Variations in the endogenous growth regulators and nitrogen content in retained and abscising bolls of cotton (Cossypium hirsutum)
Abstract
Studies on the variations in the endogenous levels of abcisic acid (ABA), gibberellin (GA3), auxin, ascorbic-acid (AA) and nitrogen (N) with the progress of boll age showed that GA3 and ABA centent was low in the retained cotton (Gossypium hirsutum L.) bolls as compared in the abscising ones of the same age indicating relatively high endogenous GAa and ABA cotent above a specific threshold to be conducive to abscission. Nitrogen content was found to be high in retained, low in yellowed and lowest in the abscising bolls. Endogenous auxin and AA content was high in retained bolls as compared to that in abscising ones of the same age. The data suggest that retention/abscission of bolls seems to be dependent on balance between these endogenous growth regulators.
