Abstract
The effects of temperature and light intensity on the growth of Scrophularia marilandica L. were studies under artificial, semi—natural, and natural environmental conditions. The plants in the controlled environment rooms were grown under 10 different combinations of temperature (48°/58°—63°/73°F) and light intensity (24—123 cal/cm 2 /day). The plants in the semi—natural experiment were grown outdoors on prepared plots representing seven levels of average radiation ranging from 20.4 to 405.7 cal/cm 2 /day. Net assimilation rate (NAR) was proportional to light intensity up to 123 cal/cm 2 /day in the growth rooms. In the semi—natural studies, it was proportional up to 150 cal/cm 2 /day and from this point up to 300 cal/cm 2 /day, NAR increased but not proportionally. Above 300 cal/cm 2 /day NAR was independent of solar radiation. Under controlled conditions NAR decreased slightly with age at the highest light levels. The length of the vegetative phase, the specific leaf area, and the leaf—area ratio were sharply decreased at higher light intensities. The dry weight of all plant organs was augmented by high light intensities. Roots and axillary shoots were especially sensitive. In the growth—room experiments, temperature effects were more pronounced than were light effects. Stem elongation was completely inhibited at temperature regimes below 63°/73°F, and leaf expansion was markedly diminished below 57°/68°F. Consequently the shoot developed a rosette habit and flowering was inhibited. Decreases in temperature to 48°/58°F had little effect of root growth. The net effect of low temperatures was to depress the shoot—root ratio. However, NAR was increased by a reduction in temperature from 63°/73° to 48°/58° at all intensities. The shoot—root ratio of shaded plants was increased to a greater extent by a rise in temperature than was that of the unshaded plants. Regardless of light level, plants at 48°/58°F consistently had a smaller shoot—root ratio than did those at 63°/73°F. Inhibition of stem elongation and subsequent rosette development at low temperatures were not affected by changes in light intensity. The usual development of greater leaf areas by plants growing under lower light intensities was partially reversed at low temperatures. In early spring shoots of native Scrophularia marilandica sprouted from crown buds attached to perennial roots. The timing differential between leaf expansion in April and shoot elongation in May appears to be a temperature—photoperiod interaction. In early spring and autumn cool temperatures which repressed shoot growth had little effect on root growth. Roots increased greatly in size through late summer into early autumn.
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Claims 20
Claim · model-written summary
In growth rooms, net assimilation rate was proportional to light intensity up to 123 cal/cm2/day.
- Taxon
- Scrophularia Marilandica
Scrophularia marilandicat0 - Treatment
- light intensitye0
- Outcome
- Net assimilation rate (NAR)e0
- Direction
- increaseinferrede0
- Qualifier
- up to 123 cal/cm 2 /daye0
- Setting
- growth roomse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Net assimilation rate (NAR) was proportional to light intensity up to 123 cal/cm 2 /day in the growth rooms”
t0“Scrophularia Marilandica”
Claim · model-written summary
In semi-natural studies, net assimilation rate was proportional to light up to 150 cal/cm2/day.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Outcome
- NARe0
- Direction
- increaseinferrede0
- Qualifier
- proportional up to 150 cal/cm 2 /daye0
- Setting
- semi—natural studiese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the semi—natural studies, it was proportional up to 150 cal/cm 2 /day and from this point up to 300 cal/cm 2 /day, NAR increased but not proportionally”
t0“Scrophularia Marilandica”
Claim · model-written summary
In semi-natural studies, from 150 up to 300 cal/cm2/day net assimilation rate increased but not proportionally.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Outcome
- NARe0
- Direction
- increasede0
- Value
- up to 300 cal/cm 2 /daye0
- Qualifier
- not proportionallye0
- Setting
- semi—natural studiese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the semi—natural studies, it was proportional up to 150 cal/cm 2 /day and from this point up to 300 cal/cm 2 /day, NAR increased but not proportionally”
t0“Scrophularia Marilandica”
Claim · model-written summary
Above 300 cal/cm2/day net assimilation rate was independent of solar radiation.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- solar radiatione0
- Outcome
- NARe0
- Direction
- no_changeinferrede0
- Qualifier
- Above 300 cal/cm 2 /daye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Above 300 cal/cm 2 /day NAR was independent of solar radiation”
t0“Scrophularia Marilandica”
Claim · model-written summary
Under controlled conditions net assimilation rate decreased slightly with age at the highest light levels.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Organ / stage
- agee0
- Outcome
- NARe0
- Direction
- decreasede0
- Qualifier
- at the highest light levelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under controlled conditions NAR decreased slightly with age at the highest light levels”
t0“Scrophularia Marilandica”
Claim · model-written summary
Vegetative phase length, specific leaf area and leaf-area ratio decreased sharply at higher light intensities.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- higher light intensitiese0
- Outcome
- The length of the vegetative phase, the specific leaf area, and the leaf—area ratioe0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The length of the vegetative phase, the specific leaf area, and the leaf—area ratio were sharply decreased at higher light intensities”
t0“Scrophularia Marilandica”
Claim · model-written summary
Dry weight of all plant organs was increased by high light intensities.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- high light intensitiese0
- Outcome
- dry weight of all plant organse0
- Direction
- augmentede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The dry weight of all plant organs was augmented by high light intensities”
t0“Scrophularia Marilandica”
Claim · model-written summary
Roots and axillary shoots were especially sensitive to light intensity.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Organ / stage
- Roots and axillary shootse0
- Outcome
- especially sensitivee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Roots and axillary shoots were especially sensitive”
t0“Scrophularia Marilandica”
Claim · model-written summary
In growth-room experiments, temperature effects were more pronounced than light effects.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- temperaturee0
- Outcome
- effectse0
- Direction
- more pronouncede0
- Comparator
- light effectse0
- Setting
- growth—room experimentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the growth—room experiments, temperature effects were more pronounced than were light effects”
t0“Scrophularia Marilandica”
Claim · model-written summary
Stem elongation was completely inhibited at temperature regimes below 63/73 F.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- temperature regimes below 63°/73°Fe0
- Outcome
- Stem elongatione0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Stem elongation was completely inhibited at temperature regimes below 63°/73°F”
t0“Scrophularia Marilandica”
Claim · model-written summary
Leaf expansion was markedly diminished below 57/68 F.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- below 57°/68°Fe0
- Outcome
- leaf expansione0
- Direction
- diminishede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leaf expansion was markedly diminished below 57°/68°F”
t0“Scrophularia Marilandica”
Claim · model-written summary
As a consequence of low temperature the shoot developed a rosette habit and flowering was inhibited.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Outcome
- rosette habit and flowering was inhibitede0
Not reportedTreatmentComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Consequently the shoot developed a rosette habit and flowering was inhibited”
t0“Scrophularia Marilandica”
Claim · model-written summary
Decreasing temperature to 48/58 F had little effect on root growth.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- Decreases in temperature to 48°/58°Fe0
- Outcome
- root growthe0
- Direction
- little effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Decreases in temperature to 48°/58°F had little effect of root growth”
t0“Scrophularia Marilandica”
Claim · model-written summary
The net effect of low temperatures was to depress the shoot-root ratio.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- low temperaturese0
- Outcome
- shoot—root ratioe0
- Direction
- depresse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The net effect of low temperatures was to depress the shoot—root ratio”
t0“Scrophularia Marilandica”
Claim · model-written summary
Net assimilation rate was increased by lowering temperature from 63/73 to 48/58 at all light intensities.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- a reduction in temperature from 63°/73° to 48°/58°e0
- Outcome
- NARe0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NAR was increased by a reduction in temperature from 63°/73° to 48°/58° at all intensities”
t0“Scrophularia Marilandica”
Claim · model-written summary
The shoot-root ratio of shaded plants was increased more by a rise in temperature than that of unshaded plants.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Material
- shaded plantse0
- Treatment
- a rise in temperaturee0
- Outcome
- shoot—root ratioe0
- Direction
- increased to a greater extente0
- Comparator
- unshaded plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The shoot—root ratio of shaded plants was increased to a greater extent by a rise in temperature than was that of the unshaded plants”
t0“Scrophularia Marilandica”
Claim · model-written summary
Inhibition of stem elongation and subsequent rosette development at low temperatures was not affected by changes in light intensity.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- changes in light intensitye0
- Outcome
- Inhibition of stem elongation and subsequent rosette development at low temperaturese0
- Direction
- not affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inhibition of stem elongation and subsequent rosette development at low temperatures were not affected by changes in light intensity”
t0“Scrophularia Marilandica”
Claim · model-written summary
The usual development of greater leaf areas under lower light intensities was partially reversed at low temperatures.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Treatment
- low temperaturese0
- Outcome
- development of greater leaf areas by plants growing under lower light intensitiese0
- Direction
- partially reversede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The usual development of greater leaf areas by plants growing under lower light intensities was partially reversed at low temperatures”
t0“Scrophularia Marilandica”
Claim · model-written summary
The timing differential between leaf expansion in April and shoot elongation in May appears to be a temperature-photoperiod interaction.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Outcome
- timing differential between leaf expansion in April and shoot elongation in Maye0
- Qualifier
- temperature—photoperiod interactione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The timing differential between leaf expansion in April and shoot elongation in May appears to be a temperature—photoperiod interaction”
t0“Scrophularia Marilandica”
Claim · model-written summary
Roots increased greatly in size through late summer into early autumn.
- Taxon
- Scrophularia MarilandicaScrophularia marilandicat0
- Organ / stage
- Rootse0
- Outcome
- Roots increased greatly in sizee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Roots increased greatly in size through late summer into early autumn”
t0“Scrophularia Marilandica”