Tagged: sexual selection

Botanists find out who’s the daddy

Growing a fruit is only one way of passing your genes on to the next generation if you’re a plant. You could also send pollen to another plant. But what factors influence siring success? Dorothy Christopher and colleagues have been reviewing the interaction between pollination and post-pollination processes in reproductive success. To successfully father a new plant, you have two problems. One is the difficulty of getting your pollen to a recipient. This can depend on pollinators getting the pollen safely from your anthers to another plant’s stigma. Once the pollen arrives it’s in competition with pollen from other plants. Getting...

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Dimorphotheca pollen is deposited onto a fly Corsomyza as it probes a flower for nectar.

Male reproductive success and floral trait evolution in animal-pollinated plants

More than 85% of flowering plant species require the services of foraging animal pollinators to transfer male gametes (pollen) to stigmas of potential mates. The vast majority (95-99%) of pollen grains produced by a plant never successfully fertilize ovules, and are instead lost during the complex and chaotic process of pollen transport. For example, some pollen grains fall to the ground as the pollinator picks up pollen or following intense gusts of wind. Other grains are deposited onto the pollinator, but then groomed to pollen carrying baskets or other locations where the grains will no longer contact stigmas of potential...

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Differential selection on pollen and pistil traits in relation to pollen competition in the context of a sexual conflict over timing of stigma receptivity

Sexual conflict and its evolutionary consequences are understudied in plants, but the theory of sexual conflict may help explain how selection generates and maintains variability in both plants and animals. In a recent study published in AoB PLANTS, Lankinen and Strandh show that pollen and pistil traits involved in a sexual conflict over timing of stigma receptivity in the mixed-mating annual Collinsia heterophylla (Plantaginaceae) are differentially advantageous during pollen competition depending on stage of floral development and varying pollen deposition schedules. Variation in success of these traits over floral development time may result from sexually antagonistic selection.

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Spear Thistle Flower

Defence dichotomy: coping with herbivores in air and water (Review)

Plant defence against herbivores is a crucial theme in the evolution of both plants and animals, yet it is expressed very differently in water and on land. Spines, hairs, and distance signalling are common in land plants but very rare in submerged aquatic plants. To account for this hitherto unrecognized dichotomy, Vermeij suggests that animal sensory capacities are in part to blame. Herbivores, pollinators and plant dispersers on land often rely on long-range visual or olfactory signals, whereas aquatic herbivores do so on a much smaller scale, all because of the contrasting properties of air and water. Both contact and...

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Sexual selection, pollinators and floral dimorphism

Sexual selection, pollinators and floral dimorphism

Sexual selection mediated by animal pollinators can potentially drive dimorphism in plant populations with unisexual flowers. Yakimowski et al. compare variation in floral traits between populations of Sagittaria latifolia with combined versus separated sexes. Male flowers are larger than females but the pattern is reversed for daily display size, probably because of improved pollen dispersal associated with prolonged male function. Both patterns are predicted signatures of sexual selection.  

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