Tuesday, November 14, 2006

Role of cellulose enzymes in wear tolerance and recovery of bermudagrass cultivars.

Theresa Bayrer, Xunzhong Zhang, Mike Goatley, and Erik Ervin. Virginia Polytechnic Institute and State University, 335 Smyth Hall, CSES Dept, Blacksburg, VA 24061-0404

In work published in 2000, L.E. Trenholm was able to establish increased rigidity as a factor in bermudagrass wear tolerance. According to Babb and Haigler (2001) the enzymes sucrose phosphate synthase (SPS) and sucrose synthase (SuSy), though independently active within other biosynthetic pathways, have been shown to work jointly when involved in the synthesis of cellulose. As such, we propose that an increase in the activity of both enzymes, whether as an immediate or delayed response to wear, could indicate bermudagrass cultivars that are better suited for wear tolerance or recovery. This research has focused on further defining the relationship between cellulose content along with the activities of SPS and SuSy within bermudagrass leaves and stolons and any relationships therein to differences in cultivar wear tolerance and recovery. Mature cultivars of ‘Riviera' [Cynodon dactylon (L.) Pers.], ‘Princess 77', ‘SR-1012', ‘Savannah', and ‘Patriot' [C. dactylon X C. transvaalensis] were worn using a modified Brinkman Traffic Simulator on multiple occasions throughout the year. Measurements of percent turfgrass coverage (both digital and subjective) were taken immediately prior to and following wear as well as weekly throughout the recovery period. Stolon and leaf samples were taken along with percent coverage data and analyzed for cellulose content, SPS and SuSy activity. Wear tolerance and recovery differences between cultivars will be discussed along with correlations to cellulose content and activities of SPS and SuSy.