Relative electrolyte leakage of frost-damaged Pine needles

Pines needles of seedlings from a common garden experiment have been artificially subjected to different levels of frost stress. They were subsequently incubated in deionized water and conductivity of the solution was measured. The samples were then autoclaved at 121ºC and conductivity was measured a second time. The two conductivity measurements are used to calculate the 'relative electrolyte leakage' (REL) of damaged needles, an index of injury for frost damage.