Tolerance to simulated ice encasement andMicrodochium nivalein USA selections of greens-typePoa annua

Abstract

Lack of winter hardiness is a limitation to the use of annual meadowgrass (Poa annua f. reptans) on golf course putting greens in northern climates. Our objectives were 1) to assess the tolerance of 13 selections of annual meadowgrass to simulated ice encasement (SIE) and pink snow mould (PSM, Microdochium nivale); 2) to determine if these tolerances were interrelated or related to plant concentrations of water soluble carbohydrates (WSC); and 3) to determine if tolerance to SIE can be associated with accumulation of toxic substances. Samples of the annual meadowgrass selections were taken from an experimental green at University Park, Pennsylvania, on four dates from 23 Nov. 2005 until 27 Mar. 2006. Samples of creeping bentgrass (Agrostis stolonifera L.) 'Penn A-4' were included for comparison in studies on SIE and WSC. Samples were vacuum-sealed in plastic bags at 1 8C for SIE and inoculated with three isolates of M. nivale for PSM tolerance. Small, but significant, differences were found among annual meadowgrass selections after 23 days of SIE, but all selections were dead after 33 days. Significant differences were detected in foliar blighting after inoculation with M. nivale, regrowth relative to uninoculated control being three times higher in the most tolerant than in the most susceptible selections. In late November, two annual meadowgrass selections contained significantly more WSC than did creeping bentgrass, but this was not correlated with tolerance to SIE or PSM, which were also not interrelated. A separate experiment with increasing duration of SIE to one of the annual meadowgrass selections and 'Penn A-4' showed that the critical exposure periods were 25Á30 and 42Á47 days, respectively. The concentrations of the phytotoxic compounds butan-l-ol and ethyl butyrate were two-to three-times higher in annual meadowgrass than in creeping bentgrass.

Ethylene regulatory treatment effects on annual bluegrass survival of freezing temperature and ice cover

“…Prolonged, nonporous ice typically leads to anoxic conditions and the presence of toxic gases in the plant canopy (Olien & Smith, ; Rochette, Dionne, & Desjardins, ; Tompkins, Ross, & Moroz, ). Toxic gases such as ethyl‐butyrate have been found to accumulate under ice cover and can cause cell membrane disruption in turfgrass plants (Aamalid, Landschoot, & Huff, ). Ice cover can be significantly damaging to plants and reduce spring regrowth or yields by damaging crown tissues.…”

“…The perennial form of annual bluegrass ( Poa annua var reptans ) is a turfgrass putting green and fairway species that is susceptible to damage from ice cover. In various studies, annual bluegrass has been reported to survive an average of 20 to 75 d of ice cover (Aamalid et al., ; Beard, ; Tompkins et al., ; Waalen, Espevig, Kvalbein, & Aamlid, ). In a freezer‐based experiment, annual bluegrass necrosis occurred in 45 d at −4°C under a 1.27‐cm nonporous ice layer (Beard, ).…”

Cold Tolerance in Annual Bluegrass Exposed to Anoxic and Hypoxic Conditions

“…Höglind et al (2010) reported a lack of correlation between water‐soluble carbohydrates and LT 50 in both timothy and perennial ryegrass, whereas Bertrand et al (2009) found no relationship between fructan concentration and freezing tolerance in AB. Additionally, Aamlid et al (2009) identified two AB selections that contained higher levels of water‐soluble carbohydrates than CB, but the higher carbohydrate levels were not correlated with tolerance to simulated ice encasement. As was seen with the carbohydrate data, the lack of a consistent or clear association between freezing tolerance and NSC concentration suggests a more complex biological relationship between the two variables, and that other factors such as concentration of phytotoxic compounds and proteins involved in cell membrane stability and reactive oxygen species scavenging are involved (Aamlid et al, 2009; Bertrand et al, 2013).…”

The Effect of Ice Encasement and Protective Covers on the Winter Survival of Six Turfgrass Species on Putting Greens

“…litoralis ). Little is known about the IE tolerance of these different species and subspecies, except that annual bluegrass is more susceptible than creeping bentgrass ( Agrostis stolonifera L.) (Tompkins et al, 2004; Valverde and Minner, 2007; Aamlid et al, 2009, Castonguay et al, 2009). Thus, the objective of this study was to assess the impact of IE and two protective covers on the winter survival and regrowth capacity of these species and subspecies under putting green management.…”