Reinvestigation of apple-seed gibberellins.

Re-investigation of the gibberellins in apple seed has established the presence of GA4 and GA7 and of traces of GA9. The fraction, previously considered to be GA7 by TLC, contains small amounts of GA4 and traces of GA9; and the fraction, characterized as GA4 by TLC, contains traces of GA7 and GA9. However the present results do not change the previous conclusions that during the stratification of apple seed the level of GA7 remains fairly constant while that of GA4 increases.