Each year I have an undergraduate student work in my program. Usually they help with crossing in the spring and do another small project of their own. Last year, Lauren M. took on a project looking very closely at raspberry seed size and shape. The inspiration for this project was some work done at the USDA-ARS Germplasm Repository and Oregon State University. In 2010, they published a manual on a way to identify blackberry cultivars by looking at thier seed size and shape. Here is a link to that work:
Lauren spent many hours cleaning and photographing seeds of 16 different raspberry and blackberry cultivars. Here are a couple examples of what she found. Once you start looking closely, you can see how different two varieties can look. We are using this as one way to catalog our breeding material.