About Rhubarb Seeds...
On small scales rhubarb is normally propagated via root stock. The roots of a 2-3 year old plant form into a clump, each root looking something like a sweet potato. The roots must be pulled or cut apart. One 3 year old victoria plant will produce about 15 new plants from roots.
On larger scales, or where transportation is a problem, such as across some borders, plants are propogated by either seeds or tissue culture (i.e. cloned). Where possible seeds are not used because rhubarb is like most plants and does not 
breed true through the seeds...i.e. a large, robust parent plant may not result in a similar offspring through seeds. However, it may be possible to produce hybrids which at least breed true through the first generation hybrid ("F1" at plant parties). It may also be possible to create such a seed for a hybrid with the most desireable traits of several extant varieties. The most important characteristics for food plants would be the pure red nature of the smaller plants with the size, taste and robust health of the larger green varieties. 
For decorative varieties the desirable qualities include crinkled leaves, large leaves, and early or large flower heads. At High Altitude Rhubarb we have numerous varieties of rhubarb and run tests with seeds produced by cross-breeding the varieties. We have a number of goals in mind. These include: creation of an F1 hybrid with the robustness, size, quality, health and yield of the large, green varieties and the color of the pure red varieties; creation of a hybrid that is more heat-tolerant; creation of a hybrid that breeds true through seeds beyond F1. We could use help. If you would like to participate in our studies please contact us. We'd love to year from you.