Progress in Creating Interspecific Hybrids with Texas Bluegrass (Poa arachnifera).
Jason Goldman, USDA-ARS, Southern Plains Range Res. Station, 2000 18th St., Woodward, OK 73801
In addition to population based breeding within Texas bluegrass for improved forage type material, an interspecific hybrid breeding program was initiated. Interspecific hybrids involve crossing Texas bluegrass with other bluegrass (Poa) species. Texas bluegrass is dioecious (separate male and female plants) which enabled hand crosses to be made in the greenhouse by transferring pollen from other species onto female Texas plants. The goal is to produce novel hybrids that combine the heat and drought qualities of Texas bluegrass with beneficial traits from other Poa species in an effort to produce novel forage or low input turf-type material. Four species of bluegrass (Argentine(A), Canadian(CA), Secunda(S), and Kentucky(KY)) were used for hybrid production. CA, KY, and Secunda reproduce by apomixis, enabling the possibility of recovering true breeding hybrids. In 2004, hand crosses resulted in recovery of six hybrid types. None of the hybrids involving an apomictic pollen donor produced hybrids that contained complete flowers and reproduced apomictically. In 2005, by using hybrids from the previous year and altering induced flowering conditions resulted in the recovery of approximately 23 hybrid types, including one putative 3-way hybrid involving three Poa species. Approximately (at least 5 so far) hybrids that appear to have complete flowers were recovered from Texas X CA or KY crosses and are being evaluated for fertility and mode of reproduction. In 2006, 54 hybrid cross types were made, many of these were complex 3-way hybrids. Future plans involve acquiring new breeding material for hybrid production, field evaluation of novel hybrids and determining which population structure, such as a single apomictic hybrid, multiple apomictic hybrids, sexual, interspecific populations or other blends, are suitable for large scale evaluation and cultivar release.