Anther culture and chromosome reduction in wheat x Thinopyrum wide crosses

There is little information on the anther culture response and cytogenetic nature of pollen-derived calli and regenerants of wide crosses in wheat. Th e anther culture response of three Thinopyrum species (wheatgrasses), their hybrids and backcrosses with wheat, and the chromosome composition of call i and regenerants were studied to determine the feasibility of efficient ch romosome elimination and production of alien addition lines from wide cross es by anther culture in comparison with conventional backcrossing and selfi ng. Wide hybrids between wheat and wheatgrasses had up to a 2% callus induc tion response. Pollen sterility of wide hybrids and recalcitrance of wheatg rass parents may largely be responsible for their low response, in addition to culture stage, media and environmental factors. Anther culturability im proved in backcrosses as the proportion of wheatgrass chromosomes decreased and fertility increased. Overall the wheat x Th. trichophorum cross had th e best response; that is up to 37% callus induction from some BC2 plants. A large variation was found in chromosome numbers in callus roots examined i n the BC2 generation. Mixoploidy was frequent. Data indicated that the chro mosome numbers in the pollen-derived organs/plants can be reduced to produc e alien addition lines.