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Biology Jun 2024Pollinators are needed for the reproduction of , and only sphingid moths have mouthparts long enough to reach the nectar at the bottom of the species' long, twisted...
Pollinators are needed for the reproduction of , and only sphingid moths have mouthparts long enough to reach the nectar at the bottom of the species' long, twisted floral tube. Though plants produce many flowers over a period of several months, one observes very few fruits in nature. We asked: (1) Are plants self-compatible, or do they need pollen from another individual to set fruit and seed? (2) Are cross-pollinations between unrelated individuals more successful than crosses with relatives? (3) How does the relatedness of pollen and ovule parent plants affect fruit set, seed number, and seed quality? We investigated the breeding system of by collecting fruits from seven sites, growing plants and performing hand pollinations over a period of several years, collecting and measuring fruits and counting seeds. is self-incompatible, though some individuals produce fruit by self-pollination. Cross-pollinations between unrelated individuals set the most fruit (59%), and those that were self-pollinated set the least (9%). Fruit set from cross-pollinations between related individuals was intermediate (32%). Although the number of seeds per fruit did not differ significantly among pollination treatments, fruits from self-pollinations had substantially fewer viable seeds than outcrossed fruits, with fruits from sibling crosses being intermediate. There were higher levels of self-compatibility in the fragment populations compared with plants from intact habitats. Self-incompatibility may explain why fruit set is low in this plant species; future investigation into the breakdown of self-incompatibility in smaller populations is warranted.
PubMed: 38927303
DOI: 10.3390/biology13060423 -
Biology Jun 2024The Yixian Formation (Lower Cretaceous) in China is famous worldwide for its fossils of early angiosperms, but there has been only one record of flower buds () hitherto,...
The Yixian Formation (Lower Cretaceous) in China is famous worldwide for its fossils of early angiosperms, but there has been only one record of flower buds () hitherto, in which only the surface of the flower bud was documented while no internal details were known. Such a partial knowledge of flower buds hinders our understanding of the evolution of flowers, and this knowledge lacuna needs to be filled. Our new specimen was collected from an outcrop of the Yixian Formation (Barremian-Aptian, Lower Cretaceous) near Dawangzhangzi, Lingyuan, Liaoning, China. Our observations reveal a new fossil flower bud, sp. nov., from the Lower Cretaceous of China. This new record of in the Yixian Formation not only confirms the truthful existence of the expected gynoecium (plus possible androecium) in a flower bud but also underscores the occurrence of typical flowers in the Early Cretaceous. This new information adds first-hand data to flower sexuality, pollination, and evolution.
PubMed: 38927293
DOI: 10.3390/biology13060413 -
PloS One 2024Animals should maximize their energy uptake while reducing the costs for foraging. For flower-visitors these costs and benefits are rather straight forward as the energy...
Animals should maximize their energy uptake while reducing the costs for foraging. For flower-visitors these costs and benefits are rather straight forward as the energy uptake equals the caloric content of the consumed nectar while the costs equal the handling time at the flower. Due to their energetically demanding lifestyle, flower-visiting bats face particularly harsh energetic conditions and thus need to optimize their foraging behavior at the flowers of the different plant species they encounter within their habitat. In flight cage experiments we examined the nectar-drinking behavior (i.e. hovering duration, nectar uptake, and the resulting feeding efficiency) of the specialized nectar-feeding bat Hylonycteris underwoodi and the more generalistic Glossophaga commissarisi at flowers of two plant species that constitute important nectar resources in the Caribbean lowland rainforests of Costa Rica and compared nectar-drinking behavior between both bat species and at both plant species. We hypothesized that the 1) specialized bat should outperform the more generalistic species and that 2) bats should generally perform better at flowers of the nectar-rich flowers of the bromeliad Werauhia gladioliflora than at the relatively nectar-poor flowers of the Solanaceae Merinthopodium neuranthum that has an extremely long flowering phase and therefore is an extremely reliable nectar resource, particularly for the specialized Hylonycteris. While we did not find substantial differences in the feeding efficiency of the generalist G. commissarisi, we observed an increased feeding efficiency of the specialized H. underwoodi at flowers of the nectar-poor M. neuranthum. This suggests that familiarity and ecological importance are more important determinants of the interaction than just morphological traits. Our results demonstrate that in addition to morphology, behavioral adaptations are also important drivers that determine the fitness of nectar-feeding bats. Both familiarity with and the ecological importance of a resource seem to contribute to shaping the interactions between pollinating bats and their plants.
Topics: Animals; Chiroptera; Flowers; Feeding Behavior; Plant Nectar; Species Specificity; Costa Rica
PubMed: 38924018
DOI: 10.1371/journal.pone.0303227 -
Brazilian Journal of Biology = Revista... 2024The identification of meliponicultural flora is fundamental for the preservation of bees, as well as enabling the development of pollinator management and reforestation...
Pollen analysis of honey and pollen stored by Melipona (Melikerria) fasciculata Smith, 1854 (Apidae Meliponini), in an Amazon and Cerrado transition area, Maranhão, Brazil.
The identification of meliponicultural flora is fundamental for the preservation of bees, as well as enabling the development of pollinator management and reforestation programs. In this context, this study aimed to investigate the types of pollen found in the honey and pollen pots of the Melipona fasciculata bee in Arari, State of Maranhão, between August 2022 and July 2023. 40 types of pollen were identified, distributed among 18 botanical families, with Fabaceae standing out (46.15% in pollen pots and 37.86% in honey pots), Myrtaceae (11.53% in pollen and 13.51% in honey) and Rubiaceae (7.69% in pollen and 5.40% in honey). Sapindaceae, in the honey pots, accounted for 5.40%. The other families showed lower percentages, 3.84% in the pollen pots and 2.70% in the honey pots. In terms of similarity, two distinct groups were observed in both the pollen and honey pots. In the pollen pots, group A (May-June ~ 97%) and group B (Feb-Mar ~ 99%) stood out, while in the honey pots, group A (Mar-Apr ~ 98%) and group B (Jun-Jul-Sept ~ 98%) showed the highest percentages. These findings highlight the wide range of resources used by the M. fasciculata species, as well asits preference for Fabaceae and Myrtaceae, due to the diversity and availability of trophic resources. An understanding of the meliponicultural flora is essential to support effective conservation strategies, which aim not only to guarantee the survival of the bees, but also to ensure the continued production of honey, a resource of great importance to local communities.
Topics: Pollen; Honey; Bees; Animals; Brazil; Seasons; Pollination
PubMed: 38922195
DOI: 10.1590/1519-6984.281066 -
Journal of Xenobiotics Jun 2024Insects are the most diverse form of life, and as such, they interact closely with humans, impacting our health, economy, and agriculture. Beneficial insect species... (Review)
Review
Insects are the most diverse form of life, and as such, they interact closely with humans, impacting our health, economy, and agriculture. Beneficial insect species contribute to pollination, biological control of pests, decomposition, and nutrient cycling. Pest species can cause damage to agricultural crops and vector diseases to humans and livestock. Insects are often exposed to toxic xenobiotics in the environment, both naturally occurring toxins like plant secondary metabolites and synthetic chemicals like herbicides, fungicides, and insecticides. Because of this, insects have evolved several mechanisms of resistance to toxic xenobiotics, including sequestration, behavioral avoidance, and enzymatic degradation, and in many cases had developed symbiotic relationships with microbes that can aid in this detoxification. As research progresses, the important roles of these microbes in insect health and function have become more apparent. Bacterial symbionts that degrade plant phytotoxins allow host insects to feed on otherwise chemically defended plants. They can also confer pesticide resistance to their hosts, especially in frequently treated agricultural fields. It is important to study these interactions between insects and the toxic chemicals they are exposed to in order to further the understanding of pest insect resistance and to mitigate the negative effect of pesticides on nontarget insect species like Hymenopteran pollinators.
PubMed: 38921652
DOI: 10.3390/jox14020043 -
Insects Jun 2024Bees are one of the best-known and, at the same time, perhaps the most enigmatic insects on our planet, known for their organization and social structure, being... (Review)
Review
Bees are one of the best-known and, at the same time, perhaps the most enigmatic insects on our planet, known for their organization and social structure, being essential for the pollination of agricultural crops and several other plants, playing an essential role in food production and the balance of ecosystems, being associated with the production of high-value-added inputs, and a unique universe in relation to bees' microbiota. In this review, we summarize information regarding on different varieties of bees, with emphasis on their specificity related to microbial variations. Noteworthy are fructophilic bacteria, a lesser-known bacterial group, which use fructose fermentation as their main source of energy, with some strains being closely related to bees' health status. The beneficial properties of fructophilic bacteria may be extendable to humans and other animals as probiotics. In addition, their biotechnological potential may ease the development of new-generation antimicrobials with applications in biopreservation. The concept of "One Health" brings together fundamental and applied research with the aim of clarifying that the connections between the different components of ecosystems must be considered part of a mega-structure, with bees being an iconic example in that the healthy functionality of their microbiota is directly and indirectly related to agricultural production, bee health, quality of bee products, and the functional prosperity for humans and other animals. In fact, good health of bees is clearly related to the stable functionality of ecosystems and indirectly relates to humans' wellbeing, a concept of the "One Health".
PubMed: 38921144
DOI: 10.3390/insects15060430 -
Insects Jun 2024The interaction between bees and flowering plants is mediated by floral cues that enable bees to find foraging plants. We tested floral cue preferences among three...
The interaction between bees and flowering plants is mediated by floral cues that enable bees to find foraging plants. We tested floral cue preferences among three common wild bee species: , , and . Preferences are well studied in eusocial bees but almost unknown in solitary or non-eusocial generalist bee species. Using standardized artificial flowers altered in single cues, we tested preferences for color hue, achromatic contrast, scent complexity, corolla size, and flower depth. We found common attractive cues among all tested bees. Intensively colored flowers and large floral displays were highly attractive. No preferences were observed in scent complexity experiments, and the number of volatiles did not influence the behavior of bees. Differing preferences were found for color hue. The specific behaviors were probably influenced by foraging experience and depended on the flower choice preferences of the tested bee species. In experiments testing different flower depths of reward presentation, the bees chose flat flowers that afforded low energy costs. The results reveal that generalist wild bee species other than well-studied honeybees and bumblebees show strong preferences for distinct floral cues to find potential host plants. The diverse preferences of wild bees ensure the pollination of various flowering plants.
PubMed: 38921142
DOI: 10.3390/insects15060427 -
Frontiers in Plant Science 2024Enhancing grain yield is a primary goal in the cultivation of major staple crops, including wheat. Recent research has focused on identifying the physiological and...
Enhancing grain yield is a primary goal in the cultivation of major staple crops, including wheat. Recent research has focused on identifying the physiological and molecular factors that influence grain weight, a critical determinant of crop yield. However, a bottleneck has arisen due to the trade-off between grain weight and grain number, whose underlying causes remain elusive. In a novel approach, a wheat expansin gene, , known for its expression in root tissues, was engineered to express in the grains of the spring wheat cultivar Fielder. This modification led to increases in both grain weight and yield without adversely affecting grain number. Conversely, a triple mutant line targeting the gene , a known negative regulator of grain weight, resulted in increased grain weight but decreased grain number, potentially offsetting yield gains. This study aimed to evaluate the two aforementioned modified wheat genotypes ( and ) alongside their respective wild-type counterparts. Conducted in southern Chile, the study employed a Complete Randomized Block Design with four replications, under well-managed field conditions. The primary metrics assessed were grain yield, grain number, and average grain weight per spike, along with detailed measurements of grain weight and dimensions across the spike, ovary weight at pollination (Waddington's scale 10), and post-anthesis expression levels of and . Results indicated that both the and the triple mutant lines achieved significantly higher average grain weights compared to their respective wild types. Notably, the line did not exhibit a reduction in grain number, thereby enhancing grain yield per spike. By contrast, the triple mutant line showed a reduced grain number per spike, with no significant change in overall yield. expression peaked at 10 days after anthesis (DAA), and its effect on grain weight over the WT became apparent after 15 DAA. In contrast, gene disruption in the triple mutant line increased ovary size at anthesis, leading to improved grain weight above the WT from the onset of grain filling. These findings suggest that the trade-off between grain weight and number could be attributed to the overlapping of the critical periods for the determination of these traits.
PubMed: 38919825
DOI: 10.3389/fpls.2024.1380429 -
Ecology and Evolution Jun 2024Genetic diversity can modulate a population's response to a changing environment and plays a critical role in its ecological function. While multiple processes act to...
Genetic diversity can modulate a population's response to a changing environment and plays a critical role in its ecological function. While multiple processes act to maintain genetic diversity, sexual reproduction remains the primary driving force. Eelgrass () is an important habitat-forming species found in temperate coastal ecosystems across the globe. Recent increases in sea surface temperatures have resulted in shifts to a mixed-annual life-history strategy (i.e., displaying characteristics of both annual and perennial meadows) at its southern edge-of-range. Given that mating systems are intimately linked to standing levels of genetic variation, understanding the scope of sexual reproduction can illuminate the processes that shape genetic diversity. To characterize edge-of-range eelgrass mating systems, developing seeds on flowering shoots were genotyped from three meadows in Topsail, North Carolina. In all meadows, levels of multiple mating were high, with shoots pollinated by an average of eight sires (range: 3-16). The number of fertilized seeds (i.e., reproductive success) varied significantly across sires (range: 1-25) and was positively correlated with both individual heterozygosity and self-fertilization. Outcrossing rates were high (approx. 70%) and varied across spathes. No clones were detected, and kinship among sampled flowering shoots was low, supporting observed patterns of reproductive output. Given the role that genetic diversity plays in enhancing resistance to and resilience from ecological disturbance, disentangling the links between life history, sexual reproduction, and genetic variation will aid in informing the management and conservation of this key foundation species.
PubMed: 38919644
DOI: 10.1002/ece3.11608 -
Horticulture Research Jun 2024Accurately predicting flowering phenology in fruit tree orchards is crucial for timely pest and pathogen treatments and for the introduction of managed pollinators....
Accurately predicting flowering phenology in fruit tree orchards is crucial for timely pest and pathogen treatments and for the introduction of managed pollinators. Making predictions requires large datasets of flowering dates, which are often limited to single locations. Consequently, the resulting phenology predictions are not representative across larger geographic areas. Citizen science may offer a solution to this data gap, with millions of biological records across a wide range of taxa recorded annually. Here, a new citizen science platform called 'FruitWatch' is introduced, monitoring the flowering dates of fruit trees in Great Britain. The objectives of this study are to assess the suitability of FruitWatch submissions to (i) detect latitudinal variation in flowering onset dates, (ii) parameterize existing phenology modelling frameworks, and (iii) make predictions of flowering onset dates across Great Britain for a single year. Using data for four cultivars from 2022, linear models reveal significant latitudinal delays in flowering onset of as much as 1.49 ± 0.63 days per degree latitude further north (Pear 'Conference'), with significant delays also seen in Cherry 'Stella' (1.39 ± 0.48 days) and Plum 'Victoria' (1.22 ± 0.18 days). FruitWatch informed phenology modelling frameworks performed well for predicting flowering onset, with root mean square error values of predictions from validation datasets ranging between 4.6 ('Victoria') and 8.0 ('Conference') days. The parameterized models also provided realistic flowering onset predictions across Great Britain in 2022, with earlier flowering dates predicted in warmer areas. These findings demonstrate the potential of citizen science data to offer growers cultivar- and location-specific phenology predictions to help inform orchard management.
PubMed: 38919557
DOI: 10.1093/hr/uhae122