Relating Freeze-induced Electrolyte Leakage Measurements to Lethal Temperature in Red Raspberry

Abstract

<jats:p>Seasonal cold hardiness of red raspberry (<jats:italic>Rubus idaeus</jats:italic> L.) canes was measured by freeze-induced electrolyte leakage test and visual rating of injury. Leakage data were transformed to percentage-adjusted injury values and related to lethal temperature by graphical interpolation and by the midpoint (T<jats:sub>50</jats:sub>) and inflection point (T<jats:sub>max</jats:sub>) estimates derived from three sigmoid (the logistic, Richards, and Gompertz) functions. T<jats:sub>max</jats:sub> estimates produced by Richards and Gompertz functions were corrected further using two different procedures. The 10 leakage-based hardiness indices, thus derived, were compared to lethal-temperature estimates based on visual rating. Graphical interpolation and T<jats:sub>max</jats:sub> of the logistic or T<jats:sub>50</jats:sub> of the Gompertz function yielded lethal-temperature estimates closest to those obtained visually. Also, T<jats:sub>max</jats:sub> values of the Gompertz function were well correlated with visual hardiness indices. The Richards function yielded hardiness estimates deviating largely from visual rating. In addition, the Richards function displayed a considerable lack of fit in several data sets. The Gompertz function was preferred to the logistic one as it allows for asymmetry in leakage response. Percentage-adjusted injury data transformation facilitated curve-fitting and enabled calculation of T<jats:sub>50</jats:sub> estimates.</jats:p>

Vegetative and Floral Chilling Requirements of Four New Kiwi Cultivars of Actinidia chinensis and A. deliciosa

“…Data were analyzed using the nonlinear procedure of the Statistical Analysis System (SAS, Cary, NC). Means were derived for each day, and dependent variables were fitted to numbers of chill hours using a Gompertz regression (Lim et al, 1998;Lindén et al, 2000). Development of the curve required a constant that was the asymptote of the function.…”

Frost Tolerance of Eight Olive Cultivars

“…Frost affects plant cell membranes, which become less permeable and even break, giving rise to the leakage of solute from damaged cells; this electrolyte leakage can be measured in terms of the electrical conductivity (EC) of the medium (Lindén and Palonen, 2000). EC measurement is a simple, quick, effective and reproducible way of selecting olive genotypes by cold hardiness.…”

“…The inflection point of the sigmoid curve (parameter c) predicts the lethal freezing temperature (LT 50 ) and corresponds to the subzero temperature at which 50% ion leakage occurs, a point reported to correspond to irreversible lethal damage (Boorse et al, 1998;Levitt, 1980;Li, 1984;Lindén and Palonen, 2000;Palliotti and Bongi, 1996).…”

Tissue damage in heated carrot slices. Comparing mild hot water blanching and infrared heating

“…Damage to cell membranes after heat treatment was tested by relative electrolyte leakage measurements, based on the principle that damage to cell membranes results in enhanced leakage of solutes into the apoplastic water (Linden, Palonen, & Linden, 2000).…”