Field and Laboratory Evaluation of Bermudagrass Germplasm for Cold Hardiness and Freezing Tolerance

Abstract

Bermudagrass [Cynodon spp. (L.) Rich.] is a high‐quality, durable turfgrass with excellent heat and drought tolerance. However, its lack of freezing tolerance limits its use in the transition zone. The development of cultivars with enhanced freezing tolerance would constitute a significant improvement in the management of bermudagrass in this region and could extend its area of adaptation further north. There has been substantial work on screening of common‐type bermudagrass [Cynodon dactylon (L.) Pers.] germplasm for freezing tolerance, but not for the African (Cynodon transvaalensis Burtt‐Davy) germplasm. The purpose of this research was to conduct multiyear field testing and laboratory‐based freezing test evaluations of winter hardiness and freezing tolerance, respectively, of an African and common bermudagrass germplasm collection. A high level of cold hardiness was observed among the germplasm in this study. In field evaluations, plant introductions (PIs) PI 290905, PI 647879, PI 255447, PI 289923, and PI 615161 were the top performers, having consistently greater spring green‐up and reduced winterkill compared with ‘Patriot’, ‘Tifsport’, ‘Quickstand’, and ‘Tifway’, though not always significantly. A comparison between field‐based ratings and calculated lethal temperatures for 50% death (LT50) from laboratory‐based freezing tests showed significant correlations of −0.26 and −0.24 for spring green‐up and winterkill, respectively, suggesting that these controlled freeze experiments could be used to prescreen materials prior to field testing. Overall, results indicate that some of the PIs evaluated in this study can be used as additional sources of cold hardiness in bermudagrass breeding.

Differences in proteome response to cold acclimation in Zoysia japonica cultivars with different levels of freeze tolerance

“…Although field evaluation of freeze tolerance provides the most realistic indication of how a cultivar will perform through winter, variable environmental conditions across year and location can make consistent and reproducible winter stress very difficult to attain (Anderson, Taliaferro, & Martin, 2002). Controlled‐environment freeze tests may be a more cost‐effective and efficient way to assess cold acclimation and freeze tolerance of turfgrass species and generally corresponded well with field screenings (Anderson et al., 2002; Dunne, Tuong, Livingston, Reynolds, & Milla‐Lewis, 2019; Qian et al., 2001). This constancy demonstrates that plants most likely undergo similar physiological changes during cold acclimation, freezing, and deacclimation in temperature‐controlled chambers as in the field.…”

“…Plants were evaluated weekly for survival for 4 wk after freezing. Survival data was taken on a binary scale of 0 (death) to 1 (survival) evaluating each individual plant for the presence of green tissue (Dunne et al., 2019). Survival data was collected 4 wk after freezing treatment.…”

“…This method uses binary data to determine the probability of survival against the temperature gradient and estimate LT 50 values according to Dunne et al. (2019). The LOGISTIC procedure in SAS version 9.4 (SAS Institute, 2013) with a stepwise selection method generates a model and maximum likelihood estimates that were used to calculate odds ratios, survival probabilities, and LT 50 values.…”

Genotype‐by‐environment interaction for turfgrass quality in bermudagrass across the southeastern United States

“…Bermudagrasses ( Cynodon spp.) are warm‐season turfgrass species widely used on golf courses, athletic fields, and home lawns in the southern United States (Dunne, Tuong, Livingston, Reynolds, & Milla‐Lewis, 2019). These species are known for their superior turf quality (TQ), excellent durability, and superior heat and drought tolerances (Beard, 1973; Schwartz et al., 2018).…”

Interphase nuclear phenotype and chromosomal variation in Cynodon dactylon (L.) pers

“…(commonly known as Bermuda grass and locally as Durba) is a typical warmseason turfgrass belonging to Poaceae. This species is widely distributed in warm, humid and semi-arid areas around the Himalayas with excellent heat and drought tolerance capacity (Harlan et al 1970, Dunne et al 2019. This grass species is widely adapted to various environments of tropical and sub-tropical regions of the world and there are some ways for genetic diversity and population structure analysis of Bermudagrass (Zheng et al 2017).…”