Tall Fescue and Bermudagrass Cultivar Response to Drought Stress at the Germination Growth Stage.

Examining and developing screening techniques to identify drought-resistant lines at the seedling stage is an important step for plant breeders. Therefore, the objectives of this research trial were to determine if the use of polyethylene glycol (PEG-6000) is an effective tool to screen for water stress during seed germination and to determine potential cultivar differences within each species tested. Bermudagrass [Cynodon dactylon (L.) Pers.] cultivars selected included ‘Hollywood’, ‘Northshore’, ‘Riviera’, and ‘Transcontinental’. Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] cultivars included ‘Jaguar 4G’, ‘Quest’, ‘Summer’, and ‘Sundial’ as well as four experimental cultivars. Water stress levels were developed using PEG-6000. For bermudagrass, seed was subjected to 0 (control), −2.5, −5.0, −7.5, and −10.0 MPa, while tall fescue water-stress treatments included 0 (control), −2.0, −4.0, −5.0, and −7.0 MPa. Bermudagrass and tall fescue relative final germination rate (FGR) and relative daily germination rate (DGR) decreased with increasing concentrations of PEG-6000. Regression analysis indicated that Sundial (−6.51 MPa) and Summer (−6.09 MPa) tall fescue and Transcontinental (−4.74 MPa) and Hollywood (−4.62 MPa) bermudagrass had the highest PEG concentration to reduce relative FGR by 50%. Results suggest PEG-6000 is an effective technique for screening turfgrass cultivars that require less water for seed germination. This study also identified cultivars that would have a competitive advantage during the establishment phase if water is a limiting factor.