Morphological Structure and Water Status in Bulbs

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Morphological structure and water status in bulbs
during their transition from dormancy to active
growth Visualization by NMR imaging
Rina Kamenetsky Hanita Zemah Annette van der
Toorn Haim D. Rabinowitch Henk van As Peter
Bendel accepted by J. exp. Bot.
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Tulip bulbs (Tulipa gesneriana L.)

• World wide use of tulip as ornamental plant
• Needs a cold period during dormancy to facilitate
  normal development and flowering
• Fundamental knowledge about bulb dormancy and
  growth is limited

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Purpose of the project

• To determine if significant differences in water
  status between bulbs stored at 4 oC and at 20 oC
  can be observed using MRI.
• Mainly using
• Visible morphological changes in the images
• Proton density determination
• R2 measurements (1/T2)
• ADC measurements (reflecting proton mobility)
• R1 measurements (1/T1)

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Morphological MR image of tulip bulb
scales
bud
basal plate
1 cm
Resolution 350 x 350 x 700 mm
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(No Transcript)
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7
30
20 oC
4o C
4 oC
20 oC
amplitude
Time- dependent change in R2 for two bulbs
R2
Time- dependent change in amplitude for two bulbs
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0
start
2 weeks
4 weeks
8 weeks
12weeks
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Planted bulbs (10 days after planting)
4 oC
20 oC
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Conclusions

• MR parameters such as R2 and ADC can be used to
  observe differences between chilled and
  non-chilled bulbs
• MRI needs to be combined with histology to
  understand the observed changes in water status
• The majority of changes in water status take
  place between 2 and 8 weeks after storage