I can understand linebreeding in animals.
"Linebreeding is mating animals so that their descendants will be kept closely related to some animal regarded as unusually desirable. It is accomplished by using for parents animals which are both closely related to the admired ancestor but are little if at all related to each other through any other ancestors. "
"WHY LINEBREEDING IS PRACTICED
Animals do not live long enough for the breeder to get all the sons and daughters he wants from the best ones. Often an animal is old or even dead before its real superiority is recognized. If its sons and daughters are mated to unrelated individuals, the offspring will get only about one-fourth of their inheritance from this outstanding grandparent. If these in turn are mated to unrelated individuals, the influence of the outstanding ancestor is again halved. Unless some form of
linebreeding is practiced, it is only a matter of three or four generations until even the most outstanding animal's influence is so scattered and diluted that no one descendant is very much like it. Linebreeding takes advantage of the laws of probability as they affect Mendelian inheritance to hold the expected amount of inheritance from an admired ancestor at a nearly constant level instead of letting it be halved with each generation, as would happen if all the matings were outbreeding."
However, the "best ones" in a perennial plant do not ever die. In a plant such as daylilies where thousands of potential "best ones" are registered every year and cultivars can become outdated rapidly, why linebreed?
