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Author Lumsden, P. J., & Furuya, M.
Title Evidence for Two Actions of Light in the Photoperiodic Induction of Flowering in <italic>Pharbitis nil</italic> Type Journal Article
Year (down) 1986 Publication Plant and Cell Physiology Abbreviated Journal
Volume Issue Pages
Keywords Plants
Abstract Using one-day-old light-grown seedlings of Pharbitis nil we have shown that there are two distinct responses to light during the inductive dark period. The first is the classic night-break, which inhibits flowering at a specific stage of the circadian rhythm (assumed to be the basis of dark time measurement). The second action is to control the phase of this rhythm. The two responses were compared at the 6th and 8th hour of darkness. They differed in their dose responses, and by using very short exposures it was possible to achieve one response without the other. The response of the rhythm to light displayed characteristics of other circadian rhythms; the direction and sensitivity of the phase shift changed between the 6th and 8th h, the rhythm was reset by longer exposures to light, and with one critical light treatment at the appropriate phase, the rhythm was apparently abolished. These results offer direct support for an external coincidence model in the photoperiodic control of floral induction.
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ISSN 1471-9053 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ intern @ Serial 2375
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Author Taylor, G.; Davies, W.J.
Title The Control Of Leaf Growth Of Betula And Acer By Photoenvironment Type Journal Article
Year (down) 1985 Publication New Phytologist Abbreviated Journal New Phytol
Volume 101 Issue 2 Pages 259-268
Keywords Plants
Abstract Leaf extension of one‐year‐old seedlings of silver birch (Betula pendula Roth.) and sycamore (Acer pseudoplatanus L.), was measured using linear variable transducers (LVDTs) interfaced to a microcomputer. Birch and sycamore seedlings exhibited contrasting patterns of leaf extension during a diurnal cycle with a 16 h photoperiod. Birch leaves grew more rapidly when illuminated; growth during the photoperiod was approximately doubled when compared with growth in the dark. Mean relative growth rates ±SE at ‘lights‐on + 3 h’ and ‘lights‐off + 5 h’ were 0.0136 ± 0.0016 and 0.0066 ± 0.0005 h−1 respectively. In direct contrast, growth of sycamore leaves was increased when leaves were darkened; mean relative growth rates + SE at ‘lights‐on+3 h’ and ‘lights‐off + 5 h’ were 0.0056 ± 0.0005 and 0.0094 ± 0.0008 h‐1 respectively.

When leaves of birch and sycamore were darkened, increased leaf turgor was measured in both species, but only in sycamore was this higher night‐time turgor associated with a higher rate of leaf growth.

Cell wall extensibility (WEX), an indication of the ability of cell walls to loosen and extend irreversibly, and cell surface pH were assessed in darkened and illuminated leaves of both species. An increase in WEX was measured when birch leaves were illuminated (P≤ 0.001) and this was accompanied by a decline in cell surface pH (P≤ 0.001). However, when leaves of sycamore were illuminated, WEX declined (P≤ 005) and cell surface pH increased (P≤ 0.001).

The ability of these species to survive beneath a woodland canopy is discussed in relation to the cellular factors controlling their leaf growth.
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ISSN 0028-646X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1992
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Author Eng, R.Y.N.; Tsujita, M.J.; Grodzinski, B.
Title The effects of supplementary HPS lighting and carbon dioxide enrichment on the vegetative growth, nutritional status and flowering characteristics ofChrysanthemum morifoliumRamat Type Journal Article
Year (down) 1985 Publication Journal of Horticultural Science Abbreviated Journal Journal of Horticultural Science
Volume 60 Issue 3 Pages 389-395
Keywords Plants
Abstract Supplementary high pressure sodium (HPS) lighting (140 µmol m−2s−1) and CO2 enrichment (1375 µl l−1) improved the vegetative growth of Chrysanthemum morifolium cv Dramatic by increases in stem length, stem diameter, root weight ratio, dry weight, relative growth and net assimilation rates. Three-week-old chrysanthemums grown under CO2 enrichment and HPS lighting had lower leaf weight and stem weight ratios as well as lower foliar nutrient content than those grown under ambient CO2 and natural light. Plants grown on to maturity under CO2 enrichment and supplementary HPS lighting had the longest stem lengths, the most flowers and greatest increase in dry weight. The combination of both additional light and CO2 was superior to either factor used alone. With 24 h HPS supplementary lighting CO2 enrichment was most effective in improving vegetative growth and flower quality when applied during the daytime. Night CO2 enrichment was not commercially beneficial at the light levels employed in this study.
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Series Volume Series Issue Edition
ISSN 0022-1589 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ intern @ Serial 2373
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Author Shillo, R., & Halevy, A. H.
Title Interaction of photoperiod and temperature in flowering-control of Gypsophila paniculata L Type Journal Article
Year (down) 1982 Publication Scientia Horticulturae Abbreviated Journal
Volume 16 Issue 4 Pages 385-393
Keywords Plants
Abstract Long day promotes flowering of Gysophila paniculata L cultivar ‘Bristol Fairy’. Repeated treatments with GA3 or GA4 + 7 in short days did not promote flowering. The long photoperiod is effective only at relatively high temperatures. At night temperatures below 12°C, the plants remain vegetative even in long days. Efficient artificial lighting is from incandescent lamps at 60–100 lux. Fluorescent lighting (Cool-White) is not effective. Lighting of 4 hours as a night-break or at the end of the night were equally effective, but 4 hours lighting as a day-extension was less effective. Whole-night lighting promoted flowering more than any of the 4-hour lighting regimes. Cyclic lighting of one third light in each cycle promoted flowering to the same extent as continuous lighting. Light intensity during the day has a decisive effect on flower production.
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Notes Approved no
Call Number IDA @ intern @ Serial 2370
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Author Myers, L.; Christian, K.; Kirchner, R.
Title Flowering responses of 48 lines of oilseed rape (Brassica spp.) to vernalization and daylength Type Journal Article
Year (down) 1982 Publication Australian Journal of Agricultural Research Abbreviated Journal Aust. J. Agric. Res.
Volume 33 Issue 6 Pages 927
Keywords Plants
Abstract Forty-eight lines of Brassica spp, of diverse origins were grown in the glasshouse either under natural daylengths or daylengths extended to 16 h by artificial illumination. Plants were either unvernalized or had been subjected to 6 weeks at 8¦C day and 6¦C night temperatures as seedlings. Lines could be classified into two major groups, according to whether or not vernalization or long photoperiods were essential for 50% flowering within 21 weeks. In six lines, both vernalization and long days were essential for prompt flowering, while only five lines did not respond to either treatment. Strong interactions between lines and treatments were found in the number of leaves and subtended buds at flowering. The results show that a wide range of responses is obtainable from material currently available, offering considerabk, scope for adaptation to different environments.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-9409 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ intern @ Serial 2369
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