Chloroplast DNA deletions associated with wheat plants regenerated from pollen: possible basis for maternal inheritance of chloroplasts.

Albinism in plants regenerated from pollen by anther culture may result from the same mechanisms as postulated to be responsible for maternal inheritance of chloroplasts. Consistent with this view, Southern blotting was used to show that large regions of the chloroplast genome (over 80% in one case) were deleted in the major ctDNA molecules present in eight albino wheat plants regenerated from separate pollen calluses. A wide variety of deleted ctDNA molecules was present in these plants. Most albino plants appeared to contain a heterogeneous population of ctDNA molecules. Albino plant 6 contained one major type of deleted ctDNA molecule that had a circular 39 kb restriction map. The retention of only two Pst l (unaltered in size) fragments in albino plant 7 may delimit a region of ctDNA that contains a replication origin.