Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: Juan Ramsay x
Clear All Modify Search

Abstract

Spur buds of apricot were sampled at intervals from late July, 1968, until bloom in 1969, and from 1 month after bloom until the end of September. The samples were freeze-dried and then extracted with 80% methanol. The extracts were partitioned into 4 phases: water, neutral ethyl acetate, acidic ether, and acidic butanol, and then bioassayed for auxins, inhibitors and gibberellins. Although an inhibitor and gibberellin-like activity were present in the extracts, no consistent auxin-type activity was found. The end of rest was correlated with a decrease in the level of inhibitor and gibberellin-like activity, with the inhibitor increasing again towards anthesis. The onset of rest in May, 1969, was correlated with a decrease in inhibitor and increase in gibberellin-like activity. The inhibitor was present in scales and floral parts of buds, while gibberellin-like activity was confined mainly to the floral parts.

Open Access

Abstract

A sample of freeze-dried apricot buds collected during December, 1968, and January, 1969, was extracted with 80% methanol. The extract was partitioned into 3 phases: water, neutral acetate, and acidic ether. The acidic ether phase contained most of the inhibitor that was present in the methanolic extract. Thus, further purification and identification was done with this fraction exclusively.

The similarity of Rf values of abscisic acid and of the apricot bud inhibitor when TL-cochromatographed using 10 different solvent systems, the equal retention times of their methylated derivatives when gas chromatographed, the congruency of their ultraviolet light spectra, and their inhibition of growth of apricot seedlings indicate that the apricot bud inhibitor is similar, if not identical, to abscisic acid.

Open Access

Abstract

Apricot shoots were defoliated and spurs were decapitated and defoliated on successive dates to determine the onset of rest in specific axillary buds. While the spurs were still growing and the leaves expanding decapitation alone would induce axillary bud growth. Later, when the spurs and leaves stopped growing both decapitation and defoliation were necessary to induce axillary bud growth. Eventually when the onset of rest occurred both decapitation and defoliation would not induce bud growth. Decapitation alone was enough to induce bud growth of terminal shoots. After the onset of rest decapitation and defoliation would not induce bud growth in the terminal shoot buds.

Open Access