DNA Contents of Texas Bluegrass Acquired from GRIN, Collected in Texas and Oklahoma and Interspecific Hybrids with Kentucky Bluegrass Determined By Flow Cytometry.

Texas bluegrass (Poa arachnifera Torr.) is a dioecious, perennial, cool-season grass native to southern Kansas, Oklahoma, western Arkansas and most of Texas. Its major use has been for forage on rangelands in Texas and Oklahoma. More recently, interspecific hybrids between Texas bluegrass and Kentucky bluegrass (P. pratensis L.) have been developed and commercially released as heat tolerant turfgrass.  Initial screening of plants collected in northwest Oklahoma and five other locations west of 33.75, -98.39 (latitude, longitude) detected plants that ranged from 9.64 -10.07 picograms (pg).  Plants collected from four sites in Texas, east of 33.20, -98.16 contained a DNA content that ranged from 14.02 - 14.75 pg.  Seedlings from GRIN accessions varied from containing a single genome size (ca. 9.5 pg) to accessions that contained a range from 9.9-15.8 pg depending on collection location and who submitted the accession.  Genome size of interspecific hybrids ranged from ca. 8 - 20 pg. Knowledge of DNA content in Texas bluegrass should be useful in a breeding program for characterizing germplasm, and identifying hybrids.