Effect of nitrogen and phosphorus deficiency in wheat on the infection of roots by Gaeumannomyces graminis var. tritici

1989 ◽  
Vol 40 (3) ◽  
pp. 489 ◽  
Author(s):  
RF Brennan
Keyword(s):  
Root System ◽  
Phosphorus Deficiency ◽  
Gaeumannomyces Graminis ◽  
Nitrogen And Phosphorus ◽  
Nodal Roots ◽  
Proximal Lesion ◽  
Nodal Root ◽  
Seminal Roots ◽  
Four Levels ◽  
Take All

Wheat was grown in a slightly acid grey sand at six levels of phosphorus and four levels of nitrogen, in the presence and absence of inoculum of Gaeurnannomyces graminis tritici (Ggt) in a glasshouse experiment. Adequate nutrition of N (400 mg/pot) and P (100 mg/pot) for wheat plants was required to overcome take-all of wheat grown for 46 days. Severely N and P deficient plants had 60% of their seminal and nodal roots infected by take-all. As the plants responded to increasing levels of N and P, the percentage of infected nodal and seminal roots steadily declined to 0% and 10% for each root system respectively at luxury levels of P and adequate N. In both the seminal and nodal root system, increasing the N and P supply decreased the length of proximal lesions (closest to seed) and increased the length of the root between the crown and the proximal lesion. The seminal root system was more severely infected with take-all than the nodal root system.

Effect of phosphorus deficiency in wheat on the infection of roots by Gaeumannomyces graminis var. tritici

1988 ◽  
Vol 39 (4) ◽  
pp. 541 ◽  
Author(s):  
RF Brennan
Keyword(s):  
Phosphorus Deficiency ◽  
Root Systems ◽  
Gaeumannomyces Graminis ◽  
Nodal Roots ◽  
Nodal Root ◽  
Seminal Roots ◽  
Phosphorus Status ◽  
Gaeumannomyces Graminis Var Tritici ◽  
P Supply ◽  
Take All

Wheat was grown in a slightly acidic grey sand at six levels of phosphorus, in the presence or absence of take-all inoculum in a glasshouse experiment. The incidence and severity of take-all was related to the phosphorus supply and the phosphorus status of wheat.Plants grown without P were more severely infected by take-all than those grown at adequate levels of phosphorus. The percentage of both nodal and seminal roots infected by take-all declined as the level of P was increased. The percentage of seminal roots infected was reduced from 35% to 13.7% by increasing the supply of phosphorus from levels severely deficient to those adequate for plant growth. Infection in nodal roots was reduced from 24% to 2.3% as the P supply increased. In both the seminal and nodal root systems, increasing the P supply decreased the length of proximal lesions (closest to seed) and increased the length of root between the crown and the proximal lesions.

Effect of copper deficiency in wheat on the infection of roots by Gaeumannomyces graminis var. tritici

1984 ◽  
Vol 35 (6) ◽  
pp. 735 ◽  
Author(s):  
MJ Wood ◽  
AD Robson
Keyword(s):  
Plant Growth ◽  
Copper Deficiency ◽  
Gaeumannomyces Graminis ◽  
Fresh Weight ◽  
Nodal Roots ◽  
Copper Status ◽  
Seminal Roots ◽  
Effect Of Copper ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Wheat was grown in a soil at five levels of copper (ranging from levels deficient, to those luxurious, for plant growth), in the presence or absence of introduced take-all inoculum (oat kernels colonized by Gaeumannomyces graminis var. tritica). The incidence and severity of take-all were related to the copper supply and hence the copper status of the wheat. Plants grown without applied copper were more severely infected by take-all than were those grown with an adequate or luxurious supply of copper. The number of lesions per gram fresh weight of roots was reduced from 6.5 to 2.4 by increasing the copper supply from that severely deficient, to that adequate for plant growth. In seminal roots, increasing the copper supply from levels severely deficient to those adequate or luxurious for plant growth, decreased the length of proximal lesions (those closest to the seed). By contrast, in nodal roots, a similar increase in copper supply had no effect on the length of proximal lesions, but increased the length of uninfected root between the crown and proximal lesions. In both seminal and nodal roots, copper supply did not affect the intensity of lesions.

Water Stressed Nodal Roots of Wheat: Effects on Leaf Growth

1997 ◽  
Vol 24 (1) ◽  
pp. 49 ◽  
Author(s):  
K. M. Volkmar
Keyword(s):  
Growth Rate ◽  
Water Content ◽  
Relative Water Content ◽  
Leaf Growth ◽  
Seminal Root ◽  
Nodal Roots ◽  
Nodal Root ◽  
Relative Water ◽  
Seminal Roots ◽  
Leaf Relative Water Content

This experiment as undertaken to determine the efects of soil drying around the nodal and/or seminal root systems on the shoot growth of wheat (Triticum aestivum L.). Two split-root experiments were conducted, the first on newly emerged nodal roots of 18-day-old wheat plants, the second on 25-day-old plants. In both experiments, nodal and seminal roots were isolated from one another and water was withheld from either the nodal root chamber, the seminal root chamber, or both, over 6 days. In the first experiment, leaf growth was unaffected by withholding water from very short nodal roots, even though leaf relative water content of the droughted plants decreased. By comparison, both leaf elongation rate and relative water content decreased by withholding water from the seminal roots. On plants that were 1 week older, leaf growth rate and leaf relative water content decreased when nodal roots were drought-stressed. Leaf growth rate of seminal root droughted plants was more impaired than their nodal root counterparts, even though leaf relative water contents of the two treatments were the same. In both experiments, drought stress applied to the nodal root system enhanced nodal root growth more than seminal roots. These results suggest that seminal and nodal roots perceive and respond to drought stress differently with respect to the nature of the message conveyed to the shoots.

Root development in seedlings of ryegrass (Lolium perenne L.) and phalaris (Phalaris aquatica L.) sown onto the soil surface

1982 ◽  
Vol 33 (4) ◽  
pp. 665 ◽  
Author(s):  
PS Cornish
Keyword(s):  
Root Development ◽  
Soil Surface ◽  
Undisturbed Soil ◽  
Growth And Survival ◽  
Small Vessels ◽  
Nodal Roots ◽  
Nodal Root ◽  
Seminal Roots ◽  
Surface Drying ◽  
Axial Resistance

The effects of surface-sowing on root type, number and xylem radius were studied in relation to the seedling growth and survival of ryegrass and phalaris. Under optimal conditions in a growth cabinet, both species produced primary and lateral seminal roots, nodal roots and, in the absence of light, a subcoleoptile internode (s.c.i.). Phalaris had fewer lateral seminal roots and, in this species, internodal roots occurred along the s.c.i. Surface placement per se had no effect on any of the measured parameters of root development, but surface drying prevented nodal root primordia from extending, even when plants were otherwise supplied with water. This effect of surface drying on nodal root development was confirmed in a glasshouse study using undisturbed soil cores (30 by 60 cm) to simulate field conditions. Phalaris was less likely than ryegrass to produce nodal roots after surface sowing. The effective xylem radius (re) of the primary seminal root was 7.9 �m in ryegrass and 11.6 �m in phalaris. Calculations using the Poiseuille equation indicated that the axial resistance to water flow through these roots would greatly restrict seedling water uptake and growth in the absence of other roots. Lateral seminal roots and internodal roots had small vessels which could not significantly reduce the axial resistance to flow. Good seedling water relations in both species therefore depend on early development of the nodal roots which contain large xylem vessels (re > 16 �m). It was concluded that the effect of soil-surface drying on nodal root development was likely to account for some cases of poor vigour and survival of surface-sown grasses.

scholarly journals Cost-Benefit Analysis of the Upland-Rice Root Architecture in Relation to Phosphate: 3D Simulations Highlight the Importance of S-Type Lateral Roots for Reducing the Pay-Off Time

2021 ◽  
Vol 12 ◽  
Author(s):  
Daniel Gonzalez ◽  
Johannes Postma ◽  
Matthias Wissuwa
Keyword(s):  
Root System ◽  
Lateral Roots ◽  
Root Hairs ◽  
P Uptake ◽  
Root Tissue ◽  
Rice Root ◽  
P Deficiency ◽  
Nodal Roots ◽  
Nodal Root ◽  
Off Time

The rice root system develops a large number of nodal roots from which two types of lateral roots branch out, large L-types and fine S-types, the latter being unique to the species. All roots including S-types are covered by root hairs. To what extent these fine structures contribute to phosphate (P) uptake under P deficiency was investigated using a novel 3-D root growth model that treats root hairs as individual structures with their own Michaelis-Menten uptake kinetics. Model simulations indicated that nodal roots contribute most to P uptake followed by L-type lateral roots and S-type laterals and root hairs. This is due to the much larger root surface area of thicker nodal roots. This thickness, however, also meant that the investment in terms of P needed for producing nodal roots was very large. Simulations relating P costs and time needed to recover that cost through P uptake suggest that producing nodal roots represents a considerable burden to a P-starved plant, with more than 20 times longer pay-off time compared to S-type laterals and root hairs. We estimated that the P cost of these fine root structures is low enough to be recovered within a day of their formation. These results expose a dilemma in terms of optimizing root system architecture to overcome P deficiency: P uptake could be maximized by developing more nodal root tissue, but when P is growth-limiting, adding more nodal root tissue represents an inefficient use of the limiting factor P. In order to improve adaption to P deficiency in rice breeding two complementary strategies seem to exist: (1) decreasing the cost or pay-off time of nodal roots and (2) increase the biomass allocation to S-type roots and root hairs. To what extent genotypic variation exists within the rice gene pool for either strategy should be investigated.

Crop and pasture rotations at Coonalpyn, South Australia: effects on soil-borne diseases, soil nitrogen and cereal production

1984 ◽  
Vol 24 (127) ◽  
pp. 555 ◽  
Author(s):  
PM King
Keyword(s):  
Dry Matter ◽  
South Australia ◽  
Grain Legumes ◽  
Gaeumannomyces Graminis ◽  
Heterodera Avenae ◽  
Soil Nitrate ◽  
Bare Patch ◽  
Root Diseases ◽  
Nodal Roots ◽  
Seminal Roots

A crop rotation experiment was conducted at Coonalpyn, South Australia from 1976 to 1979 on a deep, red duplex soil. The experiment compared the productivity of grain legumes and of volunteer and sown annual pastures, and assessed their effects on the mineral nitrogen supply for subsequent wheat and barley crops, and their capabilities for preventing the root diseases of wheat cereal cyst nematode (Heterodera avenae), bare patch (Rhizoctonia solani) and Haydie (Gaeumannomyces graminis). Satisfactory legume dominance of the annual pastures was achieved only in 1979, while the grain legumes grew well and produced more dry matter than the pastures in each season. Wheat and barley yields averaged (1977- 1979) 2.0 t/ha after volunteer and sown pastures, and 2.8 t/ha after grain legumes, with the greatest response in 1979. In that year, wheat produced 11 kg grain/mm of growing season rainfall after grain legumes, but only 6 kg after pastures. The numbers of lesions on the nodal roots caused by R. solani and on the seminal roots by G. graminis varied with the season but both were less after grain legumes than after pasture. Gaeumannomyces graminis had the greatest effect on grain yield and, with soil nitrate at seeding, explained up to 68% of the variation in yield in 1979.

Colonization of lateral, seminal and adventitious roots of wheat by the take-all fungus, Gaeumannomyces graminis var. tritici

1980 ◽  
Vol 94 (2) ◽  
pp. 325-329 ◽  
Author(s):  
C. A. Gilligan
Keyword(s):  
Adventitious Roots ◽  
Lateral Roots ◽  
Initial Period ◽  
Hyphal Growth ◽  
Gaeumannomyces Graminis ◽  
Rate Of Growth ◽  
Direct Inoculation ◽  
Seminal Roots ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

SummaryProgressive colonization of adventitious, seminal and lateral roots of wheat by Gaeumannomyces graminis var. triticiwas monitored for 18 days after direct inoculation of roots. Adventitious roots supported greater colonization by superficial runner hyphae above and below inoculation sites than did seminal roots due to more rapid establishment of colonization. Subsequent rates of superficial runner hyphal growth along the two types of root were not significantly different. In contrast with seminal and lateral roots, adventitious roots did not show any dark stelar discoloration during the period of observation. Both the rate of growth of superficial runner hyphae and of advance of dark stelar discoloration were substantially slower on lateral roots than on seminal roots. After an initial period of equal growth above and below inoculation sites, superficial runner hyphae grew more slowly below than above these sites on all three types of root.

The nodal roots of Zea: their development in relation to structural features of the stem

1986 ◽  
Vol 64 (11) ◽  
pp. 2524-2537 ◽  
Author(s):  
D. C. Hoppe ◽  
M. E. McCully ◽  
C. L. Wenzel
Keyword(s):  
Root System ◽  
Primary Root ◽  
Ground Level ◽  
Structural Features ◽  
Nodal Roots ◽  
Extensive Region ◽  
Nodal Root ◽  
The Mean ◽  
Xylem Conduits

The framework of the root system of a mature, field-grown corn plant of variety Seneca Chief consists of about 70 axile roots. One of these is the primary root. The others develop on the stem, a single tier at each of the seven basal nodes. Just over half of these roots grow out at or above ground level from nodes 6 and 7 late in the development of the plant, with those of node 7 entering the soil just before flowering. The mean diameter of the root produced at successively higher nodes increases, as does also the mean number of large metaxylem elements seen in a cross section, so that about 75% of the large xylem conduits between the root system and the stem are in the roots of the two uppermost tiers. Nodal root primordia develop initially in situ from an extensive region of dedifferentiated stem cortex. A sleeve-like extension of the stem encloses the base of each root formed at aerial nodes. At each node the complexity of vascular interconnections results in all of the framework roots being indirectly linked to each other and to the vascular traces from all of the leaves.

Effect of superphosphate and superphosphate plus flutriafol on yield and take-all of wheat

1989 ◽  
Vol 29 (2) ◽  
pp. 247 ◽  
Author(s):  
RF Brennan
Keyword(s):  
Grain Yield ◽  
Root System ◽  
Dry Matter ◽  
Disease Incidence ◽  
Gaeumannomyces Graminis ◽  
Site Location ◽  
Fungicide Application ◽  
Matter Production ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Wheat was grown in soil amended with 5 levels of superphosphate with or without 4 levels of flutriafol at 3 sites naturally infested with Gaeumannomyces graminis var. tritici. The severity of take-all was related to the rates of superphosphate and flutriafol. At all sites, the disease incidence and severity were high, with values for the moderate plus severe category (i.e. >25% of the root system discoloured by the takeall fungus) exceeding 80% for untreated plots. As plants responded to increasing levels of superphosphate and flutriafol, the percentage of infected roots declined. There was no further decline in the severity of take-all with increasing levels of flutriafol above 50 g/ha. The lowest severity of take-all was observed at the highest superphosphate level (200 kg/ha) and a fungicide level of 50 g/ha. Take-all severity for this treatment varied with the site location, being 52% at Condingup while the Mt Ridley and Neridup sites had 60% infection of take-all on the roots. There was a 25-30% increase in grain yield in response to added flutriafol at the highest superphosphate level. There were also corresponding increases in dry matter production and 1000-grain weights with superphosphate and fungicide application.

Deinking sludge influences biomass, nitrogen and phosphorus status of several grass and legume species

1997 ◽  
Vol 77 (4) ◽  
pp. 693-702 ◽  
Author(s):  
A. Fierro ◽  
J. Norrie ◽  
A. Gosselin ◽  
C. J. Beauchamp
Keyword(s):  
Soil Amendment ◽  
Mineral Soil ◽  
Nitrogen And Phosphorus ◽  
Agropyron Elongatum ◽  
Festuca Ovina ◽  
Melilotus Officinalis ◽  
Medicago Lupulina ◽  
Wide Range ◽  
Galega Orientalis ◽  
Four Levels

In a greenhouse study, deinking sludge was evaluated as a soil amendment supplemented with four nitrogen (N) fertilization levels for the growth of the grasses Agropyron elongatum (Host.) Beauv. (tall wheatgrass), Alopecurus pratensis L. (meadow foxtail), Festuca ovina var. duriuscula (L). Koch (hard fescue), and four levels of phosphorus (P) for the growth of the legumes Galega orientalis Lam. (galega), Medicago lupulina L. (black medic), Melilotus officinalis (L.) Lam (yellow sweet clover). Fertilizers were applied on the basis of sludge level to maintain uniform carbon (C)/N or C/P ratios across sludge treatments. In one experiment, sand was mixed with 0, 10, 20 or 30% sludge while, in a second experiment, mineral soil was mixed with 0, 27, 53 or 80% sludge (vol/vol). In sand mixtures of 30 and 20% sludge, grasses had similar or greater growth than in unamended mineral soil when N was added at about 6.5 and 8.4 g kg−1 deinking sludge, respectively. For all legumes but Medicago lupulina, P at about 0.8 g kg−1 sludge was required for these sand mixtures. In soil mixtures of 53 and 27% sludge, grasses grew well when supplemental N was about 5.3 and 6.9 g kg−1 sludge, respectively. Legumes required P at 0.5 and 1.2 g kg−1 sludge, respectively. In general, growth was closely related to total amount of added N or P in spite of the wide range of C/N or C/P ratios. When growing in media amended with sludge, grasses needed higher tissue N concentration for an equivalent growth than in control soil; legumes had similar tissue P concentration. The grasses Agropyron elongatum and Alopecurus pratensis as well as the legumes Melilotus officinalis and Galega orientalis are promising species for field testing, based on dry matter production. Deinking sludge can be used as soil amendment when adequate N and P supplements are provided. Key words: Soil amendment, papermill sludge, Agropyron elongatum, Alopecurus pratensis, Festuca ovina, Medicago lupulina, Galega orientalis, Melilotus officinalis

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