THE INFLUENCE OF ASSOCIATED MICROORGANISMS ON THE PATHOGENICITY OF HELMINTHOSPORIUM SATIVUM

1956 ◽  
Vol 34 (6) ◽  
pp. 865-874 ◽  
Author(s):  
W. P. Campbell
Keyword(s):  
Soil Temperature ◽  
Soil Fungi ◽  
Trichoderma Viride ◽  
Soil Extract ◽  
The Other ◽  
Internal Parasites ◽  
Helminthosporium Sativum ◽  
Extract Medium ◽  
Germination And Growth ◽  
Germ Tubes

Six species of soil fungi were studied in association with Helminthosporium sativum. Phoma humicola, Epicoccum purpurascens, and Trichoderma viride strongly inhibited the pathogenic activities of H. sativum, while Actinomucor repens, Sclerotinia trifoliorum, and Myrothecium verrucaria were only slightly inhibitory. The pathogenicity of H. sativum was increasingly depressed by each of the six fungi as soil temperature was increased from 15° to 26 °C. The pH shifts which these fungi induced in soil were not sufficient to be considered as a factor in depressing pathogenicity. In plate tests on nonenriched soil-extract medium, S. trifoliorum and A. repens did not appreciably affect H. sativum. The other four fungi all caused distortion and breakdown of the spores, while M. verrucaria and E. purpurascens were found as internal parasites in spores of H. sativum. P. humicola, E. purpurascens, and T. viride caused the breakdown of mycelium of the pathogen, and P. humicola and E. purpurascens were found as internal parasites of the mycelium. The fungi produced substances in the medium which adversely affect the germination and growth of germ tubes of spores of H. sativum. A. repens and S. trifoliorum were least effective, T. viride and P. humicola were intermediate in their action, and E. purpurascens and M. verrucaria were very severely limiting. Two antagonistic mechanisms, antibiosis and direct parasitism, were demonstrated, both of which were responsible for disorganization of the mycelium of the pathogen. Only those fungi that caused disruption of the mycelium were able to depress the pathogenicity of H. sativum appreciably.

scholarly journals Early development of corn seedlings primed with synthetic tenorite nanofertilizer

2020 ◽  
Vol 42 ◽  
Author(s):  
Michel Esper Neto ◽  
David W. Britt ◽  
Kyle Alan Jackson ◽  
Alessandro Lucca Braccini ◽  
Tadeu Takeyoshi Inoue ◽  
...  
Keyword(s):  
Seed Germination ◽  
Size Effects ◽  
Seed Priming ◽  
Seedling Development ◽  
Cuo Nanoparticles ◽  
The Other ◽  
Corn Seed ◽  
Cu Toxicity ◽  
Germination And Growth

Abstract: Fertilizer formulation alternatives that avoid unnecessary losses and environmental impacts are being investigated in agricultural management. Seed priming with nanofertilizers prior to planting, reduces concerns about non-target dispersion; however, priming formulations and concentrations must be carefully selected to avoid undesired effects. Here, seed germination and seedling development were evaluated after seed priming with CuO nanoparticles (NPs), CuO bulk and CuCl2. The seeds were immersed in priming solutions of 0, 20, 40, 80 and 160 mg.L−1 Cu for the three Cu sources. Following 8 hours priming, the seeds were evaluated for germination and vigor (first germination count). Root and shoot lengths were measured as well as shoot and root dry biomass. The copper NP did not show any toxic effects on corn seed germination and growth, and also promoted higher biomass when compared to the other Cu sources. On the other hand, CuCl2 primed seeds exhibited Cu-toxicity in roots and shoots for all concentrations tested. Bulk Cu priming results indicated the better role of NPs size effects. These findings support NP-seed priming as an alternative to delivery of essential micronutrients, such as copper, to corn seedlings.

scholarly journals Plant Growth Promotion Assessment in Rice Plant Enhanced by Inoculation of Rhizobacteria

2015 ◽  
Vol 4 ◽  
pp. 73-84
Author(s):  
Umesh Prasad Shrivastava
Keyword(s):  
Chlorophyll A ◽  
Growth Promotion ◽  
Soil Extract ◽  
Fresh Weight ◽  
Rice Varieties ◽  
Total Length ◽  
Gusa Reporter Gene ◽  
Extract Medium ◽  
Chlorophyll A Content ◽  
Weight Number

In the search of efficient biofertilizer, nine efficient strains of PGPR were evaluated by inoculation in two different rice varieties, Saryu-52 and Malviya Dhan-36 in the gnotobiotic conditions using two different media FCN-medium and soil extract medium. Agrobacterium sp. strain BN-2A showed better result in respect to other eight isolates in the total length, fresh weight, number of roots and chlorophyll-a content. By the inoculation Agrobacterium sp. strain BN-2A, total length increased in Saryu-52 (22.6%) and in Malviya Dhan-36 (52.1%), fresh weight increased in Saryu-52 (42.4%) and in Malviya Dhan-36 (68.8%) and chlorophyll-a increased in Saryu-52 (76.6%) and in Malviya Dhan-36 (37.1%). Similarly in soil extract medium, inoculation of Agrobacterium sp. strain BN-2A alone showed better result in comparison to mixture of nine strains. To prove that colonization indeed occurs, gusA reporter gene was tagged with the most efficient isolate Agrobacterium sp. strain BN-2A and colonization in the rice root was confirmed by gusA staining and histochemical analysis of gusA staining. Therefore, BN-2A has best potential to be used as biofertilizer.DOI: http://dx.doi.org/10.3126/av.v4i0.12362Academic Voices Vol.4 2014: 73-84

OVERWINTERING OF CERTAIN CEREAL PATHOGENS IN ALBERTA

1937 ◽  
Vol 15c (12) ◽  
pp. 547-559 ◽  
Author(s):  
W. R. Foster ◽  
A. W. Henry
Keyword(s):  
Winter Wheat ◽  
Fusarium Culmorum ◽  
Soil Surface ◽  
Freezing And Thawing ◽  
Tilletia Caries ◽  
Helminthosporium Sativum ◽  
Favorable Conditions ◽  
Germ Tubes ◽  
Continuous Freezing ◽  
Hardened Condition

Helminthosporium sativum, Fusarium culmorum, Ophiobolus graminis, Leptosphaeria herpotrichoides, Wojnowicia graminis, Erysiphe graminis, Tilletia caries, and Tilletia foetens readily overwinter under natural conditions at Edmonton, Alberta, Canada. The first five of these overwinter at Edmonton in both spore and vegetative stages and are highly resistant to cold. Even in a non-hardened condition several of them survived severe frost. Young germ tubes of H. sativum for instance continued growth after being frozen solid overnight. Fresh agar cultures of H. sativum, F. culmorum and O. graminis grew vigorously after exposure to sub-zero temperatures. Agar cultures of H. sativum and F. culmorum were viable after a 17-day exposure to temperatures ranging from about 0° F. to —50° F.Conidia of H. sativum proved less resistant to freezing and thawing than to continuous freezing. They survived longer than conidia of F. culmorum and F. graminearum. Mycelia of all foot-rot fungi grown on sterilized barley seeds were viable in one case after three months of continuous freezing, and in another after 40 alternate freezings and thawings. H. sativum and F. culmorum growing in soil survived 61 alternate freezings and thawings.H. sativum, F. culmorum and L. herpotrichoides, retained their viability more readily on the soil surface than when buried at depths of from 2 to 12 in. Well aerated soil seemed to favor the survival of H. sativum, although other factors besides aeration probably are involved. Strains of H. sativum from high latitudes were not better adapted to low temperatures than strains from lower latitudes.The bunt fungi, T. caries and T. foetens, are shown to be capable of overwintering at Edmonton in the form of mycelia in winter wheat. Infection of winter wheat from soil-borne spores may occur in western Canada, but in these experiments soil-borne spores did not survive to infect wheat in the spring.Erysiphe graminis overwinters in the perithecial stage at Edmonton. In the studies made, ascospores were differentiated in the spring, when favorable conditions prevailed and before the first infections of winter wheat were observed.

scholarly journals In Vitro Antagonism of Trichoderma Verede and Aspergillus Spp. against a Pathogenic Seed Borne Fungus of Sesame

2019 ◽  
Vol 43 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Md Delwar Hosen ◽  
Shamim Shamsi
Keyword(s):  
Aspergillus Flavus ◽  
Soil Fungi ◽  
Trichoderma Viride ◽  
Dual Culture ◽  
Volatile Metabolites ◽  
Inhibiting Effect ◽  
Antagonistic Potential ◽  
Academy Of Sciences ◽  
Growth Inhibiting

Four soil fungi were isolated from the soil by serial dilution and were identified as Aspergillus flavus Link, A. fumigatus Fresenius, A. niger van Tieghem and Trichoderma viride Pers. The soil fungi were selected to evaluate their antagonistic potential against seed borne fungus Fusarium merismoides isolated from sesame. In dual culture colony interaction Trichoderma viride showed the highest (45.88%) growth inhibiting effect on F. merismoides followed by A. niger (40.00%), A. flavus (36.37) and A. fumigatus (30.77%). Volatile metabolites from T. viride showed the highest growth inhibiting effect on F. merismoides (67.69%) and non-volatile metabolites from T. viride showed the highest growth inhibiting effect on F. merismoides (75.00%). Journal of Bangladesh Academy of Sciences, Vol. 43, No. 1, 17-23, 2019

THE INFLUENCE OF THE EXTRACT OF SOME CROPS AND SOIL RESIDUES ON GERMINATION AND GROWTH

1960 ◽  
Vol 40 (1) ◽  
pp. 188-197 ◽  
Author(s):  
K. F. Nielsen ◽  
W. B. Woods ◽  
T. F. Cuddy
Keyword(s):  
Seed Germination ◽  
Root Length ◽  
Deionized Water ◽  
The Other ◽  
Percentage Germination ◽  
Soil Extracts ◽  
Field Crops ◽  
Time Required ◽  
Germination And Growth ◽  
Germinated Seeds

Six plant species were germinated in sand wetted with water extracts of tissues of five field crops and three soils. Deionized water was used as a check f he study was conducted using standard seed germination techniques.Alter 7 to 10 days all of the germinated seeds were harvested and measurements made of the shoot and root lengths.Alfalfa extract caused the greatest reduction in shoot and root length as well as m percentage germination. It caused the greatest increase in the time required for germination. Timothy extract was not quite as harmful as the alfalfa. Extracts of oats, corn and potatoes were still less harmful with potato extract causing the least effect.The soil extracts generally had very little effect when compared with deionized water.Plant species showed marked differences in tolerance to the extracts alfalfa being the most resistant and timothy the least.Where water alone was used rate of germination and per cent germination were as high or higher than with the other extracts, but the root and shoot lengths were not always the greatest.

COMPARISON OF LIGHTLY GRAZED AND UNGRAZED RANGE IN THE FESCUE GRASSLAND OF SOUTHWESTERN ALBERTA

1961 ◽  
Vol 41 (3) ◽  
pp. 615-622 ◽  
Author(s):  
Alexander Johnston
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Field Study ◽  
Water Intake ◽  
Soil Profile ◽  
Basal Area ◽  
The Other ◽  
Intake Rate ◽  
Vegetative Cover ◽  
Harmful Effects

The influence of grazing on the vegetative cover of fescue grassland in southwestern Alberta was assessed by studying two adjoining sites, one lightly grazed, the other ungrazed. Percentage basal area, yield, water-intake rate, soil temperature, soil moisture, and amount of root material were compared on a paired plot basis.The data showed that light grazing resulted in the development of a richer flora dominated by Danthonia parryi. Protection from grazing appeared to simplify the flora with a trend toward a cover consisting largely of Festuca scabrella. There was little evidence of difference in productivity between the two sites. Cooler and moister conditions prevailed in the upper 12 inches of the soil profile of the ungrazed site as a result of heavy accumulation of mulch. Considerably more root material to a depth of 54 inches was present on the lightly grazed site. The harmful effects of herbage removal, shown by clipping studies, were not apparent in the field study under a light rate of grazing.

CYTOLOGICAL STUDIES OF HELMINTHOSPORIUM SATIVUM

1956 ◽  
Vol 34 (3) ◽  
pp. 321-327 ◽  
Author(s):  
S. B. Hrushovetz
Keyword(s):  
Helminthosporium Sativum ◽  
Germ Tubes

Cytological studies of Helminthosporium sativum P.K. & B. showed that a mechanism exists for the perpetuation of heterokaryons. Septa are laid down in such a way that usually the hyphal tips and mycelial cells are initially multinucleate. Hyphal fusions occur in all parts of the colony and nuclei have been observed in the bridging hyphae. Two or more nuclei generally enter the young conidiophore and several nuclei invariably enter the young conidium before the latter is delimited from the conidiophore. The multicellular, multinucleate conidia exhibit polar or bipolar germination but only the nuclei in the terminal cells of the conidium enter the germ tubes; the remaining cells and their nuclei subsequently degenerate. Germination of complete conidiophores or portions of conidiophores was also observed.

THE EFFECT OF RESIDUAL FERTILIZER COPPER ON AMMONIFICATION, NITRIFICATION AND PROTEOLYTIC POPULATION IN SOME ORGANIC SOILS

1981 ◽  
Vol 61 (2) ◽  
pp. 445-450 ◽  
Author(s):  
S. P. MATHUR ◽  
C. M. PRESTON
Keyword(s):  
Soil Enzymes ◽  
Microbial Population ◽  
Soil Extract ◽  
The Other ◽  
Toxic Effects ◽  
Organic Soils ◽  
Soil Microbial ◽  
Other Hand ◽  
Soil Microbial Population ◽  
Extracellular Proteolysis

As a part of attempts at examining the suitability of using moderate amounts of Cu for mitigating the undesirably fast decomposition and subsidence of some organic soils, this investigation revealed that both total and DTPA-TEA-extractable Cu contents of 14 samples of cultivated organic soils correlated negatively with the total microbial population counted on soil extract-acitidione-gelatin agar plates and positively with the percentage of that population capable of extracellular proteolysis. On the other hand, the concentrations of both total and extractable Cu did not correlate with either the total number of proteolytic organisms counted, or the capacities of the soils for ammonification and nitrification. The results are, therefore, in accord with the belief that Cu curtails the decomposition of organic soils primarily through inactivation of accumulated soil enzymes, but not through direct toxic effects on the general soil microbial population.

A SLIDE TECHNIQUE FOR THE STUDY OF FUNGI AND ACTINOMYCETES IN SOIL WITH SPECIAL REFERENCE TO HELMINTHOSPORIUM SATIVUM

1953 ◽  
Vol 31 (6) ◽  
pp. 718-724 ◽  
Author(s):  
S. H. F. Chinn
Keyword(s):  
Special Reference ◽  
Soybean Meal ◽  
Fusarium Culmorum ◽  
Natural Soil ◽  
Penicillium Notatum ◽  
Amended Soils ◽  
Helminthosporium Sativum ◽  
Stachybotrys Atra ◽  
Slide Technique ◽  
Germ Tubes

A slide technique suitable for studying the behavior of fungi and actinomycetes both qualitatively and quantitatively in soil is described. Besides Helminthosporium sativum, eight other fungi and one actinomycete were used to demonstrate the applicability of the method which was used for both natural and soybean meal amended soils. In the natural soil spores of Penicillium notatum, Stachybotrys atra, and the actinomycete only germinated. However, lysis or disintegration of the germ tubes of the two fungi was observed on the fourth day. Growth of the actinomycete was continuous to at least the seventh day. In the amended soil only one fungus failed to germinate. Of those that germinated, only Fusarium culmorum and the actinomycete were capable of continued growth and sporulation. Lysis or disintegration of the germ tubes of the others was noticed on the fourth day.

Sign in / Sign up

Export Citation Format

Share Document