Harlan, J.R. De Wet, J.M.J. 1969 Sources of variation in Cynodon dactylon (L) Pers. Crop Sci. 9 774 778 Karcher, D.E. Richardson, M.D. 2005 Batch analysis of digital images to evaluate turfgrass characteristics Crop Sci. 45 1536 1539 Koch, M.J. Bonos, S
Mingying Xiang, Justin Q. Moss, Dennis L. Martin, and Yanqi Wu
Michelle M. Wisdom, Michael D. Richardson, Douglas E. Karcher, Donald C. Steinkraus, and Garry V. McDonald
bulbs can persist in zoysiagrass ( Zoysia japonica Steud.) and bermudagrass ( Cynodon dactylon ) in transition zone environments, providing color and biodiversity to dormant turfgrass situations. However, both studies examined a small number of bulb
Erick Amombo, Longxing Hu, Jibiao Fan, Zhengrong Hu, and Jinmin Fu
Clonal plants can consist of connected individual ramets that enhance resource sharing through physiological integration. This integration enables the whole clone to tolerate environmental stresses. The objective of this research was to investigate the effects of physical ramet connections on the integration of antioxidant enzymes in clonal common bermudagrass (Cynodon dactylon) growing under heterogeneously distributed water; i.e., nonuniform distribution of water due to 20% polyethylene glycol (PEG 6000) treatment on some ramets and not others. The bottom, middle, upper and three fragments of clonal common bermudagrass were subjected to 20% PEG 6000 with water potential of −1.8 MPa to induce heterogeneous and homogeneous drought stress. The control was not treated with 20% PEG 6000. Within the heterogeneous treatment, water stressed clonal fragments generally had higher leaf and root antioxidant enzyme activities with respect to superoxide dismutase, catalase, peroxidase (except for root peroxidase). There was no difference in antioxidant enzyme activity within the connected clonal ramets for homogeneous treatment; i.e., three connected ramets treated with 20% PEG 6000. Osmotically stressed clonal fragments under heterogeneous environments had a lower level of malonaldehyde (MDA) compared with those in homogeneous regimes. The antioxidant enzyme integration was affected by directionality and water availability contrast. This was indicated by significant decline in MDA levels within the heterogeneous treatments as compared with homogeneous treatment, which suggested reduced lipid peroxidation. These results suggested that ramet connections facilitate integration of antioxidant enzymes within clonal plants growing in heterogeneously available water. Enzymes were integrated from clonal fragments growing in water sufficient environment to those in water stressed regimes. This enhanced reactive oxygen species scavenging capacity of the entire clone hence improved drought tolerance.
Stefano Macolino, Matteo Serena, Bernd Leinauer, and Umberto Ziliotto
Warm-season grasses are not widely accepted in Mediterranean countries because they lose color during the winter months. A study was conducted at the University of Padova (Padova, Italy) to determine whether fall and spring water-soluble carbohydrate (WSC) content in stolons of seeded bermudagrass cultivars (Cynodon dactylon) influenced spring green-up in the first year of establishment. Nine bermudagrass cultivars (La Paloma, Mohawk, NuMex Sahara, Princess 77, Riviera, SR 9554, Barbados, Contessa, and Yukon) were seeded in July 2005, and dry weight and WSC content in stolons were measured in Fall 2005 and again in Spring 2006. The percentage of green cover and days needed to achieve 80% green cover (D80) were regressed against November and March values of stolon dry weight and WSC content to determine if they were good predictors of D80. ‘Yukon’ showed earliest spring green-up by end of April, and ‘Princess 77’ and ‘Riviera’ were slowest, needing 43 to 46 days more than ‘Yukon’ to reach D80. There was a significant inverse relationship between November (r2 = 0.57) and March (r2 = 0.77) WSC content in stolons and D80 for all nine bermudagrass cultivars. These results suggest that bermudagrass cultivars with high WSC in stolons recover more rapidly from dormancy during establishment than those with low WSC content.
Jibiao Fan, Jing Ren, Weixi Zhu, Erick Amombo, Jinmin Fu, and Liang Chen
Cold stress is a key factor limiting resource use in bermudagrass (Cynodon dactylon). Under cold stress, bermudagrass growth is severely inhibited and the leaves undergo chlorosis. Therefore, rigorous investigation on the physiological and molecular mechanisms of cold stress in this turf species is urgent. The objective of this study was to investigate the physiological and molecular alteration in wild bermudagrass under cold stress, particularly the changes of transpiration rate, soluble sugar content, enzyme activities, and expression of antioxidant genes. Wild bermudagrass (C. dactylon) was planted in plastic pots (each 10 cm tall and 8 cm in diameter) filled with matrix (brown coal soil:sand 1:1) and treated with 4 °C in a growth chamber. The results displayed a dramatic decline in the growth and transpiration rates of the wild bermudagrass under 4 °C temperature. Simultaneously, cold severely destabilized the cell membrane as indicated by increased malondialdehyde content and electrolyte leakage value. Superoxide dismutase and peroxidase activities were higher in the cold regime than the control. The expression of antioxidant genes including MnSOD, Cu/ZnSOD, POD, and APX was vividly up-regulated after cold stress. In summary, our results contributed to the understanding of the role of the antioxidant system in bermudagrass’ response to cold.
Jack Fry, Randy Taylor, Bob Wolf, Dick Stuntz, and Alan Zuk
Turfgrass managers in the transition zone are interested in converting swards of cool-season grasses to cold-hardy seeded bermudagrass (Cynodon dactylon) in an effort to reduce water and fungicide inputs. The objective of this study was to evaluate the potential for establishing ‘Riviera’ bermudagrass in a perennial ryegrass (Lolium perenne) sward by using a strip-seeding technique, and then to build a machine that would facilitate the process. Four, 2-inch-wide tilled rows, 1 inch deep and 15 inches apart, were created in 6 × 6-ft plots and seeded by hand with ‘Riviera’ bermudagrass at 104 lb/acre pure live seed in July 2002. In one set of strip-seeded plots, a 7-cm-wide overspray of glyphosate (≈0.5 inch on either side of the row) was applied over tilled rows after seeding to suppress perennial ryegrass further. Plots established by the strip-seeding technique exhibited 71% bermudagrass coverage after two growing seasons, and 87% coverage when rows received a glyphosate overspray. Broadcasting ‘Riviera’ seed into perennial ryegrass plots resulted in 60% bermudagrass coverage at the end of the second season of establishment. A strip seeder was constructed and used to seed ‘Riviera’ into existing perennial ryegrass turf in late July 2004 using the aforementioned row configurations and a glyphosate overspray. Coverage evaluated the following spring, before green-up, was 10.3% compared with 0% coverage where ‘Riviera’ was broadcast seeded. At the seeding rates evaluated, 79% less ‘Riviera’ bermudagrass seed was required when using the strip-seeding method, and golfers would consider the surface more amenable to play during the establishment period compared with broadcasting glyphosate and seed. A patent is pending on the strip-seeding equipment and establishment process.
Lisa L. Baxter and Brian M. Schwartz
courses throughout the southeastern United States and collected accessions from the best turf-type bermudagrasses to be increased in a greenhouse and planted in field plots. These accessions were then crossed with common bermudagrass [ Cynodon dactylon
Filippo Rimi, Stefano Macolino, Bernd Leinauer, and Umberto Ziliotto
Winter dormancy is the main impediment to a wide acceptance of warm-season turfgrasses in the Mediterranean countries of Europe due to a loss of color during the winter months. Scalping during late winter or early spring has been recommended anecdotally to enhance spring green-up of bermudagrass (Cynodon dactylon); however, information is lacking on the effectiveness of this practice. A study was conducted to investigate the effects of spring scalping on spring green-up of eight bermudagrass cultivars (Barbados, Contessa, La Paloma, Mohawk, NuMex Sahara, Princess-77, SR 9554, and Yukon) grown in a transition zone environment. The trial was carried out in Spring of 2009 and 2010 on plots established in July 2005 at the experimental farm of the University of Padova (northeastern Italy). Half of the plots for each cultivar were subjected to spring scalping, which was applied in both years on 13 Mar. with a rotary mower set at a height of 28 mm. Soil temperatures were recorded hourly during the research period at a depth of 2.5 cm. The percentage of green cover was estimated weekly from 0 to 98 days after spring scalping (DASS). Soil temperatures in scalped plots were greater than in unscalped plots. Among the cultivars tested, ‘Yukon’ showed earliest spring green-up, with no difference between the scalping treatments, reaching 80% green cover by the end of April. For all other cultivars, scalped plots reached 80% green cover 10 to 18 days earlier than unscalped plots. Results showed that scalping enhanced spring green-up, primarily for cultivars that recover slowly from winter dormancy.
Brian M. Schwartz, Wayne W. Hanna, Lisa L. Baxter, Paul L. Raymer, F. Clint Waltz, Alec R. Kowalewski, Ambika Chandra, A. Dennis Genovesi, Benjamin G. Wherley, Grady L. Miller, Susana R. Milla-Lewis, William C. Reynolds, Yanqi Wu, Dennis L. Martin, Justin Q. Moss, Michael P. Kenna, J. Bryan Unruh, Kevin E. Kenworthy, Jing Zhang, and Patricio R. Munoz
foundation of the turfgrass industry ( Taliaferro et al., 2004 ). Development of bermudagrass for turfgrass began in the early 1900s. Much of this development has involved the hybridization of Cynodon dactylon (L.), a tetraploid recognized as an invasive
Wenjing Pang, John E. Luc, William T. Crow, Kevin E. Kenworthy, Robert McSorley, and Robin M. Giblin-Davis
bermudagrass greens. This highlights the need to select new sources of genetically superior bermudagrass accessions for use in a breeding program. Most bermudagrass cultivars that have been widely used on golf courses are triploids [ Cynodon dactylon (L.) Pers