Life Sciences Commons^™

Chromosome Counts For Packera Paupercula Variety Gypsophila, Chad Larson

Journal of Undergraduate Research at Minnesota State University, Mankato

New plant species develop when diploid plants (having two sets of chromosomes) spontaneously double their chromosomes and the resulting tetraploids (having four sets of chromosomes) are no longer able to back cross to diploid members of the population. The North American plant species Packera paupercula (balsam-leafed ragwort), is widespread and morphologically diverse. An isolated group of populations from the chalky soils of west-central Alabama was recently named Packera paupercula variety gypsophila (the chalk-loving balsam ragwort). The variety’s large diameter pollen grains suggest it may be tetraploid. This project attempts the first chromosome count for the variety by examining cells undergoing …