Screening bermudagrass germplasm accessions for tolerance to sting nematodes

Abstract

Breeding and improvement of new bermudagrass (Cynodon spp.) cultivars with superior nematode tolerance are essential because sting nematode (Belonolaimus longicaudatus Rau) is a major limitation for use of bermudagrass in the sandy coastal soils of the southeastern United States. The screening of both African (Cynodon transvaalensis) and common (C. dactylon) bermudagrass is necessary to develop triploid hybrid cultivars. Five commercial cultivars and 46 germplasm accessions of bermudagrass were tested for nematode responses in two greenhouse trials in 2009. Turfgrass was grown in sand-filled plastic conetainers and inoculated with 50 sting nematodes per conetainer. Nematode and root samples were collected 90 d after nematode inoculation. Fifteen bermudagrass accessions did not have measurable root loss from inoculation with sting nematode. Seven bermudagrass accessions, including 'Celebration', produced longer roots in sting nematode-infested soil than the standard 'Tifway'. Differences in final nematode numbers were identified among the genotypes, and different relative responses were identified in variable ploidy levels and origins. This could aid a turfgrass breeding program by elucidating the genetic diversity available for breeding future bermudagrass cultivars for golf course cultivation.