Trinexapac-ethyl influence on cell membrane thermostability of Kentucky bluegrass leaf tissue

Trinexapac-ethyl [(4-cyclopropyl-alpha-hydroxy-methylene)-3,5-dioxocyclohexanecarboxylic acid methyl ester] is a turfgrass growth regulator used to reduce clipping yields and mowing frequency. Kentucky bluegrass (Poa pratensis L.) plants treated with trinexapac-ethyl are less heat tolerant than untreated plants. Electrolyte leakage tests can determine cell membrane thermostability (CMT) of several species and is related to relative heat tolerance, but has not been, used to determine differences in CMT in plants caused by the influence of the growth regulator trinexapac-ethyl. We conducted one experiment, repeated twice with an electrolyte leakage test to determine the influence of trinexapac-ethyl on CMT of Kentucky bluegrass. Kentucky bluegrass plants treated with trinexapac-ethyl had less CMT than untreated plants. This shows that an electrolyte leakage test for CMT can determine growth regulator influences on the heat tolerance of a C., turfgrass. (C) 2002 Elsevier Science B.V. All rights reserved.