Basal and maintenance respiration of mycorrhizal and nonmycorrhizal root systems of conifers

1987 ◽  
Vol 17 (8) ◽  
pp. 872-877 ◽  
Author(s):  
John D. Marshall ◽  
David A. Perry
Keyword(s):  
Root System ◽  
Respiration Rate ◽  
Ponderosa Pine ◽  
Root Respiration ◽  
Root Systems ◽  
The Other ◽  
Silica Sand ◽  
Maintenance Respiration ◽  
Root Longevity ◽  
Respiration Rates

We measured CO2 efflux from root systems of mycorrhizal and nonmycorrhizal conifer seedlings planted in silica sand and maintained in darkness for 11 to 15 days. We first compared methods of isolating the root system for root respiration measurement using Douglas-fir seedlings (Pseudotsugamenziesii (Mirb.) Franco). Shoot excision effectively isolated the root system and affected total root respiration only slightly. We used this technique to compare respiration rates of mycorrhizal and nonmycorrhizal root systems of ponderosa pine (Pinusponderosa Laws.) seedlings. Some seedlings were uninoculated; others were infected with an ectomycorrhizal species (Laccahalaccata or Hebelomacrustuliniforme) or an unidentified ectendomycorrhizal species. After shoot excision, respiration rates declined within 48 h to a "maintenance" respiration rate. Over the next several days, the respiration rate continued to decline to a much lower "basal" rate typical of nonphotosynthetic seedlings depleting their reserves. The maintenance respiration rate of the Laccaria-infected seedlings was significantly lower than those of the other treatments. The basal respiration rates of the two ectomycorrhizal treatments (Laccaria and Hebeloma) were lower than those of the other groups. Such reductions in respiration rate might strongly affect root longevity and whole-plant carbon budgets.

scholarly journals Boron mobility in eucalyptus clones

2009 ◽  
Vol 33 (6) ◽  
pp. 1733-1744 ◽  
Author(s):  
Jackson Freitas Brilhante de São José ◽  
Ivo Ribeiro da Silva ◽  
Nairam Felix de Barros ◽  
Roberto Ferreira Novais ◽  
Eulene Francisco Silva ◽  
...  
Keyword(s):  
Organic Compound ◽  
Boric Acid ◽  
Root System ◽  
Foliar Application ◽  
Root Systems ◽  
Mature Leaf ◽  
The Other ◽  
B Mobility ◽  
Boron Mobility

Understanding the magnitude of B mobility in eucalyptus may help to select clones that are more efficient for B use and to design new practices of B fertilization. This study consisted of five experiments with three eucalyptus clones (129, 57 and 58) where the response to and mobility of B were evaluated. Results indicated that clone 129 was less sensitive to B deficiency than clones 68 and 57, apparently due to its ability to translocate B previously absorbed via root systems to younger tissues when B in solution became limiting. Translocation also occurred when B was applied as boric acid only once to a single mature leaf, resulting in higher B concentration in roots, stems and younger leaves. The growth of B-deficient plants was also recovere by a single foliar application of B to a mature leaf. This mobility was greater, when foliar-applied B was supplied in complexed (boric acid + manitol) than in non-complexed form (boric acid alone). When the root system of clone 129 was split in two solution compartments, B supplied to one root compartment was translocated to the shoot and back to the roots in the other compartment, improving the B status and growth. Thus, it appears that B is relatively mobile in eucalyptus, especially in clone 129, and its higher mobility could be due to the presence of an organic compound such as manitol, able to complex B.

Morphological and physiological attributes of root systems and seedling growth in three different Picea glauca reforestation stock

2000 ◽  
Vol 30 (11) ◽  
pp. 1669-1681 ◽  
Author(s):  
M J Krasowski ◽  
J N Owens
Keyword(s):  
Root System ◽  
Seedling Growth ◽  
Picea Glauca ◽  
Root Systems ◽  
Growing Season ◽  
System Size ◽  
The Other ◽  
Root Pruning ◽  
Growing Seasons ◽  
Forest Sites

The relationship between certain morphological characteristics of white spruce (Picea glauca (Moench) Voss) planting stock (STK) and post-planting seedling performance was evaluated. Root system size at planting, its expansion, and its capacity to conduct water during the first post-planting weeks were determined. These characteristics were related to the performance of STK planted on two forest sites and measured for three growing seasons and to the performance of seedlings grown in large wooden boxes buried in the soil outdoors for one growing season (grown without competition from other vegetation). The compared STK were (i) polystyroblock grown, (ii) polystyroblock grown with chemical root pruning, and (iii) peat-board grown with mechanical root pruning. After three growing seasons on forest sites, seedlings with mechanically pruned roots grew more above ground than did seedlings from polystyroblock containers. This difference in seedling growth performance was even more significant for seedlings grown in wooden boxes. Of these, the mechanically pruned seedlings grew more not only above the ground but they also produced larger root systems by the end of the first growing season. This was despite the initially significantly smaller root systems of mechanically pruned seedlings, compared with the other two STK. Early (5-7 weeks after planting) post-planting root expansion patterns in the three STK were significantly different, with the roots of mechanically pruned seedlings growing less than the roots in the other two STK. In spite of this, pressure-probe measured hydraulic conductivity and water flux through root systems increased during the first post-planting weeks in mechanically pruned seedlings while declining or changing little in the other two STK. It was concluded that root system size at planting and its early post-planting expansion did not relate well to the root system hydraulic properties or to the post-planting seedling growth performance.

scholarly journals Sugars and Respiration Profiles in Asparagus Spears and Changes during Storage

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 823F-823
Author(s):  
Silvanda Silva ◽  
Sven Verlinden ◽  
Robert Herner ◽  
Randolph Beaudry
Keyword(s):  
Respiration Rate ◽  
Initial Rate ◽  
The Other ◽  
Asparagus Officinalis ◽  
High Rate ◽  
Sucrose Content ◽  
Time Intervals ◽  
Respiration Rates

Base-to-tip profiles of sucrose, glucose, fructose, and respiration rate were measured for asparagus (Asparagus officinalis L.) spears stored at 0C. Fructose content was ≈3-fold and 4-fold higher than glucose and sucrose, respectively. The highest level of fructose was found in the base and was ≈15-fold higher than the tip. The changes in asparagus metabolism were characterized by loss of sucrose and a high rate of respiration within the first hours after harvest. Sucrose was more rapidly lost than the other sugars during this period. The respiration rate was measured along the length of intact spears at 0.5, 1, 2, and 3 h after harvest. Subsequent measurements were taken after larger time intervals for 23 days. The respiration rate declined rapidly to ≈60% of the initial rate within 12 h, decreasing more slowly thereafter. Initially, the respiration rate of the tip was about four times that of the base, but, after 23 days, the respiration rate of the tip was only twice that of the base. Sucrose content and respiration rates were closely correlated.

scholarly journals 593 Water Stress Influences Soil/Root Respiration Rate and Root Morphology of Young Apple Trees

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 549B-549
Author(s):  
Georgios Psarras ◽  
Ian A. Merwin
Keyword(s):  
Water Stress ◽  
Root Morphology ◽  
Root Respiration ◽  
Dry Weight ◽  
Root Systems ◽  
Respiration Rates ◽  
Electric Capacitance ◽  
Root Dry Weight ◽  
Root Size ◽  
Root Capacitance

One-year-old potted `Mutsu' apple (Malus domestica) trees on MM.111 and M.9 rootstocks were grown outdoors from May to Nov. 1997, under three levels of soil-water availability (–20, –80, and –200 kPa), to evaluate the effects of water stress on soil/root respiration and root morphology. At weekly intervals, we measured soil/root respiration using a portable infrared gas analyzer and rootsystem size or functional activity using an electric capacitance meter. These observations were tested as nondestructive methods to estimate relative differences in root size and morphology in situ compared with final dry weight and form of excavated apple rootstocks. Root size-class distributions were estimated by digital imaging and analysis of harvested root systems. Root growth was substantially reduced by water stress; the magnitude of reduction was similar for both rootstocks, but the percentage of shoot growth reduction was higher for MM.111. Root: shoot ratios were higher and average specific respiration rates over the growing season were lower for M.9 root systems. Water stress increased the root: shoot ratio, specific root length, and carbon costs of root maintenance as indicated by specific respiration rates. Soil/root respiration was more closely correlated than root electric capacitance with actual root system size. The observed r2 values between root capacitance and root dry weight were as high as 0.73, but root capacitance was also confounded by other factors, limiting its usefulness for nondestructive estimation of root size or activity. Rootstock genotype significantly affected root capacitance, which provided better estimates of root dry weight for M.9 than for MM.111.

scholarly journals (105) Holding Bareroot Colorado Spruce Trees in a Gravel Bed

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1049D-1049
Author(s):  
Robert R. Tripepi ◽  
Mary W. George ◽  
John E. Lloyd
Keyword(s):  
Root Systems ◽  
Lateral Branch ◽  
The Other ◽  
Pine Bark ◽  
Silica Sand ◽  
Gravel Bed ◽  
Gravel Beds ◽  
Picea Pungens ◽  
The Mean ◽  
Production Losses

Field-grown conifers are usually discarded if their root balls break during digging, but using an alternative holding system until the root systems recover could reduce production losses. The objective of this study was to determine if a gravel bed could be used as a holding treatment for 1.5- to 1.8-m-tall Colorado spruce (Picea pungens) trees that had soil removed from their root systems in the spring. Root systems from 12 trees were washed free from pine bark mulch and soil before the trees were randomly assigned to a gravel bed. One bed held a mixture of 88% pea gravel (1-cm minus), 2% Turface®, and 10% silica sand (by volume). The other bed contained a mixture of 90% basalt gravel (1.2-cm) and 10% sand. Trees were grown in the gravel beds for 5 or 6 months before height increases were determined. If the terminal leader died on the tree, the next highest lateral branch was measured for its increase in length. All trees survived and actually grew a little during the summer after removing all the soil from their root systems. Several trees suffered slight needle burning at the ends of random branches, but the damage appeared minimal. Tips of several small branches randomly located around the canopies on several trees died back, and up to 10 cm of the terminal leaders on about half the trees died back. Height increases were similar among the different trees grown in the two types of gravel, with the mean increase in height being 8.9 cm. The trees regenerated many roots in both types of gravel. In fact, new roots formed all over the root systems and encased large amounts of gravel, making its removal difficult. This study demonstrated that gravel beds can be used to help 1.8-m tall Colorado spruce trees recover from severe root losses.

Dark Island heath (Ninety-mile Plain, South Australia). III. The root systems

1957 ◽  
Vol 5 (1) ◽  
pp. 103 ◽  
Author(s):  
RL Specht ◽  
P Rayson
Keyword(s):  
Root System ◽  
Root Nodules ◽  
Morphological Characteristics ◽  
South Australia ◽  
Dry Weight ◽  
Root Systems ◽  
The Other ◽  
Fibrous Root ◽  
Tap Root ◽  
Heath Community

This paper describes the nature of the root systems of the most important members of the heath community. Several variations of tap-root and fibrous root systems were observed. Tap-rooted species were either shallow rooting (1–2 ft) or deep rooting (6 or more feet into the clay subsoil). Two variations of deep tap-rooted species were observed. The tap-root of one decays with age; the laterals of the other produce frequent sucker shoots. In all forms of the deep tap-rooted species an extensive lateral root system was developed within the surface 12 in. of soil — the organic A1 horizon; the tap-root and occasional secondary vertical descended, often unbranched, to the subsoil. The fibrous root system may arise from stem bases, rhizomes, tubers, or underground stocks (caudices). With the exception of underground stocks, which had extensive roots in the A2 and A3 to B horizons, the other forms of the fibrous root systems were confined to the A1 horizon. The marked concentration of roots in the organic A1 horizon was illustrated in dry weight–depth curves. Most of the roots in the A2, and A1 horizons arose from the caudex of Xanthorrhoea australis R.Br.; the remainder were vertical roots which passed directly into the subsoil from the deep-rooted species. About 70 per cent of the species recorded in the heath had morphological characteristics which enabled them to survive a fire and sprout from perennating buds buried under the surface of the ground. Thus, although the aerial organs of the heath were destroyed by fire, the root systems provided a reserve of food and nutrients for the regenerating heath. The dry weight of the root systems was therefore scarcely influenced by fire and thereafter steadily increased in the organic A1 horizon as the stand aged. The presence of root nodules on species of Leguminosae and Casuarinaoeae as well as of haustoria on Exocarpos sparteus R.Br. and Euphrasia collina R.Br. Is recorded.

EFFECT OF VARIOUS HORMONES ON THE KIDNEY RESPIRATION RATES IN THE CUTTHROAT TROUT (SALMO CLARKI CLARKI)

1960 ◽  
Vol XXXIII (III) ◽  
pp. 428-436 ◽  
Author(s):  
W. N. Holmes
Keyword(s):  
Single Dose ◽  
Respiration Rate ◽  
Cutthroat Trout ◽  
Adaptive Mechanism ◽  
Respiration Rates ◽  
Salmo Clarki

ABSTRACT Relatively large doses of vasopressin administered intraperitoneally to the trout significantly enhanced the kidney respiration rate. In contrast to vasopressin a single dose of oxytocin depressed the kidney Qo2 value. This depression continued throughout the observed 24 hour period after injection. Cortisol enhanced the kidney Qo2 values significantly and to a greater extent than vasopressin. These results are discussed in relation to possible adaptive mechanism in euryhaline species of teleosts.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

scholarly journals Clifford Spinors and Root System Induction: $$H_4$$ and the Grand Antiprism

2021 ◽  
Vol 31 (3) ◽  
Author(s):  
Pierre-Philippe Dechant
Keyword(s):  
Root System ◽  
Root Systems ◽  
Invariant Sets ◽  
Simple Construction ◽  
Reflection Groups ◽  
Computational Work ◽  
Algebraic Framework ◽  
Underlying Geometry ◽  
Coxeter Plane ◽  
Insight Into

AbstractRecent work has shown that every 3D root system allows the construction of a corresponding 4D root system via an ‘induction theorem’. In this paper, we look at the icosahedral case of $$H_3\rightarrow H_4$$ H 3 → H 4 in detail and perform the calculations explicitly. Clifford algebra is used to perform group theoretic calculations based on the versor theorem and the Cartan–Dieudonné theorem, giving a simple construction of the $${\mathrm {Pin}}$$ Pin and $${\mathrm {Spin}}$$ Spin covers. Using this connection with $$H_3$$ H 3 via the induction theorem sheds light on geometric aspects of the $$H_4$$ H 4 root system (the 600-cell) as well as other related polytopes and their symmetries, such as the famous Grand Antiprism and the snub 24-cell. The uniform construction of root systems from 3D and the uniform procedure of splitting root systems with respect to subrootsystems into separate invariant sets allows further systematic insight into the underlying geometry. All calculations are performed in the even subalgebra of $${\mathrm {Cl}}(3)$$ Cl ( 3 ) , including the construction of the Coxeter plane, which is used for visualising the complementary pairs of invariant polytopes, and are shared as supplementary computational work sheets. This approach therefore constitutes a more systematic and general way of performing calculations concerning groups, in particular reflection groups and root systems, in a Clifford algebraic framework.

On Closed Subsets of Root Systems

1994 ◽  
Vol 37 (3) ◽  
pp. 338-345 ◽  
Author(s):  
D. Ž. Doković ◽  
P. Check ◽  
J.-Y. Hée
Keyword(s):  
Weyl Group ◽  
Root System ◽  
Irreducible Component ◽  
Product Space ◽  
Root Systems ◽  
Inner Product Space ◽  
Inner Product ◽  
Closed Sets ◽  
Finite Dimensional ◽  
Real Inner Product Space

AbstractLet R be a root system (in the sense of Bourbaki) in a finite dimensional real inner product space V. A subset P ⊂ R is closed if α, β ∊ P and α + β ∊ R imply that α + β ∊ P. In this paper we shall classify, up to conjugacy by the Weyl group W of R, all closed sets P ⊂ R such that R\P is also closed. We also show that if θ:R —> R′ is a bijection between two root systems such that both θ and θ-1 preserve closed sets, and if R has at most one irreducible component of type A1, then θ is an isomorphism of root systems.

Sign in / Sign up

Export Citation Format

Share Document