scholarly journals Application of the Humid Thermal Index for Relating Bunted Kernel Incidence to Soilborne Tilletia indica Teliospores in an Arizona Durum Wheat Field

Plant Disease ◽  
2009 ◽  
Vol 93 (7) ◽  
pp. 713-719 ◽  
Author(s):  
T. W. Allen ◽  
D. C. Jones ◽  
T. N. Boratynski ◽  
R. E. Ykema ◽  
C. M. Rush
Keyword(s):  
Durum Wheat ◽  
Disease Incidence ◽  
Karnal Bunt ◽  
Weather Data ◽  
Sample Point ◽  
Tilletia Indica ◽  
Thermal Index ◽  
Wheat Field ◽  
Sample Points ◽  
Conducive Environment

A study was conducted to determine the relationship between soilborne Tilletia indica teliospore density and Karnal bunt incidence in an Arizona durum wheat field in 2005 and 2006. Soil samples were collected from 507 sample points according to a grid marked in a 7.7-ha field. Approximately 500 g of soil from the top 5 cm was collected from each sample point, and teliospores were recovered from 25-g aliquots by a modified size-selective sieving, sucrose centrifugation procedure. Twenty-five and 50 wheat heads were collected from a 1-m2 area around each sample point in May 2005 and June 2006, respectively. Wheat head samples from each sample point were bulked, threshed, and examined for the presence of bunted kernels. Additionally, data for soilborne teliospores and percent bunted kernels from 70 sample points in 2005 and 2006 that corresponded to sample points from a 2004 bunted kernel survey conducted by the USDA and Arizona Department of Agriculture were analyzed. Soilborne teliospore numbers ranged from 6 to 1,000 per 25-g soil sample in the 2-year study. No bunted kernels were recovered in 2005; however, two sample points yielded bunted kernels in 2006. Weather data from three time periods in 2004, 2005, and 2006 were applied to the humid thermal index model and suggested that a conducive environment for disease development existed in 2005. Based on the data from this research, we concluded that even though high numbers of soilborne teliospores were present in the field, and although a conducive environment was present for disease to develop on only one occasion, a direct relationship between soilborne teliospores and disease incidence may not exist.

Reaction of Australian durum, common wheat and triticale genotypes to Karnal bunt (Tilletia indica) infection under artificial inoculation in the field

2019 ◽  
Vol 70 (2) ◽  
pp. 107 ◽  
Author(s):  
Livinus Emebiri ◽  
Pawan K. Singh ◽  
Mui Keng Tan ◽  
Guillermo Fuentes-Davila ◽  
Xinyao He ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Durable Resistance ◽  
Effective Means ◽  
Karnal Bunt ◽  
Research Station ◽  
Tilletia Indica ◽  
Planting Dates ◽  
Wheat Genotypes ◽  
Australian Wheat ◽  
Cropping Seasons

Karnal bunt is a seedborne disease of wheat caused by the fungus Tilletia indica Mitra and is a major biosecurity threat for the Australian wheat industry. Host-plant resistance is an effective means of controlling this disease. This study has identified Australian wheat genotypes with durable resistance should the pathogen enter Australia and become established. These genotypes provide a basis for breeding adapted genotypes that can be recommended for growers. In the study, 196 genotypes comprising 177 common (bread) wheat (hexaploid, Triticum aestivum), eight durum (tetraploid, T. durum) and 11 triticale (× Triticosecale) genotypes were evaluated in the field for their reaction to infection by the fungus. Six experiments were carried out at CIMMYT’s research station at Obregon, Mexico, during three consecutive cropping seasons (2014–15, 2015–16 and 2016–17) and at two planting dates. In each experiment, the genotypes were screened for resistance to Karnal bunt by injecting an inoculum suspension with a hypodermic syringe into the boot at awn emergence. Disease incidence averaged 14.7% infection in 2015, 21.7% in 2016 and 25.6% in 2017. Resistant triticale genotypes, Tuckerbox, Berkshire and Hawkeye, were identified, along with three resistant wheat genotypes, Batavia, Pelsart and RAC-655, and two moderately resistant durum genotypes, Hyperno and Saintly. Stability analysis showed that RAC-655, Hyperno, Tuckerbox and Berkshire were consistently resistant to infection in different seasonal conditions and unaffected by the environment.

scholarly journals Tilletia walkeri on Annual Ryegrass in Wheat Fields in the Southeastern United States

Plant Disease ◽  
1999 ◽  
Vol 83 (7) ◽  
pp. 685-689 ◽  
Author(s):  
Barry M. Cunfer ◽  
Lisa A. Castlebury
Keyword(s):  
United States ◽  
Lolium Multiflorum ◽  
Southeastern United States ◽  
Karnal Bunt ◽  
Annual Ryegrass ◽  
Wheat Seed ◽  
Tilletia Indica ◽  
Wheat Field ◽  
South Central ◽  
Low Levels

Surveys for Tilletia walkeri on annual ryegrass (Lolium multiflorum) were conducted during 1997 and 1998 in the southeastern United States, where suspect teliospores of the Karnal bunt fungus, Tilletia indica, were found in USDA-APHIS surveys of wheat (Triticum aestivum) seed in 1996. T. walkeri is morphologically similar to T. indica. Annual ryegrass is a common weed in wheat fields in the southeastern United States. Between April and June 1997, ryegrass seed samples were collected from 190 fields of wheat in 47 counties in Georgia and from 26 fields in 17 counties in Alabama and south-central Tennessee. In 1998, 70 samples were collected from 40 counties in the same regions of the three states. The teliospores from these samples were 23 to 45 μm in diameter (average about 33 μm) and ranged from light brown to dark reddish brown. They had coarse, widely spaced cerebriform ridges on the surface and were surrounded by a gelatinous sheath. The ryegrass bunt was identified as the recently described species T. walkeri, occurring on ryegrass seed from Australia and Oregon. In 1997, teliospores of T. walkeri were found in 13 samples from eight counties in central Georgia and from one field in Tennessee. In 1998, more teliospores and bunted seeds were found, possibly due to frequent rain in the region throughout the flowering period for ryegrass. Teliospores were found in 26/70 of the samples, and among these, only a small number of bunted seed were found in 12 of 13/70 samples. In one wheat field in Morgan County, Georgia, about 50% of the ryegrass seed collected was partially bunted, and a small percentage was completely bunted. Fields with teliospores were widely distributed and generally matched the locations where teliospores were found in APHIS wheat seed surveys in 1996 to 1998. T. walkeri occurs at very low levels on ryegrass in the Southeast and is the source of teliospores, initially identified as those of T. indica, associated with wheat seed in APHIS surveys. No bunted wheat seeds or teliospores of T. indica were found in the survey.

scholarly journals Utilization of Soil Solarization for Eliminating Viable Tilletia indica Teliospores from Arizona Wheat Fields

Plant Disease ◽  
2008 ◽  
Vol 92 (12) ◽  
pp. 1604-1610 ◽  
Author(s):  
G. L. Peterson ◽  
K. L. Kosta ◽  
D. L. Glenn ◽  
J. G. Phillips
Keyword(s):  
Management Strategies ◽  
Soil Solarization ◽  
Karnal Bunt ◽  
Daily Maximum ◽  
Rapid Decline ◽  
United States Department ◽  
Tilletia Indica ◽  
Wheat Field ◽  
Soil Temperatures ◽  
Clear Plastic

Studies were conducted in Arizona to determine the efficacy of soil solarization for killing teliospores of the soilborne fungal wheat pathogen Tilletia indica. In a replicated study conducted in each of 3 years, T. indica teliospores and bunted wheat kernels were buried in a Karnal bunt-infested wheat field at depths of 5, 10, and 20 cm. Replicate samples were removed from under a clear plastic solarization cover at 7-day intervals and the number of viable teliospores determined. A rapid decline in teliospore viability occurred at all treatment depths over 38 days, with efficacy comparable with methyl bromide protocols using clear plastic sheeting. Initial viability rates of 43, 71, and 82% germination were reduced to 0.1, 7.7, and 0.2% after 38 days (across all depths) in 2003, 2005, and 2006, respectively. Mean daily maximum soil temperatures at 5 and 20 cm under clear plastic in 2003, 2005, and 2006 were 67, 53 and 60°C and 43, 38, and 43°C, respectively. Under current United States Department of Agriculture disease management strategies, the method may be useful for the rapid deregulation of Karnal bunt-affected fields.

scholarly journals Distribution and Recovery of Tilletia indica Teliospores from Regulated Wheat Fields in Texas

Plant Disease ◽  
2008 ◽  
Vol 92 (3) ◽  
pp. 344-350 ◽  
Author(s):  
T. W. Allen ◽  
H. W. Maples ◽  
F. Workneh ◽  
J. M. Stein ◽  
C. M. Rush
Keyword(s):  
Grid Point ◽  
The United States ◽  
Karnal Bunt ◽  
Tilletia Indica ◽  
Soil Factors ◽  
Wheat Field ◽  
Contour Maps ◽  
Grid Points ◽  
Single Field ◽  
Analyze Data

Eight wheat fields from the Karnal bunt-regulated regions within Texas were grid sampled to gain a better understanding of the ecology and epidemiology of teliospores produced by the causal agent, Tilletia indica. Teliospores from 25-g aliquots of soil from each grid point were extracted using a size-selective sieving sucrose-centrifugation procedure. Teliospores were recovered from all eight fields and, in some cases, from every grid point within a field. Total teliospore numbers ranged from 0 to 1,305 per 25 g of soil. Over 70% of the total grid sampled points contained one or more teliospores. The relation between soil chemical and physical characteristics and teliospore numbers from each field was evaluated. In general, no consistent, significant trend could be made between soil factors and teliospore numbers. Geostatistics were used to analyze data from grid points and create contour maps. Teliospore distribution was aggregated in four of the fields, random in three of the fields, and discontinuous (neither random nor aggregated) in a single field. This is the first report of widespread distribution and high teliospore numbers from wheat field soils in the United States.

Multiplication of secondary sporidia of Tilletia indica on soil and wheat leaves and spikes and incidence of Karnal bunt

1989 ◽  
Vol 67 (8) ◽  
pp. 2387-2390 ◽  
Author(s):  
Harcharan Singh Dhaliwal
Keyword(s):  
Durum Wheat ◽  
Bread Wheat ◽  
Karnal Bunt ◽  
Tilletia Indica ◽  
Mechanisms Of Resistance ◽  
Sterile Soil ◽  
Field Multiplication ◽  
Wheat Leaves

Secondary allantoid sporidia of Tilletia indica released from mycelial colonies germinate and multiply on sterile soil. They also germinate on surface-sterile leaves and glumes of Karnal bunt-resistant triticale, durum wheat, and bread wheat, indicating that the mechanisms of resistance operate after the germination of sporidia. Inoculated spikes produce infective secondary sporidia in the field. Multiplication of sporidia on soil, leaves, and spikes suggests that the original inoculum from soilborne teliospores may play only a starting role in Karnal bunt epidemics.

Spatial Variability of Grain Cadmium and Soil Characteristics in a Durum Wheat Field

2002 ◽  
Vol 66 (1) ◽  
pp. 268 ◽  
Author(s):  
J. Wu ◽  
W. A. Norvell ◽  
D. G. Hopkins ◽  
R. M. Welch
Keyword(s):  
Spatial Variability ◽  
Durum Wheat ◽  
Soil Characteristics ◽  
Wheat Field ◽  
Grain Cadmium

scholarly journals Screening of Durum Wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) Italian Cultivars for Susceptibility to Fusarium Head Blight Incited by Fusarium graminearum

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
Gaetano Bentivenga ◽  
Alfio Spina ◽  
Karim Ammar ◽  
Maria Allegra ◽  
Santa Olga Cacciola
Keyword(s):  
Durum Wheat ◽  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Triticum Turgidum ◽  
Disease Incidence ◽  
Morphological Characteristics ◽  
Pcr Amplification ◽  
Conidial Suspension ◽  
Head Blight ◽  
Italian Origin

In 2009, a set of 35 cultivars of durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) of Italian origin was screened for fusarium head blight (FHB) susceptibility at CIMMYT (Mexico) and in the 2019–20 cropping season, 16 of these cultivars, which had been included in the Italian National Plant Variety Register, were tested again in southern and northern Italy. Wheat cultivars were artificially inoculated during anthesis with a conidial suspension of Fusarium graminearum sensu lato using a standard spray inoculation method. Inoculum was a mixture of mono-conidial isolates sourced in the same areas where the trials were performed. Isolates had been characterized on the basis of morphological characteristics and by DNA PCR amplification using a specific primer set and then selected for their virulence and ability to produce mycotoxins. The susceptibility to FHB was rated on the basis of the disease severity, disease incidence and FHB index. Almost all of the tested cultivars were susceptible or very susceptible to FHB with the only exception of “Duprì”, “Tiziana” and “Dylan” which proved to be moderately susceptible. The susceptibility to FHB was inversely correlated with the plant height and flowering biology, the tall and the late heading cultivars being less susceptible.

scholarly journals Induction of MAP Kinase Homologues during Growth and Morphogenetic Development of Karnal Bunt (Tilletia indica) under the Influence of Host Factor(s) from Wheat Spikes

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Atul K. Gupta ◽  
J. M. Seneviratne ◽  
G. K. Joshi ◽  
Anil Kumar
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Fungal Growth ◽  
Host Factor ◽  
Host Factors ◽  
Karnal Bunt ◽  
Dependent Manner ◽  
Tilletia Indica ◽  
Mitogen Activated Protein

Signaling pathways that activate different mitogen-activated protein kinases (MAPKs) in response to certain environmental conditions, play important role in mating type switching (Fus3) and pathogenicity (Pmk1) in many fungi. In order to determine the roles of such regulatory genes inTilletia indica, the causal pathogen of Karnal bunt (KB) of wheat, semi-quantitative and quantitative RT-PCR was carried out to isolate and determine the expression of MAP kinase homologues during fungal growth and development underin vitroculture. Maximum expression of TiFus3 and TiPmk1 genes were observed at 14th and 21st days of culture and decreased thereafter. To investigate whether the fungus alters the expression levels of same kinases upon interaction with plants, cultures were treated with 1% of host factors (extracted from S-2 stage of wheat spikes). Such treatment induced the expression of MAPks in time dependent manner compared to the absence of host factors. These results suggest that host factor(s) provide certain signal(s) which activate TiFus3 and TiPmk1 during morphogenetic development ofT. indica. The results also provides a clue about the role of host factors in enhancing the disease potential due to induction of MAP kinases involved in fungal development and pathogenecity.

Effect of biofumigation with volatiles from Muscodor albus on the viability of Tilletia spp. teliospores

2009 ◽  
Vol 55 (2) ◽  
pp. 203-206 ◽  
Author(s):  
Blair J. Goates ◽  
Julien Mercier
Keyword(s):  
Organic Compounds ◽  
Seedling Emergence ◽  
Karnal Bunt ◽  
Smut Fungi ◽  
Tilletia Indica ◽  
Common Bunt ◽  
Volatile Organic ◽  
Petri Dishes ◽  
Postharvest Control ◽  
Muscodor Albus

Volatile organic compounds produced by the fungus Muscodor albus inhibit or kill numerous fungi. The effect of these volatiles was tested on dormant and physiologically active teliospores of the smut fungi Tilletia horrida , Tilletia indica , and Tilletia tritici , which cause kernel smut of rice, Karnal bunt of wheat, and common bunt of wheat, respectively. Reactivated rye grain culture of M. albus was used to fumigate dormant teliospores in dry Petri dishes and physiologically active teliospores on water agar for up to 5 days at 22 °C. Teliospores of all 3 species were incapable of germination when fumigated on agar for 5 days. When T. tritici on agar was fumigated only during the initial 48 h of incubation, viability was reduced by 73%–99%. Fumigation of dry loose teliospores of T. tritici caused a 69%–97% loss in viability, whereas teliospores within intact sori were not affected. Dormant teliospores of T. horrida and T. indica were not affected by M. albus volatiles. It appears that M. albus has potential as a seed or soil treatment for controlling seedling-infecting smuts where infection is initiated by germinating teliospores prior to seedling emergence. The volatiles were not effective for postharvest control of teliospores under conditions used in these experiments.

scholarly journals Centenary of Soil and Air Borne Wheat Karnal Bunt Disease Research: A Review

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1152
Author(s):  
Mir Asif Iquebal ◽  
Pallavi Mishra ◽  
Ranjeet Maurya ◽  
Sarika Jaiswal ◽  
Anil Rai ◽  
...  
Keyword(s):  
Agronomic Traits ◽  
Association Studies ◽  
Farmyard Manure ◽  
Wheat Breeding ◽  
Karnal Bunt ◽  
Farm Income ◽  
Resistance Locus ◽  
Genome Wide Association Studies ◽  
Tilletia Indica ◽  
Causal Pathogen

Karnal bunt (KB) of wheat (Triticum aestivum L.), known as partial bunt has its origin in Karnal, India and is caused by Tilletia indica (Ti). Its incidence had grown drastically since late 1960s from northwestern India to northern India in early 1970s. It is a seed, air and soil borne pathogen mainly affecting common wheat, durum wheat, triticale and other related species. The seeds become inedible, inviable and infertile with the precedence of trimethylamine secreted by teliospores in the infected seeds. Initially the causal pathogen was named Tilletia indica but was later renamed Neovossia indica. The black powdered smelly spores remain viable for years in soil, wheat straw and farmyard manure as primary sources of inoculum. The losses reported were as high as 40% in India and also the cumulative reduction of national farm income in USA was USD 5.3 billion due to KB. The present review utilizes information from literature of the past 100 years, since 1909, to provide a comprehensive and updated understanding of KB, its causal pathogen, biology, epidemiology, pathogenesis, etc. Next generation sequencing (NGS) is gaining popularity in revolutionizing KB genomics for understanding and improving agronomic traits like yield, disease tolerance and disease resistance. Genetic resistance is the best way to manage KB, which may be achieved through detection of genes/quantitative trait loci (QTLs). The genome-wide association studies can be applied to reveal the association mapping panel for understanding and obtaining the KB resistance locus on the wheat genome, which can be crossed with elite wheat cultivars globally for a diverse wheat breeding program. The review discusses the current NGS-based genomic studies, assembly, annotations, resistant QTLs, GWAS, technology landscape of diagnostics and management of KB. The compiled exhaustive information can be beneficial to the wheat breeders for better understanding of incidence of disease in endeavor of quality production of the crop.

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