Screening lentil (Lens culinaris) for cold hardiness under controlled conditions

This study describes the development of a highly repeatable cold screening procedure for lentil (Lens culinaris Medik.) using controlled conditions wh ich involve first, acclimation of the plants at the vegetative stage in a g rowth chamber and second, freeze testing in a freeze chamber. The seeds wer e first germinated in Petri dishes and then planted in styrofoam trays with individual cells. Initial growing temperatures in the growth chamber for t wo weeks were 25 degrees C day and 10 degrees C night with a 12 h photoperi od. In the third week the photoperiod was changed to 10 h and in the fourth the temperatures were changed to 10 degrees C day and 0 degrees C night to acclimate the plants. Using a modified freeze chamber (household deep free zer), a freeze test temperature of -15 degrees C, following a 6-8 weeks acc limation period (because both acclimation times had the same effect for col d tolerance of the genotypes), at 2 and 3 degrees C/h cooling rate, and an exposure time of 3 h at -15 degrees C were appropriate to detect significan t (P < 0.01) differences among several lines at a comparatively low degree of injury for the most cold-hardy genotypes.