The second approach requires more work. Required are cultures established from single basidiospores, and paired to ascertain whether geographically separated collections recognize each other and can successfully mate. Spores must germinate under laboratory conditions, and resulting mycelia must participate in mating experiments. One uses the property of all mushroom species to produce various enzymes. But these enzymes are not always identical, and often we see evident differences between mushroom collections by comparing their enzymes via electrophoresis.
Electrophoretic differences reflect differences in the underlying genes encoding an enzyme.
Mycology at the University of Tennessee comprises of two faculty labs. One is supervised by Ron Petersen , the other by Karen Hughes . A case in point might help. We had collected and cultured isolates of these species from most of eastern North America and from northern Europe, so we had breeding stock as well as fresh and dried fruitbodies with which to work. One of Scott's pets was Marasmius scorodonius .