Effect of Chilling Temperatures upon Cell Cultures of Tomato

Abstract
The effect of chilling temperatures upon cell cultures of tomato (Lycopersicon esculentum Mill cv. VF36 and VFNT Cherry, and L. hirsutum Humb. et Bonpl.) was tested. Doubling times for L. esculentum were 2-3 days at 28.degree. C, and 3-8 days at 12.degree. C. No growth was observed at 8.degree. C, indicating an abrupt limit to growth between 8 and 12.degree. C. Fluorescein diacetate staining indicated that 80-90% of the cells were alive when cells were maintained at 8.degree. C for up to 2 wk. When cultures kept at 8.degree. C for up to 30 days were transferred to 28.degree. C, growth resumed quickly, and at a rate virtually identical to that for unchilled cells. Similar results were found for cells maintained at 0.degree. C, and for cells of VFNT Cherry and of L. hirsutum. Under certain conditions, cultures slowly doubled in fresh weight and cell volume at 8 or 9.degree. C but additional growth at 8.degree. C did not occur, nor could growth be maintained by subculture at 8 or 9.degree. C. The results are contrary to reports that cell cultures of tomato die when exposed to temperatures < 10.degree. C for 1 or 2 wk. Chilling temperatures quickly inhibit growth of tomato cells, but do not kill them.