There is nothing at all wrong or unaccepatable in any way with crossing corns of different morphs. In fact, that IS the reason there are so many color combinations from which to choose. They have all been selectively bred to produce the colors and patterns they exhibit by way of their crossing back and forth in their ancestry.
There are two areas in which some corn snake people do have concerns, however, when it comes to breeding. Not everyone shares the same values on these issues, but it is best to understand what the issues are just the same.
Hybridization/intergradation --
Creating hybrids is where some very popular lines of animals have had their origins, and a large number of people have absolutely no problems with them in any way. Others see the hybrids created as a threat to the continued purity of cornsnakes as a species in captivity.
The jungle corn, turbo corn and others like them are the products of hybridization, using non-rat snake species, and are fairly easily identified by their appearances. The creamsicle and others are created by using rat snake genes (most often times the Great Plains Rat snake), and these animals can look VERY much like a corn in every way.
The problem arises when those who are either dishonest about their snakes, or ignorant of their animals' true acestry, sell or breed their animals as if they were pure corn. Once the "alien" genetics are introduced to a line of animals, they are impossible to extricate, and when that situation becomes widespread, it is difficult, if not impossible, to keep it out of one's own collection.
Locality corns --
There is a small sub-set of corn enthusiasts who are concerned, not about the animal's genetics, as much as they are about the animal's locality of origin. These breeders can tell you the origin of collection of every snake in their possession, and all of the babies they produce descend from locality documented stock.
The Okeetee corn is, in the eyes of many, merely a pretty version of the normal corn, exhibiting a certain look. However, for locality breeders, an Okeetee is a corn that was either collected on, or descends from ancestors that were all collected on, the grounds of the Okeetee Hunt Club. Jasper County corns are those from a wider region in the same area, and the list continues from there.
Whenever you see an ad for an "okeetee" corn, you just to make two determinations in your own mind. A. Do you care about the locality information at all? and if you do, B. Is the animal being sold a real Okeetee (having come from documented locality stock), or is it a "lookeetee" (in that is a normal corn exhibiting that okeetee look, without respect to points of origins)? Both are absolutely fine paths to pursuit, but they shouldn't be confused with one another.
Hope that all helps a bit...
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Darin Chappell
Hillbilly Herps
PO Box 254
Rogersville, MO 65742