Physiological Changes in Roughstalk Bluegrass Exposed to High Temperature
- James M. Rutledge *a,
- J.J. Volenecb,
- Y. Jiangb and
- Z.J. Reicherc
Roughstalk bluegrass (Poa trivialis L.) (RBG) is more heat sensitive than creeping bentgrass (Agrostis stolonifera L.) (CBG), but the physiological basis for this difference is poorly understood. Our objective was to determine the impact of high temperature on growth, root viability, concentrations of total nonstructural carbohydrates, fructan, glucose, protein, and amino acid in shoots and roots of RBG and CBG. One CBG (‘L93’) and two RBG cultivars (‘Laser’ and ‘Pulsar’) were grown in growth chambers at 23, 28, or 33°C and harvested 0, 10, 14, 21, 28, or 35 d after introduction (DAI) to high temperatures. Growth and physiological responses of Laser and Pulsar RBG were similar; therefore, differences between species were analyzed using Pulsar to represent RBG. Creeping bentgrass maintained better turf quality than RBG at 33°C and produced 15 mg of clipping dry wt. d−1 compared to only 0.5 mg dry wt. d−1 for RBG at 33°C 35 DAI. Root viability of RBG was higher than that of CBG at 23 and 28°C, but the reverse was true at 33°C. Fructan concentrations in RBG roots increased as exposure lengths increased, unlike in CBG. At 33°C, shoot amino acid concentration of RBG increased 223% compared to only 64% in CBG relative to concentrations in tissue exposed to 23°C. Our study identified differences in growth and physiological responses of CBG and RBG to high temperature that improve our understanding of differences between these species when grown in the field.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2012. . Copyright © by the Crop Science Society of America, Inc.