New rapid-cycling plant breeding project

Did you know that beyond Fast Plants (rapid-cycling Brassica rapa) there are rapid-cycling varieties of other Brassica species? Enter the fascinating world of Brassica oleracea!

Bred at the University of Wisconsin-Madison by Professor Paul Williams, rapid-cycling Brassica oleracea were initially developed for Brassica disease resistance research. While they’ve played important roles in research, their educational potential has yet to be fully explored.

Our mission? To refine a classroom-friendly population of rapid-cycling Brassica oleracea. What's the most exciting part of this project? This line of Brassicas may have the potential to demonstrate genetic linkage, a concept not easily taught with Wisconsin Fast Plants!

Genetic linkage, a phenomenon where neighboring genes on a chromosome tend to be inherited together, challenges Gregor Mendel’s Law of Independent Assortment (which claims genes are inherited independently). Importantly, genetic linkage is an exception to Mendel’s law.

While Wisconsin Fast Plants are terrific for teaching Mendelian inheritance, we have yet to discover any easily observable, linked traits in Fast Plants. Yet populations of rapid-cycling Brassica oleracea show some intriguing potential! It all started with Paul Williams’s observation of two phenotypic traits that tend to be associated with each other in Brassica oleracea: an anthocyaninless (non-purple) pigmentation and a significantly reduced growth habit that we've dubbed super-dwarf.

At a mere 1% frequency, these potentially linked traits piqued our curiosity! So, in order to select for these low frequency traits AND preserve genetic variation we planted over 20,000 seeds of rapid-cycling Brassica oleracea and began screening for desired traits.

Paul Williams and Dan Lauffer examine and select from trays of Brassica oleracea seedlings

The reward? Selection on our breeding population confirms Paul’s initial observations; there does seem to be a linkage between the super-dwarf and anthocyaninless traits! Although only about 200 plants out of 20,000 made the selection cut, the selected plants will produce seed for the next generation, and we are enthusiastic about this new direction.

Many generations of plant breeding and testing must unfold before this variety is ready for classroom use. Still, we are excited about the potential, and we’ll continue to keep you posted, from our lab…to your classroom!