| surface rodlets of tilletia indica teliospores. | tilletia indica teliospores were studied by use of thin sections and freeze-etch replicas. surfaces of these spores have rodlet patterns which differ from those previously reported for spores of other fungi. the rodlets on t. indica teliospores average 240 nm in length and are not grouped into fascicles. | 1983 | 6833186 |
| isolation of a species-specific mitochondrial dna sequence for identification of tilletia indica, the karnal bunt of wheat fungus. | mitochondrial dna (mtdna) from five isolates of tilletia indica was isolated and digested with several restriction enzymes. a 2.3-kb ecori fragment was chosen, cloned, and shown to hybridize with total dna restricted with ecori from t. indica and not from a morphologically similar smut fungus, tilletia barclayana. the clone was partially sequenced, and primers were designed and tested under high-stringency conditions in pcr assays. the primer pair ti1/ti4 amplified a 2.3-kb fragment from total d ... | 1996 | 8572716 |
| contemporary global movement of emerging plant diseases. | plant diseases are a significant constraint to agricultural productivity. exotic plant diseases pose a continued threat to profitable agriculture in the united states. the extent of this threat has increased dramatically in the 1980s and 1990s due to the expansion of international trade in agricultural products and frequent movement of massive volume of people and goods across national boundaries. introduction of new diseases has not only caused farm losses, but has also diminished export revenu ... | 1999 | 10681966 |
| molecular signaling in pathogenicity and host recognition in smut fungi taking karnal bunt as a model system. | karnal bunt of wheat, incited by a phytopathogen tilletia indica (syn. neovossia indica) is a floret infecting disease. in the floral tissues fungus proliferates and produces massive amount of black spores. in smut fungi, belonging to order ustilaginales, communication between cells is necessary to regulate growth, differentiation and monokaryotic to dikaryotic transition during pathogenic and sexual development. neighbouring cells are able to communicate with each other by direct cell to cell c ... | 2000 | 11116522 |
| modulation of antigenicity of mycelial antigens during developmental cycle of karnal bunt (tilletia indica) of wheat. | indirect enzyme linked immunosorbent assays (elisa) were developed using polyclonal antibodies against soluble cytoplasmic (sca) and insoluble cell wall antigens (icwa) for monitoring modulation of mycelial antigens during growth cycle of t. indica. with sca, continuous decrease in elisa reactivity was observed in maturing fungus cultures, suggesting that sca were expressed predominantly during early vegetative phase and their decreasing role was apparent as the fungus matures possibly towards s ... | 2000 | 11272415 |
| generation of anti-teliospores antibodies for immunolocalization and characterization of antigenic epitopes of teliospores of karnal bunt (tilletia indica) of wheat. | polyclonal antibodies raised against intact teliospores of t. indica in new zealand albino rabbits were used for the development of indirect immunofluorescence tests. specificity of anti-teliospore antibodies was evaluated by cross reactivity studies on other bunt, smut and related pathogens. the characteristic reactivity pattern indicated that the antibodies reacted with tilletia species only. chemical modifications, heat and enzyme treatments followed by indirect immunofluorescence tests were ... | 2001 | 12019763 |
| mapping of a resistance gene effective against karnal bunt pathogen of wheat. | a set of 130 wheat recombinant inbred lines (rils) developed from a cross between parents susceptible (wl711) and resistant (hd29) to karnal bunt (caused by tilletia indica), were screened for 3 years with the pathogen populations prevalent in northern india. when 90 simple sequence repeats (ssrs) and 81 amplified fragment length polymorphism (aflp) loci were mapped on the rils, markers on chromosomes 2a, 4b and 7b accounted collectively for about one-third of the variation in the disease reacti ... | 2003 | 12596729 |
| pcr based molecular technique for identification and discrimination of quarantined and non-quarantined tilletia sps. | polymerase chain reaction (pcr) based rapd profiles, in conjunction with six primers, of karnal bunt of wheat and rice bunt exhibiting distinct polymorphic dna. a total of 84 rapd loci were observed on polyacrylamide gel for both tilletia sps. out of 84, 16 loci were found monomorphic, while other 68 loci were unique. usefulness of random primers was also checked with other seed borne fungal pathogens of wheat and rice. none of primers gave amplification with magnaporthe grisea, a causative agen ... | 2002 | 12693693 |
| genetic analysis of karnal bunt (neovossia indica) resistance in wheat. | embryos excised from seeds of six generations (p1, p2, f1, bc1, bc2 and f2) of a cross wh 283 wh 533 were cultured on modified ms medium already inoculated with secondary sporidia of neovossia indica. significant variations for callusing response (cr) (54 55-75 55%) were observed among generations but the presence or absence of n. indicia did not affect callusing response. a clear inhibition zone (iz) was formed around each embryo showing callusing. the diameter of iz varied significantly amon ... | 2003 | 12711812 |
| immuno-pathotyping of karnal bunt (tilletia indica) isolates of wheat using anti-mycelial antibodies. | two types of polyclonal antibodies raised against whole lyophilized (lma) and fractionated mycelial antigen (fma) of most virulent, pantnagar isolate of t. indica were used for the development of immunoassay systems, viz. dot immuno-binding assay (diba) and indirect enzyme linked immuno-sorbent assay (elisa) procedures. the immuno-assays were developed by performing antigen concentration kinetics and antibody dilution curves analyses. these assays were employed for immuno-analysis of diversity a ... | 2003 | 15267157 |
| dibutyryl c-amp as an inducer of sporidia formation: biochemical and antigenic changes during morphological differentiation of karnal bunt (tilletia indica) pathogen in axenic culture. | effect of dibutyryl adenosine 3',5'-cyclic monophosphate (dbc-amp), an analogue of c-amp, was investigated on growth and morphological differentiation of tilletia indica. exponential growth was observed up to 21 days in both presence and absence of dbc-amp; however, increasing concentration of dbc-amp was deleterious to mycelial growth in liquid culture. a slow increase of mycelial biomass up to 21 days and decline at 30 days in the presence of 2.5 mm dbc-amp was observed, therefore, this concen ... | 2004 | 15286400 |
| enhanced proteolysis leads to pre-mature cell death under the influence of elicitor like mycelial components from karnal bunt (tilletia indica) pathogen in wheat callus cultures. | calli raised from mature embryos of susceptible wheat cultivar wh 542 were used in the present study as in vitro bioassay system to study the influence of disease determinant(s) of karnal bunt (tilletia indica), a semi-biotrophic fungal pathogen of wheat. influence of elicitor and conditioned medium (cm) prepared from fungal cultures of t. indica was investigated on induction of programmed cell death (pcd). induction of pcd was observed as hypersensitive response (hr) in terms of browning at loc ... | 2005 | 16121719 |
| a molecular protocol using quenched fret probes for the quarantine surveillance of tilletia indica, the causal agent of karnal bunt of wheat. | the current surveillance protocol for karnal bunt of wheat in most countries, including the usa, european union (eu), and australia, involves the tentative identification of the spores based on morphology followed by a molecular analysis. germination of spores is required for confirmation which incurs a delay of about two weeks, which is highly unsatisfactory in a quarantine situation. a two-step pcr protocol using fret probes for the direct detection and identification of tilletia indica from a ... | 2006 | 16388942 |
| nonsystemic bunt fungi--tilletia indica and t. horrida: a review of history, systematics, and biology. | the genus tilletia is a group of smut fungi that infects grasses either systemically or locally. basic differences exist between the systemically infecting species, such as the common and dwarf bunt fungi, and locally infecting species. tilletia indica, which causes karnal bunt of wheat, and tilletia horrida, which causes rice kernel smut, are two examples of locally infecting species on economically important crops. however, even species on noncultivated hosts can become important when occurrin ... | 2006 | 16480336 |
| expression of the lipid transfer protein ace-amp1 in transgenic wheat enhances antifungal activity and defense responses. | to enhance fungal disease resistance, wheat plants (cv. bobwhite) were engineered to constitutively express the potent antimicrobial protein ace-amp1 from allium cepa, driven by a maize ubiquitin promoter along with its first intron. the bar gene was used for selection of putative transformants on medium containing phosphinothricin (ppt). transgene inheritance, integration and stability of expression were confirmed over two generations by pcr, southern, northern and western blot analyses, respec ... | 2006 | 16906444 |
| influence of jasmonic acid as potential activator of induced resistance against karnal bunt in developing spikes of wheat. | induction of defense response against karnal bunt (kb)by suppressing the pathogenesis was observed upon exogenous application of jasmonic acid (ja)as evident from decrease in the coefficient of infection and overall response value in both susceptible and resistant varieties of wheat. the ultra-structural changes during disease progression showed the signs of programmed cell death (pcd). however, ja strengthened the defense barrier by enhancing the lignifications of cell walls as observed in spik ... | 2006 | 17301499 |
| molecular mapping of qtls for karnal bunt resistance in two recombinant inbred populations of bread wheat. | karnal bunt (kb) of wheat, caused by the fungus tilletia indica, is a challenge to the grain industry, owing not to direct yield loss but to quarantine regulations that may restrict international movement of affected grain. several different sources of resistance to kb have been reported. understanding the genetics of resistance will facilitate the introgression of resistance into new wheat cultivars. the objectives of this study were to identify quantitative trait loci (qtls) associated with kb ... | 2007 | 17952401 |
| [extraction of mitochondrial dna of tilletia indica mitra and application of the atp6 gene on fungal phylogenetic analysis]. | tilletia indica mitra, an important pest around the world which is the causative agent of karnal bunt of wheat, was very close to tilletia walkeri phylogenetically and morphologically. 69.6 ng mitochondrial dna (mtdna) of tilletia indica obtained from 6.4 mg total dna by the method of cscl/bisbenzimide density gradient ultracentrifugation can be used for electrophoresis, cloning, enzyme restriction analysis and pcr amplification. the atp6 gene sequence was cloned from the fragment of mtdna and s ... | 2007 | 18062255 |
| rainfall and temperature distinguish between karnal bunt positive and negative years in wheat fields in texas. | karnal bunt of wheat, caused by the fungus tilletia indica, is an internationally regulated disease. since its first detection in central texas in 1997, regions in which the disease was detected have been under strict federal quarantine regulations resulting in significant economic losses. a study was conducted to determine the effect of weather factors on incidence of the disease since its first detection in texas. weather variables (temperature and rainfall amount and frequency) were collected ... | 2008 | 18943243 |
| 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. | abstract 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 perso ... | 2002 | 18944006 |
| susceptibility of wheat to tilletia indica during stages of spike development. | abstract karnal bunt of wheat is caused by the fungus tilletia indica, which partially converts kernels into sori filled with teliospores. despite minor overall yield and quality losses, the disease is of considerable international quarantine concern. plant development stages reported susceptible to infection vary considerably. a study was designed to better define the susceptibility period by inoculating wheat spikes at different growth stages with naturally liberated secondary sporidia under o ... | 2006 | 18944051 |
| internal transcribed spacer sequence-based phylogeny and polymerase chain reaction-restriction fragment length polymorphism differentiation of tilletia walkeri and t. indica. | abstract a polymerase chain reaction-restriction fragment length polymorphism assay to distinguish tilleita walkeri, a rye grass bunt fungus that occurs in the southeastern united states and oregon, from t. indica, the karnal bunt fungus, is described. the internal transcribed spacer (its) region of the ribosomal dna repeat unit was amplified and sequenced for isolates of t. indica, t. walkeri, t. horrida, and a number of other taxa in the genus tilletia. a unique restriction digest site in the ... | 2001 | 18944119 |
| an allee effect reduces the invasive potential of tilletia indica. | abstract the karnal bunt pathogen, tilletia indica, is heterothallic and depends on encounters on wheat spikes between airborne secondary sporidia of different mating types for successful infection and reproduction. this life history characteristic results in reduced reproductive success for lower population densities. such destabilizing density dependence at low population levels has been described for a range of animals and plants and is often termed an allee effect. our objective was to chara ... | 2002 | 18944239 |
| identification and differentiation of tilletia indica and t. walkeri using the polymerase chain reaction. | abstract karnal bunt of wheat, caused by tilletia indica, was found in regions of the southwestern united states in 1996. yield losses due to karnal bunt are slight, and the greatest threat of karnal bunt to the u.s. wheat industry is the loss of its export market. many countries either prohibit or restrict wheat imports from countries with karnal bunt. in 1997, teliospores morphologically resembling t. indica were isolated from bunted ryegrass seeds and wheat seed washes. previously developed p ... | 2000 | 18944518 |
| ultrastructural studies on penetration sites of neovossia indica, the partial bunt agent of wheat. | to elucidate the mode of penetration of n. indica into the host, five wheat cultivar/lines including a susceptible cultivar (wl711), a morphologically resistant line (r1: altar 84 cd22344-a-8m-1y-1m-1y-2y-1m-0y) and three physiologically resistant lines (r2: 6811/rgb-u//ward/3/fgo/4/rabi/5/cigm89. 564-0y; r3: cmh84.1106cmh84.1106-1y-6b-1y-2b-2y-2b-0y and r4: wee/koel//weavercmbw90m132-138m-010m) were inoculated by three different methods. the sequence of events that took place from post inoculat ... | 2007 | 19070171 |
| effect of biofumigation with volatiles from muscodor albus on the viability of tilletia spp. teliospores. | 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 ... | 2009 | 19295653 |
| basal expression studies of cystatins during specific growth stages of wheat spikes for defining their possible role in differential and stage dependent immunity against karnal bunt (tilletia indica). | two genotypes showing differential immunity against karnal bunt (tilletia indica) were used to investigate the role of three members of cystatin gene family in growth stage dependent immunity in wheat (triticum aestivum l.). three members of cystatin gene family (wc1, wc2, and wc4) were cloned and sequenced. analysis of sequenced data showed that there was 76-99% nucleotide and protein sequence identity between different genes of the wheat cystatin. in silico amino acid sequence analysis reveale ... | 2010 | 19347606 |
| antagonism of some aquatic hyphomycetes against plant pathogenic fungi. | the antagonistic activity of five aquatic hyphomycetes, viz., heliscus lugdunensis, tetrachaetum elegans, tetracladium breve, t. marchalianum, and t. nainitalense, against seven plant pathogenic fungi was studied using a dual culture technique. inhibitory activity of tested aquatic hyphomycetes was determined by measuring the radial growth of plant pathogenic fungi on dual culture plates. tetrachaetum elegans showed antagonistic activity against colletotrichum falcatum, fusarium oxysporum, pyric ... | 2010 | 20454756 |
| jasmonate signal induced expression of cystatin genes for providing resistance against karnal bunt in wheat. | two wheat varieties hd-29 (resistant, r) and wh-542 (susceptible, s) were pretreated with jasmonic acid (ja) or jasmonate and then artificially inoculated with sporidial suspension of tilletia indica to study its influence in reducing karnal bunt (kb) infection by regulating cystatin gene expression. ja was found to improve the plant defense against kb as its exogenous application resulted in decrease in coefficient of infection (ci) in both susceptible and resistant varieties following pathogen ... | 2011 | 21849815 |