Teaching recurrent selection in the classroom with Wisconsin fast plants

Abstract

Plant breeding is a process that is difficult to compress into laboratory exercises for the classroom. At the heart of plant breeding is the act of selection, a process whereby differential reproduction and survival leads to changes in gene frequency. Given the relatively short span of an academic semester, it has been difficult for students to gain experience with the practice of selection using plant materials. Nearly 15 years ago, P.H. Williams developed Wisconsin Fast Plants, a model system for teaching plant biology in a classroom setting. Wisconsin fast plants are rapid-cycling versions of various Brassica species amenable to a variety of genetic studies due to their short life cycle and ease of handling. This paper describes the development of a model system using Brassica rapa L. fast plants for teaching the cyclical selection process known as recurrent selection in the context of a course on plant breeding. The system allows for up to three cycles of recurrent selection during a single 15-week semester and enables students to gain experience in planting, selection, pollination, and seed harvest during each cycle. With appropriate trait choice, phenotypic changes resulting from selection can be visualized after just three cycles. Using the Fast Plant model, recurrent selection can be practiced successfully by students in the classroom.