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  • Author or Editor: Wayne W. Hanna x
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Genetic linkage maps of bermudagrass (Cynodon spp.) species using 118 triploid individuals derived from a cross of T89 [C. dactylon (2n = 4x = 36)] and T574 [C. transvaalensis (2n = 2x = 18)] were enriched with expressed sequence tags-derived simple sequence repeat (EST-SSR) markers. Primers were developed from 53 ESTs containing SSRs producing 75 segregating markers from which 28 could be mapped to the T89 and T574 genetic maps. With the addition of previously generated marker data, 26 T89 linkage groups and eight T574 linkage groups were formed using a log-of-odds (LOD) value of 4.0. The T89 and T574 linkage maps spanned 1055 cM and 311.1 cM and include 125 and 36 single-dose amplified fragments (SDAFs), respectively. Many of the SDAFs displayed disomic segregation and thus T89 may be a segmental allotetraploid or an allotetraploid. The additional EST-SSR markers add value to the maps by increasing marker density and provide markers that can be easily transferred to other bermudagrass populations. Furthermore, EST-SSRs can be immediately used to assess genetic diversity, identify non-mutated cultivars of bermudagrass, confirm pedigrees, and differentiate contaminants from cultivars derived from ‘Tifgreen’.

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Hybrid bermudagrass (Cynodon dactylon × C. transvaalensis) varieties such as Tifway and TifSport commonly are used on athletic fields. Several experimental hybrid bermudagrasses have been recently developed. However, data describing the performance of these bermudagrasses under simulated athletic field traffic are limited. A 2-year study was conducted evaluating the traffic tolerance of five experimental (2004-76, 2004-83, 2004-78, Tift 11, and 2004-77) and three commercially available (‘Tifway’, ‘TifSport’, and ‘TifGrand’) hybrid bermudagrasses. These bermudagrasses were subjected to two mowing (mowing at 0.87 inches or mowing at 0.87 inches + grooming to a 0.10-inch depth) and overseeding [no overseeding or overseeding with perennial ryegrass (Lolium perenne) at 12 lb/1000 ft2 of pure live seed] regimes. Simulated traffic tolerance using the Cady traffic simulator (CTS) was quantified using measurements of turfgrass cover with digital image analysis (DIA). Experimental bermudagrasses Tift 11 and 2004-76 and the commercially available variety TifGrand yielded turfgrass cover values greater than or equal to ‘Tifway’, a commonly used variety, on all rating dates each year. Experimental bermudagrass 2004-83 yielded the lowest turfgrass cover values on each date. Findings suggest that ‘TifGrand’, 2004-76, and Tift 11 may be suitable for use on athletic fields.

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