Effect of nitrogen supply on rhizosphere interactions and take-all disease of wheat

1991 ◽  
Vol 37 (1) ◽  
pp. 42-51 ◽  
Author(s):  
M. E. Leggett ◽  
K. Sivasithamparam ◽  
M. J. McFarlane
Keyword(s):  
Nitrogen Deficiency ◽  
Gaeumannomyces Graminis ◽  
Fluorescent Pseudomonads ◽  
Root Weight ◽  
Fluorescent Pseudomonad ◽  
Fresh Weight ◽  
Colony Forming Units ◽  
Rhizosphere Interactions ◽  
Shoot Weight ◽  
Take All

The effect of NH4NO3 on the expression of take-all in wheat and on the ability of fluorescent pseudomonad bacteria to decrease the growth of the pathogen and the symptoms of the disease was examined in a nitrogen-deficient acidic soil from Western Australia. Application of NH4NO3 increased the fresh weight of shoots, decreased root weight and length, and offset some of the deleterious effects of infection. Inoculation with Gaeumannomyces graminis var. triciti reduced shoot weight and root weight and length at all but the highest level of applied nitrogen. Fluorescent pseudomonads applied to wheat seed (at approximately 108 colony-forming units/seed) reduced seed germination and failed to reduce the severity of take-all expressed as weight or length of shoots or N content. Although the density of black runner hyphae of G. graminis var. triciti was reduced at 40 days and the proportion of root colonized by the pathogen was lower at 28 days with bacterization under severe nitrogen deficiency, no effect of the bacteria was observed if N was added. Key words: Gaeumannomyces graminis var. triciti, fluorescent pseudomonads, wheat, nitrogen.

Effects of Certain Isolates of Bacteria and Actinomycetes on Gaeumannomyces graminis var. tritici and Take-All of Wheat

1978 ◽  
Vol 26 (6) ◽  
pp. 773 ◽  
Author(s):  
K Sivasithamparam ◽  
CA Parker
Keyword(s):  
Gaeumannomyces Graminis ◽  
Fluorescent Pseudomonads ◽  
Wheat Seedlings ◽  
Apparent Correlation ◽  
Test Organisms ◽  
Unsterile Soil ◽  
Shoot Weight ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Five isolates each of actinomycetes, bacteria and fluorescent pseudomonads from the roots of wheat were tested for antagonism against Gaeumannomyces graminis var. tritici on agar and in sterile and unsterile soil. There was no apparent correlation between the tests. Effects on the growth of the take-all fungus (TAF) on agar ranged from nil to various degrees of colony deformation and/or inhibition. In a sterile sandy subsoil growing wheat seedlings, all except one isolate had no effect on disease production by a straw inoculum of the TAF. In an unsterile soil, however, measurements of shoot weight indicated that disease was reduced by all five isolates of bacteria singly and in mixture and by four of the five isolates of actinomycetes and a mixture of all five. Although a mixture of all five isolates of fluorescent pseudomonads reduced the disease, none of them produced a similar effect when tested singly. In the absence of the pathogen none of the test organisms significantly increased the shoot weight of wheat.

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.

Genetic variation amongst swede varieties and their hybrids and their response to soil fertility

1976 ◽  
Vol 87 (2) ◽  
pp. 443-446 ◽  
Author(s):  
O. A. Denton ◽  
W. J. Whittington
Keyword(s):  
Dry Matter ◽  
Total Yield ◽  
Gene Interaction ◽  
Matter Content ◽  
Root Weight ◽  
Environment Interaction ◽  
Dry Matter Content ◽  
Fresh Weight ◽  
Partial Dominance ◽  
Shoot Weight

SummaryThe mean total yield and mean fresh weight of seven swede varieties and their F1 hybrids was increased primarily by nitrogen and also by phosphorus fertilizer. There was no evidence of genotype × environment interaction for characters concerned with yield except for dry-matter content where two varieties, Best-of-All and Reform, were less stable to fertility environments than the others. Heterosis was common amongst F1 hybrids and this suggests their use in swede improvement: the inheritance pattern of root weight showed overdominance, shoot weight showed partial dominance and drymatter content showed additivity, with no evidence of gene interaction. Segregation for root fresh weight and dry-matter content occurred in F2 populations and although an overall negative correlation was found there was evidence that progeny from certain crosses gave reasonable prospects of combining both characters.

scholarly journals Initial sunflower development (Helianthus annus L.) subject to increasing doses of nitrogen and potassium

2020 ◽  
Vol 13 (10) ◽  
pp. 21
Author(s):  
D. Riva ◽  
R. H. R. P. Ribeiro ◽  
R. V. Xavier ◽  
L. S. F. Lima ◽  
V. S. Sousa
Keyword(s):  
Plant Height ◽  
Aerial Part ◽  
Root Weight ◽  
Fresh Weight ◽  
Pet Bottles ◽  
Significant Difference ◽  
Helianthus Annus ◽  
Number Of Leaves ◽  
The Difference ◽  
Shoot Weight

The present study was carried out in the greenhouse of the IFMT Campus Confresa-MT, from April 20 t0 June 06, 2018, the trial containing 10 treatments with 4 repetitions, 5 treatments submiited to increasing doses of nitrogen and 5 treatments submiited to increasing doses of potassium, For doses of N 0,20,40,60 and 80 kg ha-1 were and for doses of K, 0,10,20,30,40 k ha‑1 the fertilizations were made with. 7,14 and 21 days after the emergence of the plants. The experiment was installed in 2 Lt, 2 dcm³ pet bottles. The characteristics evaluated were stem diameter (DC), number of leaves (NF), plant height (AP), fresh shoot weight (MPFA), fresh root weight (MFR), it was observed that statistically all treatments had a significant difference at 1% probability, plus some hypotheses that can be described that in the evaluation number of leaves at increasing doses of potassium, the control had a higher average result. Light, standardized doses of ferti-irrigation etc. nevertheless an extremely importante result for the discussion and for carrying out experiments in the fututre, however the best answers were if obtained in the variables fresh weight of the aerial part (MFPA) and fresh mass of the root (MFR), in the future we may have more results, with the repetition of the experimente and see the difference between them.

Fluctuations in the fluorescent pseudomonad and actinomycete populations of rhizosphere and rhizoplane during the growth of spring wheat

1990 ◽  
Vol 36 (4) ◽  
pp. 254-258 ◽  
Author(s):  
H. J. Miller ◽  
E. Liljeroth ◽  
G. Henken ◽  
J. A. van Veen
Keyword(s):  
Agar Medium ◽  
Fluorescent Pseudomonads ◽  
Rapid Decline ◽  
Fluorescent Pseudomonad ◽  
Wheat Line ◽  
Bacterial Populations ◽  
Nutrient Agar Medium ◽  
Colony Forming Units ◽  
Survival Studies ◽  
Wheat Lines

The total bacterial populations, fluorescent pseudomonads, and actinomycetes in the rhizosphere, rhizoplane, and endorhizosphere of two wheat lines (C-R5B and C-R5D) were investigated weekly during plant growth. The total numbers of bacteria (colony-forming units) were counted on a low-nutrient agar medium, while the numbers of fluorescent pseudomonads and actinomycetes were determined by means of selective media. Fluorescent pseudomonads generally constituted less than 0.5% of the total bacterial numbers and the percentage significantly decreased with time in the rhizosphere, rhizoplane, and root-free soil. The percentages of fluorescent pseudomonads were lower in the rhizoplane than in the rhizosphere, and in the endorhizosphere they were barely detectable. The rapid decline of fluorescent pseudomonads frequently observed in survival studies may be explained by the inability of the plant to support this group of bacteria during later development of its rhizosphere. Actinomycetes generally represented no more than 7% of the total bacterial numbers. Actinomycete percentages were highest in the rhizosphere and root-free soil and lowest in the endorhizosphere. Only minor differences were found in total bacterial numbers and in the numbers of fluorescent pseudomonads between the two wheat lines. However, numbers of actinomycetes were significantly different over the whole experiment between wheat line C-R5B and C-R5D in the rhizosphere, rhizoplane, and endorhizosphere. Key words: actinomycetes, bacteria, fluorescent pseudomonads, rhizosphere, sampling time.

scholarly journals Isolation, Characterization, and Sensitivity to 2,4-Diacetylphloroglucinol of Isolates of Phialophora spp. from Washington Wheat Fields

2010 ◽  
Vol 100 (5) ◽  
pp. 404-414 ◽  
Author(s):  
Youn-Sig Kwak ◽  
Peter A. H. M. Bakker ◽  
Debora C. M. Glandorf ◽  
Jennifer T. Rice ◽  
Timothy C. Paulitz ◽  
...  
Keyword(s):  
Sequence Comparison ◽  
Phylogenetic Trees ◽  
Washington State ◽  
Gaeumannomyces Graminis ◽  
Wild Oat ◽  
Genetic Characteristics ◽  
Oat Cultivars ◽  
Eastern Washington ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Dark pigmented fungi of the Gaeumannomyces–Phialophora complex were isolated from the roots of wheat grown in fields in eastern Washington State. These fungi were identified as Phialophora spp. on the basis of morphological and genetic characteristics. The isolates produced lobed hyphopodia on wheat coleoptiles, phialides, and hyaline phialospores. Sequence comparison of internal transcribed spacer regions indicated that the Phialophora isolates were clearly separated from other Gaeumannomyces spp. Primers AV1 and AV3 amplified 1.3-kb portions of an avenacinase-like gene in the Phialophora isolates. Phylogenetic trees of the avenacinase-like gene in the Phialophora spp. also clearly separated them from other Gaeumannomyces spp. The Phialophora isolates were moderately virulent on wheat and barley and produced confined black lesions on the roots of wild oat and two oat cultivars. Among isolates tested for their sensitivity to 2,4-diacetylphloroglucinol (2,4-DAPG), the 90% effective dose values were 11.9 to 48.2 μg ml–1. A representative Phialophora isolate reduced the severity of take-all on wheat caused by two different isolates of Gaeumannomyces graminis var. tritici. To our knowledge, this study provides the first report of an avenacinase-like gene in Phialophora spp. and demonstrated that the fungus is significantly less sensitive to 2,4-DAPG than G. graminis var. tritici.

Identification of powdery mildew (Erysiphe graminis sp. tritici) and take-all disease (Gaeumannomyces graminis sp. tritici) in wheat (Triticum aestivum L.) by means of leaf reflectance measurements

2006 ◽  
Vol 1 (2) ◽  
pp. 275-288 ◽  
Author(s):  
Simone Graeff ◽  
Johanna Link ◽  
Wilhelm Claupein
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Near Infrared ◽  
Plant Stress ◽  
Stress Factors ◽  
Gaeumannomyces Graminis ◽  
Disease Assessment ◽  
Leaf Reflectance ◽  
Reflectance Measurements ◽  
Take All

AbstractThe ability to identify diseases in an early infection stage and to accurately quantify the severity of infection is crucial in plant disease assessment and management. A greenhouse study was conducted to assess changes in leaf spectral reflectance of wheat plants during infection by powdery mildew and take-all disease to evaluate leaf reflectance measurements as a tool to identify and quantify disease severity and to discriminate between different diseases. Wheat plants were inoculated under controlled conditions in different intensities either with powdery mildew or take-all. Leaf reflectance was measured with a digital imager (Leica S1 Pro, Leica, Germany) under controlled light conditions in various wavelength ranges covering the visible and the near-infrared spectra (380–1300 nm). Leaf scans were evaluated by means of L*a*b*-color system. Visual estimates of disease severity were made for each of the epidemics daily from the onset of visible symptoms to maximum disease severity. Reflectance within the ranges of 490780 nm (r2 = 0.69), 510780nm (r2 = 0.74), 5161300nm (r2 = 0.62) and 5401300 nm (r2 = 0.60) exhibited the strongest relationship with infection levels of both powdery mildew and take-all disease. Among the evaluated spectra the range of 490780nm showed most sensitive response to damage caused by powdery mildew and take-all infestation. The results of this study indicated that disease detection and discrimination by means of reflectance measurements may be realized by the use of specific wavelength ranges. Further studies have to be carried out, to discriminate powdery mildew and take-all infection from other plant stress factors in order to develop suitable decision support systems for site-specific fungicide application.

Isolation, identification and characterization of native plant growth promoting bacteria and their plant growth promotion in Zea mays

2021 ◽  
Vol 16 (8) ◽  
pp. 75-80
Author(s):  
Pitchaiah Pelapudi ◽  
Sasikala Ch ◽  
Swarnabala Ganti
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Root Length ◽  
Growth Promotion ◽  
Shoot Length ◽  
Root Weight ◽  
Plant Growth Promoting Bacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Shoot Weight

In the present rapid growing world, need for a sustainable agricultural practice which helps in meeting the adequate food demand is much needed. In this context, plant growth promoting bacteria were brought into the spot light by the researchers. Though the plant growth promoting bacteria have several beneficial applications, due to some of the disadvantages in the field conditions, they lagged behind. In the current research work, native PGPR were isolated from the rhizosphere soil samples of maize with an aim to isolate the nitrogen fixing, phosphate solubilising and potash solubilising bacteria. Out of the several isolates, potent PGPR isolates viz., Paenibacillus durus PCPB067, Bacillus megaterium PCBMG041 and Paenibacillus glucanolyticus PCPG051 were isolated and identified by using the 16 S rRNA gene sequencing studies. Genomic DNA sequences obtained were deposited in the NCBI Genbank and accession numbers were assigned as MW793452, MW793456 and MW843633. In order to check the efficacy of the PGPR isolates, pot trials were conducted by taking maize as the host plant. Several parameters viz. shoot length, shoot weight, root length, root weight and weight of the seeds were tested in which PGP treatment showed good results (shoot length - 187±3.5 cm, shoot weight - 31±4 g, root length - 32±3.6 cm, root weight - 17±2 g, yield- 103.3±6.1 g) when compared to the chemical fertilizer treatment (shoot length - 177±3.5 cm, shoot weight - 25±3.6 g, root length - 24±3.5 cm, root weight - 14.6±1.52 g, yield- 85.6±7.6 g). Based on the results, it can be stated that these native PGPR isolates can be effectively used in the plant growth promotion of maize.

Gaeumannomyces graminis var. tritici. [Descriptions of Fungi and Bacteria].

1973 ◽  
Author(s):  
J. Walker
Keyword(s):  
Geographical Distribution ◽  
Root Hairs ◽  
Seed Transmission ◽  
Gaeumannomyces Graminis ◽  
Root Infection ◽  
Root Death ◽  
Meristematic Region ◽  
Germ Tubes ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Abstract A description is provided for Gaeumannomyces graminis var. tritici. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Gramineae, especially Triticum, Hordeum, Secale, Agropyron and several other grass genera and, more rarely, Sorghum and Zea; also recorded from the roots of plants in other families. DISEASE: Take-all of cereals and grasses (also referred to as deadheads or whiteheads, pietin and pied noir (France), Schwarzbeinigkeit and Ophiobolus Fusskrankheit (Germany), Ophiobolusvoetziekt (Netherlands) and others). Root infection is favoured by soil temperature from 12-20°C (Butler, 1961). Ascospore germ tubes penetrate root hairs and the epidermis in the meristematic region (Weste, 1972) leading to plugging of xylem and root death. GEOGRAPHICAL DISTRIBUTION: (CMI Map 334, ed. 3, 1972). Widespread, especially in temperate zones. Africa; Asia (India, Iran, Japan, USSR): Australasia and Oceania; Europe; North America (Canada, USA); South America (Argentina, Brazil, Chile, Colombia, Uruguay). TRANSMISSION: In soil on infected organic fragments, as runner hyphae on roots of cereals and grasses and, under special conditions, by ascospores. Seed transmission very doubtful (47, 3058).

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