Sunday, January 6, 2013

Guest Blog: Yuval Sapir and 50 Shades of Pink

A field of wild anemones flowering in early January.
Note that most of the flowers are not red.
Dr. Yuval Sapir is Director of the Tel Aviv University Botanical Gardens

The crowned anemone, Anemone coronaria, is well-known for its red flowers. But its flowering season, January to March, is also characterized by non-red anemone flowers, particular early in the season. 

While the red flowers are pollinated by glaphyrid beetles, the non-red ones are pollinated by any possible insect hovering around in the winter. All except beetles. But no worries - beetles are anyhow not around in this early period of the winter (January). Indeed, the non-red anemones flower earlier than the red ones, even where they grow in the same place. 

Another difference between the two types (red and non-red) is that while the red ones are common everywhere, from extreme desert to the northernmost Mediterranean parts of Israel, the non-red anemones are unique to humid Mediterranean ecosystems. This is probably due to drought tolerance trait linked to the red-color allele. The genetic system for the color of the anemone includes two possibilities (alleles): red, or non-red. Red is recessive, this means that a only if both alleles are red, the flowers are red. If one of the alleles is non-red, the flower will be any other shade of pink, from white to purple. Despite the superiority of the non-red alleles, they are non-exist in the southern populations, in the dry Mediterranean and in the desert. This linkage between flower color and environmental adaptation is interesting, and has not been extensively studied.

6 comments:

  1. Look at Israel's pollinator population. Plant going non-red may be because many insects have no red (650nm) wavelength receptor, making red flowers hard to find.
    Some insects do have the 650nm stimulate their active green 540nm receptor & so those insects could still pollinate red flower. But presume those insects are not active in Israel then.
    If the flower has a nectar guide the angle of the Israeli winter sun or overcast sky may make the reflectance spectrum look different. A red petal flower might interfere with the nectar guide & not match pollinators preference. Moonlight or starlight, for example, alters reflectance spectrum & I think anemone flowers droop night time to spare their pollinators wasting e.nergy during confusing signal time


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    1. Yuval has replied to you below. Thanks for the comment!

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  2. Anemones have no nectar, and no nectar guides, so it doesn't matter where the light comes from. While the red anemones are pollinated by glaphyrid beetles who can see red (see the next post in this blog), the non-red anemones are flowering earlier and are pollinated by relatively narrow spectrum of insects. Most are honey bees and flies, which do not see red.

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  3. 50 shades of pink!
    Awesome post!
    Thank you for sharing!

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