590 research outputs found

    Inherited biotic protection in a Neotropical pioneer plant

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    Chelonanthus alatus is a bat-pollinated, pioneer Gentianaceae that clusters in patches where still-standing, dried-out stems are interspersed among live individuals. Flowers bear circum-floral nectaries (CFNs) that are attractive to ants, and seed dispersal is both barochorous and anemochorous. Although, in this study, live individuals never sheltered ant colonies, dried-out hollow stems - that can remain standing for 2 years - did. Workers from species nesting in dried-out stems as well as from ground-nesting species exploited the CFNs of live C. alatus individuals in the same patches during the daytime, but were absent at night (when bat pollination occurs) on 60.5% of the plants. By visiting the CFNs, the ants indirectly protect the flowers - but not the plant foliage - from herbivorous insects. We show that this protection is provided mostly by species nesting in dried-out stems, predominantly Pseudomyrmex gracilis. That dried-out stems remain standing for years and are regularly replaced results in an opportunistic, but stable association where colonies are sheltered by one generation of dead C. alatus while the live individuals nearby, belonging to the next generation, provide them with nectar; in turn, the ants protect their flowers from herbivores. We suggest that the investment in wood by C. alatus individuals permitting stillstanding, dried-out stems to shelter ant colonies constitutes an extended phenotype because foraging workers protect the flowers of live individuals in the same patch. Also, through this process these dried-out stems indirectly favor the reproduction (and so the fitness) of the next generation including both their own offspring and that of their siblings, alladding up to a potential case of inclusive fitness in plants

    Genetic diversity of Tamarindus indica populations: Any clues on the origin from its current distribution?

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    Tamarindus indica is a domesticated species of high economic value for the Sahel region. Despite this importance, very few data is available on its diversity as well as its structure leading to controversialdiscussions on its origin. Thus it is questionable whether the knowledge of its genetic diversity and organisation may help in identifying the area of its origin. We have studied 10 populations using markers RAPDs with the seeds collected from Asia (India and Thailand), Africa (Burkina Faso, Senegal, Kenya and Tanzania), from three islands (Madagascar, Réunion and Guadeloupe). The results showed that T. indica has a high intra population genetic variability with a higher value obtained in the population from Cameroon. This high intra-population variability did not allow us to determinate the origin of the species. However, if we take into account the paleontological and anthropological results, we can assume that T. indica has an African origin

    Breeding system and pollination biology of the semidomesticated fruit tree, Tamarindus indica L. (Leguminosae: Caesalpinioideae): Implications for fruit production, selective breeding, and conservation of genetic resources

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    In this paper, we provide data on the breeding system of Tamarindus indica, examining fruit production as well as pollen tube growth under different controlled pollination experiments (open, cross and selfpollination). We discuss implications of the results for management for fruit production in Tamarind, conservation of genetic resources and the potential for selective breeding. Observation of the germination and the pollen tubes growth under various pollination modes show that the tamarind is an incompatible species partially. This incompatibility appears at the pre level zygotic (IE on the level of the stigmatic, style and ovary) and post zygotic by the abortion of seeds

    The probing behaviour of nymphs of Vanduzeea arquata and Enchenopa binotata (Homoptera: Membracidae) on host and non-host plants

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    1. Nymphs of Vanduzeea arquata Say have been found to be more host-specific in nature and to show a higher degree of selectivity in host discrimination experiments than nymphs of Enchenopa binotata (Say), It was hypothesized that this differential selectivity would be reflected in the probing behaviour of individuals placed on twigs of host and non-host plants. Probing behaviour was examined by direct observation of nymphs and by sectioning and staining the probed plant tissues. 2. All nymphs probed readily and for extended periods on both host and non-host twigs. E.binotuta nymphs showed no consistent differences in probing behaviour on hosts versus non-hosts, but V.atquuta nymphs were more likely to withdraw their stylets within 60 s when on non-host twigs and produced honeydew only when on their host species. V.urquatu nymphs reached the phloem sieve elements only when on host twigs and broke many cells in peripheral plant tissue layers while probing. E.binotata nymphs broke few cells and often reached the phloem of non-host as well as host plants. 3. Nymphs of V.arquata always reject non-host plants, apparently in the course of probing and prior to encountering the phloem sap. Chemical compounds released from ruptured parenchyma cells may act as probing stimulants or inhibitors. E.binotura nymphs often feed on non-host plants in a non-choice situation; their preferential settling on host twigs in discrimination experiments may reflect a tendency to abandon non-host twigs more readily than host twigs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72791/1/j.1365-2311.1984.tb00840.x.pd

    An extreme case of plant-insect co-diversification: figs and fig-pollinating wasps

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    It is thought that speciation in phytophagous insects is often due to colonization of novel host plants, because radiations of plant and insect lineages are typically asynchronous. Recent phylogenetic comparisons have supported this model of diversification for both insect herbivores and specialized pollinators. An exceptional case where contemporaneous plant insect diversification might be expected is the obligate mutualism between fig trees (Ficus species, Moraceae) and their pollinating wasps (Agaonidae, Hymenoptera). The ubiquity and ecological significance of this mutualism in tropical and subtropical ecosystems has long intrigued biologists, but the systematic challenge posed by >750 interacting species pairs has hindered progress toward understanding its evolutionary history. In particular, taxon sampling and analytical tools have been insufficient for large-scale co-phylogenetic analyses. Here, we sampled nearly 200 interacting pairs of fig and wasp species from across the globe. Two supermatrices were assembled: on average, wasps had sequences from 77% of six genes (5.6kb), figs had sequences from 60% of five genes (5.5 kb), and overall 850 new DNA sequences were generated for this study. We also developed a new analytical tool, Jane 2, for event-based phylogenetic reconciliation analysis of very large data sets. Separate Bayesian phylogenetic analyses for figs and fig wasps under relaxed molecular clock assumptions indicate Cretaceous diversification of crown groups and contemporaneous divergence for nearly half of all fig and pollinator lineages. Event-based co-phylogenetic analyses further support the co-diversification hypothesis. Biogeographic analyses indicate that the presentday distribution of fig and pollinator lineages is consistent with an Eurasian origin and subsequent dispersal, rather than with Gondwanan vicariance. Overall, our findings indicate that the fig-pollinator mutualism represents an extreme case among plant-insect interactions of coordinated dispersal and long-term co-diversification

    Permanent Genetic Resources added to Molecular Ecology Resources Database 1 February 2013-31 March 2013

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    This article documents the addition of 142 microsatellite marker loci to the Molecular Ecology Resources database. Loci were developed for the following species: Agriophyllum squarrosum, Amazilia cyanocephala, Batillaria attramentaria, Fungal strain CTeY1 (Ascomycota), Gadopsis marmoratus, Juniperus phoenicea subsp. turbinata, Liriomyza sativae, Lupinus polyphyllus, Metschnikowia reukaufii, Puccinia striiformis and Xylocopa grisescens. These loci were cross-tested on the following species: Amazilia beryllina, Amazilia candida, Amazilia rutila, Amazilia tzacatl, Amazilia violiceps, Amazilia yucatanensis, Campylopterus curvipennis, Cynanthus sordidus, Hylocharis leucotis, Juniperus brevifolia, Juniperus cedrus, Juniperus osteosperma, Juniperus oxycedrus, Juniperus thurifera, Liriomyza bryoniae, Liriomyza chinensis, Liriomyza huidobrensis and Liriomyza trifolii. © 2013 John Wiley & Sons Ltd.Peer Reviewe
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