Hi Absent,

I'm no expert, but I'd imagine that bigeneric crosses between plants with similar 2n counts would increase the chance of obtaining a fertile hybrid or viable seed. As a rule, crosses between parents of differing 2n counts are difficult to impossible and any resultant seedlings are usually sterile. That's where a chromosone doubling agent such as colchicine is brought in to try and induce fertility. There was a previous thread on bigeneric hybrids that you may find interesting (link below).

Here is a link that might be useful: Bigeneric Hybrids Thread

The "hybrids" of oats and maize typically have all the oat chromosomes with one or two maize chromosomes.
http://www.intl-pag.org/4/abstracts/p167.html

Karl

Here is a link that might be useful: CybeRose & Bulbs

The paper linked below has pictures of some oat-maize lines.

Karl

Here is a link that might be useful: A Complete Set of Maize Individual Chromosome Additions to the Oat Genome