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Examination of Cold Deacclimation Sensitivity of Annual Bluegrass and Creeping Bentgrass
Author(s) -
Hoffman Lindsey,
DaCosta Michelle,
Ebdon J. Scott
Publication year - 2014
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2013.05.0329
Subject(s) - biology , freezing tolerance , shoot , poa annua , acclimatization , agrostis , agrostis stolonifera , botany , cold tolerance , horticulture , perennial plant , cold sensitivity , cultivar , poaceae , agronomy , biochemistry , gene , mutant
Annual bluegrass ( Poa annua L.) (AB) frequently exhibits increased susceptibility to winter injury compared to other cool‐season turfgrass species such as creeping bentgrass ( Agrostis stolonifera L.) (CB). Interspecific differences in winter survival of these two species may be associated with enhanced sensitivity of AB to decreases in freezing tolerance (deacclimation) during winter and early spring months; however, there is limited understanding of the factors associated with cold deacclimation between these two species. Therefore, the objective of this research was to determine the deacclimation sensitivity of one AB ecotype and one CB cultivar in response to varying temperature increases and durations. Total shoot growth and freezing tolerance (lethal temperature resulting in 50% mortality [LT 50 ]) of AB and CB was monitored throughout cold acclimation (20, 2, and –2°C) and following exposure to a combination of 4, 8, or 12°C for 1 or 5 d. Overall, freezing tolerance of AB (LT 50 of –17.7°C) was significantly lower than CB (LT 50 of –21.2°C) following cold acclimation, and in general CB maintained higher levels of freezing tolerance throughout deacclimation compared to AB (LT 50 of –16.2 and –12°C, respectively). Both AB and CB exhibited deacclimation in response to above‐freezing temperatures; however, the threshold temperature required to induce greater losses in freezing tolerance was lower for AB compared to CB. Specifically, a 2.5‐fold greater loss in freezing tolerance was detected in AB compared to CB following exposure to 4°C. Furthermore, total shoot growth and LT 50 were correlated during deacclimation in these species.