scholarly journals Wheat Root-dip Inoculation with Fusarium graminearum and Assessment of Root Rot Disease Severity

BIO-PROTOCOL ◽  
2017 ◽  
Vol 7 (6) ◽  
Author(s):  
Qing Wang ◽  
Sven Gottwald
Keyword(s):  
Disease Severity ◽  
Fusarium Graminearum ◽  
Root Rot ◽  
Wheat Root ◽  
Root Rot Disease ◽  
Rot Disease

scholarly journals A nondestructive method to assess rot root severity of Lactuca sativa L

2013 ◽  
Vol 66 ◽  
pp. 375-375
Author(s):  
P. Suvarnaphaet ◽  
V. Tanmala ◽  
M. Kanjanamaneesathian
Keyword(s):  
Image Analysis ◽  
Disease Severity ◽  
Digital Image ◽  
Lactuca Sativa ◽  
Root Rot ◽  
Digital Image Analysis ◽  
Disease Assessment ◽  
Root Rot Disease ◽  
Diseased Root ◽  
Rot Disease

Root rot disease caused by aquatic fungi such as Aphanomyces sp and Pythium sp is prevalent in Lactuca sativa grown in a dynamic root floating technique (DRFT) hydroponic system in Phetchaburi College of Agriculture and Technology Thailand Roots of this plant have been severely infected with these fungi and plant growth has been affected resulting in a decline of yield over time Symptoms of root rot are initially characterised by tissue discoloration in some parts of the root followed by a loss of tissue integrity of the whole root In the DRFT system root rot symptoms of L sativa range from severe (complete) root rot to a healthylooking root (no symptoms)This study investigated the potential for using digital images as an objective tool for assessing disease severity with the aim of the tool being applied by assessors with no previous experience in disease assessment Lactuca sativa that had been grown in DRFT for 30 days and had various degrees of root rot symptoms were selected for the study Visual evaluation of the diseased root indicated that there were six levels of disease severity with root colour ranging from white (healthy looking) to completely black (severe root rot)When the diseased root samples were subjected to digital image analysis between the black and white extremes there was one shade of grey and three shades of brown The images of these six levels of severity were analysed using Hunter L a and b values It was found that the six levels of root rot severity could be distinguished based upon the L parameters The value of Lightness (Hunter L) which is transformed from RGB digital image (using a color calculator in http//wwweasyrgbcom) decreased exponentially (from severity level 1 to 6) with a constant value at 048 This indicates that digital image analysis using this simple tool can be utilised to objectively assess root rot disease in L sativa Once this technology is thoroughly studied developed and validated for lettuce growing in the DRFT system there is potential for it to be a useful tool to assist lettuce growers in making a decision to implement control measures

scholarly journals Associated SNPs, Heritabilities, Trait Correlations, and Genomic Breeding Values for Resistance in Snap Beans (Phaseolus vulgaris L.) to Root Rot Caused by Fusarium solani (Mart.) f. sp. phaseoli (Burkholder)

2021 ◽  
Vol 12 ◽  
Author(s):  
Abigail R. Huster ◽  
Lyle T. Wallace ◽  
James R. Myers
Keyword(s):  
Phaseolus Vulgaris ◽  
Disease Severity ◽  
Root Rot ◽  
Root Architecture ◽  
Snap Bean ◽  
Breeding Values ◽  
Disease Reaction ◽  
Root Rot Disease ◽  
Root Angle ◽  
Rot Disease

Root rot is a major constraint to snap bean (Phaseolus vulgaris) production in the United States and around the world. Genetic resistance is needed to effectively control root rot disease because cultural control methods are ineffective, and the pathogen will be present at the end of one season of production on previously clean land. A diversity panel of 149 snap bean pure lines was evaluated for resistance to Fusarium root rot in Oregon. Morphological traits potentially associated with root rot resistance, such as aboveground biomass, adventitious roots, taproot diameter, basal root diameter, deepest root angle, shallowest root angle, root angle average, root angle difference, and root angle geometric mean were evaluated and correlated to disease severity. A genome wide association study (GWAS) using the Fixed and random model Circulating Probability Unification (FarmCPU) statistical method, identified five associated single nucleotide polymorphisms (SNPs) for disease severity and two SNPs for biomass. The SNPs were found on Pv03, Pv07, Pv08, Pv10, and Pv11. One candidate gene for disease reaction near a SNP on Pv03 codes for a peroxidase, and two candidates associated with biomass SNPs were a 2-alkenal reductase gene cluster on Pv10 and a Pentatricopeptide repeat domain on Pv11. Bean lines utilized in the study were ranked by genomic estimated breeding values (GEBV) for disease severity, biomass, and the root architecture traits, and the observed and predicted values had high to moderate correlations. Cross validation of genomic predictions showed slightly lower correlational accuracy. Bean lines with the highest GEBV were among the most resistant, but did not necessarily rank at the very top numerically. This study provides information on the relationship of root architecture traits to root rot disease reaction. Snap bean lines with genetic merit for genomic selection were identified and may be utilized in future breeding efforts.

scholarly journals The influence of rhizosphere soil fungal diversity and complex community structure on wheat root rot disease

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12601
Author(s):  
Xuejiang Zhang ◽  
Heyun Wang ◽  
Yawei Que ◽  
Dazhao Yu ◽  
Hua Wang
Keyword(s):  
Root Rot ◽  
Fungal Diversity ◽  
Rhizosphere Soil ◽  
Pathogenic Fungi ◽  
Wheat Root ◽  
Ammonium Nitrogen ◽  
Wheat Roots ◽  
Root Rot Disease ◽  
Filling Stage ◽  
Rot Disease

Wheat root rot disease due to soil-borne fungal pathogens leads to tremendous yield losses worth billions of dollars worldwide every year. It is very important to study the relationship between rhizosphere soil fungal diversity and wheat roots to understand the occurrence and development of wheat root rot disease. A significant difference in fungal diversity was observed in the rhizosphere soil of healthy and diseased wheat roots in the heading stage, but the trend was the opposite in the filling stage. The abundance of most genera with high richness decreased significantly from the heading to the filling stage in the diseased groups; the richness of approximately one-third of all genera remained unchanged, and only a few low-richness genera, such as Fusarium and Ceratobasidium, had a very significant increase from the heading to the filling stage. In the healthy groups, the abundance of most genera increased significantly from the heading to filling stage; the abundance of some genera did not change markedly, or the abundance of very few genera increased significantly. Physical and chemical soil indicators showed that low soil pH and density, increases in ammonium nitrogen, nitrate nitrogen and total nitrogen contributed to the occurrence of wheat root rot disease. Our results revealed that in the early stages of disease, highly diverse rhizosphere soil fungi and a complex community structure can easily cause wheat root rot disease. The existence of pathogenic fungi is a necessary condition for wheat root rot disease, but the richness of pathogenic fungi is not necessarily important. The increases in ammonium nitrogen, nitrate nitrogen and total nitrogen contributed to the occurrence of wheat root rot disease. Low soil pH and soil density are beneficial to the occurrence of wheat root rot disease.

scholarly journals Response of Cover Crops to Phytopythium vexans, Phytophthora nicotianae, and Rhizoctonia solani, Major Soilborne Pathogens of Woody Ornamentals

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 742
Author(s):  
Milan Panth ◽  
Anthony Witcher ◽  
Fulya Baysal-Gurel
Keyword(s):  
Rhizoctonia Solani ◽  
Disease Severity ◽  
Cover Crops ◽  
Production System ◽  
Root Rot ◽  
Phytophthora Nicotianae ◽  
Soilborne Pathogens ◽  
Damping Off ◽  
Root Rot Disease ◽  
Rot Disease

Management of plant diseases is a subject of concern for researchers as well as growers. Different management practices are being developed and used to combat the rising number of plant pathogens, which threaten nursery crop production. Use of cover crops for sustainable management of soilborne diseases is being explored as an alternative strategy to the chemicals. However, the potential threat of these cover crops acting as a secondary host of these devastating soilborne pathogens has not been described. We studied the response of the major cover crops being used by woody ornamental growers in the Southeastern United States to Phytopythium vexans, Phytophthora nicotianae, and Rhizoctonia solani in greenhouse conditions to identify the effective cover crops that can be used in a nursery field production system. Data related to post-emergence damping-off and plant growth parameters (plant height increase and fresh weight) were recorded. Similarly, cover crop roots were assessed for root rot disease severity using a scale of 0–100% roots affected. Among the tested cover crops, the grass cover crops triticale (×Triticosecale Wittm. ex A. Camus.), annual ryegrass (Lolium multiflorum L.), Japanese millet (Echinochloa esculenta (A. Braun) H. Scholz), and the legumes Austrian winter pea (Pisum sativum var. arvense (L.) Poir) and cowpea ‘Iron and Clay’ (Vigna unguiculata (L.) Walp.), showed lower root rot disease severity and post-emergence damping-off in the soil inoculated with P. nicotianae, R. solani, or P. vexans compared to the other crops. Since these cover crops can act as non-host crops and benefit the main crop in one way or another, they can be used in the production system. Further research is recommended to evaluate their performance in a natural field setting.

scholarly journals Insights Into Triticum aestivum Seedling Root Rot Caused by Fusarium graminearum

2015 ◽  
Vol 28 (12) ◽  
pp. 1288-1303 ◽  
Author(s):  
Qing Wang ◽  
Stefanie Vera Buxa ◽  
Alexandra Furch ◽  
Wolfgang Friedt ◽  
Sven Gottwald
Keyword(s):  
Triticum Aestivum ◽  
Life Cycle ◽  
Fusarium Graminearum ◽  
Root Rot ◽  
Fungal Pathogens ◽  
Resistance Breeding ◽  
Root Infection ◽  
Head Blight ◽  
Root Rot Disease ◽  
Rot Disease

Fusarium graminearum is one of the most common and potent fungal pathogens of wheat (Triticum aestivum), known for causing devastating spike infections and grain yield damage. F. graminearum is a typical soil-borne pathogen that builds up during consecutive cereal cropping. Speculation on systemic colonization of cereals by F. graminearum root infection have long existed but have not been proven. We have assessed the Fusarium root rot disease macroscopically in a diverse set of 12 wheat genotypes and microscopically in a comparative study of two genotypes with diverging responses. Here, we show a ‘new’ aspect of the F. graminearum life cycle, i.e., the head blight fungus uses a unique root-infection strategy with an initial stage typical for root pathogens and a later stage typical for spike infection. Root colonization negatively affects seedling development and leads to systemic plant invasion by tissue-adapted fungal strategies. Another major outcome is the identification of partial resistance to root rot. Disease severity assessments and histological examinations both demonstrated three distinct disease phases that, however, proceeded differently in resistant and susceptible genotypes. Soil-borne inoculum and root infection are considered significant components of the F. graminearum life cycle with important implications for the development of new strategies of resistance breeding and disease control.

scholarly journals FIELD EVALUATION OF ROOT ROT DISEASE AND RELATIONSHIP BETWEEN DISEASE SEVERITY AND YIELD IN CASSAVA

2005 ◽  
Vol 41 (3) ◽  
pp. 357-363 ◽  
Author(s):  
T. J. ONYEKA ◽  
A. G. O. DIXON ◽  
E. J. A. EKPO
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Yield Loss ◽  
Single Point ◽  
Negative Relationship ◽  
Disease Assessment ◽  
African Countries ◽  
Root Rot Disease ◽  
Progress Curve ◽  
Rot Disease

Reports of cassava root rot disease from different African countries have increased in recent times. Field studies were conducted from July 1998 to October 1999 to determine a reproducible disease assessment method that would allow the comparison of results from different locations and an evaluation of the relationship between disease severity and root yield. Single point disease assessments at 6, 9, 12 and 15 months after planting (MAP) were compared to multiple points assessment based on the area under a disease progress curve (AUDPC). Single point assessments at 12 and 15 MAP, and the AUDPC identified continuous variation (p≤0.01) among the genotypes. However, a consistent result across trials was obtained only with the assessment based on AUDPC. Root dry yield (DYLD) at 15 MAP showed a strong negative correlation with AUDPC (r=−0.74). Regression analysis also confirmed the negative relationship between yield and root rot severity. The five genotypes compared were separated into resistant (91/02324, 30572 and 92/0427) and susceptible (92/0057 and TME-1) groups. It was concluded that root rot disease may cause significant yield loss; however, the magnitude of the yield loss will depend on the susceptibility of the cassava genotype.

scholarly journals Biocontrol Agents for Controlling Wheat Root Rot Disease under Greenhouse Conditions

2020 ◽  
Author(s):  
M.M. Abdel-Kader ◽  
N.S. El-Mougy ◽  
M.S.A. Khalil ◽  
N.G. El-Gamal
Keyword(s):  
Root Rot ◽  
Pathogenic Fungi ◽  
Wheat Root ◽  
Infested Soil ◽  
Wheat Seedlings ◽  
Fungal Isolation ◽  
Root Rot Disease ◽  
Wheat Diseases ◽  
Rot Disease ◽  
Soil Borne Fungi

Background: The most important wheat diseases that caused by soil-borne fungi are the root-rot disease. The current investigation conducted with evaluation the efficacy of some bioagents, Bacillus subtilis, Pseudomonas fluorescens, Azospirillum brasilense, Trichoderma harzianum, commercial bioagent (Planta guard) and chitosan against the causal pathogenic organisms of wheat root rot disease under greenhouse conditions. Methods: Wheat seedlings infected with root rot disease were subjected to the causal fungal isolation trails. In greenhouse, wheat grains were sown individually in pots containing artificially infested soil with the pathogenic fungi R. solani or F. graminearum. Furthermore, the tested bioagents and the fungicide Topsin-M 70 were applied to the infested soil before sowing. Result: The isolated fungi were R. solani or F. graminearum had proved their pathogenic ability to induce root rot disease of wheat. In pot experiment, all applied treatments affect root rot incidence of grown wheat seedlings in artificially infested soils with disease incidents. In infested soils with root rot incidents, bacterial bioagents reduced root rot incidence by 84.5-93.6% and 28.4- 35.3% 66.6, respectively and by 43.7% for T. harzianum. Moderate effect was obtained by chitosan and planta guard treatments in soil infested with either pathogenic fungi.

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