Morphological acclimation to light intensity in Douglas-fir seedlings

1977 ◽  
Vol 55 (15) ◽  
pp. 2033-2042 ◽  
Author(s):  
Allan P. Drew ◽  
William K. Ferrell
Keyword(s):  
Light Intensity ◽  
Root Growth ◽  
Dry Weight ◽  
Frost Damage ◽  
Douglas Fir ◽  
Stem Length ◽  
Low Light ◽  
Spring Frost ◽  
Terminal Bud ◽  
Leaf Surface Area

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were grown outdoors under 9, 44, and 100% light intensity and were sampled periodically over their first growing season for stem, leaf, and root dry weights, and the data were analyzed allometrically. In addition, seedlings were assessed for number of needles per stem length, ratio leaf surface area: leaf dry weight, and maximum seedling dry weight. The experiment was repeated during a 2nd, warmer, year.Maximum growth occurred under partial shade and moderate temperatures. In the 1st year, seedlings allocated progressively more dry matter to shoot than to root growth as light intensity decreased. In the 2nd year, root growth was favored at the expense of shoot growth. In both years, shoot structural alterations were such as to favor enhanced photosynthesis under low light. Acclimative changes are explained in terms of an interaction between light, temperature, and seedling size.A second experiment showed that seedlings grown under low light set a terminal bud sooner in the fall and broke bud sooner the next spring than seedlings preconditioned to high light. They also suffered more spring frost damage and showed greater incidence of lammas growth in the 2nd year. No effect of 1st-year preconditioning on timing of budbreak was evident in the 3rd year.

scholarly journals Light Intensity Affects Growth, Photosynthetic Capability, and Total Flavonoid Accumulation of Anoectochilus Plants

HortScience ◽  
2010 ◽  
Vol 45 (6) ◽  
pp. 863-867 ◽  
Author(s):  
Zengqiang Ma ◽  
Shishang Li ◽  
Meijun Zhang ◽  
Shihao Jiang ◽  
Yulan Xiao
Keyword(s):  
Light Intensity ◽  
Chlorophyll Concentration ◽  
Dry Weight ◽  
Total Flavonoid ◽  
Stem Length ◽  
Photon Flux ◽  
Low Light ◽  
Four Levels ◽  
Anoectochilus Formosanus ◽  
Flavonoid Accumulation

Anoectochilus formosanus, a medicinal plant used to treat hypertension, lung disease, and liver disease, was grown to maximize biomass and secondary metabolite production in a controlled environment under four levels of photosynthetic photon flux (PPF), namely, 10, 30, 60, or 90 μmol·m−2·s−1, that is L10, L30, L60, and L90 treatments, respectively. On Day 45, all growth values were greatest for the L30 plants. Dry weight was lowest for the L10 plants. Leaf area, stem length, and fresh weight were lowest for the L90 plants. The chlorophyll concentration was highest in the L10 treatment and decreased with increasing PPF. Electron transport ratios of leaves were highest in the L30 treatment and lowest in the L90 for the second leaf (counted down from the apex) and in the L10 for the third leaf. An increase in light intensity from 10 to 60 μmol·m−2·s−1 increased the superoxide dismutase activity and was associated with an increase in the total flavonoid concentration. The total flavonoid concentration (mg·g−1 DW) was greatest in the L60 and lowest in the L90. However, the total flavonoid content (mg/plant) was highest in the L30 plants as a result of great biomass. The results indicated that A. formosanus is a typical shade plant suitable to grow under low light intensity at PPF of 30 to 50 μmol·m−2·s−1 for both growth and production of total flavonoid. A light intensity of 90 μmol·m−2·s−1 induced stress on plant growth and reduced photosynthetic capability and the flavonoid accumulation.

Changes in drought resistance and root growth capacity of container seedlings in response to nursery drought, nitrogen, and potassium treatments

1992 ◽  
Vol 22 (5) ◽  
pp. 740-749 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Drought Stress ◽  
Root Growth ◽  
Drought Resistance ◽  
Lodgepole Pine ◽  
Dry Weight ◽  
White Spruce ◽  
Douglas Fir ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
N Treatment

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), lodgepole pine (Pinuscontorta Dougl.), and white spruce (Piceaglauca (Moench) Voss) seedlings, each represented by two seed lots, were grown in Styroblock containers in a greenhouse and plastic shelter house from February 1989 to January 1990. The seedlings were exposed to two nitrogen (N) treatments and three potassium (K) treatments arranged factorially within three drought treatments. After winter storage, seedlings from a complete set of treatments were planted into hygric, mesic, and xeric sand beds during 12–14 March. Increasing nursery drought stress increased survival of Douglas-fir and lodgepole pine after planting, and high N treatment level increased survival of lodgepole pine and white spruce. Under xeric conditions, combined nursery drought and high N treatments increased survival of lodgepole pine by 33%, indicating the importance of nursery cultural regime for stock quality. Increase in nursery drought decreased seedling size relatively little, but increase in N increased seedling size one season after planting. A positive relationship between shoot/root ratio and survival in lodgepole pine and white spruce indicated that increase in N increased both shoot growth and drought resistance over the N range investigated. Only Douglas-fir showed an interaction between drought and N treatment and a small response in both survival and dry weight to K. Root growth capacity, measured at the time of planting, showed an approximate doubling in all species due to high N treatment, and was also increased in white spruce by drought stress. Survival and root growth capacity were poorly correlated, but dry-weight growth in sand beds was well correlated with root growth capacity. Shoot dry weight and percent N in shoots measured after nursery growth were correlated with root growth capacity. Manipulation of root growth capacity by changing nursery treatment was apparently possible without altering resistance to drought stress after planting.

Carbohydrate reserves and root growth potential in Douglas-fir seedlings before and after cold storage

1982 ◽  
Vol 12 (4) ◽  
pp. 905-912 ◽  
Author(s):  
Gary A. Ritchie
Keyword(s):  
Root Growth ◽  
Cold Storage ◽  
Drought Resistance ◽  
Dry Weight ◽  
Douglas Fir ◽  
Growth Potential ◽  
Frost Hardiness ◽  
Root Growth Potential ◽  
Carbohydrate Reserves ◽  
Before And After

Carbohydrate reserves and root growth potential (RGP) of 2 + 0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were monitored through a lifting season and during dark, cold storage. Concentrations of total nonstructural carbohydrate and extractable sugars in root and stem tissues remained relatively constant through winter, while foliar sugars showed a sharp midwinter peak at about 195 mg•g−1 dry weight. RGP was lowest in November and March and peaked in January. During storage at +2 and −1 °C, carbohydrates were depleted in all tissues through respiratory consumption. In contrast, RGP increased during the first 6 months in storage and then fell rapidly. The results do not support the view that changes in RGP are driven by changes in carbohydrate concentrations. Storage may affect frost hardiness and drought resistance through its effect on sugar concentrations.

Growth kinetics of Marquis wheat. II. Carbon dioxide dependence

1972 ◽  
Vol 50 (4) ◽  
pp. 883-889 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Carbon Dioxide ◽  
Light Intensity ◽  
Carbon Dioxide Concentration ◽  
Dry Weight ◽  
Maximum Growth ◽  
Carbon Dioxide Enrichment ◽  
Low Light ◽  
Growth Coefficient ◽  
Light Intensities ◽  
Wide Range

Marquis wheat was grown in growth rooms with four different concentrations of carbon dioxide and four to seven different intensities of light in a 16-h photoperiod at 25 °C. Growth was expressed quantitatively as the pseudo-first-order rate coefficient. Carbon dioxide stimulated growth, but the effect was greater the lower the light intensity in opposition to the known effect on photosynthesis. Carbon dioxide and light, in effect, did not influence the "rate" of growth of wheat additively but, rather, mutually compensated over a wide range. The growth coefficient of the roots was a little less than that of the shoots at all carbon dioxide concentrations and light intensities, probably owing to the cost of translocation. However, root growth benefited most from carbon dioxide enrichment at low light intensities. At intermediate light intensity there appeared to be a carbon dioxide concentration optimal for shoot growth. Carbon dioxide enrichment did not influence the maximum growth coefficient of Marquis wheat with respect to light intensity. The light-using efficiency of growth, calculated for vanishingly low light intensity at which it is maximal, was maximal for shoots at 1300 ppm CO2 but that for laminal area and root dry weight increased with CO2 to 2200 ppm at which the value for "leaves" was nearly fourfold that for roots. Unlike photosynthesis, the stimulation of growth by raised CO2 concentration was accomplished by increased efficiency of, and not capacity for, the net photosynthetic use of light.

Optimizing growth and development of 2-0 Douglas-fir seedlings by altering light intensity

1983 ◽  
Vol 13 (3) ◽  
pp. 425-428 ◽  
Author(s):  
Allan P. Drew
Keyword(s):  
Light Intensity ◽  
Root Development ◽  
Growth And Development ◽  
Dry Matter ◽  
Dry Weight ◽  
Growing Season ◽  
Douglas Fir ◽  
Total Weight ◽  
Planting Stock

Douglas-fir (Pseudotsitgamenziesii (Mirb.) Franco) seedlings were grown outdoors in pots under 71% of full light the first growing season and full light the second. Another group of seedlings was given full light continuously for 2 years. At the end of the 1st year, seedlings given initial shade had grown larger in total weight (root + shoot) than those grown under full light. With removal of shading, the larger plants with lower shoot/root ratios began to allocate increased dry matter to root development relative to their shoots. By the end of 2 years, shoot/root ratios for the two groups were no different, yet the plants shaded in their 1st year were 69% larger in dry weight. By proper use of shading during development, larger 2-0 planting stock having good root development may be produced. Such stock, grown without the use of costly fertilizer, may be better suited to regeneration of droughty sites in the Northwest than the usual 2-0 planting stock, nursery grown under full light.

Factors affecting growth and distribution of kauri (Agathis australis Salisb.) II. Effect of light intensity on seedling growth

1959 ◽  
Vol 7 (3) ◽  
pp. 268 ◽  
Author(s):  
RL Bieleski
Keyword(s):  
Light Intensity ◽  
Seedling Growth ◽  
Seedling Establishment ◽  
Dry Weight ◽  
Forest Tree ◽  
Stem Length ◽  
Tree Seedlings ◽  
Seedling Mortality ◽  
Seedling Morphology ◽  
Effect Of Light

The effect of various light intensities on the growth of kauri seedlings is described. Daylight was screened to the required level with lath screens. There was no significant effect of light on seedling mortality in the light intensity range 0.40–0.02 full daylight. Seedling morphology was affected by light intensity, the ratios stem dry weight/root dry weight, stem length/root length, and fresh weight / dry weight increasing significantly with decreasing light intensity. Seedling growth was a linear function of log (light intensity), the growth rates and assimilation rates being similar to those for other forest tree seedlings. The compensation point was at 0.009 full daylight, close to the low light intensity limit to seedling establishment in the field but low compared with those of other tree seedlings. There was no high light intensity limit to seedling growth, such as that shown for seedling establishment in the field. The apparent discrepancy is discussed.

A comparison of the root and shoot growth of winter barley and winter wheat, and the effect of an early application of chlormequat

1984 ◽  
Vol 103 (2) ◽  
pp. 257-264 ◽  
Author(s):  
P. L. Bragg ◽  
P. Rubino ◽  
F. K. G. Henderson ◽  
W. J. Fielding ◽  
R. Q. Cannell
Keyword(s):  
Winter Wheat ◽  
Root Growth ◽  
Grain Yield ◽  
Dry Weight ◽  
Winter Barley ◽  
Stem Length ◽  
Early Application ◽  
Area Index ◽  
The Difference ◽  
Number Of Shoots

SUMMARYIn a field experiment where winter wheat and winter barley were sown on the same date, the patterns of root growth of the two species were similar, with a few roots reaching a depth of at least 120 cm. Roots senesced sooner in barley, in association with earlier maturity of the shoots and grain. The number of shoots and leaf area index of the barley were greater than for the wheat, but rates of dry-matter production until anthesis of the barley were similar in both species. The grain yield of wheat was about 10% heavier than for barley. Where chlormequat had been applied in early December at the 3- to 4-leaf stage, when shoot apices of both species were still vegetative, root density of the winter wheat in the following March and April was slightly greater than for untreated plants, but the difference disappeared later. For winter barley there was no effect of chlormequat on root growth until July when root length tended to be greater at depth after the chlormequat treatment. The chlormequat treatment significantly shortened stem length, but did not significantly affect the number of shoots, crop dry weight or grain yield of either species.

Effect of Climatic Conditions on Phytotoxicity of Terbutryn

Weed Science ◽  
1972 ◽  
Vol 20 (1) ◽  
pp. 60-63 ◽  
Author(s):  
L. F. Figuerola ◽  
W. R. Furtick
Keyword(s):  
Light Intensity ◽  
Dry Weight ◽  
High Light Intensity ◽  
Climatic Conditions ◽  
High Light ◽  
Controlled Environment ◽  
Low Light ◽  
Carbon Dioxide Uptake ◽  
Low Light Intensity ◽  
The Difference

Phytotoxicity of 2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine (terbutryn) on winter wheat (Triticum aestivum Vill. ‘Host’) was investigated in a controlled environment. Highly significant differences in foliage dry weight were caused by different light intensities and rates of terbutryn. Injury symptoms appeared much earlier in plants under high light intensity. Carbon dioxide uptake by wheat plants was reduced by terbutryn at high light intensity. At low light intensity the reduction was less severe and developed later. Respiration (CO2 evolved in the dark) was reduced only by the highest rates. Terbutryn was significantly less toxic to wheat than 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine). The difference was more noticeable at low rates under high light intensity. At low light intensity no injury was observed with terbutryn.

Ecological adaptations in Douglas-fir (Pseudotsugamenziesii var. glauca) populations. III. Central Idaho

1983 ◽  
Vol 13 (4) ◽  
pp. 626-632 ◽  
Author(s):  
Gerald E. Rehfeldt
Keyword(s):  
Cold Hardiness ◽  
High Growth ◽  
Frost Damage ◽  
Douglas Fir ◽  
Growth Potential ◽  
Bud Burst ◽  
Population Means ◽  
Spring Frost ◽  
Selection For ◽  
Central Idaho

Growth, phenology, and cold hardiness of seedlings from 74 populations of Douglas-fir (Pseudotsugamenziesii var. glauca (Beissn.) Franco) from central Idaho were compared in four contrasting environments. Analyses of 3-year-old seedlings revealed population differentiation for eight variables: bud burst, bud set, multiple flushing, height, deviation from regression of 3-year height on 2-year height, spring frost damage, fall frost damage, and winter injury. These analyses, as well as high intercorrelations among population means, suggested that adaptations result from a balance between selection for a high growth potential in mild environments and selection for cold hardiness in severe environments. Consequently, genetic variation among populations was closely related to the elevation, geography, and climate of the seed source.

Interior spruce seedlings compared with emblings produced from somatic embryogenesis. I. Nursery development, fall acclimation, and over-winter storage

1994 ◽  
Vol 24 (7) ◽  
pp. 1376-1384 ◽  
Author(s):  
S.C. Grossnickle ◽  
J.E. Major ◽  
R.S. Folk
Keyword(s):  
Somatic Embryogenesis ◽  
Root Growth ◽  
Freezing Tolerance ◽  
Growth Rates ◽  
Frozen Storage ◽  
Dry Weight ◽  
Growing Season ◽  
First Year ◽  
Terminal Bud ◽  
Interior Spruce

Interior spruce (Piceaglauca (Moench) Voss × Piceaengelmannii Parry) seedlings and emblings (plants produced via somatic embryogenesis tissue culture) were grown as container 1 + 0 plants. Seedling and embling morphological development was monitored during the growing season. Needle freezing tolerance, days to terminal bud break (DBB1), root growth capacity (RGC), and shoot dry weight fraction (DWF) were monitored during the fall and in frozen storage. Emblings had slower height, diameter, and root growth rates during the initial 2.5 months in the nursery. Thereafter, seedlings and emblings had equal height growth rate, while emblings had greater diameter and root growth rates. At the end of the growing season, seedlings and emblings, respectively, had 23.8 and 14.2 cm shoot height, 4.0 and 3.4 mm diameter, and 0.81 and 0.80 g root dry weight. During the fall, DBB1 of both seedlings and emblings decreased, with emblings having a more rapid decrease. Both seedlings and emblings showed a similar increase in freezing tolerance. Emblings had a greater increase in DWF. During the fall, RGC decreased then increased, with seedlings displaying a greater increase than emblings. While in frozen storage, seedlings and emblings maintained a low DBB1, and a high RGC and DWF. Freezing tolerance decreased while in frozen storage, with the loss more pronounced among seedlings. A degree growth stage model describes the first year cycle of development for seedlings and emblings. Results indicate that seedlings and emblings have slightly different patterns of first year growth and fall acclimation. However, both seedlings and emblings were at the end of rest when lifted for frozen storage.

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