INFLUENCE OF WILD AND CULTIVATED PLANTS ON THE MULTIPLICATION, SURVIVAL AND SPREAD OF CEREAL FOOT-ROTTING FUNGI IN THE SOIL

1935 ◽  
Vol 12 (5) ◽  
pp. 575-589 ◽  
Author(s):  
G. W. Padwick
Keyword(s):  
Bromus Inermis ◽  
Cultivated Plants ◽  
Wheat Seedlings ◽  
Helminthosporium Sativum ◽  
Soil Infestation ◽  
Loam Soil ◽  
Unsterilized Soil ◽  
Take All ◽  
Do So

Using the severity of infection of wheat seedlings as a measure of soil infestation, it is shown that susceptible grasses such as Agropyron tenerum, A. cristatum, A. repens and Bromus inermis encourage the multiplication and survival of inoculum of the take-all fungus Ophiobolus graminis in both sterilized and unsterilized soil. The same grasses also aided the survival of Helminthosporium sativum in sterilized soil. In these experiments, however, only one, namely B. inermis, appeared to favor the survival of Fusarium graminearum.The fungus O. graminis, which failed to spread laterally to any appreciable extent in bare, unsterilized black loam soil of the Edmonton district of Alberta, was able to do so when such soil was occupied by living, susceptible plants.

THE NATURAL MICROFLORA OF THE SOIL IN RELATION TO THE FOOT-ROT PROBLEM OF WHEAT

1931 ◽  
Vol 4 (1) ◽  
pp. 69-77 ◽  
Author(s):  
A. W. Henry
Keyword(s):  
Marked Effect ◽  
Black Soil ◽  
Plant Diseases ◽  
Foot Rot ◽  
Wheat Seedlings ◽  
Helminthosporium Sativum ◽  
Natural Microflora ◽  
Loam Soil ◽  
Unsterilized Soil ◽  
Inhibitive Action

In these studies the natural microflora of the black loam soil typical of the Edmonton district of Alberta had a marked inhibitive action on the development of the wheat foot-rotting fungus Helminthosporium sativum when the latter was grown directly in this soil. The severity of foot-rot infection of wheat seedlings caused by this pathogene was correspondingly reduced as a result of this action. A trace of unsterilized soil serving as a source of the saprophytic soil organisms had almost as great an influence as a relatively large amount. A similar effect on Fusarium graminearum, another fungous pathogene which causes loot-rot of wheat, is indicated.Bacteria, actinomycetes and fungi isolated from black soil each had a suppressive action on H. sativum in the soil and reduced the severity of foot-rot infection caused by it, but the fungi were considerably more effective than the bacteria and actinomycetes tested. A combination of all of these organisms produced the most marked effect and one equivalent to that produced by the organisms of unsterilized soil.The significance of the results in connection with the foot-rot problem of wheat is briefly discussed and their possible bearing on other plant diseases caused by soil-borne pathogenes is mentioned.

RELATIVE DECLINE OF OPHIOBOLUS GRAMINIS, HELMINTHOSPORIUM SATIVUM AND FUSARIUM CULMORUM IN THE SOIL

1960 ◽  
Vol 40 (2) ◽  
pp. 288-294 ◽  
Author(s):  
G. Semeniuk ◽  
A. W. Henry
Keyword(s):  
Fusarium Culmorum ◽  
Wheat Crop ◽  
Natural Soil ◽  
Large Measure ◽  
Wheat Seedlings ◽  
Helminthosporium Sativum ◽  
Loam Soil ◽  
Marked Decline ◽  
Relative Decline ◽  
Micro Organisms

The relative decline of three cereal root pathogens, Ophiobolus graminis Sacc., Helminthosporium sativum P. K. B., and Fusarium culmorum (W. G. Sm.) Sacc., in natural and sterilized black loam soil, was studied using inoculum grown in a sterilized soil-cornmeal medium. Since the severity of infection of wheat seedlings by the above fungi proved directly proportional to the amount of inoculum added to natural soil, it was used as a measure of the amount of effective inoculum in the soil at a given time. It was found by this means that inoculum of all three pathogens diminished greatly in amount in natural soil during the first few days following its addition, with that of O. graminis declining least, that of H. sativum more, and that of F. culmorum most. The decline rate was proportional to the amount of inoculum. After one week the decline had progressed further, but it was less for O. graminis than for the other two pathogens. In 3–4 weeks the amount of all three had reached a near-zero quantity. In sterilized soil the decline was similar to that in natural soil after the sterilized soil became recontaminated. However, that of F. culmorum was less pronounced here than in natural soil. Marked decline of O. graminis also occurred in natural soil supporting a seedling wheat crop. In large measure the decline studied appeared to be a quantitative degenerating process resulting from the activity of soil micro-organisms.

STUDIES ON THE MICROBIOLOGY OF RECONTAMINATED STERILIZED SOIL IN RELATION TO ITS INFESTATION WITH OPHIOBOLUS GRAMINIS SACC.

1943 ◽  
Vol 21c (11) ◽  
pp. 343-350 ◽  
Author(s):  
R. A. Ludwig ◽  
A. W. Henry
Keyword(s):  
Trichoderma Viride ◽  
Severe Infection ◽  
Black Soil ◽  
Plate Count ◽  
Wheat Seedlings ◽  
Number Of Microorganisms ◽  
Plate Count Method ◽  
Unsterilized Soil ◽  
Suppressive Action ◽  
Take All

In these studies recontaminated steam-sterilized black soil, when infested with the take-all fungus, Ophiobolus graminis, gave, as a rule, less severe infection of wheat seedlings than similarly infested unsterilized soil. One explanation suggested is that the microflora that develops in sterilized soil following recontamination has a greater suppressive action on Ophiobolus graminis than that normally present in unsterilized soil. These two microfloras were found to differ both quantitatively and qualitatively. In general the number of microorganisms, as determined by the plate count method, was found to be much greater in sterilized recontaminated soil than in unsterilized soil. The fact that the fungus Trichoderma viride develops rapidly and becomes a dominant organism in sterilized recontaminated soil is considered to be of especial significance. The antagonism of this fungus toward Ophiobolus graminis probably plays an important role in suppressing the latter.

scholarly journals Activity of Fengycin and Iturin A Isolated From Bacillus subtilis Z-14 on Gaeumannomyces graminis Var. tritici and Soil Microbial Diversity

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiawen Xiao ◽  
Xiaojun Guo ◽  
Xinlei Qiao ◽  
Xuechao Zhang ◽  
Xiaomeng Chen ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Relative Abundance ◽  
Gaeumannomyces Graminis ◽  
Control Effect ◽  
Soil Bacterial Diversity ◽  
Soil Microbial Diversity ◽  
Wheat Seedlings ◽  
Iturin A ◽  
Soil Microbial ◽  
Take All

Bacillus subtilis Z-14 can inhibit phytopathogenic fungi, and is used as a biocontrol agent for wheat take-all disease. The present study used the soil-borne fungus Gaeumannomyces graminis var. tritici (Ggt), which causes wheat take-all disease, and the soil microbial community as indicators, and investigated the antifungal effects of fengycin and iturin A purified from strain Z-14 using high performance liquid chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, respectively. The results showed that fengycin destroyed the internal structure of Ggt cells by digesting the cytoplasm and organelles, forming vacuoles, and inducing hyphal shrinkage and distortion. Iturin A induced cell wall disappearance, membrane degeneration, intracellular material shrinkage, and hyphal fragmentation. A biocontrol test demonstrated a 100% control effect on wheat take-all when wheat seedlings were treated with fengycin at 100 μg/ml or iturin A at 500 μg/ml. Iturin A and fengycin both reduced the relative abundance of Aspergillus and Gibberella. At the genus level, iturin A reduced the relative abundance of Mortierella and Myrothecium, while fengycin reduced that of Fusarium. Only fengycin treatment for 7 days had a significant effect on soil bacterial diversity.

THE RELATION OF SPECIES OF AGROPYRON AND CERTAIN OTHER GRASSES TO THE FOOT-ROT PROBLEM OF WHEAT IN ALBERTA

1933 ◽  
Vol 8 (4) ◽  
pp. 349-363 ◽  
Author(s):  
G. W. Padwick ◽  
A. W. Henry
Keyword(s):  
Phleum Pratense ◽  
Native Plant ◽  
Severe Damage ◽  
University Of Alberta ◽  
Rye Grass ◽  
Helminthosporium Sativum ◽  
Hordeum Jubatum ◽  
The University ◽  
Brome Grass ◽  
Take All

A survey was made of certain wild and cultivated grasses in Alberta in order to ascertain to what extent they are harboring fungi capable of causing foot rots of wheat. Quack grass, Agropyron repens, and western rye grass, Agropyron tenerum, were found to be particularly important in this respect. Both were found heavily attacked under natural conditions with strains of the take-all fungus, Ophiobolus graminis, which proved capable of causing as severe damage to wheat as strains from wheat. Strains of Helminthosporium sativum which proved highly pathogenic to wheat were also isolated from these two grasses. Strains of Fusarium obtained from A. repens and A. richardsonii caused little or no damage to wheat.Agropyron repens is already an important weed in central Alberta. It was found infesting cultivated fields in summerfallow as well as those in crop. In summerfallow this weed appears to encourage the survival of Ophiobolus graminis, while in wheat fields infected quack grass was found associated with severe take-all damage to the crop. Agropyron tenerum is one of our most popular forage grasses and occurs commonly as a wild native plant in Alberta. Observations indicate that in the moister parts of the province wheat following this grass in rotations may be severely injured by take-all. In a rotation at the University of Alberta, wheat showed little or no take-all damage after timothy and alfalfa, moderate damage after brome grass and severe damage after western rye grass. In this experiment western rye grass itself was almost killed out prematurely in all replicates, apparently by the take-all fungus.Artificial inoculation of the various grasses was made with wheat strains of foot-rotting fungi by adding inoculum to the soil. All species of Agropyron tested including crested wheat grass, Agropyron cristatum, proved highly susceptible to Ophiobolus graminis, moderately susceptible to Helminthosporium sativum, but only slightly susceptible to Fusarium graminearum, though the latter was responsible for considerable non-emergence of the seedlings. Bromus inermis and B. ciliatus proved quite susceptible to all three pathogenes. Hordeum jubatum was heavily attacked by Ophiobolus graminis but not by the other two fungi. Avena sativa was not attacked by O. graminis and only slightly by H. sativum and F. graminearum, while timothy, Phleum pratense, appeared immune from all three fungi.

scholarly journals NEW PLANT BREEDING TECHNOLOGIES FOR A SUSTAINABLE AGRICULTURE

2020 ◽  
Author(s):  
Martin Kater
Keyword(s):  
New Technology ◽  
Green Revolution ◽  
Cultivated Plants ◽  
Human Consumption ◽  
World Population ◽  
Biotic And Abiotic Stresses ◽  
Political Ideologies ◽  
Increase Food Production ◽  
Selection Of ◽  
Do So

Agriculture has a 10,000-year history. During this period, humans selected natural mutants that were found to be useful for cultivation and human consumption. However, the selected characteristics are not always favorable for the plants themselves, often compromising their ability to survive and adapt to the natural environment. In this way, cultivated plants have become dependent, for their survival, on man as man is dependent on plants to survive. The increase in agricultural production was notable during the green revolution and even afterwards new genetic knowledge made it possible to drastically increase food production. However, now with the rapid growth of the world population, the selection of new cultivars has become necessary, not only capable of producing more but also able to do so with less water, fertilizers, insecticides etc. Plants that are more resistant to biotic and abiotic stresses, which are increasingly frequent in a world where climate change is becoming a major challenge for the future. Studying the genomes of plants and the functions of their genes is the only way to accelerate the genetic improvement of plants while protecting the environment. A very important technology to try to solve these problems is "genome editing", using the CRISPR-Cas system. Unfortunately, in Europe the use of this new technology in agriculture has found it is not easy to apply not so much for scientific reasons but for political ideologies contrary to this type of innovation in agriculture.

The Effect of Salicylic Acid on Resistance in Wheat (Triticum aestivum) Seedling Roots Against the Take-All Fungus, Gaeumannomyces graminis var tritici

1996 ◽  
Vol 44 (4) ◽  
pp. 499 ◽  
Author(s):  
S Seah ◽  
K Sivasithamparam ◽  
DW Turner
Keyword(s):  
Triticum Aestivum ◽  
Salicylic Acid ◽  
Wheat Seedling ◽  
Triticum Aestivum L ◽  
Gaeumannomyces Graminis ◽  
Resistance Response ◽  
Wheat Seedlings ◽  
Seedling Roots ◽  
Wheat Seedling Roots ◽  
Take All

The effect of salicylic acid (SA) applied as foliar dip, foliar wipe, root drench or pre-germination soak on the susceptibility of wheat (Triticum aestivum L.) seedlings to Gaeumannomyces graminis (Sacc.) Arx & Olivier var. tritici Walker (take-all fungus, Ggt) was studied. It was hypothesised that an increase in SA concentration applied using these methods would increase the resistance in wheat seedling roots against Ggt. Leaves (by foliar wipe and foliar dip) and roots (by root drench) of 1-2-week-old wheat seedlings grown in Lancelin sand, were treated with 0, 0.1 or 1 mM SA, and treatments of 0, 0.1 or 0.5 mM SA were applied in a pre-germination soak method. Ggt infection reduced (P Ͱ4 0.05) chlorophyll content and concentration and root length (P Ͱ4 0.10). Experiments that were conducted suggested that the SA treatments failed to induce a resistance response because they did not stimulate phenylalanine ammonia-lyase and peroxidase activities in the wheat seedling roots. Therefore, SA applied using these methods was not effective in reducing the susceptibility of wheat seedlings to Ggt. The chemical or biological induction of resistance in plant roots and its applicability as a root disease control strategy requires further clarification.

VARIABILITY IN ASSOCIATION EFFECTS OF OTHER SOIL FUNGI ON THE VIRULENCE OF HELMINTHOSPORIUM SATIVUM ON WHEAT SEEDLINGS

1940 ◽  
Vol 18c (11) ◽  
pp. 562-565 ◽  
Author(s):  
G. B. Sanford ◽  
M. W. Cormack
Keyword(s):  
Pure Culture ◽  
Plant Pathogens ◽  
Soil Fungi ◽  
Culture Conditions ◽  
Wheat Seedlings ◽  
Helminthosporium Sativum ◽  
Preliminary Study

Random isolates of Penicillium, Actinomyces, and certain miscellaneous soil-inhabiting fungi were tested in steam sterilized soil, under pure culture conditions, for their association effects on the virulence of Helminthosporium sativum P. K. and B. on wheat seedlings. Certain isolates of the first two genera mentioned exerted a marked degree of suppression, some had no effect, while others increased the virulence. Similarly, these effects varied widely within certain species of Penicillium. This preliminary study indicates that the random isolates of many genera and species of fungi may differ widely in ability to affect the virulence of certain plant pathogens.

Reduced growth and yield of wheat with conservation cropping. II. Soil biological factors limit growth under direct drilling

1995 ◽  
Vol 46 (1) ◽  
pp. 75 ◽  
Author(s):  
JA Kirkegaard ◽  
R Munns ◽  
RA James ◽  
PA Gardner ◽  
JF Angus
Keyword(s):  
Shoot Growth ◽  
Dominant Role ◽  
Growth And Yield ◽  
Cultivated Plants ◽  
Biological Factors ◽  
Wheat Seedlings ◽  
Sowing Depth ◽  
Cultivated Soil ◽  
Controlled Environments

Wheat was grown in intact cores of soil removed from a field experiment in which seedlings had grown more slowly in direct-drilled soil than in cultivated soil. Experiments were conducted in controlled environments to resolve (1) whether shallower sowing of direct-drilled crops caused slower growth, (2) whether the soil factors causing the slower growth were physical or biological and (3) if biological, whether Rhizoctonia solani was the major pathogen. The conditions of the experiments removed possible constraints of water and nutrient supply but otherwise simulated the environment of wheat seedlings in southern Australia. Shallower sowing led to faster emergence and increased seedling growth, but irrespective of sowing depth, direct-drilled plants grew more slowly than plants in cultivated soil. Shoot growth of direct-drilled plants was 25-65% less than that of cultivated plants. These growth reductions were largely overcome by sterilizing the soil with y radiation or by fumigation with methyl bromide, indicating that biological factors were primarily responsible. Rhizoctonia was implicated as the cause of the reduced shoot growth when infection was severe (>3 on a 0-5 scale). There was no correlation between infection severity and shoot growth at moderate levels (<3) and significant reductions in shoot growth occurred in the absence of Rhizoctonia. These reductions were evident on the first leaf suggesting a direct influence on shoot growth rather than one mediated through inadequate uptake of water or nutrients. Infection of the germinating seed by Pythium spp. or the effects of phytohormones produced by inhibitory bacteria on the roots are possible causes of reduced shoot growth of direct-drilled seedlings. The dominant role of biological factors in determining plant response to soil management indicates the need for further studies to identify the organisms responsible, to determine the mechanism by which they influence shoot growth, and the effect of management on their populations and activity.

Sign in / Sign up

Export Citation Format

Share Document