Abstract
Some chemical characters and the biological activities of gibberellins obtained from embryo and endosperm in seed, and from cotyledon and hypocotyl in seedling in the dwarf variety, Kidachi, the tall variety, Tendan, and their F1-hybrids of reciprocal crosses in Pharbitis nil Chois. were examined using the paper-chromatography. There was little difference in the pattern of gibberellin activity found in the acid fractions among all the strains, and the activity in all the tissues except cotyledon is probably due to free gibberellins A3, A5 and A20. On the other hand, very clear difference in the gibberellin activity between Kidachi and Tendan was found in the water-soluble fractions from the endosperm in seed and the seedling tissues, indicating that Tendan contains much more bound gibberellins of GA3-glucoside and related substances than Kidachi. Each of the hybrids gives similar pattern inchromatographic behaviour to its respective maternal veriety in regard to the bound gibberellins contained in the endosperm and the seedling tissues, suggesting the possibility for maternal inheritance of the characters concerned with GA3-glucoside and other bound gibberellins in plant tissue. The activities in the two types of gibberellins contained in the hypocotyl of the hybrids were found to be less than those in Tendan irrespective of hybrid vigour in hypocotyl elongation.
