Euphytica 32 (1983) 17-3 1 CURRENT STATUS OF WIDE HYBRIDIZATION IN WHEAT’ H.C.SHARMAandB.S.GILL Department ofPlant Pathology, Kansas State University, Manhattan, KS 66506, USA Received 19 March 1982 INDEX WORDS Triticum. Aegilops, Secale, Agropyron, El.ymus. Haynaldia. Hordeum, wide hybridization, intergeneric crosses, alien gene transfer. SUMMARY Current status of wide hybridization in wheat is considered in the light of the number of hybrids produced, the number of genes transferred to commercial cultivars and their use in world wide agricuture. Some original results are presented and results of other authors are compiled to provide update information regarding wide crosses in wheat. Barriers to wide hybridization and progress made in overcoming such barriers are discussed. Areas requiring more research are indicated. INTRODUCTION Wide hybridization is an important cytogenetic and plant breeding tool in wheat. Wide hybridization, including both interspecific and intergeneric hybridization, is the first step to introduce alien variation and to transfer desirable traits from wild species into cutivated species. It provides a means to study genome structure and phylogeny, and sometimes may provide a new taxon or a new crop. Despite that, up-to-date informa- tion on wide hybridization in wheat is lacking. BARELLE made the first interspecific cross in wheat in 1806 (CIFERRI, 1955). Since then wide hybridization has been practiced widely in wheat and the literature contains voluminous but scattered information. KIHARA (1937) reviewed early work on wide- hybrids, especially wheat-degilops hybrids. WHITE (1940) reviewed early work on wheat-Agropyron hybrids. SMITH (1943) summarized the investigations on crossing Triticum and other grasses with particular emphasis on hybridization of T. durum DESF. and T. aestivum L. with Agropyron species. KNOBLOCH (1968) prepared a list of crosses in Gramineae. This list is by no means complete and correct. In the thirteen years since then, there has been no such compila- tion. KIMBER & ABUBAKER (1979) collected comprehensive information of meiotic analyses. STALKER (1980) presented an overview of transfer of useful genes from wild species to related field crops including wheat. The work on wide crosses in wheat will be reviewed with respect to successful hybri- dizations and alien genetic transfers. Current status of wide hybridization in wheat will be considered in the light of the number of hybrids produced, the number of genes transferred to commercial cultivars and their use in worldwide agriculture. Bar- ‘Contribution No. 82-154-j, Kansas Agricutural Experiment Station, Manhattan, KS 66506 USA. 17