Primulaceae is an example. Hybrids are produced by a cross between two different species or between divergent members of the same species. Hybrids are favored because they often have hybrid vigor - produce more and larger seeds. Hybrids are often sterile due to chromosome incompatibilities. One way to break through the sterility barrier is via polyploidy.
Polyploids occur naturally and can also be induced artificially.
Breeding - takes advantage of inbreeding to produce homozygous individuals. Inbred, homozygous lines can be produced by crosses between one of the parents with the offspring or crosses between offspring. Inbred lines can then be used to produce hybrids. Example - take a wild plant with a desirable trait that is closely related to an agriculturally important crop. Cultivation of hybrids in centers of origin of crop plants can greatly reduce germ plasm base.