Sunday, May 6, 2007
Julie's New and Hot (Week 6)
Horsenettle (Solanum carolinense)
"Male and bisexual flowers studied"
From Science Daily on May 2, 2007
This article summarizes the results from studies published in The American Naturalist about the "evolutionary engima" in which both male and bisexual flowers on the same plant. This type of sexual strategy is used by about 4000 different plant species. Researchers studying the horsenettle found that male flowers increase the reproductive success of both males and females. They present possible explanations such as:
1. Making smaller male flowers would save resources that could be used for other needs such as seed development.
2. Male flowers may be more attractive to pollinators.
3. Male flowers may required less pollen from pollinators, making more pollen available overall.
I found this interesting because before I had thought that the main advantage of this sexual strategy would be to increase genetic diversity. This makes me wonder about other species, such as the hemaphroditic nematode C. elegans. In a natural population of C. elegans, males are not common. However, in the lab, males can be induced by heat shock or by maintainence through hemaphrodite and male crosses (as male sperm is more successful than hemaphrodite sperm). So why do males emerge during heat shock? Why is male sperm more successful?