Wide Crosses in Herbaceous Perennials1

Abstract

Abstract A wide cross may be defined as one in which the production of viable hybrid seed is difficult when only traditional methods are using for growing or pollinating the respective parents. It assumes a level of knowledge and skill on the part of the breeder that permits him or her to be successful in making crosses among compatible parents such as those in the “primary gene pool” described by Harlan and deWet (32). Wide crosses would include hybridization of plant materials in that “primary gene pool” with those in the secondary or tertiary gene pools — or beyond. The definition implies that the breeder has a good understanding of the morphology of the reproductive organs of the cultivars/species being used, is aware of existing incompatibility mechanisms, and has access to equipment needed to manipulate plants and the environment in which they are grown. Wide crosses could include those made between: 1) species within a genus; 2) cultivars or species within a genus that differ in ploidy level; 3) cultivars or species from different genera within a family, and, 4) cultivars or species from genera in different families.