The Effects of Chemical and Cultural Treatments on Gibberlin Levels in Strawberry Leaves and on the Induction of Secondary Flowering

Gibberellins 3, 4 and 7 were isolated from "Shasta" Strawberry (Fragaria X ananassa Duch.) leaves and identified by gas and thin layer chromatography. In young expanding leaves GA3 occurred at 5 times the concentration of either GA4 or GA7. CCC (2-chloroethyl-trimethylammonium chloride), S...

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Bibliographic Details
Main Author: Arteca, Richard N.
Format: Others
Published: DigitalCommons@USU 1976
Subjects:
Online Access:https://digitalcommons.usu.edu/etd/3133
https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=4152&context=etd
Description
Summary:Gibberellins 3, 4 and 7 were isolated from "Shasta" Strawberry (Fragaria X ananassa Duch.) leaves and identified by gas and thin layer chromatography. In young expanding leaves GA3 occurred at 5 times the concentration of either GA4 or GA7. CCC (2-chloroethyl-trimethylammonium chloride), SADH (Succinamic acid-2,2-dimethyl hydrazide), ethephon (2-chloroethylphosphonic acid), and UBI-P293 (2,3-dihydro-5-6-diphenyl-1,4-oxathiin) were applied to established plantings of three June-bearing strawberry (Fragaria X ananassa Ouch.) cultivars: 11 Shasta, 11 "Fresno" and "Tioga." Treatments were applied on alternate days for three weeks following anthesis of the king blossom. Levels of GA3 and GA4 were reduced by all treatments, but GA7 occurred at such low concentrations that treatment effects could not be measured statistically. Three weeks' exposure to short-daylengths (8 hours of light and 16 hours of darkness) resulted in no change in GA3 or GA7, but GA4 concentrations were significantly reduced . Leaf tissue was analyzed t o e valuate treatment effects on chlorophyll content; no significant changes were observed. No secondary flowering as a result of photoperiod , post-harvest defoliation or growth retardant treatments was observed.