Origin of agricultural plant pathogens: Diversity and pathogenicity of Rhizoctonia fungi associated with native prairie grasses in the Sandhills of Nebraska

2020 ◽  
Author(s):  
Srikanth Kodati
Keyword(s):  
Plant Pathogens ◽  
Agricultural Plant ◽  
Native Prairie ◽  
Prairie Grasses

scholarly journals Origin of agricultural plant pathogens: Diversity and pathogenicity of Rhizoctonia fungi associated with native prairie grasses in the Sandhills of Nebraska

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249335
Author(s):  
Srikanth Kodati ◽  
Anthony O. Adesemoye ◽  
Gary Y. Yuen ◽  
Jerry D. Volesky ◽  
Sydney E. Everhart
Keyword(s):  
Disease Severity ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Native Grasses ◽  
Agricultural Plant ◽  
Native Prairie ◽  
Little Bluestem ◽  
Complex Ecosystem ◽  
Greenhouse Assay ◽  
Sand Bluestem

The Sandhills of Nebraska is a complex ecosystem, covering 50,000 km2 in central and western Nebraska and predominantly of virgin grassland. Grasslands are the most widespread vegetation in the U.S. and once dominated regions are currently cultivated croplands, so it stands to reason that some of the current plant pathogens of cultivated crops originated from grasslands, particularly soilborne plant pathogens. The anamorphic genus Rhizoctonia includes genetically diverse organisms that are known to be necrotrophic fungal pathogens, saprophytes, mycorrhiza of orchids, and biocontrol agents. This study aimed to evaluate the diversity of Rhizoctonia spp. on four native grasses in the Sandhills of Nebraska and determine pathogenicity to native grasses and soybean. In 2016 and 2017, a total of 84 samples were collected from 11 sites in the Sandhills, located in eight counties of Nebraska. The samples included soil and symptomatic roots from the four dominant native grasses: sand bluestem, little bluestem, prairie sandreed, and needle-and-thread. Obtained were 17 Rhizoctonia-like isolates identified, including five isolates of binucleate Rhizoctonia AG-F; two isolates each from binucleate Rhizoctonia AG-B, AG-C, and AG-K, Rhizoctonia solani AGs: AG-3, and AG-4; one isolate of binucleate Rhizoctonia AG-L, and one isolate of R. zeae. Disease severity was assessed for representative isolates of each AG in a greenhouse assay using sand bluestem, needle-and-thread, and soybean; prairie sandreed and little bluestem were unable to germinate under artificial conditions. On native grasses, all but two isolates were either mildly aggressive (causing 5–21% disease severity) or aggressive (21–35% disease severity). Among those, three isolates were cross-pathogenic on soybean, with R. solani AG-4 shown to be highly aggressive (86% disease severity). Thus, it is presumed that Rhizoctonia spp. are native to the sandhills grasslands and an emerging pathogen of crops cultivated may have survived in the soil and originate from grasslands.

Wheat Crops and Native Prairie in Relation to the Nutritional Ecology of Camnula pellucida (Scudder) (Orthoptera: Acrididae) in Saskatchewan

1963 ◽  
Vol 95 (7) ◽  
pp. 764-770 ◽  
Author(s):  
R. Pickford
Keyword(s):  
Dominant Role ◽  
Nutritional Ecology ◽  
Bouteloua Gracilis ◽  
Field Cage ◽  
Agropyron Smithii ◽  
Native Prairie ◽  
Prairie Grasses ◽  
Complete Life Cycle ◽  
Stipa Comata ◽  
Mixed Prairie

AbstractField cage experiments conducted through the complete life cycle of Camnula pellucida (Scudder) demonstrated that wheat, the major cereal crop grown in Saskatchewan, played the dominant role in the nutritional ecology of this grasshopper. A native sod mixture, comprising Stipa comata, Bouteloua gracilis, Agropyron smithii, and Carex eleocharis, four of the dominant species of the mixed prairie association, was consistently unfavourable during all stages of grasshopper growth and development. Grasshoppers reared on wheat survived better, were considerably larger and laid up to 20 times more eggs than those reared on the native prairie grasses. The presence of the native sod with wheat contributed nothing nutritionally to the food combination. The unfavourable qualities of the native grasses, although resulting in small adults, low fecundity and small pods, did not affect the hatchability of eggs laid or the development and survival of nymphs that hatched from them.

Using molecular techniques applied to beneficial microorganisms as biotechnological tools for controlling agricultural plant pathogens and pest

2020 ◽  
pp. 333-349
Author(s):  
Liliana Aguilar-Marcelino ◽  
Pedro Mendoza-de-Gives ◽  
Laith Khalil Tawfeeq Al-Ani ◽  
María Eugenia López-Arellano ◽  
Olga Gómez-Rodríguez ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Molecular Techniques ◽  
Agricultural Plant ◽  
Beneficial Microorganisms

Competition of five native prairie grasses with Bromus inermis under three moisture regimes

1997 ◽  
Vol 75 (12) ◽  
pp. 2140-2145 ◽  
Author(s):  
Dean Nernberg ◽  
Mark R. T. Dale
Keyword(s):  
Competitive Ability ◽  
Environmental Gradients ◽  
Bromus Inermis ◽  
Reciprocal Relationship ◽  
Shoot Biomass ◽  
Native Grasses ◽  
Native Prairie ◽  
Prairie Grasses ◽  
Moisture Regimes ◽  
Reduced Water

We examined the effect of moisture on the competitive ability of five native grasses (Agropyron and Stipa) in competition with the non-native grass Bromus inermis Leyss. The plants were grown in large pots in growth rooms, and the moisture treatment was imposed by the frequency of watering. The competitive ability of the five native grasses, as measured by shoot biomass ratio, increased with reduced water availability, but even under the driest conditions, they competed poorly with B. inermis. The order of competitive ability found in this experiment did not match the order predicted from field observations based on the hypothesis of a strict reciprocal relationship between stress tolerance and competitive ability. Stipa viridula Trin. was the best competitor of the five, and Stipa curtiseta (A.S. Hitchc.) Barkworth was consistently the least competitive. The order of competitive ability was more variable when measured by the effect on Bromus than when measured by the effect on the native grasses themselves. The results suggest that tolerance of abiotic stress is less important than competitive exclusion in determining species distributions on environmental gradients Key words: competitive hierarchy, competitive reversal, transitivity.

scholarly journals Traditional and current-prospective methods of agricultural plant diseases detection: A review

2022 ◽  
Vol 951 (1) ◽  
pp. 012002
Author(s):  
A Khakimov ◽  
I Salakhutdinov ◽  
A Omolikov ◽  
S Utaganov
Keyword(s):  
Disease Control ◽  
Early Identification ◽  
Plant Pathogens ◽  
Molecular Genetic ◽  
Visual Observation ◽  
Plant Diseases ◽  
Traditional Methods ◽  
Agricultural Plant ◽  
Protection Method ◽  
Phylogenetic Identification

Abstract As it is known, a significant part of the yield of agricultural crops is lost due to harmful organisms, including diseases. The article reveals the data on the widespread types of plant diseases (rot, wilting, deformation, the formation of tumors, pustules, etc.) and their symptoms. Early identification of the pathogen type of plant infection is of high significance for disease control. Various methods are used to diagnose pathogens of disease on plant. This article discusses the review of the literature data on traditional methods for diagnosis of plant pathogens, such as visual observation, microscopy, mycological analysis, and biological diagnostics or the use of indicator plants. Rapid and reliable detection of plant disease and identification of its pathogen is the first and most important stage in disease control. Early identification of the cause of the disease allows timely selection of the proper protection method and ensures prevention of crop losses. There are a number of traditional methods for identifying plant diseases, however, in order to ensure the promptness and reliability of diagnostics, as well as to eliminate the shortcomings inherent in traditional diagnostics, in recent years, new means and technologies for identifying pathogens have been developed and introduced into practice. As well as the article provides information on such innovative methods of diagnosis of diseases and identification of their pathogens, which are used widely in the world today, such as immunodiagnostics, molecular-genetic (and phylogenetic) identification, mass spectrometry, etc.

Native prairie grasses and microbial community responses to reclamation of taconite iron ore tailing

1995 ◽  
Vol 73 (10) ◽  
pp. 1645-1654 ◽  
Author(s):  
Robert K. Noyd ◽  
F. L. Pfleger ◽  
Michael R. Norland ◽  
Michael J. Sadowsky
Keyword(s):  
Microbial Biomass ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Soil Microbial Biomass ◽  
Plant Cover ◽  
Arbuscular Mycorrhizal ◽  
Yard Waste ◽  
Soil Microbial ◽  
Native Prairie ◽  
Prairie Grasses

The effect of reclamation treatments on seeded native grass cover and species composition, soil microbial biomass carbon, and populations of actinomycetes, fungi, free-living N2-fixing bacteria, and aerobic heterotrophic bacteria was compared in field plots in coarse taconite tailing. Reclamation treatments consisted of all possible combinations of three rates of composed yard waste, three rates of fertilizer, and inoculation with arbuscular mycorrhizal fungi. Composted yard waste increased plant cover, soil microbial biomass, and populations of all groups of microorganisms compared with unamended, non-inoculated control plots. Microbial populations and biomass in tailing plots were low compared with natural soils and were correlated with plant cover and available P. Mycorrhizal inoculation resulted in a 6% increase in plant cover, although this was not significant, and significantly enhanced N2-fixer populations in June but did not affect other groups of microorganisms. There were no differences between moderate and high rates of composted yard waste. We conclude that incorporation of a moderate rate of organic matter can ameliorate the stressful conditions of coarse taconite tailing and can enhance the initiation of a functional soil ecosystem able to support the establishment of seeded native prairie grasses and may provide a long-term solution to reclamation of taconite tailing. Key words: arbuscular mycorrhizal fungi, mine reclamation, soil microorganisms, composted yard waste.

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