to six genera across both elevations. Elevation did not influence CNMB diversity (Simpson’s diversity index) or genera richness per flower, however only three genera were found at the high elevation while six were found at the low elevation. Elevation had a significant effect on colony abundance with a 95% increase in the number of colonies in nectar samples at low compared to the high elevation. Variation in abundance and overall genera composition of fungal colonies across elevations may have the potential to affect nectar quantity and quality and ultimately pollination success. This study adds to our understanding of the drivers of CNMB composition across spatial scales its potential implications for plant-pollinator interactions.

Successful pollinator seed mixes include low grass density and high forb richness across a range of total seeding densities

Successful pollinator seed mixes include low grass density and high forb richness across a range of total seeding densities

Multi-habitat landscapes are more diverse and stable with improved function

Conservation, restoration and land management are increasingly implemented at landscape scales1,2. However, because species interaction data are typically habitat- and/or guild-specific, exactly how those interactions connect habitats and affect the stability and function of communities at landscape scales remains poorly understood. We combine multi-guild species interaction data (plant–pollinator and three plant–herbivore–parasitoid communities, collected from landscapes with one, two or three habitats), a field experiment and a modelling approach to show that multi-habitat landscapes support higher species and interaction evenness, more complementary species interactions and more consistent robustness to species loss. These emergent network properties drive improved pollination success in landscapes with more habitats and are not explained by simply summing component habitat webs. Linking landscape composition, through community structure, to ecosystem function, highlights mechanisms by which several contiguous habitats can support landscape-scale ecosystem services.

Synergistic actions of three MYB transcription factors underpin blotch formation in tree peony.

Blotches in floral organs attract pollinators and promote pollination success. Tree peony (Paeonia suffruticosa Andr.) is an internationally renowned cut flower with extremely high ornamental and economic value. Blotch formation on P. suffruticosa petals is predominantly attributed to anthocyanin accumulation. However, the endogenous regulation of blotch formation in P. suffruticosa remains elusive. Here, we identified the regulatory modules governing anthocyanin-mediated blotch formation in P. suffruticosa petals, which involves the transcription factors PsMYB308, PsMYBPA2, and PsMYB21. PsMYBPA2 activated PsF3H expression to provide sufficient precursor substrate for anthocyanin biosynthesis. PsMYB21 activated both PsF3H and PsFLS expression and promoted flavonol biosynthesis. The significantly high expression of PsMYB21 in non-blotch regions inhibited blotch formation by competing for anthocyanin biosynthesis substrates, while conversely, its low expression in the blotch region promoted blotch formation. PsMYB308 inhibited PsDFR and PsMYBPA2 expression to directly prevent anthocyanin-mediated blotch formation. Notably, a smaller blotch area, decreased anthocyanin content, and inhibition of anthocyanin structural gene expression were observed in PsMYBPA2-silenced petals, while the opposite phenotypes were observed in PsMYB308-silenced and PsMYB21-silenced petals. Additionally, PsMYBPA2 and PsMYB308 interacted with PsbHLH1-3, and their regulatory intensity on target genes was synergistically regulated by the PsMYBPA2-PsbHLH1-3 and PsMYB308-PsbHLH1-3 complexes. PsMYB308 also competitively bound to PsbHLH1-3 with PsMYBPA2 to fine-tune the regulatory network to prevent overaccumulation of anthocyanin in blotch regions. Overall, our study uncovers a complex R2R3-MYB transcriptional regulatory network that governs anthocyanin-mediated blotch formation in P. suffruticosa petals, providing insights into the molecular mechanisms underlying blotch formation in P. suffruticosa.

Negative and sex-specific effects of drought on flower production, resources and pollinator visitation, but not on floral scent in monoecious Cucurbita pepo.

The globally changing climatic condition is increasing the incidences of drought in several parts of the world. This is predicted and already shown to not only impact plant growth and flower development, but also plant-pollinator interactions and the pollination success of entomophilous plants. However, there is a large gap in our understanding of how drought affects the different flowers and pollen transfer among flowers in sexually polymorphic species. Here, we evaluated in monoecious Styrian oil pumpkin, and separately for female and male flowers, the responses of drought stress on flower production, petal size, nectar, floral scent and visitation by bumblebee pollinators. Drought stress adversely affected all floral traits studied, except floral scent. Although both flower sexes were adversely affected by drought stress, the effects were more severe on female flowers, with most of the female flowers even aborted before opening. The drought had negative effects on floral visitation by the pollinators, which generally preferred female flowers. Overall, our study highlights that the two flower sexes of a monoecious plant species are differently affected by drought stress and calls for further investigations to better understand the cues used by the pollinators to discriminate against male flowers and against flowers of drought-stressed plants.

What's that smell? The putrid scent of Rafflesia consueloae, its origin and developmental regulation

We report the floral scent composition of the endophytic holoparasite Rafflesia consueloae for the first time. Using a non-destructive in situ method that we developed, we identified 13 volatile compounds present in the scent of R. consuelaoe. Among the compounds detected were several benzenoids, organosilicons, an oligosulfide, a monoterpenoid, and a fatty acid-derived compound. Comparing the scent profiles of different reproductive stages, we found that all stages produced a similar set of volatiles, except for the flowers in bloom. The sulfur-containing dimethyl disulfide (DMDS), which is mainly responsible for the rotten smell of the flower, was only detected in the scent of full-bloom flowers indicating that its synthesis only takes place when the aperture is fully open and the flies are able to access the sex organs. Moreover, an analysis of the scent components of different floral parts from full-bloom flowers revealed that the different floral structures had varying scent profiles. The diaphragm and chamber floor produced the most volatiles. Notably, DMDS was only detected from the diaphragm and the central disk. Emission of putrid-smelling volatiles in these tissues may lure the flies into entering the floral chamber where the reproductive structures are located, thus increasing pollination success. Overall, this pioneering study of the R. consueloae floral scent composition provides valuable insights into the pollination mechanisms of the enigmatic Rafflesia genus and parasitic floral ecology in general.

Attractiveness of Tetragonula laeviceps (Hymenoptera: Apidae) to Citrus Volatile Compounds and Flower Colors in Indoor Microclimate Conditions

Tetragonula laeviceps plays a vital role as a primary pollinator of citrus flowers for successful pollination. However, there is still a lack of understanding about how T. laeviceps can find citrus flowers. This study aimed to elucidate the factors influencing the attraction of T. laeviceps to citrus flowers, focusing on microclimate conditions, and visual and olfactory factors. For this, we conducted six-choice assays in a stingless bee house using artificial flowers as visual cues and citrus essential oils as olfactory stimuli. Three pairs of red or white artificial flowers were displayed to adult workers, with each pair placed in glass vials filled with diluted orange (Citrus reticulata) essential oil, lemon (Citrus limon) essential oil, or solvent. Simultaneously, microclimate conditions were measured, including temperature, relative humidity, and light intensity. We observed that the highest number of T. laeviceps visited the artificial flowers at 11:00, irrespective of visual and olfactory factors. We also found a positive correlation between the number of visits and both temperature and light intensity, whereas there was a negative correlation with humidity. The number of visits did not exhibit a significant difference between flower colors. In contrast, we observed the highest visitation to the orange essential oil, followed by the lemon essential oil and solvent. Gas Chromatograph – Mass Spectrometry (GC-MS) analysis revealed common terpenes in orange and lemon essential oils, while linalool and α-citral were predominantly detected in the orange essential oil. These characteristic terpenes could potentially be the attractants for T. laeviceps.

Семенная продуктивность и качество семян Pinus sylvestris L. в лесных культурах на крымских яйлах

The seed production and quality of Pinus sylvestris seeds in forest plantations on the Crimean yaylas has been studied. The dynamics of biometric indicators of cones and seeds by year and in connection with the peculiarities of growing conditions has been characterized. Significant differences in the quality of seeds of P. sylvestris trees have been revealed in terms of the level of germination energy. It has been shown that, along with the temperature regime, a significant impact on the effectiveness of P. sylvestris reproduction processes is exerted by air humidity and the nature of precipitation, as well as the dynamics of air mass movement, since the success of pollination is determined by the quantity and quality of pollen that has reached the female reproductive structures. Based on the analysis of weather phenomena and the dynamics of seed quality, it has been found that the level of seed germination is best reflected by an integrated index that takes into account the combined effect of several factors – the dryness index. In addition, the results of the analysis allowed us to conclude that the efficiency of the pollination process of female cones of P. sylvestris under yayla conditions is most likely influenced by the number of hours of sunshine. The germination energy and seed germination differ not only within the studied plantations, but also depending on the year of study. During the observation period, the forest plantations of the Ai-Petrinskaya Yayla have produced the highest quality seeds. In 2014, in the plantations with a density of 0.5, the seed germination rate was 74.5±2.2 %. The lowest level of germination energy and seed germination has been noted in artificial plantations of P. sylvestris on the Tirke Yayla; in 2012, these indicators here amounted to 15.2±0.7 and 46.2±2.1 %, respectively. In general, the development of the generative sphere of P. sylvestris in artificial plantations on the Crimean yaylas is quite effective. Based on this, a conclusion has been made that the growing conditions on the yaylas are favourable for the implementation of the initial stages of the ontogenesis of the species.

The timing of visits by large and small bees differentially affects pollination success in Mimulus ringens.

Cross-fertilization in most flowering plants is facilitated by mobile animals that transport pollen while foraging for floral rewards. The contributions of different visitors can vary widely, depending on the amount of pollen transferred during a single visit and on the frequency and timing of the visits of each pollinator taxon. We used three approaches to measure the pollination value of bees that visit Mimulus ringens: pollinator interviews, field population observations, and caging studies. The single-visit effectiveness of small bees (primarily Halictidae) was only half that of larger bees (primarily Bombus) for pollen delivery and removal. In five field populations, we found substantial temporal and spatial variation in visitation and pollination. In most sites big bees were active before 08:00 hours, and by 10:00-11:00 hours, stigmas were usually fully pollinated and closed, and little pollen remained in anthers. Small bees seldom visited before 10:00 hours. Excluding big bees from plants confirmed that pollination is reduced and delayed in this ecological context. Big bees are the primary pollinators of M. ringens, accounting for at least 75% of seed production. Not only are they more effective per visit, in most situations they also visit before small bees become active. Although small bees are not usually important pollinators of M. ringens, they have the potential to partially replace them as a "fail-safe" pollinator in contexts where big bees are not abundant. In a world where pollinator abundance is declining, such backup pollinators may be important for maintaining plant reproduction.

Temporal and spatial variation in the direct and indirect effects of climate on reproduction in alpine populations of Ranunculus acris L

AbstractPlant reproduction in alpine environments is affected by climate both directly through climate impacts on growth and phenology, and indirectly through impacts on the biotic interactions affecting pollination success. These effects can be highly variable in time and space. In this study we investigated how different abiotic and biotic factors influence reproductive investment and success in populations of Ranunculus acris across an alpine landscape over a two-year period. In an alpine area at Finse, southern Norway, we measured reproductive investment (total seed mass) and reproductive success (seed-set rate) in 38 sites differing in temperature (related to elevation) and length of the growing season (related to time of snowmelt). To assess biotic interactions, we measured floral density and pollinator visits and conducted a supplemental pollen experiment. Reproductive investment and success increased with temperature, but only when floral density and/or number of pollinator visits was high, and only in the warmer year (2016). Reproduction in R. acris was pollen-limited in both years, especially at warmer temperature and in sites with early snowmelt. Pollinator visits increased with temperature and with higher floral density, suggesting a shift in relative importance of the biotic factors (from plants to pollinators) in limiting reproduction with increasing temperature. Our study shows that reproductive investment and success in R. acris is affected by climate through the interactive effects of abiotic and biotic processes. These effects vary between years and across the landscape, suggesting a potential for larger-scale buffering of climate change effects in heterogeneous landscapes.

Crops dependency on pollinators to secure pollination success and fruit development: A case study of almond varieties from Morocco

AbstractThe contribution of insects to pollination constitutes a globally important ecosystem service. Due to the increasing demand for entomophilous crops, the nutritional and economic importance of insect‐pollinated crops and the inability of managed pollinators (Apis mellifera L) to meet the high demand for their services indicate that agriculture heavily relies on wild pollinators. Almonds are an economically valuable crop in Morocco. Therefore, it is essential to understand the fundamental pollination requirements of major almond varieties to promote their production. The main objectives of this study were to assess the dependency of three almond cultivars (Espoir, Largueta and Planeta) on insect pollination, and then to evaluate the pollination deficit resulting from the lack of these pollinators. For this purpose, we used insect‐proof net bags constructed around branches of almond trees to compare fruit set and yield with open and open + hand‐pollinated flowers. The results of the fruit set experiment confirmed that all three varieties require insect pollination, as fruit set and yield were significantly higher in insect‐pollinated than insect‐isolated trees. All three almond varieties were categorized as obligatory dependent on biotic pollinators. In addition, two out of the three studied almond varieties showed high pollination deficit resulting from the lower abundance and/or diversity of pollinating insects. The results of the current study highlights the important role of insect pollinators for almond crops and the urgent need for the implementation of sustainable strategies to preserve pollinators within agricultural ecosystems.

Effects of climate change on plant-pollinator interactions and its multitrophic consequences

AbstractThere is wide consensus that climate change will seriously impact flowering plants and their pollinators. Shifts in flowering phenology and insect emergence as well as changes in the functional traits involved can cause alterations in plant-pollinator interactions, pollination success and plant reproductive output. Effects of rising temperatures, advanced snowmelt and altered precipitation patterns are expected to be particularly severe in alpine habitats due to the constrained season and upper range margins. Yet, our understanding of the magnitude and consequences of such changes in life history events and functional diversity in high elevation environments is incomplete.This special issue collects novel insights into the effects of climate change on plant-pollinator interactions in individual plant species and on network structure of entire plant and pollinator communities in alpine ecosystems. Using simulated changes of earlier snowmelt, natural gradients of variation in temperature, precipitation and snowmelt, or a long-term monitoring approach, these studies illustrate how plant species, plant communities, and pollinators respond to variation in environmental conditions associated with scenarios of ongoing climate change.The collection of papers presented here clearly demonstrates how spatial or temporal variation in the environmental climatic context affects flower abundances and plant community composition, and the consequences of these changes for pollinator visitation, pollination network structure, pollen transfer dynamics, or seed production. As changes in the availability of flowers, fruits, and seeds are likely to impact on other trophic levels, the time is ripe and pressing for a holistic multitrophic view of the effects of climate change on biotic interactions in alpine ecological communities.

PENGARUH WAKTU PENYERBUKAN TERHADAP KUALITAS HASIL TANAMAN MELON (Cucumis melo L) DENGAN PERKAWINAN SILANG TANAMAN SEMANGKA (Citrullus vulgaris L)

Decreased production of melon (Cucumis melo L) which is due to constraints in fruit quality decreases due to the ability of fruit formation is naturally low due to a failure in the process of pollination. The success of pollination it self is influenced by the maturity of the male flowers and female flowers itself. Therefore we need a suitable time to perform pollination to see the stigma receptivity and pollen viability at the same level. To overcome these problems need to develop crops melon (Cucumis melo L) through the technique of cultivation is called plant breeding to obtain the production of melon (Cucumis melo L) qualified by determining the time of pollination and crossed with a watermelon (Citrullus vulgaris L). This research is experimental research design using a randomized block design (RAK) 1 factor with 5 treatment combinations and each treatment using 10 replications. The treatment factors are as follows: PA = at 05:00 to 06:00, PB = at 07:00 to 08:00, PC = at 09:00 to 10:00, PD = at 11 : 00 to 12:00 and PE = at 13:00 to 14:00. The data were collected and presented in tables and statistical analysis of test One-Way ANOVA (Analysis Of Variance). If there is a real difference followed by testing of LSD (Least Significant Difference) (p <0.05). Statistical analysis One-Way ANOVA test and LSD show that there is the influence of pollination time on the fruit weight, average fruit diameter and weight of seed resulting from cross-breeding melon (Cucumis melo L) and watermelon (Citrullus vulgaris L). Data show that the PA treatment is the best treatment compared with other treatments. This happens Because the quality of pollen in the morning are of better quality compared to during the day so that pollen powderd in the morning better able to fertilize the pistil to the maximum.