AABB - BBBB Crosses
Updated: 15 May, 2002 Returning? Jump to Photos
In the present system, any cultivar that has one complete set of aril chromosomes but more non-aril than aril is classified as an OB-, RB-, or OGB-, depending on whether it has onco heritage, regelia heritage, or both. These are commonly called quarterbreds, because that was the predominant type under the old quantum system and the term was adopted for the modified chromosome set system to apply to anything at least one-quarter but less than one-half aril.
This page presents one type of quarterbred, first-generation seedlings, from crosses between the fertile family of halfbreds and a non-aril (such as a TB). These crosses produce only ABBB-type chromosome complements and are thus relatively easy to evaluate.
All have limited fertility, at best, but this is often enough to be effective when used in more complex programs.
Click on a thumbnail to see a larger version of the photo.
