The Use of ISSR Markers to Identify Texas Bluegrass Interspecific Hybrids.

Texas bluegrass is a perennial cool-season native grass species that contains separate male and female plants.  Hybrids with other bluegrass species can be created by controlled movement of pollen from other bluegrass species onto female Texas bluegrass plants.  Texas bluegrass hybrids with Kentucky bluegrass have the potential to produce turf-type material with a wider geographic range of adaption than pure Kentucky bluegrass.  Hybrids are generally identified visually after they are established, based on inheritance of morphological/physiological traits from both parents.  DNA based markers have the potential to identify hybrids prior to establishment.  In this study, 17 ISSR primers were tested on Texas bluegrass (Poa arachnifera), Poa species (Kentucky (KY) P. pratensis, Canadian(CA) P. compressa, Argentine (ARG) P. ligularis, and cv. Sherman, P. Secunda), and putative Texas x Kentucky (TK) and other hybrids.  Nine of the 17 primers tested consistently produced robust fingerprints and nine 2-way primer combinations were also selected.  DNA fingerprints were highly reproducible and the majority of the selected primers (16/18) amplified hybrid profiles using two putative TK full-sib hybrids.  Combined with a rapid DNA extraction protocol, the ISSR technique enabled a fast and practical way to detect F₁ interspecific hybrids early in the breeding program and could also be useful for other applications that require DNA based markers.