Tuesday, November 6, 2007
169-11
Cultivar Variation in Rooting Characteristics Associated with Drought Tolerance in Creeping Bentgrass.
Stephen McCann and Bingru Huang. Plant Biology, Rutgers University, 59 Dudley Road, New Brunswick, NJ 08901
ABSTRACT. Previous studies have examined various shoot parameters as selection criterion for drought tolerance in crop species. However, limited research has been done on root growth related to drought tolerance in creeping bentgrass. The objectives of this study were to compare drought tolerance among different creeping bentgrass cultivars and to determine rooting characteristics associated with drought tolerance variation in differing cultivars. Polyvinyl chloride (PVC) tubes (40cm) were established with sod pieces of six creeping bentgrass cultivars, ranging from drought sensitive to drought tolerant, and included A-4, Declaration, Independence, L-93, Penncross, and Putter. Plants were maintained in a growth chamber and either well-watered or withheld irrigation until plants of stress sensitive cultivars become severely desiccated (leaf relative water content drops to below 30%). Overall drought tolerance was evaluated by measuring turf quality, leaf relative water content, evapotranspiration rate, growth rate, and photochemical efficiency. Rooting characteristics such as total dry weight, viability, branching, shoot/root dry weight ratio, and root cell membrane stability were measured. Results suggest various physiological differences between cultivars, both in shoots and roots, leading to either improved or declined drought tolerance.