FREEZING TOLERANCE AND THE HISTOLOGY OF RECOVERING NODES IN ST.AUGUSTINEGRASS
St.Augustinegrass Stenotaphrum secundatum (Walt.) Kuntze is a coarse-textured turfgrass commonly utilized for its excellent shade tolerance.However,its range is limited primarily to the southeastern US,due to inferior cold tolerance in comparison to other warm-season grasses.‘Raleigh’ and ‘Seville’,two St.Augustinegrass cultivars at either extreme of freezing tolerance,were evaluated with different cold-acclimation treatments and at two freezing temperatures for effects of nodal position and histological response of tissues within the node to freezing stress.Overall,Raleigh was significantly more freezing tolerant than Seville,but Seville appeared to have benefited more from coldacclimation than Raleigh.Significant differences in survival rates were found in the nodal position of the stolon as well.Nodes in the mid region of the stolon were more freezing tolerant than immature nodes in the apical region and older nodes in the basal region.Histological analysis of nodes 14 days after freezing revealed that xylem vessels were plugged,possibly with phenolic compounds.In addition,the basipetal regions of the nodes appeared to have more structural damage than the apical region.Since new shoots are regenerated from meristematic regions within the node,the observation that new shoots were produced during recovery,despite severe damage to all surrounding tissue,suggests that the most freezing tolerant regions of the plant are meristematic regions within the node.Data generated in this study contribute to the understanding of freezing processes and survival in St.Augustinegrass which should aid in the development of methods that are more effective in the evaluation of freezing survival.
freezing tolerance histology St. Augustinegrass
Susana R. Milla-Lewis Jennifer A. Kimball Tito E. Claure Tan D. Tuong Consuelo Arellano David P. Livingston Ⅲ
Dept. ofCrop Science,North Carolina State University,Raleigh,NC27695 USA U.S. Dept.of Agriculture and Dept. of Crop Science,North CarolinaState University,Raleigh,NC 27695 U Dept.of Statistics,North Carolina State University,Raleigh,NC27695 USA
国际会议
The 12th International Turfgrass Research Conference(第十二届国际草坪学术大会)
北京
英文
523-530
2013-07-14（万方平台首次上网日期，不代表论文的发表时间）