Genotypic and phenotypic evaluation of off-type grasses in hybrid Bermudagrass [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy] putting greens using genotyping-by-sequencing and morphological characterization

Abstract

BackgroundInterspecific hybrid bermudagrass [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy] is one of the most widely used grasses on golf courses, with cultivars derived from ‘Tifgreen’ or ‘Tifdwarf’ particularly used for putting greens. Many bermudagrass cultivars established for putting greens can be genetically unstable and lead to the occurrence of undesirable off-type grasses that vary in phenotype. The objective of this research was to genetically and phenotypically differentiate off-type grasses and hybrid cultivars. Beginning in 2013, off-type and desirable hybrid bermudagrass samples were collected from golf course putting greens in the southeastern United States and genetically and phenotypically characterized using genotyping-by-sequencing and morphology.ResultsGenotyping-by-sequencing determined that 11% (5) of off-type and desirable samples from putting greens were genetically divergent from standard cultivars such as Champion, MiniVerde, Tifdwarf, TifEagle, and Tifgreen. In addition, genotyping-by-sequencing was unable to genetically distinguish all standard cultivars from one another due to their similar origin and clonal propagation; however, over 90,000 potentially informative nucleotide variants were identified among the triploid hybrid cultivars.ConclusionsAlthough few genetic differences were found in this research, samples harvested from golf course putting greens had variable morphology and were clustered into three distinct phenotypic groups. The majority of off-type grasses in hybrid bermudagrass putting greens were genetically similar with variable morphological traits. Off-type grasses within golf course putting greens have the potential to compromise putting surface functionality and aesthetics.

The genome of the warm-season turfgrass African bermudagrass (Cynodon transvaalensis)

“…In this study, we used C. transvaalensis (Fig. 1a ) for whole-genome sequencing 34 . Based on Illumina data (~18.8 Gb), k -mer frequency analysis revealed that the genome size was ~454.4 Mb (Supplementary Fig.…”

Morphological variation in Cynodon dactylon (L.) Pers., and its relationship with the environment along a longitudinal gradient

“…Morphological variation as a response to environmental changes at different geographic positions is common in C. dactylon [38,39]. A study of 260 accessions of bermudagrass germplasm indicated that there is extensive morphological variation in C. dactylon populations along longitudinal gradients, which has been found in some other studies [31,40,41]. The correlation analysis showed that the traits of width and dimeter were seldom significantly correlated with the longitude, soil nuriture or climate.…”

An examination of turfgrass species use on golf course putting greens

“…Golf Association, 2017). Manifestation of off‐type grasses in genetically unstable ultradwarf bermudagrasses used on putting greens (Reasor et al., 2018) may be another factor encouraging golf course superintendents to use creeping bentgrass in lieu of ultradwarf bermudagrass. Nearly 87% (213 of 243 golf courses) reported using winter protective covers to maintain ultradwarf bermudagrass putting greens, including 100% of respondents in Alabama, Arkansas, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Texas, and Virginia.…”