Genetic Differentiation of Tetraploid Creeping Bentgrass and Hexaploid Redtop Bentgrass Genotypes by AFLP and their Use in Turfgrass Breeding

Abstract

The turf industry in the last decade has seen doubling in number of new creeping bentgrass [Agrostis stolonifera var. palustris (Huds.) Farw. and A. stolonifera var. stolonifera Huds.] cultivars, many with unknown variability and lineage. Understanding the genetic diversity of putative parental and wild stocks would be useful in plant breeding programs. Amplified fragment length polymorphism (AFLP) analysis was conducted to investigate genetic variability among old and new cultivars of creeping bentgrasses, redtop bentgrasses (Agrostis gigantea Roth), plant introductions, and selected creeping bentgrass genotypes with resistance to gray snow mold (Typhula incarnata Lasch). Seven chosen primer combinations resulting in 355 polymorphic markers were used to differentiate the bentgrasses. Three groups were extracted by principal component analysis (PCA). With unweighted pair group method with the arithmetic mean (UPGMA) analysis, mean similarity coefficients of creeping bentgrass genotypes found in the first group was 0.78. Creeping bentgrasses in the USA were clustered as a subgroup and separated from European plant introductions, indicating that most selection and genetic exchanges in the last fifty years have evolved locally. Redtop bentgrasses were the most diverse and were found in different groups. Selected lines from northern Michigan, MI 20104, MI 20215, and MI 203164, were well differentiated from the other cultivars and would be advantageous to use as sources of disease-resistant traits and for development of populations for future gene mapping.