Abstract
Field, greenhouse, and laboratory studies were conducted with the following objectives: (1) develop an efficient extraction and analytical method for determining concentration of major flavonoids in apple (Malus domestica Borkh.) leaves, (2) determine if differences exist in levels of these components in leaves of ten apple cultivars and if these differences explain variation in cultivar susceptibility to spider mites ( Acari: Tetranychidae), (3) understand the effects of varying light and nutritional regimes on apple leaf flavonoid levels, (4) assess if the flavonoid phloridzin, when applied to bush bean plants, affects Two Spotted Spider Mite population density, and (5) Determine if summer pruning of mature, field-grown apple trees influences levels of foliar phloridzin. An efficient extraction and HPLC analytical method is presented using commonly available and least toxic solvents and an isocratic HPLC run of short duration allowing calculation of unknown concentrations with a high degree of accuracy. Different cultivars showed significant differences in mite susceptibility and in phloridzin concentration in leaves. However, phloridzin differences do not appear to explain variation in cultivar susceptibility to spider mites. Greenhouse trials indicated that phloridzin concentration was significantly lower in leaves of potted trees of the four cultivars tested under 70% shade cloth than under full sun. All cultivars responded similarly to sun or shade in regard to percent dry weight phloridzin. Nutrition treatments appeared to have an effect on phloridzin levels only in 1995. Horticultural bush bean plants (Phaeseolus vulgaris) were either sprayed or injected through a cotton wick with 0.01 M phloridzin or distilled water, and seeded with 5 gravid female Tetranychus urticae mites. Phloridzin, either when applied topically to bean plants, or when introduced into the transpirational stream via a cotton wick, resulted in smaller numbers of T. urticae compared to plants which were not treated with phloridzin. Summer pruning of mature, field grown “McIntosh” apple had no effect on phloridzin concentration, likely indicating that summer pruning is not a stimulus of induced changes in flavonoid content.
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Claims 10
Claim · model-written summary
An efficient, accurate extraction and HPLC method for apple leaf flavonoids was presented.
- Taxon
- apple
Malus domesticat0 - Outcome
- calculation of unknown concentrations with a high degree of accuracye0
- Comparator
- commonly available and least toxic solventse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“An efficient extraction and HPLC analytical method is presented using commonly available and least toxic solvents and an isocratic HPLC run of short duration allowing calculation of unknown concentrations with a high degree of accuracy.”
t0“apple”
Claim · model-written summary
Apple cultivars differed significantly in mite susceptibility.
- Taxon
- appleMalus domesticat0
- Material
- cultivarse0
- Interactor
- mitee0pest
- Outcome
- mite susceptibilitye0
- Direction
- differencese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Different cultivars showed significant differences in mite susceptibility and in phloridzin concentration in leaves.”
t0“apple”
Claim · model-written summary
Apple cultivars differed significantly in leaf phloridzin concentration.
- Taxon
- appleMalus domesticat0
- Material
- cultivarse0
- Outcome
- phloridzin concentration in leavese0
- Direction
- differencese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Different cultivars showed significant differences in mite susceptibility and in phloridzin concentration in leaves.”
t0“apple”
Claim · model-written summary
Leaf phloridzin differences did not appear to explain cultivar variation in spider mite susceptibility.
- Taxon
- appleMalus domesticat0
- Interactor
- spider mitesTetranychidaee0pest
- Compound
- phloridzine0
- Outcome
- cultivar susceptibility to spider mitese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“phloridzin differences do not appear to explain variation in cultivar susceptibility to spider mites.”
t0“apple”
Claim · model-written summary
Under 70% shade cloth, apple leaf phloridzin concentration was significantly lower than in full sun.
- Taxon
- appleMalus domesticat0
- Treatment
- 70% shade clothe0
- Outcome
- phloridzin concentratione0
- Direction
- lowere0
- Qualifier
- four cultivarse0
- Comparator
- full sune0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“phloridzin concentration was significantly lower in leaves of potted trees of the four cultivars tested under 70% shade cloth than under full sun.”
t0“apple”
Claim · model-written summary
All four apple cultivars responded similarly to sun and shade in percent dry weight phloridzin.
- Taxon
- appleMalus domesticat0
- Outcome
- percent dry weight phloridzine0
- Direction
- similarlye0
- Qualifier
- sun or shadee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All cultivars responded similarly to sun or shade in regard to percent dry weight phloridzin.”
t0“apple”
Claim · model-written summary
Nutrition treatments appeared to affect apple phloridzin levels only in 1995.
- Taxon
- appleMalus domesticat0
- Treatment
- Nutrition treatmentse0
- Outcome
- phloridzin levelse0
- Qualifier
- only in 1995e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nutrition treatments appeared to have an effect on phloridzin levels only in 1995.”
t0“apple”
Claim · model-written summary
Topically applied phloridzin reduced T. urticae numbers on bean plants relative to untreated plants.
- Taxon
- bean plantse0
- Treatment
- Phloridzine0
- Interactor
- T. urticae
.jpg?width=60)
Tetranychus urticaee0pest - Outcome
- numbers of T. urticaee0
- Direction
- smallere0
- Qualifier
- applied topicallye0
- Comparator
- plants which were not treated with phloridzine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Phloridzin, either when applied topically to bean plants, or when introduced into the transpirational stream via a cotton wick, resulted in smaller numbers of T. urticae compared to plants which were not treated with phloridzin.”
Claim · model-written summary
Phloridzin introduced by wick reduced T. urticae numbers on bean plants relative to untreated plants.
- Taxon
- bean plantse0
- Treatment
- Phloridzine0
- Interactor
- T. urticaeTetranychus urticaee0pest
- Outcome
- numbers of T. urticaee0
- Direction
- smallere0
- Qualifier
- introduced into the transpirational stream via a cotton wicke0
- Comparator
- plants which were not treated with phloridzine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phloridzin, either when applied topically to bean plants, or when introduced into the transpirational stream via a cotton wick, resulted in smaller numbers of T. urticae compared to plants which were not treated with phloridzin.”
Claim · model-written summary
Summer pruning of mature McIntosh apple did not affect leaf phloridzin concentration.
- Taxon
- appleMalus domesticae0
- Material
- McIntoshe0
- Treatment
- Summer pruninge0
- Outcome
- phloridzin concentratione0
- Direction
- no effecte0
- Setting
- field growne0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Summer pruning of mature, field grown “McIntosh” apple had no effect on phloridzin concentration”
The same questions in other papers
pruning · molecular: metabolites · Malus domestica (apple)Positive and negative results
7 papers in the same direction as this paper · 11 in the opposite direction
- positive
- positive
- positive
15 papers more in this group
See all 19 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.