NUCLEAR GAMETOPHYTIC GENES FROM CHROMOSOME ARM 1RS IMPROVE REGENERATION OF WHEAT MICROSPORE-DERIVED EMBRYOS

The effect of the IRS chromosome arm from rye on plant regeneration fr om microspore-derived embryos was studied using anther culture technol ogy with genotypes carrying the IBL-IRS translocated chromosomes, the normal wheat chromosome IBL-IBS, and ditelosomic lines DT IBS and DT I BL. A significant difference was observed in microspore-derived green plants between chromosome structure concerned with IRS and IBS arms. A n analysis of the inheritance of the IB-IR translocation was performed on the basis of the frequency of male gametes IBL-IRS in the microspo re-derived green plants and that of the IB-IR translocation inherited through the pollen or the egg cell from structurally heterozygous hybr ids IBL-IBS/IBL-IRS. Both the normal IB and the translocated IBL-IRS c hromosomes were sexually transmitted through the pollen grains with th e same frequency. The IBL-IRS chromosome is only transmitted through 4 5% of the egg cells. On the contrary, two-thirds of the microspore-der ived green plants regenerated from the anther culture experiments poss ess the translocated chromosome. The involvement of the rye chromosome arm IRS from 'Aurora' on regeneration capacity of the microspore-deri ved embryos has been proposed through the effect of a ''gametophytic g ene.''