RAPID RECOVERY OF PHOTOSYNTHETIC CELL-SUSPENSION CULTURES FOLLOWING HETEROTROPHIC BLEACHING

Seven suspension-cultured lines of five different species (Amaranthus powellii, Datura innoxia, Glycine max, Gossypium hirsutum, and Nicotia na tabacum X Nicotiana glutinosa fusion hybrid), which had been grown under photomixotrophic conditions, were placed under heterotrophic con ditions (darkness and media with 3% sucrose or starch) where the chlor ophyll levels declined to near zero. After three transfers over a 70-d period, the cells were placed back into photomixotrophic or photoauto trophic conditions where regreening occurred rapidly and continued gro wth was observed. This rapid adaptation to photosynthetic conditions c ontrasts with the original initiation process for these cultures, whic h required many months and an apparent selection since many of the ori ginal cells died. Thus, these seven photosynthetic cell suspension cul tures appear to be different from the original cultures due possibly t o genetic or adaptive changes.