Tuesday, November 6, 2007 - 11:30 AM
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Heritability Estimates for Cold Tolerance in Seeded Bermudagrass.
Thomas R. Stefaniak1, Tim Phillips2, Charlie Rodgers3, and David Williams2. (1) University of KY, 322 Plant Sciences Bld, Lexington, KY 40546, (2) University of Kentucky, UK Coll of Ag. Dep. of Plant & Soil Sci. Rm 325, Plant Sci. Bldg. 1405 Veterans Dr., Lexington, KY 40546-0312, (3) Seeds West, 37860 W. Smith-Enke Rd., Maricopa, AZ 85239
One of the principle factors which limits the areas to which seeded bermudagrass can be adapted is low temperatures. Therefore, increasing the winter tolerance of seeded bermudagrass cultivars has been a goal of turfgrass breeders for many years. Design of an efficient breeding method for developing cultivars with increased tolerance to cool and freezing temperatures could be enhanced by having accurate heritability estimates for traits correlated to this trait. Parental clones and their respective polycross half-sib families were established in a randomized complete block design with four replications in 2004 in Lexington, KY. Differences in spring green up and fall dormancy measured in 2006 were detected between genotypes within the progeny and parental groups. Broad-sense heritability estimates were found to be 0.92 and 0.60 for spring green up and fall dormancy respectively. Narrow-sense heritability estimates of 0.92 and 0.42 were calculated based on a parent-offspring covariance analysis. These preliminary results indicate that genetic gains for cold tolerance could be achieved more easily by selecting for improved spring green up as opposed to fall dormancy.