scholarly journals 173 Calorimetric Evaluation of Metabolic Intensity of Apple Lateral Buds and Roots during the Transition from Para- to Endodormancy

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 420B-420
Author(s):  
J. Llamas ◽  
A.A. Gardea ◽  
J.J. Martinez-Tellez ◽  
V. Guerrero-P ◽  
E. Carvajal-Millan ◽  
...  
Keyword(s):  
Isothermal Calorimetry ◽  
Sampling Period ◽  
Dry Weight ◽  
Metabolic Efficiency ◽  
Root Tips ◽  
Lateral Buds ◽  
Current Growth ◽  
Metabolic Intensity ◽  
Old Trees ◽  
Apical Section

Potted 1-year-old `Starking Spur' and `Golden Delicious' trees on MM.106 were used to characterize the metabolic changes in lateral buds and rrots during their transition from para- to endodormancy. Sampling period was from 4 Sept. to 25 Nov. 1999 at 10-day intervals. Well-formed lateral buds were collected from the apical section of current growth; while root samples were white rootlets. Isothermal calorimetry at 25 °C was used to evaluated metabolic activity (q), respiration rate (RCO2), metabolic efficiency (q/RCO2), and growth rate (RSG·ΔHB). In both cultivars, q from buds showed significant differences (P ≤ 0.05) among sampling dates; `Starking' rose from 1.8 to 3.7 μW/mg dry weight (dw), while in `Golden' change was from 2.1 to 3.3 μW/mg dw. RCO2, q/RCO2, and RSG·ΔHB showed a pattern similar to q. On each sampling date, cuttings were also forced to break and, in all dates, buds broke after 21 days, demonstrating a paradormant condition. MM.106 root tips q behave differently depending on the variety they were grafted on to. When grafted with `Starking', root tips produced a small, but significant, increase in q (from 9.1 to 15.7 μW/mg dw) as the season progressed. RCO2 and RSG·ΔHB behaved similarly, increasing from 27.6 to 57.6 mmol CO2/mg dw and 3.4 to 8.3 μW/mg dw, respectively. These conditions agreed with a dynamic root growth. A small decrease in q/RCO2 was observed. However, when grafted with `Golden' root tips metabolic responses did not increase; furthermore, q decreased while RCO2, q/RCO2, and RSG·ΔHB did not show a defined pattern. Four complete 2-year-old trees of each variety, kept in 1-m3 containers, were sampled. The relation of root/wood dry matter was estimated, with difference found between varieties.

scholarly journals Selection of drought tolerant wheat genotypes by osmotic stress imposed at germination and early seedling stage

2018 ◽  
Vol 15 (2) ◽  
pp. 177-192
Author(s):  
RR Saha ◽  
A Hannan ◽  
A Nessa ◽  
MA Malek ◽  
MR Islam
Keyword(s):  
Osmotic Stress ◽  
Dry Weight ◽  
Seedling Stage ◽  
Metabolic Efficiency ◽  
Wheat Genotypes ◽  
Shoot Dry Weight ◽  
Vigour Index ◽  
Peg Treatment ◽  
Early Seedling ◽  
Different Levels

An experiment on hundred wheat genotypes under different levels of osmotic stress was carried out during 2014 to select the genotype(s) tolerant to drought at germination and early seedling stage. Different levels of osmotic stress were imposed by using polyethylene glycol (PEG). Three osmotic stress levels viz. control (distilled water), 15% PEG solution and 25% PEG solution were used. Among the 100 genotypes the rate of germination percentage, final germination (%), root and shoot dry weight, amount of respiration and vigour index under PEG treatment was found significantly lower than that of control condition. Compared to control condition relative decrease in rate of germination, final germination, amount of respiration and vigour index among the wheat genotypes were found more at 25% PEG than that of 15% PEG treatment. However, the seed metabolic efficiency was significantly higher in wheat genotypes under both 15% PEG and 25% PEG treatment compared to the control condition. A significant positive correlation exists between the important growth parameters like rate of germination (%), final germination (%), shoot dry weight, root dry weight and vigour index. On the basis of these physiological traits against osmotic stress, nine genotypes of wheat such as BD-480, BD-498, BD- 501, BD-513, BD-514, BD-519, BD-592, BD-618 and BD- 633 were selected as drought tolerant.SAARC J. Agri., 15(2): 177-192 (2017)

Infection of adventitious roots of Agrostis palustris by Pythium species at different temperature regimes

1994 ◽  
Vol 72 (3) ◽  
pp. 378-383 ◽  
Author(s):  
Clinton F. Hodges ◽  
Douglas A. Campbell
Keyword(s):  
Low Temperatures ◽  
Adventitious Roots ◽  
Root Hairs ◽  
Dry Weight ◽  
Agrostis Palustris ◽  
Pythium Species ◽  
Root Tips ◽  
Pythium Arrhenomanes ◽  
Temperature Regimes ◽  
Disease Complexes

Pathogenicity of several isolates of Pythium species to the adventitious roots of Agrostis palustris was evaluated at high (35:24, light:dark) and low (24:13 °C, light:dark) temperature regimes. Isolates of P. graminicola–arrhenomanes, P. rostratum, P. torulosum, P. vanterpoolii, and one unclassified species were evaluated. All isolates of all species infected roots. Some isolates of P. graminicola–arrhenomanes (PGA-5), P. torulosum (PT-1, PT-2, PT-3, PT-5), P. vanterpoolii (PV-1), and an unclassified species (UP-1) infected roots and decreased dry weight at both the high and low temperature regimes. Other isolates of P. graminicola–arrhenomanes (PGA-1, PGA-2, PGA-4, PGA-6, PGA-7) and P. torulosum (PT-4) infected roots and decreased dry weight only at the high temperatures. Isolate PGA-7 of P. graminicola–arrhenomanes also stimulated plant growth at low temperatures. The remaining isolates of P. graminicola–arrhenomanes (PGA-3), P. rostratum (PR-1), and P. vanterpoolii (PV-2) infected roots and decreased dry weight only at the low temperatures. Infection of roots was limited to root hairs, root tips, and epidermal and cortical tissues. The observations are discussed relative to the function of Pythium species as minor root pathogens and their potential function in disease complexes. Key words: disease complexes, infection, minor pathogens, pathogenesis, pathogenicity, Pythium arrhenomanes, P. graminicola, P. graminicola–arrhenomanes, P. rostratum, P. torulosum, P. vanterpoolii.

Effects of Growing Wheat in Hypoxic Nutrient Solutions and of Subsequent Transfer to Aerated Solutions. I. Growth and Carbohydrate Status of Shoots and Roots

1988 ◽  
Vol 15 (4) ◽  
pp. 585 ◽  
Author(s):  
EG Barrett-Lennard ◽  
PD Leighton ◽  
F Buwalda ◽  
J Gibbs ◽  
W Armstrong ◽  
...  
Keyword(s):  
Dry Weight ◽  
Triticum Aestivum L ◽  
Seminal Root ◽  
Platinum Electrodes ◽  
Root Tips ◽  
Seminal Roots ◽  
Crown Roots ◽  
Carbohydrate Status ◽  
Nutrient Solutions ◽  
Oxygen Concentrations

This paper evaluates the effects of hypoxia (imposed by flushing N2 gas through the nutrient solution) on the growth and carbohydrate status of wheat (Triticum aestivum L.), and the reversibility of these effects once aeration is resumed. Plants were transferred to hypoxic nutrient solutions (containing 0.003 mol O2 m-3) at the early tillering stage, when they had 3-4 leaves, well developed seminal roots, and a few crown roots. Hypoxia for 10-14 days had little adverse effect on shoot growth, whereas the seminal roots stopped growing, i.e. elongating and increasing in dry weight; in contrast, the crown roots elongated to a maximum of 9 cm and continued to increase in dry weight. Hypoxia increased the porosity of crown roots 2-3-fold compared with those grown under aerated conditions; in contrast, the porosity of seminal roots was unaffected. Oxygen concentrations in the gas filled pores of hypoxic crown roots (65 mm or longer) were estimated from measurements of radial oxygen loss using cylindrical platinum electrodes. Oxygen concentrations in the root tips were substantially lower than the critical oxygen pressures required for maximum respiration. Further, both oxygen concentrations in root tips and rates of root elongation were higher in shorter than in longer roots. Plants grown in hypoxic nutrient solutions had substantially higher sugar concentrations in shoots and roots than plants grown in aerated solutions. Sugars were not deficient in hypoxic roots since concentrations over a diurnal cycle remained higher than in aerated roots in both the bulk of the seminal and crown roots, and in the tips of the crown roots. Furthermore, tips of seminal roots had similar sugar concentrations when exposed to either aerated or hypoxic solutions. Hypoxia presumably killed seminal root apices, since the seminal axes did not resume elongation once aeration was restored. In contrast, crown roots resumed elongation when aeration was resumed. Although seminal root tips were moribund, the bulk of the seminal root was still alive. Following the transfer to aerated solutions, there was a rapid increase in the dry weight of both crown and seminal roots, in the latter case due to the proliferation of laterals.

The significance of petiole length, leaf area, and light interception in competition between strains of subterrranean clover (Trifolium subterraneum L.) grown in swards

1960 ◽  
Vol 11 (3) ◽  
pp. 277 ◽  
Author(s):  
JN Black
Keyword(s):  
Leaf Area ◽  
Leaf Development ◽  
Plant Competition ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Sampling Period ◽  
Dry Weight ◽  
Petiole Length ◽  
Petiole Elongation ◽  
Light Profiles

Three strains of subterranean clover differing in leaf development were grown in pure swards and in all combinations in mixtures. The strain Yarloop has relatively few large leaves held on long petioles; Tallarook has many small leaves and short petioles; Bacchus Marsh is intermediate in all these respects. The swards were grown in boxes and were sampled on four occasions during the period of vegetative growth. Leaf area in each 2 cm layer of the sward was determined separately, and for both strains in the mixed swards, and measurements of the light intensity reaching each layer were obtained. Root weights were determined for all swards and separately for each component of the mixed swards. Examination of the dry weights showed that the growth of the strain having the lesser petiole elongation was suppressed. In the extreme instance Tallarook was so suppressed when grown with Yarloop that in the final inter-sampling period it grew completely in the dark, and lost about half its dry weight. Bacchus Marsh also suppressed Tallarook, but to a lesser extent, while Bacchus Marsh was itself suppressed in competition with Yarloop. The amount of light energy intercepted by the two components of the mixed swards was calculated from the leaf area and light profiles, and confirmed the importance of the spatial distribution of leaves in plant competition. It was concluded that, in the absence of defoliation, the success of a strain under competition was associated with its potential petiole elongation.

scholarly journals Interactive effect of AM fungi with Trichoderma viride and Pseudomonas fluorescens on growth and yield of broccoli

2013 ◽  
Vol 49 (No. 3) ◽  
pp. 137-145 ◽  
Author(s):  
A. Tanwar ◽  
A. Aggarwal ◽  
S. Kaushish ◽  
S. Chauhan
Keyword(s):  
Pseudomonas Fluorescens ◽  
Glomus Intraradices ◽  
Interactive Effect ◽  
Trichoderma Viride ◽  
Am Fungi ◽  
Dry Weight ◽  
Growth And Yield ◽  
Vegetable Crops ◽  
Fresh Weight ◽  
Root Tips

Most of the vegetable crops are known to depend upon arbuscular mycorrhizal fungal (AM) symbiosis for growth and development, since AM fungi provide nutrients and water in exchange for photosynthates.  The influences of AM fungi (Glomus intraradices (G) and Acaulospora laevis (A)) with Trichoderma viride (T) and Pseudomonas fluorescens (P) alone and in combinations on growth, mycorrhization, chlorophyll content, nutrient uptakes, and yield of broccoli plants were studied in pot culture under glasshouse conditions. The obtained results demonstrated that the single inoculation of broccoli plants with T. viride significantly increased the above ground fresh weight, root length, chlorophyll b, head diameter, root phosphorus, and shoot nitrogen in comparison to uninoculated control plants. On the other hand, consortium of G+A+T+P significantly increased plant height, above ground dry weight, root fresh weight, chlorophyll a, head fresh weight, and root nitrogen content. Similarly, G+T showed maximum leaf area, and P alone showed maximum uptake of shoot phosphorus. Whereas when P was supplied along with T, early flowering was recorded. AM fungal colonisation was negligible and only root tips were found infected in G or A treated plants which confirms low dependency of broccoli on AM fungi.  

Reduction of Cladophora Biomass and Tissue Phosphorus in Lake Ontario, 1972–83

1987 ◽  
Vol 44 (12) ◽  
pp. 2212-2215 ◽  
Author(s):  
D. S. Painter ◽  
G. Kamaitis
Keyword(s):  
Soluble Reactive Phosphorus ◽  
Lake Ontario ◽  
Sampling Period ◽  
Dry Weight ◽  
Weight Basis ◽  
Remote Site ◽  
Net Production ◽  
Control Programs ◽  
Reactive Phosphorus ◽  
Tissue Phosphorus

Cladophora biomass and tissue phosphorus concentrations at seven sites in Lake Ontario have decreased from 1972 to 1983 in response to phosphorus control programs introduced in the early 1970's. Biomass and tissue phosphorus were significantly different between 1972 and 1982–83 (ANOVA, P < 0.001) but not significantly different between 1982 and 1983. The lakewide average tissue phosphorus was 0.49% in 1972 but by 1982 and 1983 had dropped to 0.26 and 0.20%, respectively, on an ash-free dry weight basis. Tissue phosphorus concentrations did not limit growth in 1972 but in 1983 had begun to limit growth. Model-predicted net production for a 6-wk sampling period in 1983 was 1.7 times greater in the western end of the lake than at a remote site in eastern Lake Ontario due to higher soluble reactive phosphorus concentrations.

Studies on the growth and development of Agropyron repens: interacting effects of humidity, calcium, and nitrogen on growth of the rhizome apex and lateral buds

1987 ◽  
Vol 65 (7) ◽  
pp. 1427-1432 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Apical Dominance ◽  
Water Status ◽  
Dry Weight ◽  
Apical Growth ◽  
High Humidity ◽  
N Supply ◽  
Lateral Buds ◽  
Low Humidity ◽  
Bud Growth ◽  
Agropyron Repens

A previous investigation of apical dominance in the rhizome of Agropyron repens showed that keeping the rhizome in a high humidity promoted the outgrowth of the lateral buds but strongly inhibited the growth of the rhizome apex. A study of these related responses demonstrated that the inhibition of apical growth was not prevented by excision of the lateral buds and was also induced when only the apex of the rhizome received the high humidity treatment. The necrotic lesions that developed in the arrested apices and the reduction of apical inhibition produced by various Ca treatments indicated that the inhibition of apical growth was caused by Ca deficiency. When the rhizome apex was exposed to low humidity, a localized high-humidity treatment of the lateral buds did not release the buds from apical dominance in low-N rhizomes but strongly promoted bud growth at a higher N level. When growth of the buds was induced at low humidity by increasing the N supply, the increase in bud weight was preceded by an increase in the water content of the bud when expressed on a dry weight basis. These results agree with those of previous investigations and suggest that the interacting effects of N and humidity on the water status of the buds may play a significant role in the mechanism of apical dominance.

Effect of Copper Toxicity on Root Morphology, Ultrastructure, and Copper Accumulation in Moso Bamboo (Phyllostachys pubescens)

2014 ◽  
Vol 69 (9-10) ◽  
pp. 399-406 ◽  
Author(s):  
Junren Chen ◽  
Danli Peng ◽  
Mohammad Shafi ◽  
Song Li ◽  
Jiasen Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Root Morphology ◽  
Copper Toxicity ◽  
Dry Weight ◽  
Moso Bamboo ◽  
Copper Accumulation ◽  
Root Surface Area ◽  
Phyllostachys Pubescens ◽  
Root Tips ◽  
Effect Of Copper

Abstract A hydroponic culture experiment was conducted to study the effect of copper toxicity on root morphology, ultrastructure, and copper accumulation in Moso bamboo (Phyllostachys pubescens). Root ultrastructure of Moso bamboo was studied by transmission electron microscopy and scanning electron microscopy. Application of 200 μM Cu resulted in an accumulation of 810 mg kg-1 dry weight and 91 mg kg-1 dry weight Cu in roots and shoots, respectively. The majority of the plants did not survive the application of 400 μM Cu. Biomass production declined consistently with application of each additional increment of Cu. Root growth was more severely inhibited than shoot growth. Cu adversely affected the root morphology of the plants, however, root surface area and number of root tips increased slightly at low levels of Cu. Root cell ultrastructure and organelles changed significantly under Cu stress, in particular, cell walls, mitochondria, and xylem parenchyma were affected.

scholarly journals Multivariate Tools for Evaluating the Use of Organic Fertilizers on Soil Microbial Properties and Maize Yield

2020 ◽  
Vol 8 (3) ◽  
pp. 257
Author(s):  
Layana Dorado Correia Belinato ◽  
Elston Elston Kraft ◽  
Rafael Solivo ◽  
Patrícia Aparecida de Oliveira ◽  
Evandro Spagnollo ◽  
...  
Keyword(s):  
Swine Manure ◽  
Poultry Manure ◽  
Sampling Period ◽  
Maize Yield ◽  
Organic Fertilizers ◽  
Animal Origin ◽  
Metabolic Efficiency ◽  
Soil Microbial ◽  
Manure Compost ◽  
The Impact

The global demand for protein led to the increase of animal production in the world and, mainly, in Brazil. As a consequence, there was an increase in the amount of waste produced, and the need to seek alternatives for its sustainable use. Microbial indicators and multivariate tools can assist in the proper measurement of the impact of the use of this waste on the soil. This study aimed to: 1) measure the effect of the application of organic fertilizers of animal origin in the no-tillage system on soil microbial attributes and its relationship with maize yield; 2) evaluate the potential of separation/discrimination of the different sources of organic fertilizers based on yield and soil microbial and chemical-physical attributes, using multivariate tools. Treatments consisted of annual application of: poultry manure (PM), liquid swine manure (LSM), poultry manure compost (PMC), swine manure compost (SMC), cattle manure compost (CMC) and control (C), without fertilization. Organic fertilizers promoted higher values of microbial biomass (MB) and MBC:TOC ratio in treatments CMC, SMC and PM in the first sampling season (E1), followed by PM, LSM and PMC in the second sampling period (E2). The data show that PM promoted microbial growth in both seasons, with higher metabolic efficiency increasing maize yield by 30% in relation to the treatment with the second highest production, PMC. Multivariate analysis techniques prove to be important tools to study soil quality indicators in systems which use organic fertilizers.

scholarly journals 606 PB 246 Effect of planting density on root length distribution and mineral content in Y-shaped self rooted `Flordaprince' peach trees

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 519a-519
Author(s):  
T. Caruso ◽  
F.P. Marra ◽  
A. Motisi ◽  
D. Giovannini
Keyword(s):  
Root Length ◽  
Mineral Content ◽  
Root Length Density ◽  
Length Distribution ◽  
Dry Weight ◽  
Planting Density ◽  
Black Plastic ◽  
Old Trees ◽  
Peach Trees ◽  
Two Sides

Length and distribution of the roots of 2-year old cv. `Flordaprince' peach trees grown under polyethylene greenhouse were studied over a two year period. The self-rooted, micropropagated trees were spaced 4.9 m between the row and 70, 52 and 42 cm. along the row to obtain a density of 3000, 4000 and 5000 trees/ha respectively. Orchard was clean cultivated, mulched along the row with black plastic fabric 1 m wide, and drip fertigated. Soon after harvest, for each density, the root system of one tree was totally excavated and root length, distribution, dry weight and nutrients content were determined. Total root length per tree was negatively related to planting density in two-year old trees (470, 380 and 320 m/tree respectively for 3000, 4000 and 5000 trees/ha). The shallowest root systems were found at 5000 trees/ha density and their length was unchanged from year to year. Root length density, ranging from 220 to 250 m/m), was only slightly affected by spacing in the two years. The roots were evenly distributed between the two sides of the rows.

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