Genetic Variations in Drought Tolerance in Creeping Bentgrass.

Drought is a major problem in turfgrass management, especially for species such as creeping bentgrass which require frequent irrigation to maintain functionality and aesthetic qualities. One of the most economically effective methods reducing drought stress is use of tolerant plants. The objective of this research was to determine shoot and root characteristics of 23 commercially available creeping bentgrass cultivars growing under drought. Grasses were germinated in polyethylene glycol (PEG) at 0 (i.e. control) or -0.4 MPa (i.e. drought). Data were collected on shoot dry weight (SDW), the longest root length (LRL), and LRL/SDW ratio. Shoot dry weight was 68.1 mg at -0.4 MPa, significantly higher than that at 0 MPa when data were pooled across cultivars. ‘Focus’ and ‘Memorial’ had the highest and lowest SDW, respectively when data were pooled across PEG levels. A cultivar x drought interaction was observed in LRL. ‘Penn A-4’ and ‘V8’ had the longest (2.0 cm) and shortest root length (0.5 cm), respectively under the control treatment; while ‘007’ (3.9 cm) and ‘Penn A-1’ (1.2 cm) were the best and worst performer under drought. LRL/SDW ratio was not affected by PEG, cultivar, or their interaction. The differences of SDW and LRL in creeping bentgrass cultivars under the drought condition may be mostly due to genetic variations in growth habit.