Mutations Induced in Vegetatively Propagated Turf Bermudagrasses by Gamma Radiation 1

Most improved cultivars of turf bermudagrass ( Cynodon sp .) are vegetatively propagated because of trlploid‐induced sterility or poor seed‐setting characteristics. Further improvement of these specialized turfgrasses is unlikely because they cannot be hybridized or easily constructed from parental stocks. New techniques are needed to circumvent these breeding barriers. Physical or chemical mutagens offer a practical approach. Rhizomes of two turf bermudagrass cultivars were treated with gamma rays to evaluate the mutation‐breeding technique for these vegetatively propagated grasses. Dosages of 9,000 and 11,300 rads produced 71 distinct mutations in the treated material screened. Mutations to dwarfism and changes in color hue of the stolons were most frequently noted. Gamma‐ray induction of mutations was of such frequency as to recommend use of this approach for the practical and successful breeding improvement of vegetatively propagated turf bermudagrass. Methods reported here also apply to the forage bermudagrasses and other vegetatively propagated grasses.