Irradiation of Acer buergerianum with Cobalt-60 for Sterility Breeding

Acer buergerianum Miq., commonly referred to as trident maple, is a commercially important ornamental landscape tree in the United States.  These apparently self-incompatible trees do not set seed when planted in isolation.  When two different genotypes of A. buergerianum are planted in close proximity, seed set becomes extremely problematic due to the tremendous proliferation of seed and their ability to disperse, germinate, and thrive in the landscape.  For these reasons sterility is a highly desirable trait.  No sterile cultivars have been developed for this species as of 2016.  A common method for obtaining sterility in a population is genetic mutation via irradiation.  This study examined dosage effects of Cobalt-60 (⁶⁰Co) on A. buergerianum by examining treatmens at four irradiation levels: an un-irradiated control, 50 grays (Gy), 100 Gy, and 150 Gy.  After normalizing with data obtained from the control, seedling survivability for 50 Gy, 100 Gy, and 150 Gy treatments was 86%, 85%, and 56%, respectively.  We are continuing to monitor the M1 population in order to observe differences in growth indices among treatments.  Seedlings will be tracked until reaching sexual maturity and then screened for sterility and novel phenotypes.