Bermudagrass (Cynodon spp.) is the predominant turfgrass used in the southern United States and other warm regions in the world. A limitation for the use of bermudagrass in the southeastern United States is the sting nematode (Belonolaimus longicaudatus), which is frequently found in sandy coastal soils. It has been considered the most damaging plant–parasitic nematode on bermudagrass in Florida (Crow, 2005; Luc et al., 2007) where it causes damage to greens, fairways, and rough areas on golf courses as well as athletic fields and lawns (Crow and Han, 2005). With the cancellation of fenamiphos (Nemacur; Bayer CropScience, Research Triangle Park, NC), turfgrass managers are in need of new nematode management strategies. Use of resistant or tolerant cultivars would be the most desirable, least costly nematode management practice with the minimum number of ecological effects on non-target species (Giblin-Davis et al., 1992b). Breeding and improvement of new bermudagrass cultivars with superior nematode responses are essential. Giblin-Davis et al. (1992b) tested the sting nematode tolerance and resistance of seven commercial bermudagrass cultivars and 30 experimental accessions. They found that 26 accessions showed a significant reduction in root dry weights compared with the uninoculated controls and that 25 supported reproduction of sting nematode. They also determined that ‘Tifway’ was among the most tolerant of the cultivars evaluated. Currently, there are few known sting nematode-resistant or -tolerant bermudagrass genotypes available. Except for ‘TifEagle’, all bermudagrass cultivars used on greens are related to each other; therefore, environmental pressure exists for the development of a significant pest problem on 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. var. dactylon × C. transvaalensis Burtt-Davy] derived from hybridizations of tetraploid common bermudagrass and diploid African bermudagrass. Previous development of sterile, triploid hybrids has focused primarily on the selection of a superior common bermudagrass parent. This was attributable, in part, to a lack of knowledge regarding the genetic diversity and potential of improvement for African bermudagrass. Information is now available that indicates that improvement of African bermudagrass is possible for several turfgrass performance traits (Kenworthy et al., 2006). This necessitates the screening of both African and common bermudagrass. The University of Florida bermudagrass breeding program through multiyear evaluations has identified superior, Florida-adapted, experimental accessions of common and African bermudagrass to use in crosses to develop new sterile bermudagrass hybrids for use on golf courses. Sting nematode responses to these bermudagrass accessions remain uncharacterized and could provide valuable information in the selection of parents to develop progeny and cultivars resistant to this serious turfgrass pest. The objectives of this study were to test the responses caused by sting nematodes among superior University of Florida accessions of common and African bermudagrass and to select accessions with superior responses for future cultivar breeding and development.
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