Modeling the Risk of Entry, Establishment, Spread, Containment, and Economic Impact of Tilletia indica, the Cause of Karnal Bunt of Wheat, Using an Australian Context

Modeling techniques were developed to quantify the probability of Tilletia indica entering and establishing in Western Australia (WA), and to simulate spread, containment, and the economic impact of the pathogen. Entry of T. indica is most likely to occur through imports of bulk grain or fertilizer (0.023 ± 0.017 entries per year and approximately 0.009 ± 0.009 establishments per year). Entry may also occur through straw goods, new or second-hand agricultural machinery, and on personal effects of travelers who have visited regions with infected plants. The combined probability of entry and establishment of T. indica, for all pathways of entry, is about one entry every 25 years and one establishment every 67 years. Alternatively, sensitivity analysis does show that increases in quarantine funding can reduce the probability of entry to about one entry every 50 years and less than one establishment every 100 years. T. indica is spread efficiently through contaminated farm machinery, seed and soil, rain, air currents, and animals. Depending on the rate of spread of the pathogen and the amount of resources allocated for detection, the time until first detection could range from 4 to 11 years and the economic impact could range from 8 to 24% of the total value of wheat production in WA.

Download Full-text

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

The Scientific World JOURNAL ◽

10.1100/2012/539583 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 2

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.

Download Full-text

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

Canadian Journal of Microbiology ◽

10.1139/w08-104 ◽

2009 ◽

Vol 55 (2) ◽

pp. 203-206 ◽

Cited By ~ 21

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.

Download Full-text

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

Biology ◽

10.3390/biology10111152 ◽

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.

Download Full-text

Development of Seed Immunoblot Binding Assay for Detection of Karnal bunt (Tilletia indica) of Wheat

Journal of Plant Biochemistry and Biotechnology ◽

10.1007/bf03263048 ◽

1998 ◽

Vol 7 (2) ◽

pp. 119-120 ◽

Cited By ~ 17

Author(s):

Anil Kumar ◽

A. Singh ◽

G. K. Garg

Keyword(s):

Binding Assay ◽

Karnal Bunt ◽

Tilletia Indica

Download Full-text

Invasion Pathways of Karnal Bunt of Wheat into the United States

Plant Disease ◽

10.1094/pdis.2003.87.8.999 ◽

2003 ◽

Vol 87 (8) ◽

pp. 999-1003 ◽

Cited By ~ 18

Author(s):

David Marshall ◽

Timothy T. Work ◽

Joseph F. Cavey

Keyword(s):

United States ◽

El Paso ◽

Weather Conditions ◽

The United States ◽

Karnal Bunt ◽

Border Crossings ◽

Tilletia Indica ◽

Invasion Pathways ◽

Established Disease ◽

Made In

Karnal bunt of wheat (caused by Tilletia indica) was first detected in the United States in Arizona in 1996. The seed lots of infected, spring-habit, durum wheat associated with the initial detection were traced to planted fields in California, Arizona, New Mexico, and Texas. However, in the summer of 1997, the disease appeared in unrelated, winter-habit, bread wheat located over 700 km from the nearest potentially contaminated wheat from 1996 (and destroyed prior to reinfection). Here, we examined potential invasion pathways of the fungus associated with the movement of wheat into the United States. We analyzed the USDA/APHIS Port Information Network (PIN) database from 1984 through 2000 to determine likely pathways of introduction based on where, when, and how the disease was intercepted coming into the United States. All interceptions were made on wheat transported from Mexico, with the majority (98.8%) being intercepted at land border crossings. Karnal bunt was not intercepted from any other country over the 17-year period analyzed. Most interceptions were on wheat found in automobiles, trucks, and railway cars. The majority of interceptions were made at Laredo, Brownsville, Eagle Pass, and El Paso, TX, and Nogales, AZ. Karnal bunt was intercepted in all 17 years; however, interceptions peaked in 1986 and 1987. Averaged over all years, more interceptions (19.2%) were made in the month of May than in any other month. Our results indicate that Karnal bunt has probably arrived in the United States on many occasions, at least since 1984. Because of the relatively unaggressive nature of the disease and its reliance on rather exacting weather conditions for infection, we surmised that it is possible this disease has a long period of latent survival between initial arrival and becoming a thriving, established disease.

Download Full-text

Evaluation of Aegilops tauschii (Coss.) germplasm for Karnal bunt resistance in a screen house with simulated environmental conditions

Plant Genetic Resources ◽

10.1017/s1479262108982654 ◽

2008 ◽

Vol 6 (02) ◽

pp. 79-84 ◽

Cited By ~ 6

Author(s):

Parveen Chhuneja ◽

Satinder Kaur ◽

Kuldeep Singh ◽

H. S. Dhaliwal

Keyword(s):

Host Plant ◽

Plant Resistance ◽

Environmental Conditions ◽

Host Plant Resistance ◽

Aegilops Tauschii ◽

Karnal Bunt ◽

Tilletia Indica ◽

D Genome ◽

Moderately Resistant ◽

Screen House

Karnal bunt (KB) of wheat, caused byTilletia indica(Mitra) Mundkur, adversely affects international wheat trading and the movement of germplasm between countries due to quarantine restrictions. Breeding for host plant resistance requires the identification of KB resistance sources. Accessions of the D genome progenitor of bread wheat,Aegilops tauschii, were screened in a specially designed screen-house, where the optimum environmental conditions conducive for KB development were simulated by controlling temperature, humidity, fogging and shading. The 183 accessions were subjected to artificial inoculation with a mixture of nine KB isolates, and seven proved highly resistant and four moderately resistant over three rounds of screening over 3 years.

Download Full-text