Female and male sterility cause low fruit set in a clone of the `Trevatt' variety of apricot (Prunus armeniaca)

This study investigated ovule and anther structure of the `Trevatt Blue' variety of apricot (Prunus armeniaca) using bright field microscopy following reports of low fruit set. Ovules and anthers from fertile `Moorpark' and `Trevatt Knight' flowers were compared with those of the `Trevatt Blue'. In the `Moorpark' and `Trevatt Knight' ovules, all reproductive structures were present including embryo sacs with a complete set of eight nuclei and the anthers contained mature pollen grains. Multiple ovules which were small and retarded in development were present in the `Trevatt Blue' apricot flowers and the anthers contained degenerated microspores, with some failure in tapetal breakdown. This is the first report of a simultaneous mutation in both female and male function in apricot. # 1999 Elsevier Science B.V. All rights reserved.