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  • 2010-2014  (6)
  • 1
    Publication Date: 2014-09-12
    Description: The last meal of a horse that lived in the northern part of the Sakha Republic (Russia) c . 5400 years ago was studied using pollen, spores, botanical macroremains, lipid composition, and ancient DNA in order to reconstruct its components. Pollen of Poaceae was superabundant, but this may be because of over-representation as a consequence of grazed inflorescenses of grasses. We evaluate the paleo-environmental indicator value of the different methods applied. Botanical macrofossils and chemical data show what the animal had eaten. Pollen grains and the aDNA record also give information about taxa that occurred elsewhere in the landscape. The combined data point to an open landscape of a coastal tundra dominated by graminoids (Poaceae, Cyperaceae) with a limited amount of Birch and Alder.
    Print ISSN: 0959-6836
    Electronic ISSN: 1477-0911
    Topics: Geography , Geosciences
    Published by Sage
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  • 2
    Publication Date: 2024-01-12
    Description: \xe2\x80\xa2 Premise of the Study: Although many species in the orchid genus Coelogyne are horticulturally popular, hardly anything is known about their pollination. Pollinators of three species were observed in the fi eld in Nepal. This information is urgently needed because many orchid species in Nepal are endangered. Whether the exudates produced by extrafl oral nectaries played a role in protection against herbivory was also investigated. \n\xe2\x80\xa2 Methods: Pollinators of C. fl accida , C. nitida , and Otochilus albus were filmed, captured, and identifi ed. Ant surveys and exclusion experiments were carried out. To investigate whether pollinators are needed for fruit set, plants were wrapped in mesh wire bags. Infl orescence stems were examined with microscopy. Fehling \xe2\x80\x99 s reagent was used to detect sugars in extrafl oral exudates. \n\xe2\x80\xa2 Key Results: Coelogyne fl accida and C. nitida need pollinators to set fruit and are pollinated by wild bees identifi ed as Apiscerana . Otochilus albus was found to be pollinated by Bombus kashmirensis. Extrafl oral nectar was found to be exuded by nectary-modifi ed stomata and contained high amounts of sugars. Different species of ants were observed collecting these exudates. A signifi cant difference was found in damage infl icted by fl ower and leaf-eating beetles between C. nitida plants living in trees with ant nests and those in ant-free trees. \n\xe2\x80\xa2 Conclusions: Floral syndromes include scented and colored trap fl owers without reward to their pollinators. All orchids investigated exude extrafl oral nectar by nectary-modifi ed stomata. This nectar was found to fl ow from the phloem to the stomata through intercellular spaces in the outer parenchymatous layer of the inflorescence.
    Keywords: ants ; Apis cerana ; Bombus kashmirensis ; Coelogye ; herbivory ; nectary-modified stomata ; Nepal ; Otochilus ; Pholidota ; pollination
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
    Format: application/pdf
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  • 3
    Publication Date: 2024-01-12
    Description: Pollination based on insect deception has been debated in the scientific community since it was first reported over two hundred years ago. A vast majority of deceptive syndromes occur within the orchid family. While many cheating flowers have been described and are well known, there are still many curious cases that need further investigation. One prime example of such a case is Cypripedium calceolus, known as European lady\xe2\x80\x99s slipper orchid. While the flower has been of interest to many prominent scientists for over a century, its pollination is still not fully understood. Both visual and olfactory cues seem to play an important role in pollinator attraction. In this study we focussed on the olfactory cues in order to explore their relationship (in future experiments) with floral visual cues, including the unique asymmetry of these flowers. Some of the plants\xe2\x80\x99 floral fragrances were used in Electroantennography experiments. Eleven chemical compounds were applied to the antennae of Bombus terrestris and Apis mellifera. Even though these species are not regular visitors of C. calceolus, we were interested to see whether there were common principles in their responses to the flowers\xe2\x80\x99 scent that might justify extrapolating to other pollinator species such as sand bees that get trapped in these orchids and fly out of the flowers afterwards with pollen smeared on their body. The results show that while both species react similarly to most of the odours, some of the tested acetates induced a significantly greater reaction in B. terrestris antennae. These acetates play an important role in bumblebee pheromones, but their relevance for the natural pollinators of C. calceolus remains to be confirmed to see whether chemical mimicry by these flowers is deliberately employed to attract pollinators.
    Keywords: bees ; behaviour ; chemical mimicry ; deception ; EAG ; pollination
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
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  • 4
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    In:  Contributions to Zoology vol. 81 no. 2, pp. 75-78
    Publication Date: 2024-01-12
    Description: Left-right asymmetry patterns in the body shapes of animals and plants have been a continuous source of interest among biologists. Recently, inroads have been made to developing a coherent research programme that makes use of the unique fact that chiral patterns may be studied (and generalities deduced) by comparisons across many unrelated groups, even across Kingdoms. The papers delivered at the symposium \xe2\x80\x98Evolution of Chirality\xe2\x80\x99 during the 2011 European congress of evolutionary biology (ESEB) provide examples of the various research programs that are currently developing within this field. The present paper provides a summary of the symposium, an introduction to this Special Issue of Contributions to Zoology, as well as suggestions for further collaboration among left-right asymmetry researchers.
    Keywords: chirality ; development ; evolution ; evo-devo
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
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  • 5
    Publication Date: 2024-01-12
    Description: De taxonomie van Viola stagnina (Melkviooltje) is bestudeerd met behulp van elekronenmicroscopisch onderzoek, een transplantatie-experiment, kruisingen en chromosoomtellingen. Uit de analyses blijkt dat de hoogte van de planten, bladkleur, grootte en vorm van de steunblaadjes en vorm van de stijl veel fenotypische variatie vertoont tussen de twee vormen van V. stagnina die binnen Nederland voorkomen, te weten var. stagnina (Veenmelkviooltje) en var. lacteoides (Heidemelkviooltje). Het door ons uitgevoerde transplantatie-experiment laat zien dat een aantal van deze kenmerken be\xc3\xafnvloed wordt door abiotische factoren zoals licht en vochtigheid. Er zijn echter ook kenmerken zoals lengte van de bladsteel en bladschijf die significant van elkaar blijven verschillen onder gelijke omstandigheden en dus veroorzaakt worden door genetische differentiatie. Een kruisingsexperiment toont aan dat planten bestoven met pollen van de andere vorm nog steeds levensvatbare zaden opleveren, hetgeen ook verwacht mag worden bij kruising van taxa die nog tot dezelfde soort behoren. Er werd ook geen verschil in het aantal chromosomen gevonden. Op basis van al eerder gevonden genetische en morfologische verschillen en de uitkomsten van de hier gepresenteerde gegevens vinden we dat de endemische vorm van V. stagnina als aparte vari\xc3\xabteit lacteoides erkend moet blijven worden. Voor de taxonomische status van aparte (onder)soort verschillen de twee vormen nog te weinig en overlappen ze geografisch teveel.
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
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  • 6
    Publication Date: 2024-02-09
    Description: Indian snakeroot (Rauvolfia serpentina) is a valuable forest product, root extracts of which are used as an antihypertensive drug. Increasing demand led to overharvesting in the wild. Control of international trade is hampered by the inability to identify root samples to the species level. We therefore evaluated the potential of molecular identification by searching for species-specific DNA polymorphisms. We found two species-specific indels in the rps16 intron region for R. serpentina. Our DNA barcoding method was tested for its specificity, reproducibility, sensitivity and stability. We included samples of various tissues and ages, which had been treated differently for preservation. DNA extractions were tested in a range of amplification settings and dilutions. Species-specific rps16 intron sequences were obtained from 79 herbarium accessions and one confiscated root, encompassing 39 different species. Our results demonstrate that molecular analysis provides new perspectives for forensic identification of Indian snakeroot.
    Keywords: forensic science ; DNA typing ; Apocynaceae ; CITES ; medicinal plants ; Rauvolfia ; rps16 intron
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
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