A Seed Lab Exercise In Plant Propagation

While most plant propagation laboratory exercises with seeds address such topics as breaking dormancy, germination, and viability testing, additional ideas can be derived from seed technology courses.   In the plant propagation course at the University of Hawaii, students collect fruits, extract the seeds, and carry out various dormancy-breaking, germination, and viability exercises on their own seeds.  Over the years, many different kinds of seeds have been accumulated.  Some are readily associated with the plants they came from because of special characteristics such as colored arils, presence of fibers, or other superficial features.  A set of cards has been created using 10 different seeds glued onto them. Students are asked to create a key to distinguish among the different kinds of seeds using criteria such as size, shape, texture, color, position of the attachment point (hilum), presence of external features, etc.   This leads to a capacity to identify seeds and to determine contaminants in seed lots.  Some of these factors also lead to techniques to separate seeds from chaff and contaminating seeds.   Additional advantages of the exercise are that no special growing-out space is required and it can be used near the end of a semester when there is insufficient time to grow out seedlings.