Root chemistry of Douglas-fir seedlings grown under different nitrogen and potassium regimes

1998 ◽  
Vol 28 (10) ◽  
pp. 1566-1573 ◽  
Author(s):  
Terry M Shaw ◽  
James A Moore ◽  
John D Marshall
Keyword(s):  
Pseudotsuga Menziesii ◽  
Dry Matter ◽  
Douglas Fir ◽  
Root Tip ◽  
Root Tips ◽  
Seedling Biomass ◽  
High K ◽  
Root Chemistry ◽  
Low K ◽  
Root Collar

Root chemistry and biomass allocation of Douglas-fir (Pseudotsuga menziesii var. glauca (Bessn.) Franco) seedlings under optimal and deficient levels of nitrogen (N) and potassium (K) were studied. Seedlings receiving high-N treatments were significantly larger and allocated more dry matter to their stems and less to their roots than those receiving the low-N treatments. The K treatments did not significantly affect total seedling biomass or root/shoot ratios. Root tip starch concentrations were significantly higher and root tip sugar concentrations were lower in plants receiving the low-N treatments. Seedlings receiving the high-N, low-K treatment had significantly lower concentrations of phenolics and tannins and lower ratios of these compounds to sugars in the root tips than seedlings receiving the high-K treatments. Samples taken from two locations on the root system show that concentrations of phenolics, tannins, sugars, and starches were substantially higher in the root collar than in the root tips. Because of lower within tissue variation, we recommend sampling at root tips to better detect treatment differences. This study shows that N levels affect starch concentrations in the roots, while K levels affect root phenolic and tannin concentrations. Possible relationships between low root phenolic and tannin concentrations and lessened resistance of Douglas-fir to root disease are discussed.

Impact of clearcutting and slash burning on ectomycorrhizal associations of Douglas-fir seedlings

1984 ◽  
Vol 14 (1) ◽  
pp. 94-100 ◽  
Author(s):  
David P. Pilz ◽  
David A. Perry
Keyword(s):  
Douglas Fir ◽  
Root Tip ◽  
Root Tips ◽  
Clear Cut ◽  
Clear Cutting ◽  
Ectomycorrhizal Types ◽  
Different Types ◽  
Undisturbed Forest ◽  
Soil Origin ◽  
Slash Burning

The effect of clear-cutting, with and without slash burning, on ectomycorrhizal formation of Douglas-fir seedlings (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) was studied in field and greenhouse bioassays. Twelve ectomycorrhizal types were found in three western Cascade Mountain sites on seedlings planted in soils exchanged among burned and unburned portions of clear-cuts and undisturbed forest. Rhizopogon sp. and an unidentified brown type consistently formed at least two-thirds of the ectomycorrhizal root tips. Regardless of soil origin, more ectomycorrhizae formed in clear-cuts than in undisturbed forest (primarily due to more brown mycorrhizae). Soil origin did not affect total numbers of ectomycorrhizae; however, more different types formed in undisturbed forest soils than in clear-cut soils, irrespective of aboveground environment. More nonmycorrhizal tips occurred in clear-cut soils. Seedlings grown in the same soils formed the same proportions of Rhizopogon and brown types in field and greenhouse, but not the same proportions of less common ectomycorrhizal types. Soil pasteurization increased root-tip numbers. Inoculated soils (1 part nonpasteurized: 9 parts pasteurized) produced as many ectomycorrhizae as nonpasteurized field soils and generally fewer tips than pasteurized soils. Formation of major (but not minor) ectomycorrhizal types on all sites was influenced more by aboveground changes that accompany clear-cutting and site preparation than by alterations in soil chemistry or biology.

High Intake of Magnesium in Relation to the Ruminal Transmural Potential Difference and Magnesium Absorption in Wethers

2004 ◽  
Vol 74 (3) ◽  
pp. 217-222
Author(s):  
Jittakhot ◽  
Schonewille ◽  
Haddad ◽  
Wouterse ◽  
Yuangklang ◽  
...  
Keyword(s):  
Dry Matter ◽  
Latin Square ◽  
Potential Difference ◽  
High Intake ◽  
Individual Values ◽  
High Potassium ◽  
High K ◽  
The Mean ◽  
The Individual ◽  
Low K

High potassium (K) intakes are known to decrease magnesium (Mg) absorption in ruminants by increasing the transmural potential difference (PDt, serosal side = positive). High Mg intakes are known to increase the amount of Mg absorbed, which may be explained by increasing the ruminal Mg concentration, but an effect on the PDt cannot be excluded. The objective of this study was to determine whether or not Mg intake affects the PDt. In a 3x3 Latin square design, six ruminally fistulated wethers were fed a low-Mg, low-K ration (3.88 g Mg/kg dry matter (DM); 30.7 g K/kg DM), a high-Mg, low K-ration (16.79 g Mg/kg DM; 30.7 g K/kg DM), and a low-Mg ration high-K (3.88 g Mg/kg DM or 62.1 g K/kg DM). When compared with the low-Mg, low-K ration, the high-Mg, low-K ration raised the absolute apparent Mg absorption (g/day) by 421% and the low-Mg, high-K ration decreased it by 20%. The intake of extra K produced a significant increase in the PDt. The intake of extra Mg did not change the PDt across the rumen wall but produced a significant increase of the ruminal Mg concentrations. On the basis of the individual values for three rations, the mean post feeding ruminal Mg concentrations were found to be unrelated to the PDt (Pearson's r = –0.329, p = 0.183, n = 18). Thus, it is concluded that the observed increase in Mg absorption after a high Mg intake can be explained by an increase in the ruminal Mg concentration rather than by a change in PDt.

Ethanol in Douglas-fir with black-stain root disease (Leptographium wageneri)

1998 ◽  
Vol 28 (8) ◽  
pp. 1207-1212 ◽  
Author(s):  
Rick G Kelsey ◽  
Gladwin Joseph
Keyword(s):  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Root Disease ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Coos Bay ◽  
Root Collar

Diseased and healthy Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were identified at two black-stain root disease centers, caused by Leptographium wageneri var. pseudotsugae Harrington & Cobb, in the Oregon Coast Range near Coos Bay. Phloem and sapwood near the root collar were sampled monthly for 1 year, whereas roots were sampled in October and November. Ethanol concentrations in sapwood of diseased trees near the root collar were 4-24 times higher than in healthy trees for all months of a year, except January and June. Roots from diseased trees in October had 5 times more ethanol in the phloem and 19 times more ethanol in the sapwood than corresponding tissue from healthy trees. Ethanol concentrations in roots from diseased trees in November were no different from October. Within trees, ethanol concentrations varied substantially among positions around the root collar and among different roots. Ethanol may play an important role in the biology of L.wageneri and beetle-pathogen interactions in Douglas-fir. Ethanol also may be useful in detecting stressed or diseased trees.

Influence of soil biota on Douglas-fir (Pseudotsuga menziesii) seedling growth: the role of rhizosphere bacteria

1992 ◽  
Vol 70 (5) ◽  
pp. 1025-1031 ◽  
Author(s):  
C. P. Chanway ◽  
F. B. Holl
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Growth ◽  
Growth Promotion ◽  
Douglas Fir ◽  
Rhizosphere Bacteria ◽  
Soil Biota ◽  
Shoot Biomass ◽  
Growth Responses ◽  
Seedling Biomass ◽  
Sowing Seed

The influence of soil biota on Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedling growth was investigated by sowing seed collected from two ecologically distinct zones in British Columbia, Chilliwack and Williams Lake, in soil collected from the same two areas. Seedling biomass of both Douglas-fir ecotypes was greatest in unpasteurized soil collected from the same area as was the seed, but pasteurization negated this effect. In addition, Chilliwack seedlings responded specifically to biota present only in Chilliwack soil. To determine if rhizosphere bacteria were involved in these growth responses, bacteria were isolated from the rhizosphere of wild Douglas-fir seedlings collected from both locations, and putative growth promoting bacteria were selected in a screening experiment. Selected bacteria were then tested for seedling growth response specificity using a factorial design in which seed, soil, and bacteria from both locations were evaluated in all combinations. Inoculation of Douglas-fir seed with some of the selected bacterial isolates increased seedling biomass in pasteurized soil to a level similar to that of seedlings grown in unpasteurized soil, but there was no evidence that adaptive relationships involving bacteria, Douglas-fir, and the soil in which they naturally grew were important in effecting seedling growth promotion. However, Douglas-fir shoot biomass increased 39% and root biomass 68% after bacterial inoculation in some treatment combinations involving pasteurized soil. Key words: Douglas-fir seedlings, growth, rhizosphere bacteria.

Controlling Gray Mold on Container-Grown Douglas-Fir by Modified Styroblocks and Under-Bench, Forced Air Ventilation

1990 ◽  
Vol 5 (3) ◽  
pp. 75-79 ◽  
Author(s):  
Michael J. Peterson ◽  
Jack R. Sutherland
Keyword(s):  
Pseudotsuga Menziesii ◽  
Spore Germination ◽  
Gray Mold ◽  
Douglas Fir ◽  
Air Movement ◽  
Air Ventilation ◽  
Vertical Ventilation ◽  
Forced Air ◽  
Mold Spore ◽  
Root Collar

Abstract Gray mold (Botrytis cinerea) control on Douglas-fir (Pseudotsuga menziesii) seedlings was investigated using under-bench ventilation and styroblocks (growing containers) modified with vertical ventilation holes to allow air movement through the seedling canopy. Gray mold incidence and severity were reduced in three treatments: modified styroblocks with aeration holes at each intercavity intersection and vented from below with heated forced air, like the preceding treatment, but vented with unheated forced air, and modified styroblocks vented with unheated unforced air. In vented styroblocks, gray mold occurred on 25% of the 7-month-old seedlings compared to greater than 75% incidence in unmodified (control) styroblocks. Disease on individual seedlings was also less severe in ventilated styroblocks. The reduced incidence of gray mold in the treatments with ventilation was attributed to more rapid drying of seedling foliage following irrigation. The lowest incidence of humidity and temperature episodes that were ideal for gray mold spore germination and infection occurred in the canopy of seedlings grown in the unheated forced air ventilation treatment There were no practical differences in seedling heights or root collar diameters among treatments. Use of ventilated styroblocks should significantly reduce both gray mold losses and fungicide usage in nurseries. West. J. Appl. For. 5(3):75-79, July 1990

scholarly journals Changes in Interior Douglas-Fir Root Development in Containers after Copper and Auxin Treatments

2000 ◽  
Vol 15 (4) ◽  
pp. 213-216
Author(s):  
K.R. Dumroese
Keyword(s):  
Root Growth ◽  
Pseudotsuga Menziesii ◽  
Root Development ◽  
Root Morphology ◽  
Douglas Fir ◽  
Shoot Biomass ◽  
Copper Treatment ◽  
Reduced Height ◽  
Napthaleneacetic Acid ◽  
Root Collar

Abstract Growing interior sources of Douglas-fir (Pseudotsuga menziesii var. glauca) seedlings in containers with four root-modifying treatments changed root morphology and subsequent abundance and location of new roots. Copper, 1-napthaleneacetic acid (NAA), and copper + NAA treatments reduced height and shoot biomass about 20% compared with the control, but root collar diameters were similar. In a root growth chamber, however, 30% more new roots occurred in the copper treatment compared with the control, and new roots originating in the upper portion of the root plug increased 3X. NAA increased the total number of new roots and roots growing from the upper root plug when compared with the control but not to the same extent as copper. Combining copper and NAA decreased the number of deliverable seedlings by about 50% when compared with all other treatments. West. J. Appl. For. 15(4):213–216.

Accuracy and precision of measuring cross-sectional area in stem disks of Douglas-fir infected by Armillaria root disease

2002 ◽  
Vol 32 (9) ◽  
pp. 1542-1547 ◽  
Author(s):  
Mike G Cruickshank
Keyword(s):  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Irregular Shapes ◽  
Accuracy And Precision ◽  
Armillaria Root Disease ◽  
Root Collar ◽  
Disk Area

Stem cross-sectional areas were checked for accuracy and precision of area measurements in healthy and Armillaria ostoyae (Romagn.) Herink infected 18-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Ten trees were randomly selected in each combination of two size classes and four infection classes, and stem disks were taken at the soil line (0 m) and at 1.3 m. Disks were marked at the longest radius, 90° to the longest radius, the shortest radius, and at radii determined by the sum of the largest diameter and the diameter at 90° divided by four. These radii were used to calculate cross-sectional area, then these calculated areas were compared with the corresponding digitized areas. Cross-sectional areas calculated from radial measurements were generally not within 5% of digitized areas. Radii were also drawn on the disks corresponding to the positions at which healthy and infected roots arose from the root collar below. For 0-m disks, the stem radii over healthy roots averaged 7 mm longer than over infected roots. At 1.3 m, the stem radii over healthy roots were 4 mm longer, but this was reduced with increasing infection of the root system. Offset piths and irregular shapes formed because of radial reduction over infected roots, and corresponding radial expansion over healthy roots affected the accuracy of disk area estimation.

Transient Lowering of Plasma Vitamin B12 Concentrations in Ouessant Sheep Fed on a Potassium-Rich Ration

1999 ◽  
Vol 69 (4) ◽  
pp. 273-276
Author(s):  
Smit ◽  
Schonewille ◽  
Beynen
Keyword(s):  
Vitamin B12 ◽  
Dry Matter ◽  
Vitamin B ◽  
Plasma Vitamin ◽  
High Intake ◽  
Adequate Amount ◽  
High K ◽  
Low K ◽  
Positive Controls

The hypothesis tested was that a high intake of potassium (K) interferes with cobalt (Co)-vitamin B12 metabolism in ruminants. Ouessant sheep were fed either a low- (8 g K/kg dry matter) or high-K diet (43 g K/kg dry matter) with an adequate amount of Co (124 mug Co/kg dry matter). Plasma vitamin B12 concentrations were measured. Sheep fed a low-K diet, but containing only 70 mug Co/kg dry matter, served as positive controls. Feeding the low-Co ration produced a significant decrease in plasma vitamin B12 concentrations. The high- versus low-K ration induced a significant decrease in plasma vitamin B12 during the first 6 weeks, but thereafter the values in the high-K group rose to those seen in the low-K group. The mechanism by which dietary K may interact with Co-vitamin B12 metabolism in sheep is unknown.

Variation in the root bark phenolics/sugar ratio of Douglas-fir grown in two plantations in northern Idaho

2002 ◽  
Vol 32 (3) ◽  
pp. 556-560 ◽  
Author(s):  
Jennifer H Myszewski ◽  
Lauren Fins ◽  
James A Moore ◽  
Marc Rust ◽  
Peter G Mika
Keyword(s):  
Environmental Factors ◽  
Pseudotsuga Menziesii ◽  
Height Growth ◽  
Douglas Fir ◽  
Significant Source ◽  
Root Bark ◽  
Bark Tissue ◽  
Bark Chemistry ◽  
Root Chemistry ◽  
Northern Idaho

Several studies have linked high phenolics/sugar ratios in the inner root bark tissue of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) to decreased susceptibility to Armillaria spp. While these studies have identified environmental factors that influence root chemistry, none have examined whether the phenolics/sugar ratio is genetically controlled. In this study, we investigated the effects of genetics and environment on the root bark chemistry of 20 families of 15-year-old Douglas-fir planted in two sites in northern Idaho. Only sugar concentrations varied significantly among families, but site was a significant source of variation for phenolics and the phenolics/sugar ratio. Family × site interactions were significant for the concentrations of all measured root bark compounds as well as for the phenolics/sugar ratio. Phenotypic correlations between height and the phenolics/sugar ratio and between height and sugar concentrations were not significant. However, families with superior height growth and below-average sugar concentrations could be found at both sites. Should a high phenolics/sugar ratio prove effective in selecting genotypes for resistance to Armillaria infection, these results suggest that gains could be made more efficiently by selecting for low sugar concentrations.

Electron Probe Analysis of Vertebrate Smooth Muscle: Distribution of Ca and Ci

1976 ◽  
Vol 34 ◽  
pp. 334-335 ◽  
Author(s):  
Avril V. Somlyo ◽  
H. Shuman ◽  
A.P. Somlyo
Keyword(s):  
Smooth Muscle ◽  
Electron Probe ◽  
Preliminary Report ◽  
Cell Damage ◽  
Electron Probe Analysis ◽  
Perinuclear Space ◽  
Probe Analysis ◽  
High K ◽  
Low K ◽  
Initial Results

This is a preliminary report of electron probe analysis of rabbit portal-anterior mesenteric vein (PAMV) smooth muscle cryosectioned without fixation or cryoprotection. The instrumentation and method of electron probe quantitation used (1) and our initial results with cardiac (2) and skeletal (3) muscle have been presented elsewhere.In preparations depolarized with high K (K2SO4) solution, significant calcium peaks were detected over the sarcoplasmic reticulum (Fig 1 and 2) and the continuous perinuclear space. In some of the fibers there were also significant (up to 200 mM/kg dry wt) calcium peaks over the mitochondria. However, in smooth muscle that was not depolarized, high mitochondrial Ca was found in fibers that also contained elevated Na and low K (Fig 3). Therefore, the possibility that these Ca-loaded mitochondria are indicative of cell damage remains to be ruled out.

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