The purpose of this invention is to preserve the germplasm which are compatibly graftable for each other in the specific environment. The preserved [interstock] is protected by the rootstock which is used to the stresses from underground, and the “topstock” which is tolerant to the stresses from aboveground.
The compound plant (Top-interstock-rootstock) is different from the traditional combinations which the interstock impove the impatibility between scion and rootstock. The interstock in this design must be compatible with its top and rootstock parts and keep “paradormancy” in the germplasm repository.
Preservation of pear species & cultivars will be presented to describe the details of the techinque.