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In ecological speciation, incipient species diverge due to natural selection that is ecologically based. In flowering plants, different pollinators could mediate that selection (pollinator-mediated divergent selection) or other features of the environment that differ between habitats of 2 species could do so (environment-mediated divergent selection). Although these mechanisms are well understood, they have received little rigorous testing, as few studies of divergent selection across sites of closely related species include both floral traits that influence pollination and vegetative traits that influence survival. This study employed common gardens in sites of the 2 parental species and a hybrid site, each containing advanced generation hybrids along with the parental species, to test these forms of ecological speciation in plants of the genus Ipomopsis. A total of 3 vegetative traits (specific leaf area, leaf trichomes, and photosynthetic water-use efficiency) and 5 floral traits (corolla length and width, anther insertion, petal color, and nectar production) were analyzed for impacts on fitness components (survival to flowering and seeds per flower, respectively). These traits exhibited strong clines across the elevational gradient in the hybrid zone, with narrower clines in theory reflecting stronger selection or higher genetic variance. Plants with long corollas and inserted anthers had higher seeds per flower at the Ipomopsis tenuituba site, whereas selection favored the reverse condition at the Ipomopsis aggregata site, a signature of divergent selection. In contrast, no divergent selection due to variation in survival was detected on any vegetative trait. Selection within the hybrid zone most closely resembled selection within the I. aggregata site. Across traits, the strength of divergent selection was not significantly correlated with width of the cline, which was better predicted by evolvability (standardized genetic variance). These results support the role of pollinator-mediated divergent selection in ecological speciation and illustrate the importance of genetic variance in determining divergence across hybrid zones.

Societal Impact Statement: The family Orchidaceae is renowned for its reliance on specialized pollinators and mycorrhizal symbioses. This study examined how the nonphotosynthetic orchid Gastrodia elata thrives on the dim forest floor, focusing on its pollination biology, particularly the chemical properties of pseudopollen and reproductive assurance mechanisms. It was found that G. elata mainly relies on Lasioglossum bees, attracted by its starch‐rich pseudopollen. Additionally, G. elata in the studied population can produce fruit through agamospermy (seeds from unfertilized ovules). Overall, the findings reveal that G. elata relies on fungi for nutrition and employs reproductive strategies such as mimicking pollen to attract bees and resorting to asexual reproduction when pollinators are scarce. Summary: Mycoheterotrophy is an adaptation that allows survival in environments with low irradiance and minimal competition from autotrophic plants. However, such environments can negatively impact bee pollination, as most bees prefer open habitats. Despite this, the mycoheterotrophic orchid Gastrodia elata is known to rely on Lasioglossum bees for pollination.We investigated the reproductive biology of G. elata to understand how it overcomes pollinator limitation. Our research focused on the chemical composition and anatomical basis of G. elata pseudopollen (a substance that mimics pollen and may facilitate pollination), based on micromorphological and nutritional analyses, as well as observations of pollinator behavior. Additionally, we explored the potential presence of autogamy or agamospermy as mechanisms for reproductive assurance.The pseudopollen in G. elata originates from the disintegration of the adaxial parenchymatous tissue of the callus and is rich in starch. This contrasts with pseudopollen in most orchids, which typically originates from lip hairs and whose potential attractant is protein. Lasioglossum bees pollinating G. elata visit multiple flowers and actively collect pseudopollen. Furthermore, agamospermy serves as a reproductive safeguard in shaded habitats where insect‐mediated pollination is infrequent, at least in the investigated population.Our findings suggest that Gastrodia elata pseudopollen plays an important role in enhancing insect‐mediated pollination, particularly in relatively open habitats, while agamospermy ensures fruit set in shaded environments of the investigated population. Both pseudopollen production and agamospermy likely help overcome the pollination constraints posed by the mycoheterotrophic lifestyle. [ABSTRACT FROM AUTHOR]

Pollen morphology and the reproductive biology of Calophyllum brasiliense were investigated in Parque Estadual das Fontes do Ipiranga, São Paulo, Brazil. The study encompassed pollen analyses using light, scanning, and transmission electron microscopy. Additionally, we collected data on reproductive biology, main visitors/pollinators, fruit set, and seed germination. The species exhibits individuals with perfect flowers (hermaphrodites) as well as male individuals with staminate and perfect flowers. Flowering occurs in October and November, and flowers have diurnal anthesis and pollen as a floral resource. Pollen grains are monads of medium size, isopolar, oblate-spheroidal to prolate-spheroidal, 3-(4)-zonocolporate, with exine fossulate-perforate with supratectal microechini. Hermaphrodite individuals have the highest proportion of malformed pollen due to their reduced grain size. The pollen grains from the hermaphrodite individuals displayed a low viability (0.06%), while those from male individuals had higher viability (66.38% and 55.78% for perfect and staminate flowers, respectively). The stigma was receptive throughout the anthesis period. Cross-pollination between perfect flowers of male and hermaphrodite individuals resulted in 8.80% success in fruit set, but led to the development of one abnormal seedling. Cross-pollination between staminate flowers and perfect flowers of hermaphrodite individuals showed a 7.70% success rate and the control group showed an 8.00% success rate, both groups leading to the development of normal seedlings. This tree species shows relatively low reproductive success and relies on pollinators (mainly Apis mellifera, Paratrigona subnuda, Tetragonisca angustula, and Halictidae sp. 1) for the setting of fruits and seeds. [ABSTRACT FROM AUTHOR]

The flowers of selected Camellia yuhsienensis Hu specimens were studied at different stages of flowering to determine the volatile components of floral fragrance and how their concentrations changed during efflorescence. The mechanism of fragrance formation and release was also studied in order to provide a theoretical basis for the practical use of C. yuhsienensis Hu flowers. Headspace solid‐phase microextraction (HS‐SPME) was used to extract the natural floral volatile oils of C. yuhsienensis Hu at the different stages, and the floral fragrance components were analysed by gas chromatography–mass spectrometry (GC–MS). A total of 31, 59 and 55 compounds were detected at the budding, early‐blooming and full‐blooming stages respectively. These floral fragrance components included terpene alcohols, as well as other aromatic and aliphatic compounds, and the relative concentrations of the various compounds at different stages of flowering, were different, and those of fatty alcohols and terpene alcohols having higher relative contents at all stages. The main component at the budding stage of C. yuhsienensis Hu was ocimene, which has a grassy fragrance, accompanied by the scent of neroli oil, which gives it a refreshing, gentle and sweet, and explains why the floral fragrance of C. yuhsienensis Hu at the budding stage is extremely thin: the main component during the early‐blooming stage was 3‐carene. A higher percentage of 3‐carene increased the sweetness of the scent, manifesting the typical fragrant characteristics of C. yuhsienensis Hu. The main identified compound at the full‐blooming stage was α‐farnesene, which has a delicate fragrance, accompanied by a balsamic aroma, similar to the scent of gardenia, which is consistent with the sensory characteristics of C. yuhsienensis Hu. [ABSTRACT FROM AUTHOR]

Worldwide, both cultivated and wild plants are pollinated by the honey bee, Apis mellifera. Bee numbers are declining as a result of a variety of factors, including increased pesticide use. Cyflumetofen controls pest mites in some plantations pollinated by bees, which may be contaminated with residual sublethal concentrations of this pesticide, in nectar and pollen. We evaluated the effects of a sublethal concentration of a cyflumetofen formulation on the midgut, hypopharyngeal gland, and fat body of A. mellifera workers orally exposed for 72 h or 10 days. The midgut epithelium of treated bees presented digestive cells with cytoplasm vacuoles and some cell fragmentation, indicating autophagy and cell death. After being exposed to the cyflumetofen formulation for 72 h, the midgut showed a higher injury rate than the control bees, but after 10 days, the organs had recovered. In the hypopharyngeal gland of treated bees, the end apparatus was filled with secretion, suggesting that the acaricide interferes with the secretory regulation of this gland. Histochemical tests revealed differences in the treated bees in both exposure periods in the midgut and hypopharyngeal glands. The acaricide caused cytotoxic effects on the midgut digestive cells, with apical protrusions, plasma membrane rupture, and several vacuoles in the cytoplasm, features of cell degeneration. In the hypopharyngeal glands of the treated bees, the secretory cells presented small electron‐dense and large electron‐lucent secretory granules. The fat body cells had no changes in comparison with the control bees. In conclusion, the cyflumetofen formulation at sublethal concentrations causes damage to the midgut and the hypopharyngeal glands of honey bee, which may compromise the functions of these organs and colony fitness. Environ Toxicol Chem 2024;43:2455–2465. © 2024 SETAC [ABSTRACT FROM AUTHOR]

Mauritius raspberry (Rubus rosifolius) is an exotic plant cultivated in Indonesia. Studies showed that the productivity of exotic plants is reducing due to a lack of pollination agent for their origin region. Several methods could be applied to overcome this problem. The study aimed to find the most effective method for pollinating this plant among four pollination regimes: Self-pollination, wild insects, stingless bees (Tetragonula laeviceps), and hand-pollination. The observation was conducted on the insect pollinators' activities (visitation rate, flower constancy, and flower handling time), pollination efficiency, and quality of the fruits produced (fruit volume). The results showed a higher visitation rate (10 to 70 per hour), higher flower constancy (visited from 07.00 to 16.00), and longer flower handling time (13.6 s) of T. laeviceps on raspberry flowers than other insects. High activities related to better raspberry pollination success (96%) and bigger fruits produced. Based on this study, applying stingless bees as pollination agents for exotic plants was the best and potentially applicable to other exotic crops. [ABSTRACT FROM AUTHOR]

Sunflower, Helianthus annuus, is one of the major cash crops in Tanzania. Despite the importance of the crop, its productivity is still low. In that respect, farmers have been experiencing poor seed-set in sunflowers leading to recorded lower yields. The introduction of honey bees, Apis mellifera, in sunflower production has for a long time been considered an effective strategy for improving sunflower productivity; however, studies on the potential of this phenomenon particularly in Tanzania have been limited. We conducted experiments between July and December 2019 in Mtwara Tanzania, to investigate the potential of honey bees in improving sunflower production. Findings revealed that the weight of sunflower seeds per head in the plots colonized with honey bees was 32.15 g, accounting for three and half times higher than the case without any pollinators (9.41 g). We recorded a significantly (Kruskal-Wallis Test H = 25.81, χ2 prob = p < 0.001) higher 1000-sunflower seed weight of 53.68 g for plots with honey bees vis-a-vis plots with other pollination treatments (wild pollinators = 42.07 g, without pollinators 29.51 g). The percentage of chaffiness was lower in the plots with managed honey bees and wild pollination, accounting for a reduction of 28.25% (for managed honey bees only) and 16.68% (for wild pollination) as compared to plots without pollinators. Therefore, the study results revealed that pollination services from managed honey bees are the appropriate strategies that can contribute to the improvement of sunflower productivity. Further studies based on different agroecological conditions are recommended. [ABSTRACT FROM AUTHOR]

The stingless bee, Tetragonisca angustula, known in most regions of Brazil as Jataí, is characterized as an advanced eusocial bee with a wide distribution throughout the country. This species has an ecologically and economically important role in pollination and honey production. In terms of phylogeny, it belongs to the Meliponini tribe within the corbiculate group of bees. The corbicula is a modification on the third pair of the worker bee's legs, with a concave shape that enables the bees to store and transport pollen. The corbicular area in Apis mellifera is described as having a correlation with overall honey yield. Our aim, in this study, was to unravel the heritability traits and possible correlations related to colony health and honey production. We measured the corbicular area and body weight of 600 individuals of T. angustula from different hives and applied a Bayesian approach to estimate the genetic variance and heritability. In addition, we investigated whether or not other morphometric traits were correlated with the corbicular area. Heritability estimates were 0.56 and 0.39 for corbicular area and weight, respectively. The phenotypic correlations demonstrated a strong relationship between the corbicular area and weight, thorax and abdomen length, and also abdomen and head width. These phenotypic correlations were greater than 0.50, suggesting that the corbicular area could be a proxy trait that related to other morphometric traits such as weight. Traits like honey production and pot size should be included in further studies, unraveling the actual relation between the corbicular area and direct honey yields. [ABSTRACT FROM AUTHOR]

DNA analysis of the faeces of wild animals is a major step towards our understanding of the dietary requirements of cryptic and sometimes threatened species. The presence of digested and liquefied matter undetectable to the naked eye can be identified and used to detect the presence of plant resources. Validating the consumption of plant material is tricky and often controversial, as it may have been taken unintentionally while hunting prey. Here, we present the very first dietary DNA metabarcoding analysis of the gecko Euleptes europaea. We identified one class and three orders of Arthropoda, and two classes of plants. To validate the results of plant presence, we set up a novel feeding selectivity protocol, followed by video surveillance in the wild. We offered four plant resources, two of which were close relatives to the found metabacoded taxa. While a food selectivity protocol combined with DNA analysis validated the consumption of plant resources, they showed that these geckos had a preference for plant pollen but refused other sweet resources. These results raise the possibility of a pollinating role of this gecko, which can sometimes be the only vertebrate to inhabiting the smallest islets in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Pollinator‐mediated reproductive interactions among co‐flowering plant species provide a canonical example of how biotic factors may contribute to species coexistence, yet we lack understanding of the exact mechanisms. Flowering‐dominant and unusually attractive “magnet species” with disproportionate contributions to pollination may play key roles in such reproductive interactions, but their relative roles within the same community have rarely been assessed. We experimentally removed either a flowering‐dominant or a highly attractive magnet species and compared effects on visitation frequency, pollinator richness, and seed set of co‐flowering plants. Removal of either the flowering‐dominant species or the magnet species reduced community‐level pollinator visitation. Removal of the magnet species had the most consistent effect, including reduced pollinator visitation and richness, and reduced seed set of most co‐flowering plants. These results suggest that the magnet species, which interacts with a wider range of pollinator species than does the dominant species, promotes the visitation and reproductive fitness of most other species. Removal of the flowering‐dominant species affected only certain species, perhaps because these plants had floral traits similar to the dominant species. Our results highlight the role of attractive magnet species within a community in structuring reproductive interactions and identify potential mechanisms involved in coexistence facilitated by reproductive interactions. [ABSTRACT FROM AUTHOR]

We investigated the flower visitors and floral traits of two dioecious shrub species Eurya japonica Thunb. (Pentaphylacaceae) and Eurya emarginata (Thunb.) Makino in temperate Kochi and subtropical Okinawa in Japan during the cool seasons. We demonstrated that the two Eurya species could be pollinated by a wide spectrum of flower visitors—mainly Diptera. The main pollinators were probably Chironomidae and Empididae for E. japonica in Kochi and Calliphoridae and Syrphidae for the remaining species–site combinations (i.e., E. emarginata in Kochi, E. japonica in Okinawa, and E. emarginata in Okinawa). We demonstrated that several dominant families of Dipteran visitors have the ability to pollinate the two Eurya species. Interestingly, floral traits (corolla diameter and nectar concentration) could not explain the difference in the assemblages. These results indicate that floral traits are not specifically adapted to their local pollinators. The fruit set rate was significantly lower for naturally pollinated flowers than for hand‐pollinated flowers, indicating pollen limitation in both Eurya species. However, there was no apparent difference in the number of seeds per fruit between naturally pollinated and hand‐pollinated flowers. [ABSTRACT FROM AUTHOR]

Premise Methods Results Conclusions Volatile emissions from flowers and fruits play a key role in signalling to animals responsible for pollination and seed dispersal. Here, we investigated the pollination biology and chemical ecology of reproduction in Apodolirion buchananii, an African amaryllid that flowers in a leafless state soon after grassland vegetation is burnt in the dry late‐winter season.Pollinators were identified through field collection and pollen loads were quantified. Floral traits including spectral reflectance and scent chemistry were documented. Bioassays using cup traps were used to test the function of floral volatiles. Fruiting biology was investigated using controlled hand‐pollination experiments and chemical analysis of fruit scent. Seed germination was scored in greenhouse trials. Seed dispersal was monitored using observations and camera trapping.The sweetly scented white flowers of A. buchananii are pollen‐rewarding and pollinated mainly by a diverse assemblage of bees. Cup‐trap experiments demonstrated that pollinators are attracted to phenylacetaldehyde, the dominant volatile in the floral scent. Plants are shown to be self‐incompatible, and the fleshy fruits were found to emerge from the soil six months after pollination during the peak of the summer rains. Fruits emit a diverse blend of aliphatic and aromatic esters and contain large fleshy recalcitrant seeds which germinate within days of fruits splitting open. Seed dispersal by ants was recorded.This first account of the reproductive biology of a species in the genus Apodolirion highlights an outcrossing mating system involving bees attracted to color and scent as well as the unusual fruiting biology and ant‐mediated system of seed dispersal. [ABSTRACT FROM AUTHOR]

Introduction: Sampling for describing plant-pollinator interaction networks has been performed using techniques that either focus on the plants (with flowervisit data) or the animals (with analyzing pollen on the body surface of flower visitors). The differences in the structure of the networks obtained using these methods likely influences our understanding of the contribution of nocturnal pollinators, yet this key finding has yet to be the focus of study. Methods: In this study, we conducted an intensive diurnal field survey in the subalpine meadows of the Dajiuhu Wetland and supplemented the data with an analysis of diurnal and nocturnal pollen data to examine the changes in pollination networks. Results: We observed 41 plant and 154 pollinator species, corresponding to 665 specific interactions. Visitation and pollen analyses showed significant differences in the composition and interaction between network plants and pollinators, resulting in important structural changes in the network. Given that the diurnal pollen data showed new links that were preferentially attached to highly connected nodes, the level of asymmetric specialization did not decrease; however, nestedness increased 1.3-fold, and mean pollinator connectivity from 3.1 to 5.1. As the behaviors of nocturnal pollinators tended to be more specialized, the inclusion of nocturnal pollen data led to an increase in the number of extreme-specialist pollinator species. Consequently, nestedness decreased 0.8-fold, but mean plant connectivity went from 14.2 to 16.2. Discussion: These findings suggest that the structure of pollination networks is influenced by the sampling methods and the level of detail of the investigation. Our study has strong implications for the development of monitoring schemes for plant-pollinator interactions. Due to the practical difficulties of nocturnal field visitation, when conducting research, combining diurnal field visitation with both diurnal and nocturnal pollen analyses is the most convenient and realistic method to capture the full complexity of these networks. [ABSTRACT FROM AUTHOR]

A study on the pollination of Ophrys fuciflora (Orchidaceae), which is not a native orchid of Japan, was carried out in a botanical garden in Japan, where the flowers attracted the solitary bee, Eucera nipponensis. Six male bees were observed visiting the flowers over a period of 8 h. The pollinia of O. fuciflora became attached to these bees and four were successfully transferred to the stigmas of nearby flowers. The present study verifies that a species of Ophrys can attract pollinators in Japan, which is at least 8,700 km far from their natural habitat. Thus, it is likely that species of Ophrys could potentially extend their distribution by forming new alliances with other species of bees. [ABSTRACT FROM AUTHOR]

Pollination stands out as the paramount ecosystem service facilitated by insect pollinators, providing benefits to over three quarters of the world’s major crops. The conservation and effective management of honeybees constitute integral components for ensuring the sustainable productivity of cross-pollinated crops. The present study aimed to document the potential pollinators of lucerne in the Bundelkhand region in India, which is known for its subtropical climatic conditions. Further, the foraging behaviour, including foraging rate and speed, was meticulously documented. A total of 13 insect species from seven families across three insect orders were observed visiting lucerne flowers. Hymenopterans comprised the majority of the floral visitors (73.48%), followed by Lepidoptera (26.51%) during the study period. Among them, Apis dorsata (Hymenoptera: Apidae) emerged as the most predominant floral visitor, exhibiting peak activity at 12:00 h with a density of 7.85 bees/m2/10 min. Surprisingly, among the major floral visitors, A. florea has the highest mean foraging rate (number of flowers visited/minute/forager), i.e., 11.56, 11.59 and 10.79 bees/flowers/minute during the initial flowering stage, peak flowering stage and late flowering stage, respectively. However, the foraging speed (time spent by the forager on each flower) was longest in A. dorsata, i.e., 5.05, 3.78 and 5.41 s/flower during initial, peak and late flowering stages, respectively. The findings emphasize the importance of enhancing honeybee activity to boost lucerne seed yield. Further, the outcomes of the study can be leveraged to optimize honeybee colony management, scheduling field operations such as pesticide application and weeding during periods of minimal honeybee activity. [ABSTRACT FROM AUTHOR]

Summary Hybridization is increasingly recognized as an important evolutionary process across the tree of life. In many clades, phylogenomic approaches have permitted unparalleled insight into the extent and frequency of hybridization. However, we continue to lack a deep understanding of the factors that limit and shape patterns of hybridization, especially in evolutionary radiations. In this study, we characterized patterns of introgression across Costus (Costaceae), a young evolutionary radiation of tropical understory plants that maintain widespread interfertility despite exhibiting strong prezygotic reproductive isolation. We analyzed a phylogenomic dataset of 756 genes from 54 Costus species using multiple complementary approaches – D‐statistics, gene‐tree‐based tests, and phylogenetic network analyses – to detect and characterize introgression events throughout the evolutionary history of the radiation. Our results identified a moderate number of introgression events, including a particularly ancient, well‐supported event spanning one of the deepest divergences in the clade. Most introgression events occurred between taxa or ancestral lineages that shared the same pollination syndrome (bee‐pollinated or hummingbird‐pollinated). These findings suggest that prezygotic barriers, including pollinator specialization, have been key to the balance between introgression and reproductive isolation in Costus. [ABSTRACT FROM AUTHOR]

BackgroundAimsMethodsResultsConclusionTo 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).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.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.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.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. [ABSTRACT FROM AUTHOR]

All 32 Brazilian species of Parodia Speg (Cactaceae) occurring in Rio Grande do Sul State are considered threatened, according to the IUCN criteria. Until 2021, Parodia rechensis (CR) was known by only two small populations. However, a new population with over 400 individuals was discovered in 2021, prompting the study of its reproductive biology as a way to promote its conservation. Anthesis, breeding system, and natural pollination were studied in the field. The breeding system was studied by applying controlled pollination treatments to plants excluded from pollinators (bagged). Germination features were studied at the Seed Bank of the Porto Alegre Botanical Garden under controlled temperatures (20, 25, and 30 °C). The anthesis is diurnal and lasts for up to four days. The flowers offer pollen as the sole resource to the pollinators. The study species is unable to set fruit and seed without the agency of pollinators and has self-incompatible (unable to set fruit and seeds when pollinated with pollen of the same individual) characteristics that can considerably restrict its reproduction. Native bees of Halictidae and Apidae (Hymenoptera) are the main pollinators, with a smaller contribution of Melyridae (Coleoptera) and Syrphidae (Diptera). Natural fruit set is moderate (≤64%, per individual), but the species presents vegetative growth, producing several branches from the mother plant. Seeds showed the optimum germination rate at 20 °C and an inhibition of 75% in germinability at 30 °C. Our findings suggest the need to manage the species' habitat to guarantee the permanency of the plants and healthy populations of pollinators as well. Our findings raise concerns about the germination and establishment of new individuals in the context of rising temperatures caused by climate change. Suggestions for the possible management of the extant populations are made. [ABSTRACT FROM AUTHOR]

Background: Heterosis is a common phenomenon in plants and has been extensively applied in crop breeding. However, the superior traits in the hybrids can only be maintained in the first generation but segregate in the following generations. Maintaining heterosis in generations has been challenging but highly desirable in crop breeding. Recent study showed that maternally produced diploid seeds could be achieved in rice by knocking out three meiosis related genes, namely REC8, PAIR1, OSD1 to create MiMe in combination with egg cell specific expression of BBM transcription factor, a technology called clonal seeds. Interestingly, there has been very limited reports indicating the feasibility of this approach in other crops. Results: In this study, we aimed to test whether clonal seeds could be created in cotton. We identified the homologs of the three meiosis related genes in cotton and used the multiplex CRISPR/Cas9 gene editing system to simultaneously knock out these three genes in both A and D sub-genomes. More than 50 transgenic cotton plants were generated, and fragment analysis indicated that multiple gene knockouts occurred in the transgenic plants. However, all the transgenic plants were sterile apparently due to the lack of pollen. Pollination of the flowers of the transgenic plants using the wild type pollens could not generate seeds, an indication of defects in the formation of female sexual cells in the transgenic plants. In addition, we generated transgenic cotton plants expressing the cotton BBM gene driven by the Arabidopsis egg cell specific promoter pDD45. Two transgenic plants were obtained, and both showed severely reduced fertility. Conclusions: Overall, our results indicate that knockout of the clonal seeds related genes in cotton causes sterility and how to manipulate genes to create clonal seeds in cotton requires further research. [ABSTRACT FROM AUTHOR]

Pollination is one of the most fascinating aspects of insect-plant interactions. Pollen is the male reproductive element of flowering plants, gathered by foraging Honeybees from the male parts of flowering plants called the anther. Guizotia abyssinica (L.f) is an important oilseed crop cultivated in Ethiopia and India, which belongs to the family Asteraceae. Although self-incompatibility is found in Guizotia abyssinica, a higher seed set is experienced in places with an active Honeybees population. Agricultural practices usually focus on inputs such as fertilizer application to improve seed yield of Guizotia abyssinica. However, these practices have little effect on yield if the availability of insect pollination is too low. To fill this gap, an experiment was carried out at Dandi district, West Shao zone, Oromia, Ethiopia to see the effect of Honeybees pollination management as an agronomic input. Pollination management of Honeybees was tested under feeding and non-feeding of colonies management. Pollen was trapped with and without sugar syrup feeding. The results discovered that Honeybees fed sugar syrup collected much more pollen than colonies not fed sugar syrup. The proportion of Guizotia abyssinica pollen collected through sugar syrup feeding of the colony was greater (62.2%), compared to the proportion of Guizotia abyssinica pollen trapped without sugar syrup feeding (37.8%). This indicates that sugar syrup feeding enhances the collection of pollen and probably enhances the pollination efficiency of Honeybees since they visit frequently to fulfill their daily protein requirement of pollen. Therefore, Honeybees pollination services should be included as one of the agronomic inputs with sugar syrup feeding as pollination management that might increase the yield of Guizotia abyssinica since it increases visiting frequency. [ABSTRACT FROM AUTHOR]

BackgroundAimsMethodsResultsConclusionAquatic plants can reproduce through abiotic or biotic pollination. In Cyperaceae anemophily is plesiomorphic, but studies have registered floral visitors in some genera, including Eleocharis. Wind and insects, therefore, can act together in the pollination, characterising ambophily. However, so far there has been no evidence that water could also be a pollen vector in this family.Expand understanding of the pollination mechanisms in Cyperaceae.We analysed the floral biology, pollen to ovule ratio, floral visitors, performed pollen vector exclusion experiments, characterised the floral colour in the models of insect vision and analysed the chemical composition of floral scent of Eleocharis geniculata and E. mutata.Both species have anemophilous attributes. In Eleocharis mutata, wind was an effective pollen vector, increasing the fruit set. Individuals of E. geniculata exposed to water were more likely to produce fruits (p < 0.01). Eight species of insects were recorded as floral visitors of E. mutata, among which an Ephydroidea fly acting as the main pollinator. Flowers of both species had the same scent as the vegetative parts, and were shown to be visible and distinguishable from the background in both Hymenoptera and Diptera vision models.Our results suggest a new pollination strategy (hydrophily in E. geniculata), and another case of ambophily in Cyperaceae. [ABSTRACT FROM AUTHOR]

The impacts of climate change may be particularly severe for geographically isolated populations, which must adjust through plastic responses or evolve. Here, we study an endangered Arctic plant, Primula nutans ssp. finmarchica, confined to Fennoscandian seashores and showing indications of maladaptation to warming climate. We evaluate the potential of these populations to evolve to facilitate survival in the rapidly warming Arctic (i.e. evolutionary rescue) by utilizing manual crossing experiments in a nested half-sibling breeding design. We estimate G-matrices, evolvability and genetic constraints in traits with potentially conflicting selection pressures. To explicitly evaluate the potential for climate change adaptation, we infer the expected time to evolve from a northern to a southern phenotype under different selection scenarios, using demographic and climatic data to relate expected evolutionary rates to projected rates of climate change. Our results indicate that, given the nearly 10-fold greater evolvability of vegetative than of floral traits, adaptation in these traits may take place nearly in concert with changing climate, given effective climate mitigation. However, the comparatively slow expected evolutionary modification of floral traits may hamper the evolution of floral traits to track climate-induced changes in pollination environment, compromising sexual reproduction and thus reducing the likelihood of evolutionary rescue. [ABSTRACT FROM AUTHOR]

ABSTRACT Although huge progress has been made over the past 200 years in identifying the diversity of pollinators of angiosperms and other plants, new discoveries continue to be made each year, especially in tropical areas and in the fossil record. In this perspective article I address the following questions: Just how diverse are the pollinators and what are the phylogenetic limits to that diversity? Which other groups of animals, not currently known to regularly engage with flowers, might be found to be pollinators in the future? Can we predict, from the fossil record and from discoveries in under‐researched parts of the world, which animal groups might turn out in the future to contain pollinators? I also discuss why adding to our knowledge of plant–pollinator interactions is important, but also stress that an incomplete knowledge may not be a bad thing if it means that remote, inaccessible and relatively pristine parts of the world remain that way. [ABSTRACT FROM AUTHOR]

Under the EU's new "Farm to Fork" strategy, crop production systems should rapidly become more environmentally friendly. In particular, by adopting agroecological measures that support functional biodiversity and improve ecosystem services for crop production, this paper contributes to the ongoing efforts in characterizing the socio-economic effects that the upscaling of these measures entails, by looking into two key measures: flower strips and mulching. One important socio-economic aspect of their adoption is their potential impact on agricultural income; however, knowledge on costs and benefits of measures enhancing functional biodiversity at the farm level is still limited. In order to improve these shortcomings our approach makes use of data from field experiments completed with interviews to provide cost–benefit results for flower strips and organic mulching. The estimations show that for "flower strips," on average costs could be covered by compensation payments. Regarding the in-crop measure "organic mulching," the benefits potentially outweigh the costs under the frame conditions of organic agriculture. The analysis also highlights some obstacles and knowledge gaps in the estimation of benefits, especially for off-crop measures like flower strips. [ABSTRACT FROM AUTHOR]

The first record of the squash and pumpkin bee, Eucera (Peponapis) fervens (Smith 1879) (Hymenoptera: Apidae), is presented for Peru. This species was found in the departments of Apurímac, Ayacucho, Cusco, and Piura, pollinating Cucurbita maxima Duchesne in Lam., C. ficifolia Bouche, and C. pepo L. Additionally, the presence of Eucera (Peponapis) citrullina is reported in the departments of Huancavelica, Ica, Lambayeque, and Lima. This species had previously been recorded in the regions of Lima and Piura. [ABSTRACT FROM AUTHOR]

Premise: 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. Methods: 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. Results: 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. Conclusions: 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. [ABSTRACT FROM AUTHOR]

The biodiversity of Brazil provides an excellent climate and favorable pollination conditions for Apis mellifera L., especially in the Eastern Amazon region, which boasts vast floral wealth, including an abundance of açaí (Euterpe oleracea) flowers and fruits. In the present study, seven types of honey were evaluated: three containing floral nectar from açaí (Açaí honey) collected in the Eastern Amazon region (Açaí honey from Breu Branco (AH1 and AH2) and Açaí honey from Santa Maria (AH3), both from the state of Pará, Brazil) and four honeys from different regions of Brazil (Aroeira honey from Minas Gerais, Cipó-Uva honey from Distrito Federal, Mangue honey from Pará, and Timbó honey from Rio Grande do Sul). The characteristics of these honeys were evaluated by examining their physicochemical properties, melissopalynological aspects, color, antioxidant potential, and their constituent compounds, which were confirmed through GC-MS analysis. Açaí floral nectar honeys presented physicochemical results similar to those of other honeys, aligning with Brazilian legislation norms, but differed in their high values of free acidity, apparent sugars, and lower reducing sugars, which are directly related to their botanical origin. These differences correlate with unique flavor and distinct aroma characteristics. Melissopalynological analysis confirmed the botanical origin of the honeys containing açaí floral nectar, which had a color range from amber to dark amber. The three açaí honeys demonstrated high antioxidant capacity and superior flavonoid and polyphenol content compared to other honeys, particularly the açaí honey from Breu Branco (AH1), which had four times the content to combat free radicals compared to the honey with the highest potential (Aroeira honey). GC-MS analysis confirmed the presence of antioxidant properties as well as potential anti-inflammatory, antibacterial, antimicrobial, and antitumor capabilities in açaí honeys, which have not yet been fully studied. [ABSTRACT FROM AUTHOR]

Pandanus is a morphologically unique plant group of the Paleotropical flora, with approximately 450 known species occupying diverse habitats. Because the male inflorescences of this genus are pendent and nectarless, they are commonly assumed to be wind-pollinated; however, their floral scent coupled with the observation that female inflorescences mature while still covered by bracts suggest the possibility of an alternative pollination mechanism. We studied the pollination system of Pandanus odorifer in subtropical Japan. A peroxidase assay was conducted to determine the timing of stigma receptivity, which showed that the stigmas were sensitive to peroxidase while the female inflorescences were covered by bracts. We found numerous pollen-bearing adult beetles of the genus Amystrops on both male and female inflorescences. Nitidulid larvae were also found on male inflorescences, and the larvae became adults of the same Amystrops species as found on the inflorescences by feeding only on Pandanus pollen. Last, floral temperature was monitored to test for floral thermogenesis. Both male and female inflorescences were thermogenic at night when insect visitation occurred. This study provides the first examples of insect pollination and floral thermogenesis in Pandanaceae. Most known Amystrops species are associated with Pandanus inflorescences, suggesting a widespread, specialized Pandanus – Amystrops association. [ABSTRACT FROM AUTHOR]

Plant species bearing extrafloral nectaries (EFNs) may indirectly influence other plant species by sharing protective ants, potentially altering herbivory levels. However, the propagation of indirect effects in this type of mutualism has seldom been investigated.We investigated indirect effects via ant sharing among 21 EFN‐bearing plant species of the tribe Bignonieae distributed on 28 plots in the central Brazilian Amazon. We used an ecological network index to quantify potential indirect effects among plant species through shared dominant and subordinate ant species.Plant species that were more attractive to ants (promoter species) had the highest potential to indirectly influence ant visitation to less attractive plant species (receptor species) in the community, primarily through changes in the attraction of dominant ant species. However, these potential indirect effects did not result in significant differences in herbivory patterns among the studied plants. Ant attendance and herbivory levels were similar among promoter species, neighbouring plants, and non‐neighbouring plants. Unlike other mutualisms involving plants (e.g., pollination), the indirect effects among plant species that share protective ants had limited consequences. The low levels of herbivory and the small foraging areas of shared ant defenders could be responsible for the observed limited impact of indirect interactions among plant species in this system.Synthesis: This study demonstrates that plant species with EFNs can indirectly influence other plant species through ant sharing. The attractiveness of certain plants to ants enables them to affect the ant visitation patterns of less attractive plants in the community. However, these indirect effects did not significantly alter herbivory levels among plants. Overall, this study advances ecological understanding by showing that the sharing of protective ants among plant species can in some cases confer limited costs and benefits, leading indirect interactions to have minimal impact on herbivory patterns. [ABSTRACT FROM AUTHOR]

Trapping trichomes, a common trait found in protogynous trap flowers, are thought to enable interaction with pollinators, promoting both pollen removal and fruit set. However, this hypothesis has yet to be empirically confirmed.In this study, we experimentally tested whether trapping trichomes favour male and female functions in trap flowers. Using protogynous South American Aristolochia esperanzae trap flowers, we observed the temporal variation in both sexual functions and associated them with the wilting of the flower and trapping trichomes. Next, we described the trapping trichomes features associated with the capture, entrapment and release of pollinators. Finally, we used manipulative experiments involving trapping trichome removal to quantify their influence on pollinator entrapment, pollen removal and fruit set.While flowers wilted after the end of the female phase, the trapping trichomes only wilted some hours after pollen presentation, promoting a delay in the exit of pollinators, so they carried pollen. Trapping trichomes features, such as a density gradient towards the interior of the tube, unidirectional orientation and epicuticular waxes, may be important in the capture and entrapment of pollinators. Trapping trichome removal decreased drastically the probability of pollinator entrapment and pollen removal, leading to no fruit set.These results indicate that the evolution and maintenance of trapping trichomes in trap flowers probably occurred through selective pressures from both sexual functions and highlight their role in the functioning of this highly phenotypically specialized pollination system. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Competition for nectar is expected to result in feeding niche differentiation. Here, we targeted the sexually size-dimorphic Volcano Sunbird (Cinnyris preussi) on Mount Cameroon. We investigated whether males and females feed on different plant species, whether females with shorter bills than males prefer shorter flowers, and whether larger dominant males visit more energetic flowers that produce higher amounts of nectar sugars. We also asked whether feeding niches were spatially separated along the elevation gradient and whether this separation varied between the two contrasting seasons. We collected data on the frequency of visits to individual plant species and analyzed the male-to-female ratios in the mist-netted dataset. In addition, we estimated production of nectar sugar in individual habitats and seasons. Despite the large dataset collected, encompassing 6476 bird–plant interactions, our findings did not provide evidence of differences in the spectra of the visited plant species. In addition, females did not visit flowers with shorter tubes, nor did males visit flowers that produced higher amounts of sugars. However, we observed a sex-specific dispersion of sunbirds during the wet season. During the dry breeding season, both males and females feed mainly in nectar-rich montane and submontane forests. In the wet season, the production of nectar sugar in these habitats decreased dramatically, and females largely disappeared. In contrast, female activity increased in the lowest and highest parts of the altitudinal range. Our findings on elevational movements are important in the current context, in which species face potential threats from habitat destruction and climate change. [ABSTRACT FROM AUTHOR]

This article explores the effects of hurricanes on the relationship between plants and pollinators in the Caribbean. Specifically, it examines the impact of Hurricane Maria on the mutualism between two species of Heliconia plants and the purple-throated carib hummingbird. Before the hurricane, this mutualism was highly specialized, but afterwards, other hummingbird species and a generalized passerine pollinator began visiting the Heliconia flowers at similar rates. This suggests that the population decline of the purple-throated carib allowed for increased visitation by other species, leading to a breakdown in competitive exclusion. The study also raises concerns about the conservation of these relationships in the face of increasing hurricane frequency and intensity due to global warming. [Extracted from the article]

Summary: Plants employ a diversity of reproductive safeguarding strategies to circumvent the challenge of pollen limitation. Focusing on southern African Lachenalia (Asparagaceae: Scilloideae), we test the hypothesis that the evolution of reproductive safeguarding traits (self‐compatibility, autonomous selfing, bird pollination and clonal propagation) is favoured in species occupying conditions of low insect abundance imposed by critically infertile fynbos heathland vegetation and by flowering outside the austral spring insect abundance peak.We trace the evolution of these traits and selective regimes on a dated, multi‐locus phylogeny of Lachenalia and assess their evolutionary associations using ordinary and phylogenetic regression.Ancestral state reconstructions identify an association with non‐fynbos vegetation and spring flowering as ancestral in Lachenalia, the transition to fynbos vegetation and non‐spring flowering taking place multiple times. They also show that self‐compatibility, autofertility, bird pollination and production of multiple clonal offsets have evolved repeatedly.Regression models suggest that bird pollination and self‐compatibility are selected for in fynbos and in non‐spring flowering lineages, with autofertility being positively associated with non‐spring flowering. These patterns support the interpretation of these traits as reproductive safeguarding adaptations under reduced insect pollinator abundance. We find no evidence to support the interpretation of clonal propagation as a reproductive safeguarding strategy. See also the Commentary on this article by Burd, 244: 7–9. [ABSTRACT FROM AUTHOR]

The current study aims to understand the role of various morphological features of pollen grains in attachment with moth proboscides. To test the hypothesis, moth samples are collected from 11 sites in three districts of Arunachal Pradesh and West Bengal, North East India. Pollen of 18 angiosperm families are isolated from the proboscides of 16 moth species in four families. We selected proboscides for the isolation of pollen because it is the most important organ of moths which interacts with flowers during moth visitation. The isolated pollen is studied for various morphological characters like pollen shape, unit, exine ornamentation, thickness, aperture numbers, and aperture types along with specialized structures i.e., viscin thread and pollenkitt, and analyzed for their attachment on the proboscides. The present study revealed the significant role of pollen shape, unit, exine characters, viscin thread, and pollenkitt in attachment with proboscides. Whereas, the aperture numbers and aperture types are found insignificant in the process of pollen attachment. Studies on the formation of viscin thread and pollenkitt may be established as an important tool to understand the specialized and generalized interactions between moths and angiosperms. The present study will open up a new horizon in pollination ecology. [ABSTRACT FROM AUTHOR]

• The pompom weed is likely pollinated by Apis mellifera and Hypolimnas misippus. • Gametophytic apomixis with autonomous endosperm development in triploids. • The co-occurrence of apomixis and polyploidy may be facilitating its invasiveness. • There is high pollen grain viability despite apomictic reproduction. • Low genetic diversity within and among the sampled triploid populations. Polyploidy and apomixis enable successful plant invasions into new regions. Campuloclinium macrocephalum (pompom weed) is a successful alien invasive species in South Africa that has been shown to comprise multiple ploidy levels. Despite the identification of triploid and tetraploid cytotypes in South African populations, the primary reproductive strategy was unknown. We investigated the reproductive strategy used by triploid populations of the pompom weed. We assessed whether insects contributed to pollen transfer using pollinator exclusion experiments, estimated genetic diversity, evaluated pollen tube growth in the styles, and estimated male fertility using pollen grain size and viability. We found evidence that strongly suggests that the pompom weed can reproduce via gametophytic apomixis with autonomous endosperm development. Pollinator exclusion experiments showed that while insects may positively influence reproductive success, the pompom weed can set lower quantities of seed in the absence of pollinators and that overall seed viability did not differ between open and excluded pollinator treatments. Further, while individuals are capable of uniparental reproduction, seed set appears to be independent of fertilization because we did not observe pollen tubes growing down the styles and/or reaching the ovules, despite high pollen viability. The sampled triploid populations also showed low genetic diversity, which may be a result low recombination frequencies. The low genetic variation should result in all of the sampled populations being equally susceptible to the biocontrol agents; however, this is not being observed in the sampled populations. Only one out of the four sampled populations showed a significant reduction in seed set and germination percentages due to the damage from Puccinia eupatorii (rust fungus) and Liothrips tractabilis (thrips). Nevertheless, the combination of an apomictic reproductive strategy and polyploidy is likely contributing to making pompom weed a formidable invader in South Africa. [ABSTRACT FROM AUTHOR]

Plant–hummingbird interactions are considered a classic example of coevolution, a process in which mutually dependent species influence each other's evolution. Plants depend on hummingbirds for pollination, whereas hummingbirds rely on nectar for food. As a step towards understanding coevolution, this review focuses on the macroevolutionary consequences of plant–hummingbird interactions, a relatively underexplored area in the current literature. We synthesize prior studies, illustrating the origins and dynamics of hummingbird pollination across different angiosperm clades previously pollinated by insects (mostly bees), bats, and passerine birds. In some cases, the crown age of hummingbirds pre‐dates the plants they pollinate. In other cases, plant groups transitioned to hummingbird pollination early in the establishment of this bird group in the Americas, with the build‐up of both diversities coinciding temporally, and hence suggesting co‐diversification. Determining what triggers shifts to and away from hummingbird pollination remains a major open challenge. The impact of hummingbirds on plant diversification is complex, with many tropical plant lineages experiencing increased diversification after acquiring flowers that attract hummingbirds, and others experiencing no change or even a decrease in diversification rates. This mixed evidence suggests that other extrinsic or intrinsic factors, such as local climate and isolation, are important covariables driving the diversification of plants adapted to hummingbird pollination. To guide future studies, we discuss the mechanisms and contexts under which hummingbirds, as a clade and as individual species (e.g. traits, foraging behaviour, degree of specialization), could influence plant evolution. We conclude by commenting on how macroevolutionary signals of the mutualism could relate to coevolution, highlighting the unbalanced focus on the plant side of the interaction, and advocating for the use of species‐level interaction data in macroevolutionary studies. [ABSTRACT FROM AUTHOR]

Female solitary bees collect pollen for their brood at the expense of using sugars in the nectar as fuel for flight. When flowers provide both pollen and nectar, solitary bees can refuel from the flowers to sustain pollen foraging. However, not all flowers provide both pollen and nectar. This study investigates how females of the solitary bee Andrena taraxaci orienticola secure fuel to sustain pollen foraging when flowers provide scarce nectar. By using DNA barcoding, we identified the Japanese dandelion Taraxacum platycarpum as their primary food source. This dandelion produces almost no nectar in the early morning when female bees collect almost no nectar but collect substantial amounts of pollen. We also found that these bees leave the nest with significantly more nectar at the first flight of the day than at later flights. When we restricted their fuel load by preventing nectar feeding, significantly more females failed to collect pollen on the first flight of the following day. These results suggest females hold back some part of the nectar collected at the end of a day's foraging and use it the following morning as fuel to sustain pollen foraging from flowers providing little nectar. [ABSTRACT FROM AUTHOR]

Context: Resupination is the movement of developing buds that leads to a vertical inversion of the flowers at an angle of 180°. Chamaecrista nictitans exhibits two anther sizes, and nonresupinate and resupinate flowers in the same individual, which is known as monomorphic resupinate dimorphy. Aims: We aimed to investigate the influence of monomorphic resupinate dimorphy upon pollen deposition on pollinators, capture by the stigma and on plant reproduction, using three populations of C. nictitans from NE Brazil as a model. Methods: We assessed the floral biology, the proportion of nonresupinate and resupinate flowers in the populations, dynamics of pollen transfer between floral morphs, and the plant's reproductive system. Key results: All flowers have two anther sizes with similar pollen viability. The proportion of nonresupinate:resupinate flowers was 3:1 in all populations. The bee Florilegus (Euflorilegus) sp. was the only pollinator observed and had pollen of both flower morphs deposited on the underside part of the thorax and abdomen. The stigma of nonresupinate flowers received pollen from the pollinators' underside of the abdomen, whereas the stigma of resupinate flowers received pollen from the pollinators' underside of the thorax. The species is self-compatible but does not set fruits by spontaneous self-pollination. Therefore, natural fruit set had resulted from both intramorph- and intermorph-pollination in the same or in different individuals. Conclusions: Both flower types have a similar pattern of pollen deposition on the pollinator's body (underside of the abdomen and thorax) and only differ in relation to areas of pollen capture by the stigma (underside of the abdomen or underside of thorax). Implications: The monomorphic resupinate dimorphy observed here improves the area of pollen deposition by the anthers on pollinator's body and makes the capture of pollen by stigma sectored in the different floral types, similar to what is observed in other species presenting floral polymorphisms. Resupination is the movement of floral buds that leads to flowers turning upside down. We tested the reproductive functioning of this characteristic in the native legume Chamaecrista nictitans and found that it causes pollen to be deposited in particular portions of pollinators' bodies, improving pollination. Image by Natan Messias Almeida and Paulo Estêvão Araújo Vilaça Júnior. [ABSTRACT FROM AUTHOR]

Heat stress will be an increasing problem for plants and pollinators. Some Romneya coulteri flowers self-shade reproductive parts with vertically oriented petals; this keeps pistils 3–8 °C cooler. A previous study conducted outside of the plant's native range found that self-shading flowers experienced higher seed set than flowers with petals that were experimentally forced to all be horizontal (open) or vertical (shaded). Hand-pollinated flowers had higher seed set which negated the effect of petal orientation, suggesting that insect pollination may have driven seed set. In this study, we observed insect visitors and their effects on seed set in R coulteri's native range. Plant performance was again limited by pollen such that experimentally adding outcross pollen increased seed set. Native and introduced bees showed no proclivity toward either petal orientation. However, the most common visitor, a native beetle (Lytta auriculata), was strongly biased toward approaching and ultimately accepting flowers with vertical petals that provided shade. Beetles were covered with R. coulteri pollen. Flowers bagged with only beetles for 24 h produced as many seeds as controls left open to all visitors. However, beetles also consume pollen and chew petals. Flowers with vertical petals received more beetle damage and damaged flowers produced 35% fewer seeds than those without chewed petals. Despite the potential role of beetles as pollen vectors, flowers with vertical petals did not experience higher seed production. The outcome of beetle visitation on seed set is likely context-dependent. Petals that affected microclimate were attractive to at least one potential pollinator. [ABSTRACT FROM AUTHOR]

Pointed gourd (Trichosanthes dioica Roxb.) is an economically important dioecious vegetable crop having separate plants growing male and female flowers. Cross-pollination is imperative for its fruit settings and insects play a pivotal role in this. Although a nitidulid beetle was reported to be a primary pollinator in pointed gourd, its species identification and validation were needed to enhance the fruit production. The beetles collected from the pointed gourd have revealed presence of abundant round or spheroidal, trizonopororate, sticky pointed gourd pollens. Further, role of beetle was validated in farmers field where no fruit set was recorded when beetle's visit was curtailed. Twenty adult beetles were artificially released into a caged pot, and the maximum fruit setting (30.43%) indicated its potential role in pointed gourd pollination in vegetable ecosystem. Beetle-pollinated fruits had higher fruit length (6.88 cm), width (2.83 cm), fruit weight (22.63 g), and lesser number of seeds (16.75) than the hand-pollinated fruits (6.21 cm, 2.77 cm, 19.41 g, and 21.75 numbers, respectively). The morphological and molecular analysis identified the species as Epuraea motschulskyi and the study hereby reports for the first time that E. motschulskyi is the primary pollinator in pointed gourd. The study also suggests that the release and protection of the beetle in pointed gourd field would lead to enhanced fruit set. [ABSTRACT FROM AUTHOR]

After normal pollination and fertilization of pseudoparthenocarpic seedless grapes, their embryos often stop developing due to certain developmental factors, resulting in embryo abortion. Hybrid breeding using seedless grapes as the maternal parent requires embryo rescue breeding technology. This technology plays a crucial role in seedless grape breeding. Although previous studies have extensively explored this technology, knowledge regarding its impact on embryo abortion and the effectiveness of rescue techniques remains limited. This study aimed to investigate the correlation between embryo rescue and hormonal changes in seedless grapes. Four Eurasian seedless grape cultivars, "Thompson Seedless," "Flame Seedless," "Heshi Seedless," and "Ruby Seedless," were selected for examination. We investigated endogenous hormone levels, including indole-3-acetic acid (IAA), gibberellic acid (GA3), and abscisic acid (ABA), in both berries and in vitro ovules during the most suitable embryo rescue time for these cultivars. Based on the observed fluctuations in endogenous hormone levels and previous research findings, appropriate doses of exogenous hormones, such as IAA, GA3, and ABA, were applied during seedless grape embryo rescue. The results indicated significant differences in endogenous hormone levels between berrieswith varying ovule counts of the same cultivar and ovules cultured in vitro, suggesting a hormonal influence on ovule abortion and embryo development in seedless grapes. Further research has identified effective ratios of exogenous hormones: 30 mg·L-1 IAA + 30 mg·L-1 ABA for berry ovule development, 1.0 mg·L-1 IAA + 2.0 mg·L-1 6-benzylaminopurine (6-BA) + 1.0 mg·L-1 GA3 + 1.0 mg·L-1 ABA for in vitro ovule development, and 1.0 mg·L-1 IAA + 2.0 mg·L-1 6-BA + 1.0 mg·L-1 GA3 for embryo germination and seedling formation. In summary, hormonal changes significantly influence ovule and embryo development and are closely related to seedless grape embryo rescue breeding. This study deepened our understanding of the correlation between seedless grape embryo rescue and hormonal changes. It also resulted in the successful production of a batch of embryo rescue seedlings, further improving embryo rescue breeding technology and providing new germplasm materials for developing new seedless grape cultivars. [ABSTRACT FROM AUTHOR]

Anthropogenic disturbances have drastic negative effects on the biodiversity, thereby also compromising the ecosystem service it provides. Bees are one of the key players since they provide essential pollination services for both natural and agriculture ecosystems. Nevertheless, these insects are facing an increasing threat due to expansion of urban areas and inappropriate land use practices. Therefore, understanding the impact of different anthropogenic disturbances on bee communities is essential to assure the ecosystem functioning and human well-being. In this study, we made use of a well-known bee group, i.e., euglossine bees (Euglossine: Apidae), and of a fast-growing city to investigate the impact of anthropogenic disturbance on bee community. Using scent traps, we monthly collected male euglossine bees in seven sampling areas, differing in terms of the anthropogenic use/disturbance. Land use in each area was characterized through pre-georeferenced images and mapping software and from these data we calculated an Anthropogenic Transformation Index. Our results reveal that anthropogenic disturbance negatively impacts the euglossine bee community, in contrast to the positive effect of the proximity to the river. However, and perhaps the most alarming aspect of our findings, is the interaction effect between these two conditions, demonstrating that as we approach the river, parameters such as abundance, species richness, and diversity of these bee communities become more compromised by disturbance. Our study shows the urgent need to implement effective conservation strategies and sustainable management practices to protect and restore riparian forests in Caatinga urban areas, aiming to safeguard its associated biota and the valuable ecosystem services they provide. [ABSTRACT FROM AUTHOR]

The habitat suitability for pollinators is an important factor for biodiversity and crop-based ecosystem services. Most flowering plants, including wild plants, rely on pollination ecosystem services for fructification and reproduction. Suitable nesting sites and accessible floral food resources are crucial to the abundance of pollinator insects. Therefore, the suitability for pollinators and the pollination service itself are influenced by the type of land use, the composition of the land cover and structures in the landscape. One way to estimate pollinator habitat suitability is to use computer models such as ESTIMAP and InVEST. Both models calculate the habitat suitability based on spatial land use data and their suitability as nesting and feeding habitats. Besides the decision for a model, the selected spatial dataset also has important effects on the modelling results. In Germany, a large number of Land Use and Land Cover (LULC) datasets is available, such as the European CORINE Land Cover, CORINE Urban Atlas, Biotope types, ATKIS or Open Street Map. These datasets differ in terms of spatial and thematic resolutions, LULC types, and abundance of structural elements, which are crucial input factors for modelling with ESTIMAP and InVEST. We applied and tested both models on the basis of two different datasets in the study area Hannover region in central Germany. A literature-based estimation and expert-based questionnaire determined the biophysical properties required for modelling with ESTIMAP and InVEST. The differences between the results based on two different spatial datasets and the differences between the models were estimated and the results that can be obtained by using freely available data were investigated and compared with the results based on non-publicly available data. The comparison of the results shows that the proportion of near-natural structures in the landscape are a decisive factor for modelling results. The comparison of the models shows that ESTIMAP estimates a higher influence of small structures in the landscape than InVEST, resulting in a higher pollinator habitat suitability. The median similarity index of the two models is between 0.68 to 0.93 for the highly detailed biotope type dataset and 0.40 to 0.79 for the less detailed Corine dataset. The results provide a guidance on how to choose the appropriate model and data to assess pollination ecosystem services. [ABSTRACT FROM AUTHOR]

Summary Climate change is disrupting floral traits that mediate mutualistic and antagonistic species interactions. Plastic responses of these traits to multiple shifting conditions may be adaptive, depending on natural selection in new environments. We manipulated snowmelt date over three seasons (3–11 d earlier) in factorial combination with growing‐season precipitation (normal, halved, or doubled) to measure plastic responses of volatile emissions and other floral traits in Ipomopsis aggregata. We quantified how precipitation and early snowmelt affected selection on traits by seed predators and pollinators. Within years, floral emissions did not respond to precipitation treatments but shifted with snowmelt treatment depending on the year. Across 3 yr, emissions correlated with both precipitation and snowmelt date. These effects were driven by changes in soil moisture. Selection on several traits changed with earlier snowmelt or reduced precipitation, in some cases driven by predispersal seed predation. Floral trait plasticity was not generally adaptive. Floral volatile emissions shifted in the face of two effects of climate change, and the new environments modulated selection imposed by interacting species. The complexity of the responses underscores the need for more studies of how climate change will affect floral volatiles and other floral traits. [ABSTRACT FROM AUTHOR]

Hybridization between rare and widespread species can result in loss of genetic integrity for the rarer species, which can have management and conservation implications. One rare species, Phlox hirsuta, is a serpentine endemic in northern California, and it frequently co‐occurs with a widespread congener, Phlox speciosa. Putative hybrids were recognized based on intermediate morphology, so the possibility of hybridization was explored using floral morphological and molecular data. Ninety‐eight individuals of P. hirsuta and P. speciosa were collected from each of three sites, and floral features were measured and compared. Eleven microsatellite loci were amplified for species and putative hybrids, and inter‐ and intraspecific genetic diversity and relationships were investigated with multiple methods. Variation in morphological and molecular data was recovered. Floral variation was greater for P. hirsuta than P. speciosa. Putative hybrids were genetically allied with P. speciosa, but two individuals of P. hirsuta were resolved to have genetic similarity with P. speciosa. While hybridization is possible between the species, it is uncommon and appears to be primarily unidirectional. The small number of recognized hybrids may be due to ineffective interspecific pollination, hybrids being less fit than parents, and/or small sample sizes. Reinforcement does not appear to play a role in secondary contact between species. Both microsatellite loci and floral morphology varied across the small geographic range of P. hirsuta, suggesting local differentiation and adaptation are possible over short distances. [ABSTRACT FROM AUTHOR]

In carnivorous plants, the fitness impacts of phenotypic variation in traits involved in prey attraction and capture have been well documented. However, floral traits could also contribute to the fitness of carnivorous plants. Pinguicula moranensis is a carnivorous plant that presents colorful zygomorphic flowers, which suggests some degree of specialization in its interactions with pollinators. We first tested pollen limitation experimentally by comparing the fruit set in plants that were manually cross‐pollinated with those that were pollinated naturally. Then, using a path analysis approach, we explored the effects of plant size and floral traits (corolla shape, corolla size, spur length, nectar guide size, and stalk length) on fitness (seed number per fruit). We performed two independent path analyses—one with the naturally pollinated plants and the other with the hand pollinated plants—to consider the impacts of these variables with and without the pressure of pollinator attraction. We expected stronger selection on floral traits in naturally pollinated plants. We found evidence of pollen limitation in the fruit set of the naturally pollinated group, suggesting that pollinator availability could impose selective pressures. The path analyses showed a marked direct positive effect of rosette size on plant fitness in both groups. The direct effects of all floral traits had similar magnitudes between the naturally pollinated and hand pollinated plants, except for corolla shape that showed higher coefficients in the first group. Thus, although we evidenced pollen limitation, our prediction about the role of pollinators as selective agents of floral traits in P. moranensis was barely supported. [ABSTRACT FROM AUTHOR]

Resources salvaged when flowers wilt on a perennial plant could promote reproduction by, in preference order, the same flowers (Hypothesis 1), adjacent flowers on the same plant (Hypothesis 2), or during the next flowering season by the same plant (Hypothesis 3). We tested the above hypotheses for Blandfordia grandiflora, a perennial species, where some plants included flowers that were allowed to wilt, while equivalent flowers on other plants were prevented from wilting. The abilities of these plants to produce seed were determined by liberally pollinating all flowers. To test Hypotheses 1 and 2, seed set per flower and per plant were compared between plants with and without wilting flowers. To specifically test Hypothesis 3, reproduction was prevented in all flowers. For each experiment, flowering was monitored in the same plants during the next flowering season, thus also enabling Hypothesis 3 to be tested. The results were consistent with Hypothesis 3, but not with Hypotheses 1 and 2. Hence, we verified, for the first time, that plants may benefit from salvaging resources from wilting flowers and re‐using these resources for subsequent reproduction. However, contrary to expectations, plants re‐used these resources to promote reproduction during subsequent flowering, and not during current flowering by either the same flowers or other flowers on the same plant. The plants must have transferred resources from wilting flowers to underground corms and roots, which provided resources necessary for subsequent flowering. This is likely part of a general plant strategy to salvage resources invested in reproduction during one flowering season and reuse these resources during subsequent flowering. [ABSTRACT FROM AUTHOR]

Species traits greatly influence interactions between plants and pollinators where floral nectar is the primary energy source fostering this mutualism. However, very little is known about how nectar traits mediate interactions in pollination networks compared with morphological traits. Here, we evaluated the role of morphological and nectar traits in shaping plant–hummingbird interaction networks along an elevation gradient. For this, we assessed patterns in floral phenotypic traits and network properties of plant species across elevations in Costa Rica. We also analysed whether plant species with generalized flower traits are ecological generalists and how morphological trait matching versus nectar traits affect interactions. We found marked variation in floral phenotypic traits and flower abundance of hummingbird-visited plant species across 10 sites along the elevation gradient. We did not find evidence for a relationship between flower morphology and nectar traits or between morphological and ecological generalization of plant species. Plant–hummingbird interaction frequency increased when the lengths of hummingbird bill and flower corolla were similar, indicating morphological matching, whereas nectar traits were unrelated to interactions. While nectar may play a difficult-to-detect secondary role within plant–hummingbird networks, our results reinforce the idea that morphological matching is an important factor in structuring ecological communities. [ABSTRACT FROM AUTHOR]

Plant resource allocation strategies are thought to be largely a consequence of changing abiotic conditions and evolutionary history. However, biotic interactions also influence how a plant allocates resources. As a result, plants mediate indirect interactions between organisms above‐ and belowground through resource allocation. Neighboring plants can influence plant fitness directly through competition for resources, and indirectly by altering associated community interactions (associational effects), such as pollination, herbivory, and a suite of belowground interactions. Given the importance of community interactions for plant success, and the known ability for plant neighbors to change these interactions, the goal of this “pandemic project” was to understand how heterospecific plant neighbors alter plant resource allocation, whether this occurred through above‐ or belowground mechanisms, and whether this in turn alters biotic interactions and the relationship between a focal plant and its herbivore and soil community interactions. To do so, we established a common garden experiment, manipulating plant neighbor identity and the extent of interaction among neighbors (aboveground only, vs. above‐ and belowground interactions, using customized pot types), and measured changes to a focal plant and its biotic interactions over two growing seasons. We found evidence of both neighbor effects and pot type, showing that neighbor interactions affect a focal plant through both above‐ and belowground processes, and how the focal plant is affected depends on neighbor identity. Though neighbors did not directly alter herbivory or most soil microbial interactions, they did alter the relationship between belowground microbial communities and a plant response trait (specific leaf area). Plant resource allocation responses were reduced with time, showing the importance of extending experiments beyond a single growing season, and are an important consideration when making predictions about plant responses to changing conditions. This study contributes to a growing body of work showing how community contexts affect the above‐ and belowground interactions of a plant through plant resource allocation strategies. [ABSTRACT FROM AUTHOR]