"One of the things that makes this so amazing is that where we expected to see 12 chromosomes from each parent (the polyploid has 24 chromosomes), it turns out there aren't 12 and 12, there are 11 from one parent and 13 from the other, or 10 and 14," Soltis said. "We're hoping through some ongoing studies to be able to link these results with the occurrence of another interesting phenomenon the loss of genes and also see what effect these changes have on the way the plants grow and perform."
The polyploid's two parent species, Tragopogon dubius and Tragopogon pratensis, were introduced to the U.S. in the 1920s. Because its flower only blooms for a few hours in the morning, Tragopogon miscellus is often referred to as "John-go-to-bed-at-noon," and its common name is goatsbeard. It looks like a daisy except for being yellow in color.
"People have looked at these chromosomes before, but until you could apply these beautiful painting techniques, you couldn't tell which parent they each came from," Soltis said.
Of the six populations examined from Washington and Idaho, 69 percent of the plants showed a deviation from the expected 12 and 12 chromosome pattern.
"In order for most plants to be able to interbreed successfully, their chromosomes need to match up," Chester said. "That doesn't necessarily happen when you don't have equal numbers, so there may be some chromosomal barriers to fertility that develop as a result of this sort of chromosomal variation. This mechanism may also explain low fertility in other plants, such as crops. This is something we are looking into with Tragopogon."
The two-year study was funded by the National
|Contact: Pam Soltis|
University of Florida