WATER STATUS OF BLUEBERRY FLOWER BUDS AND ITS RELATIONSHIP TO DORMANCY AND COLD HARDINESS

Authors: PARMENTIER, CECILE - CONTRACT EMPLOYEE; Rowland, Lisa; Line, Michael

Submitted to: Blueberry Research Extension North American Workers Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/27/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Previous investigations reported that water is bound while buds
of woody plants are dormant and in a freer form after the
chilling requirement has been satisfied. The status of water
could provide clues as to the mechanisms of maintenance and
breaking of bud dormancy in woody perennials. Experiments were
conducted to evaluate the changes in water status of blueberry
flower buds, using Nuclear Magnetic Resonance, along with the
changes in dormancy intensity, throughout the accumulation of
chilling that leads to release from dormancy. Bluecrop was found
to be the most dormant cultivar and Gulfcoast to be the least
dormant. Tifblue had an intermediate dormancy. Under our
experimental conditions, the chilling requirements (CRs) of
Tifblue, Bluecrop and Gulfcoast were evaluated to be 1200 h, 1500
h and 140 h, respectively. Whatever the cultivar, the state of
water as well as the water content did not change with chilling
accumulation, even after CRs were satisfied. On the other hand,
a transition to freer water, but no change in the water content,
occurred if the plants were placed under forcing conditions.
Forcing was ineffective in freeing water before the CR was
satisfied. Therefore, NMR can be developed as a tool for
scientists to distinguish buds that are strictly dormant (before
satisfaction of the CR) from buds whose inability to break is
imposed by the environmental factors (not enough warm
temperature). Results also suggested that bound water would be
more associated with cold hardiness than with dormancy.