Genetic Variability for Adaptive, Morphological, and Reproductive Traits in Selected Cold-Hardy Germplasm of Common Bermudagrass

Common bermudagrass [Cynodon dactylon (L.) Pers.] has been widely used as a major warmseason turf and forage grass in the southern United States and in other regions with similar climates around the world. However, it will suffer severe winterkill when grown beyond its region of adaptation. Cold-hardy bermudagrass germplasm have been developed, but its genetic variation for important turfgrass traits remains unknown. The objective of this study was to quantify genetic variability and determine relationships among adaptive, morphological, and reproductive traits in selected cold-hardy common bermudagrass germplasm, including 48 clonal plants from 'Riviera' and 50 clonal plants from ` Yukon'. Large genetic variability existed for 12 of 13 adaptive, morphological, and reproductive traits within this germplasm. Spring greenup was found to be positively correlated with turf density and fall color retention. Leaf spot disease had negative correlations with spring greenup and inflorescence prolificacy, and percentage seed set was negatively associated with raceme length. Broad-sense heritability estimates were 0.03 to 0.25 for first internode length and fourth leaf blade width, 0.36 for first internode diameter, 0.64 for fourth leaf blade length, and 0.72 to 0.80 for inflorescence prolificacy, raceme length, and percentage seed set. The large genetic variability within the winterhardy germplasm will provide value in selecting superior parental plants, for producing improved interspecific hybrids, and in forming improved synthetic cultivars and breeding populations.