Effect of supplemental light intensity on white spruce, Engelmann spruce, and mountain hemlock seedlings grown under an extended photoperiod

1985 ◽  
Vol 15 (2) ◽  
pp. 295-300 ◽  
Author(s):  
J. T. Arnott ◽  
D. E. Macey
Keyword(s):  
Light Intensity ◽  
Root Weight ◽  
Forming Process ◽  
Engelmann Spruce ◽  
Light Intensities ◽  
Terminal Bud ◽  
Collar Diameter ◽  
Shoot Weight ◽  
Terminal Buds ◽  
Sodium Vapour

Piceaglauca (Moench) Voss, Piceaengelmannii Parry and Tsugamertensiana (Bong.) Carr. were grown in an unheated "shelterhouse" container nursery, with a high pressure sodium vapour lamp providing a 19-h photoperiod and light intensities of 1600, 800, 400, 200, and 100 lx. The control seedlings received natural daylight and photoperiod. None of the light intensities effectively prevented terminal bud formation in the first two species while no terminal buds were formed at the 1600 lx level in the third one. Higher light intensities delayed the bud forming process in the first and third species, produced significant differences in the number of stem units of the first two, and resulted in larger mean stem unit lengths of the last two species. The longest seedling shoots of all three species were grown under light intensities of 800, 100, and 400 lx, respectively. There were no significant differences in seedling shoot weight, root weight, and root collar diameter among the five light intensity levels used to extend the photoperiod in the first growing season. Light intensity had little effect on 2-year shoot growth of all three species.

Effect of Interspecific Interference, Light Intensity, and Soil Moisture on Soybean (Glycine max), Common Cocklebur (Xanthium strumarium), and Sicklepod (Cassia obtusifolia) Water Uptake

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 534-540 ◽  
Author(s):  
Ronald E. Jones ◽  
Robert H. Walker
Keyword(s):  
Soil Moisture ◽  
Light Intensity ◽  
Leaf Area ◽  
Water Uptake ◽  
Root Weight ◽  
Pressure Potential ◽  
Unit Leaf Area ◽  
Unit Leaf ◽  
Shoot Weight ◽  
The Relationship

Greenhouse and growth chamber experiments with potted plants were conducted to determine the effects of interspecific root and canopy interference, light intensity, and soil moisture on water uptake and biomass of soybean, common cocklebur, and sicklepod. Canopy interference and canopy plus root interference of soybean with common cocklebur increased soybean water uptake per plant and per unit leaf area. Root interference with soybean decreased common cocklebur water uptake per plant. Canopy interference of soybean with sicklepod increased soybean water uptake per unit leaf area, while root interference decreased uptake per plant. Combined root and canopy interference with soybean decreased water uptake per plant for sicklepod. Soybean leaf area and shoot weight were reduced by root interference with both weeds. Common cocklebur and sicklepod leaf area and shoot weight were reduced by root and canopy interference with soybeans. Only common cocklebur root weight decreased when canopies interfered and roots did not. The relationship between light intensity and water uptake per unit leaf area was linear in both years with water uptake proportional to light intensity. In 1991 water uptake response to tight was greater for common cocklebur than for sicklepod. The relationship between soil moisture level and water uptake was logarithmic. Common cocklebur water uptake was two times that of soybean or sicklepod at −2 kPa of pressure potential. In 1991 common cocklebur water uptake decreased at a greater rate than soybean or sicklepod in response to pressure potential changes from −2 to −100 kPa.

QUALITY APPRAISAL OF WHITE SPRUCE AND WHITE PINE SEEDLING STOCK IN NURSERIES

1960 ◽  
Vol 36 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Alexander Dickson ◽  
Albert L. Leaf ◽  
John F. Hosner
Keyword(s):  
White Spruce ◽  
Seedling Quality ◽  
Root Weight ◽  
Quality Appraisal ◽  
White Pine ◽  
Root Collar Diameter ◽  
Integrated Index ◽  
Collar Diameter ◽  
Shoot Weight ◽  
Root Collar

Total seedling weight, shoot weight and root weight in grams on an oven dry basis, root collar diameter in millimeters, and height in centimeters were used to develop an integrated index of seedling quality.

Effect of light intensity during extended photoperiod on growth of amabilis fir, mountain hemlock, and white and Engelmann spruce seedlings

1979 ◽  
Vol 9 (1) ◽  
pp. 82-89 ◽  
Author(s):  
J. T. Arnott
Keyword(s):  
High Pressure ◽  
Light Intensity ◽  
Growth Response ◽  
Significant Positive Effect ◽  
Engelmann Spruce ◽  
Bud Set ◽  
Terminal Bud ◽  
Positive Effect ◽  
Minimum Intensity ◽  
Effect Of Light

Abiesamabilis (Dougl.) Forbes, Tsugamertensiana (Bong.) Carr., Piceaglauca (Moench) Voss, and Piceaengelmannii Parry seedlings were grown in an outdoor container nursery using one high-pressure sodium vapor lamp to provide a 24-h photoperiod. Eight intensities of lighting were arranged, viz., 220, 80, 40, 20, 12, 8, 5, and 0 lx.Extending the photoperiod and increasing the light intensity had a significant positive effect on the length and weight of seedling shoots and delayed terminal bud set. Root growth response to these treatments was negative, although the differences were rarely significant. Seedlings grown under a light intensity of 220 lx were the largest. The minimum intensity required to produce seedling shoot lengths which were significantly larger than the controls was in the range 20–80 lx.

Étude de la plasticité phénotypique chez le Chrysanthemum leucanthemum. I. Croissance, allocation de la biomasse et reproduction

1988 ◽  
Vol 66 (11) ◽  
pp. 2285-2298 ◽  
Author(s):  
Céline Boutin ◽  
Pierre Morisset
Keyword(s):  
Phenotypic Plasticity ◽  
Light Intensity ◽  
Leaf Area ◽  
Weight Ratio ◽  
Total Weight ◽  
Root Weight ◽  
Intensity Level ◽  
Nutrient Levels ◽  
Light Intensities ◽  
Chrysanthemum Leucanthemum

Phenotypic plasticity was experimentally studied in plants sampled from two tetraploid populations of ox-eye daisy, Chrysanthemum leucanthemum L. Plants were cloned and ramets were grown in an outdoor garden, in two independent experiments aimed at measuring the effects of light intensity (three treatments) and nutrient level (three treatments). When plants of the same genotype were grown under different light intensities, phenotypic plasticity was high for the following characteristics: total biomass, root weight to total weight ratio, leaf area, leaf area to total weight or specific leaf weight ratio, stem height, branching, number of heads, and time of flowering and fruiting. Genotypes grown under the three nutrient levels showed less plasticity, especially for leaf-related features. Biomass allocation patterns were also measured. Generally, lower light intensities resulted in an increase of allocation to leaves and a corresponding decrease of allocation to roots. On the other hand, lower nutrient levels caused an increase of allocation to roots accompanied by a decrease of allocation to heads, but had little effects on allocation to leaf material. The effective reproductive effort (percentage of biomass allocated to mature achenes) was higher under the lowest light intensity level, but did not change significantly with nutrient levels. The results are discussed in relation to the specificity of plastic responses with respect to the nature of environmental stresses. The prolific production of heads that remained immature at the onset of cold autumn temperatures is interpreted as a nonadaptative tactic in C. leucanthemum.

scholarly journals Effect of seedbed steaming on Cylindrocladium floridanum, soil microbes and the development of white pine seedlings

2005 ◽  
Vol 79 (1) ◽  
pp. 35-43 ◽  
Author(s):  
M.T. Dumas ◽  
S. Greifenhagen ◽  
G. Halicki-Hayden ◽  
T.R. Meyer
Keyword(s):  
Soil Microbes ◽  
Root Weight ◽  
White Pine ◽  
Root Collar Diameter ◽  
Fluorescent Pseudomonas ◽  
Pine Seedlings ◽  
Collar Diameter ◽  
Cylindrocladium Floridanum ◽  
Shoot Weight ◽  
Root Collar

The Egedal® bed steamer produced sufficient heat to kill mierosclerotia of Cylindrocladium floridanum at 5 and 10 cm soil depths in one bareroot forest seedling nursery. At a second nursery, the buried inoculum was killed only to a depth of 5 cm. Soil steaming did not affect the mierosclerotia at 15 cm. The steaming reduced populations of fluorescent pseudomonas to undetectable levels to a depth of 20 cm and populations of Trichoderma species were significantly reduced in the upper 10 cm of the seedbed. Density of white pine seedlings sown in the steamed beds was significantly higher (P= 0.05), and height, root collar diameter, shoot weight and root weight were significantly greater (P= 0.05) 4 months after steaming than that of control seedlings sown in unsteamed beds.

EFFECT OF CONTAINER TYPE AND GROWING MEDIA ON GERMINATION AND SEEDLING GROWTH PARAMETERS AT NURSERY STAGE IN ALLEPO PINE IN KASHMIR VALLEY, INDIA

2018 ◽  
Vol 24 (2) ◽  
Author(s):  
AMERJEET SINGH ◽  
MOHIT HUSAIN ◽  
SYED ROUHULLAH ALI
Keyword(s):  
Plant Height ◽  
Seedling Growth ◽  
Growth Parameters ◽  
Dry Weight ◽  
Root Weight ◽  
Fresh Biomass ◽  
Growing Medium ◽  
Collar Diameter ◽  
Shoot Weight ◽  
Allepo Pine

The present investigation on Allepo pine indicated that container type exert significant influence on germination and seedling growth parameters. Root trainer 300 cc (C3) raised seedlings exhibited maximum plant per cent (70.00), plant height (16.27 cm), collar diameter (1.90 mm), root dry weight (0.21 g), shoot dry weight (0.42 g), shoot root ratio (2.34) and total fresh biomass (1.37 g) per seedling variation in seedling growth parameters in different containers can be attributed to the size and type of the containers. The minimum values in all these parameters were observed in seedlings raised in polytubling of size 150 cc (C4). Besides other seedling growth parameters, the poly bag of different size raised seedlings have shown slightly lower values for plant height, collar diameter and total biomass. Among growing media, forest soil: sand: FYM: dalweed (1:2:3:3) resulted in significantly highest plant per cent (67.97), plant height (15.03 cm), collar diameter (1.93 mm), dry root weight (0.22 g), dry shoot weight (0.44 g), shoot root ratio (2.47) and total fresh biomass (1.42 g) in the seedlings under nursery condition. The study also reveal that growing medium exert significant influence on germination and seedling growth parameters in Allepo pine. The data in Table 01 to 03 indicated significantly high germination (67.97%) and seedling growth parameters like plant height (15.03 cm), collar diameter (1.93 mm), dry root weight (0.22 g), dry shoot weight (0.44 g), shoot root ratio (2.47), and total fresh biomass (1.42 g) when seedlings were raised in growing medium of soil: sand: FYM: dalweed in the ratio of 1:2:3:3 (M3). The better growth of seedlings raised in potting mixture M3 may be attributed to the fact that more nitrogen from the FYM as a component of potting mixture having the better decomposition rate leading to the narrower C:N ratio. .

Incidence and Performance of Multiple-Leadered Seedlings of Black and White Spruce in Canadian Nurseries

1988 ◽  
Vol 5 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Gerry Hofstra ◽  
Cathy M. McLeod ◽  
John Ensing
Keyword(s):  
White Spruce ◽  
Northern Ontario ◽  
Southern Ontario ◽  
Black And White ◽  
Terminal Bud ◽  
Collar Diameter ◽  
Shoot Weight ◽  
And Performance ◽  
Multiple Leaders ◽  
Root Collar

Abstract The incidence of multiple leaders in spruce seedlings was assessed in Ontario nurseries from 1980 to 1984 and in provincial nurseries across Canada in 1982. The occurrence of multiple-leadered seedlings averaged 30 to 40% and at times exceeded 50%. In northern Ontario nurseries, frosts and winter injury appeared responsible. Terminal bud injury resulted in 50 to 90% multiple leadering. In southern Ontario the formation of abnormal buds was the principle cause of multiple-leadered seedlings. The highest incidence of abnormal bud formation was most frequently found in 2 + 0 white spruce. Although 20 to 30% shorter, multiple-leadered seedlings of black and white spruce had the same total shoot weight and root collar diameter as normal seedlings. North. J. Appl. For. 5:99-103, June 1988.

scholarly journals Effect of chlorophyll biosynthesis-related genes on the leaf color in Hosta (Hosta plantaginea Aschers) and tobacco (Nicotiana tabacum L.)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingying Zhang ◽  
Changhai Sui ◽  
Huimin Liu ◽  
Jinjiao Chen ◽  
Zhilin Han ◽  
...  
Keyword(s):  
Light Intensity ◽  
Antioxidant Capacity ◽  
Aminolevulinic Acid ◽  
Chlorophyll Biosynthesis ◽  
Expression Level ◽  
Virus Induced Gene Silencing ◽  
Leaf Color ◽  
Color Changes ◽  
Light Intensities ◽  
Structure Changes

Abstract Background ‘Regal Splendour’ (Hosta variety) is famous for its multi-color leaves, which are useful resources for exploring chloroplast development and color changes. The expressions of chlorophyll biosynthesis-related genes (HrHEMA, HrPOR and HrCAO) in Hosta have been demonstrated to be associated with leaf color. Herein, we isolated, sequenced, and analyzed HrHEMA, HrPOR and HrCAO genes. Subcellular localization was also performed to determine the location of the corresponding enzymes. After plasmid construction, virus-induced gene silencing (VIGS) was carried out to reduce the expressions of those genes. In addition, HrHEMA-, HrPOR- and HrCAO-overexpressing tobacco plants were made to verify the genes function. Changes of transgenic tobacco were recorded under 2000 lx, 6000 lx and 10,000 lx light intensity. Additionally, the contents of enzyme 5-aminolevulinic acid (5-ALA), porphobilinogen (PBG), chlorophyll a and b (Chla and Chlb), carotenoid (Cxc), superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), proline (Pro) and catalase (CAT) under different light intensities were evaluated. Results The silencing of HrHEMA, HrPOR and HrCAO genes can induce leaf yellowing and chloroplast structure changes in Hosta. Specifically, leaves of Hosta with HrCAO silencing were the most affected, while those with HrPOR silencing were the least affected. Moreover, all three genes in tobacco were highly expressed, whereas no expression was detected in wild-type (WT). However, the sensitivities of the three genes to different light intensities were different. The highest expression level of HrHEMA and HrPOR was detected under 10,000 lx of illumination, while HrCAO showed the highest expression level under 6000 lx. Lastly, the 5-ALA, Chla, Cxc, SOD, POD, MDA, Pro and CAT contents in different transgenic tobaccos changed significantly under different light intensities. Conclusion The overexpression of these three genes in tobacco enhanced photosynthesis by accumulating chlorophyll content, but the influential level varied under different light intensities. Furthermore, HrHEMA-, HrPOR- and HrCAO- overexpressing in tobacco can enhance the antioxidant capacity of plants to cope with stress under higher light intensity. However, under lower light intensity, the antioxidant capacity was declined in HrHEMA-, HrPOR- and HrCAO- overexpressing tobaccos.

Regulation of cell reproduction in bud meristems of Tradescantia paludosa

1973 ◽  
Vol 51 (6) ◽  
pp. 1137-1145 ◽  
Author(s):  
Kyu-Byung Yun ◽  
J. M. Naylor
Keyword(s):  
Apical Dominance ◽  
Mitotic Cycle ◽  
Plant Cells ◽  
Central Zone ◽  
Apparent Absence ◽  
Cell Reproduction ◽  
Terminal Bud ◽  
Terminal Buds ◽  
Regulation Of Growth ◽  
Tradescantia Paludosa

The mitotic cycle can be arrested in the apical summit of vegetative terminal buds of Tradescantia paludosa by restricting the level of nitrogen or light available to the plant. Cells in this portion of the bud are much more sensitive to these stress conditions than those in the subjacent portion of the meristem. This differential response induced the establishment of a quiescent "central zone" which is distinguished from the rest of the meristem by the apparent absence of mitosis and DNA synthesis, larger nuclear volume, and a lower histone content of chromatin. These features are identical with those imposed by apical dominance in apices of inhibited lateral buds.The results support the view that competition for nutrients is an important causal factor in apical dominance. They suggest also that competition for nutrients within the terminal bud meristem is important in the regulation of growth in vegetative shoots in respones to conditions of the environment.

A laboratory study of vertical migration

1955 ◽  
Vol 144 (916) ◽  
pp. 329-354 ◽  
Keyword(s):  
Light Intensity ◽  
Vertical Migration ◽  
Time Course ◽  
Tap Water ◽  
Low Light ◽  
Overhead Light ◽  
Light Intensities ◽  
Orientation Response ◽  
Reduced Light ◽  
Characteristic Maximum

In a tank filled with a suspension of indian ink in tap water, a population of Daphnia magna will undergo a complete cycle of vertical migration when an overhead light source is cycli­cally varied in intensity. A ‘dawn rise’ to the surface at low intensity is followed by the descent of the animals to a characteristic maximum depth. The animals rise to the surface again as the light decreases, and finally show a typical midnight sinking. The light intensities at the level of the animals in this experiment are of the same order as those which have been reported in field observations; the time course of the movement also repeats the natural conditions in the field. The process is independent of the duration of the cycle and is related only to the variation in overhead light intensity. At low light intensity the movement of the animal is determined solely by positive photo-kinesis; the dawn rise is a manifestation of this, and is independent of the direction of the light. At high light intensities there is an orientation response which is superimposed upon an alternating positive (photokinetic) phase and a negative phase during which movement is inhibited. The fully oriented animal shows a special type of positive and negative phototaxis, moving towards the light at reduced light intensities and away from it when the light intensity is increased. In this condition it follows a zone of optimum light intensity with some exactness. Experiments show that an animal in this fully oriented condition will respond to the slow changes of intensity characteristic of the diurnal cycle, while being little affected by tran­sient changes of considerable magnitude.

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