Tuesday, November 6, 2007
169-6
Effect of Dwarfism on Creeping Bentgrass Growth and Development in Low Light Environment.
Aneta Studzinska, Dave Gardner, and T. Karl Danneberger. 2001 Fyffe Court, Ohio State University - Columbus, The Ohio State University, Department of Horticulture & Crop Science, Columbus, OH 43210-1086
Shade stress causes physiological and morphological changes in turf plants, significantly decreasing their quality. Creeping bentgrass (Agrostis palustris) is a species commonly used in high maintenance turf areas, often under shade. The objective of this study was to determine the effect of genetically induced dwarfism on creeping bentgrass shade tolerance under low mowing heights. A randomized split-plot greenhouse study with 3 replicates has been conducted at The Ohio State University, Columbus , OH from July 10 to August 3. Two glyphosate-tolerant controls: Ar237 and Ar261 events that contain the CP4 EPSPS gene, two lines Ax6548and Ax6549, transformed with CP4 EPSPS and the runner bean GA2- oxidase gene, and two conventional creeping bentgrass cultivars, ‘LS44’ and ‘Crenshaw’ were subjected to three different light environments: full sun, canopy shade (reduced photosynthetic photon flux and red: far red ratio), and neutral shade (reduced PPF). Light reduction and R: FR was 90% and .28, and 85% and 1.29 for canopy shade and neutral shade, respectively. Treated turf was evaluated weekly for density and color, vertical growth rate, dry weight, total nonstructural carbohydrates levels, and chlorophyll a and b concentrations. We predict that the data collected from this study will prove that shade tolerance and turf performance might be improved due to the down regulation of gibberellic acid.