Hermsen, J.G.Th2014-09-182014-09-181984-05Iowa State Journal of Research, May 1984, Vol.58 No.4http://hdl.handle.net/123456789/5823It is shown that the extent to which wild species and primitive forms are utilized in crop breeding depends on the nature of the crop and on the availability and accessibility of the species. Useful genes derived from related species are predominantly those for resistance to diseases and insects, but adaptability, quality traits, and yield also could be improved by including wild species and primitive forms in breeding. Some special applications are the induction of haploids, (re)synthesis of allopolyploids and induction of cytoplasmic male sterility. Gene transfer is usually brought about through normal recombination, but, in cereals, induced recombination and translocation have also been applied. It is emphasized that the normal recombination is most effective. This implies that species that are closely related to crop plants are to be preferred. The breeder should resort to remote species only if they carry unique genes not available in more closely related species. The concept of prebreeding within wild and primitive species before crossing with cultivated forms is explained along with the concept of column breeding for polygenic traits. An integrated breeding procedure based on these concepts is presented. The concepts, though basically correct, need to be critically evaluated as to their practicability in breeding. Pre- and postzygotic barriers to interspecific hybridization are listed along with ways to overcome them. Evolutionary and genetic aspects of interspecific barriers are discussed and data presented on the genetic control of crossability of species. Some experimental data in Solarium and grass species clearly illustrate the nature and extent of various interspecific barriers in remote hybridization. Index Descriptors: interspecific hybridization, crossability, prebreeding, column breeding, interspecific barriers, Solatium, grasses, and introgression.enArticle