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Pots experiment has been conducted in the 2017 - 2018 season in plant protection directory/Abu-ghreeb/Baghdad. Ten wheat varieties were used in recent study (Bohooth10, Bohooth22, Bohooth95, Bohooth158, Ipaa99, Sham6, Abu-ghreeb, Adenh, Latefiya and Rasheed), to study their resistance and susceptibility to the one T.tritici isolate which causing common bunt disease on wheat crop. Seeds of wheat contaminated with teliospors of T. tritici isolate and sowing in pots at three replication for each variety, the incidence ratio, plant height and length of spike was estimated at the end of growth season. Lowest incidence ratio observed in Rasheed, Bohooth 95 and Bohooth 10 (0.0, 1.5, 1.8) % respectively without significant differences between them, highest incidence ratio was recorded in Bohooth 22 variety 33% with significant differences comparison with other varieties. Other tested variety recorded incidence ratio about (23-27) %. Result from this study show reduction in plants height and length of spikes in the all bunted plants with significant differences comparison with the control (healthy plants). from recent study can be concluded, wheat varieties differs in their resistance and susceptibility to common bunt disease, and this disease caused reduction in the plant height and length of spike in the bunted plants. [ABSTRACT FROM AUTHOR]

The location of new genes for resistance to common bunt in wheat is valuable for gene pyramiding in breeding. For this purpose, the genetics of the relatively high level of resistance in the European winter wheat variety Trintella was investigated using a doubled haploid mapping population of a cross between Trintella and the susceptible variety Piko. The population was scored for bunt infection in the field for 2 years following inoculation with a mixture of teliospores of Tilletia tritici and T. laevis. A genetic map consisting of 29 linkage groups was constructed using polymorphic simple sequence repeat markers. This map was used for QTL analysis, and in both years, results indicated that resistance to common bunt could mostly be attributed to a gene on chromosome 1B, near to the centromere and closest to marker Xgwm273 on the short arm. Additionally, in 2008, smaller QTL effects were ascribed to chromosomes 7A and 7B, and another smaller QTL effect to chromosome 5B in 2009 only. [ABSTRACT FROM AUTHOR]

Abstract: A bunt fungus, exhibiting a spore germination pattern unique to known reticulate-spored species of Tilletia was found infecting plants in seed production fields of Festuca rubra ssp. rubra (red fescue) and F. rubra ssp. fallax (Chewing''s fescue) in Oregon, and in seed lots of Lolium perenne (perennial ryegrass) from Australia and Germany. Teliospores germinated to form 20–40 uninucleate, non-conjugating basidiospores, and colonies derived from single basidiospores produced teliospores in culture. In inoculation studies using single basidiospore colonies, perennial ryegrass and L. perenne ssp. multiflorum (Italian or annual ryegrass) were infected. A phylogenetic analysis, based on ITS region rDNA, eukaryotic translation elongation factor 1 alpha, and the second largest subunit of RNA polymerase II demonstrated that the fescue and ryegrass bunts are conspecific, and distinct from known species of Tilletia. [Copyright &y& Elsevier]

Alien translocations in wheat have been exhaustively investigated relative to various diseases, except for common bunt. During the period 2005-2006, an experiment was carried out at the Lithuanian Institute of Agriculture (LIA) in an artificially inoculated nursery. The test cultivars represented the latest Western European winter wheat genotypes. The total mean winter wheat infection in the common bunt nursery was 80.9% and the mean for the selected 36 cultivars 76.2%. The high infection level enabled us to screen the cultivars for the level of partial resistance. Of the selected 36 cultivars with or without various alien translocations, only 'Quebon' was found to be resistant. The least infected cultivars 'Tommi' and 'Bill', can be classified as medium susceptible -- 15.0% and 17.2%, respectively. The rest of the cultivars were very susceptible, the mean infection level ranging from 53.5% to 98.8%. Cultivars with Aegilops ventricosa translocation were the least infected of the selected genotypes. The mean infection of eight cultivars was 74.9%, and the mean for the rest of the cultivars was 81.2%. As a result, this translocation could additionally possess some barely effective genes of partial resistance. Complex translocation from Secale cereale did not possess effective partial resistance. The mean infection of cultivars with other translocations was not really different from that of the selected cultivars. Cultivars with translocation from A. tauschii were infected more than the mean 87.4%, whereas cultivars with translocation from Triticum dicoccum were infected less than the mean 75.4%. [ABSTRACT FROM AUTHOR]

To develop winter wheat varieties suitable for organic farming, it is necessary to collect plant genetic resources resistant to common bunt, because no seed treatment (with synthetic pesticides) is allowed. For this purpose, the breeding lines developed at the Lithuanian Institute of Agriculture and winter wheat varieties registered in Lithuania were investigated during 2001-2004, using artificial inoculation with Tilletia tritici and Tilletia leavis spores. It was found that among advanced breeding lines 0.0-1.7% were very resistant and 0.0-16.2% resistant to common bunt. Among the gene collection varieties tested, 0.0-7.7% were very resistant and 1.6-36.2% resistant to common bunt depending on the year of testing. Most lines and varieties were infected by 10% to 50%. This means that development and collection of plant genetic recourses resistant to common bunt is one of the limiting factors in organic wheat breeding. Investigations of common bunt resistance of Lithuania-registered winter wheat varieties showed that among 26 varieties two -- 'Begra', 'Baltimor' -- were resistant while 'Korweta' and 'Bill' medium-resistant to common bunt. These varieties can be used in crosses to improve resistance to common bunt. The infection in most varieties reached 16.5-55.3%. The most susceptible varieties were 'Flair', 'Aspirant' and 'Pegasos' (infection 75.9-87.4%). The Lithuanian winter wheat variety 'Milda' was medium-susceptible and 'Ada', 'Seda', 'Alma', 'Širvinta' susceptible to Tilletia tritici. [ABSTRACT FROM AUTHOR]

Fourteen Mexican genotypes of bread wheat (Triticum aestivum L.) with good to moderate levels of resistance to Karnal bunt (Tilletia indica (Mitra)) were crossed with the highly susceptible cultivar WL711 to determine the genetic basis of resistance. The parents, F1, F2 and backcross populations of the 14 crosses were evaluated under artificial epiphytotic conditions during the 1993-94 season for Karnal bunt resistance. The F1 data suggested that the resistance was dominant to partially dominant over susceptibility. The χ² analysis of the segregation ratios in the F2 and backcross generations indicated that the resistance in the wheat genotypes Luan, Attila, Vee # 7/Bow, Star, Weaver, Milan, Sasia and Turacio/Chil is controlled by two genes. The resistance in genotypes Cettia, Irena, Turaco, Opata, Picus, and Yaco was found to be conditioned by a single dominant gene. The genotypes with two genes for resistance expressed a higher level of resistance than those with a single gene and, therefore, are better sources of resistance to Karnal bunt. [ABSTRACT FROM AUTHOR]

Genetic resistance to common bunt is a cost-effective, environmentally friendly, and sustainable approach to controlling the disease. To date, 16 race specific common bunt resistance genes (Bt1-Bt15 and Btp) have been reported in wheat. However, a limited number have been mapped and few markers have been identified, which limits the usage of molecular markers in a marker-assisted breeding program. A total of 125 synthetic hexaploid wheats (SHWs) were evaluated for reactions to a mixture of common bunt races under field conditions in Turkey in 2016 and 2017. The objectives of this study were to identify common bunt resistant genotypes, identify genomic regions conferring resistance to common bunt using 35,798 genotyping-by-sequencing derived single nucleotide polymorphisms (SNPs), and investigate the significant SNPs present within genes using the functional annotations of the underlying genes. We found 29 resistant SHWs that can be used in wheat breeding. The genome-wide association study identified 15 SNPs associated with common bunt resistance and a haplotype block comprising three SNPs in perfect linkage disequilibrium. Five of them were novel and were located on chromosomes 2A, 3D, and 4A. Furthermore, seven of the 15 SNPs were found within genes and had annotations suggesting potential role in disease resistance. This study identified several favorable alleles that decreased common bunt incidence up to 26% in SHWs. These resistant SHWs and candidate genomic regions controlling common bunt resistance will be useful for wheat genetic improvement and could assist in further understanding of the genetic architecture of common bunt resistance. [ABSTRACT FROM AUTHOR]

A Karnal bunt (KB)-free wheat stock (‘KBRL22’) obtained from a cross of two resistant lines (‘HD29’ and ‘W485’) was used as a donor to introgress the KB-free trait into ‘PBW343’ (an ‘Attila’ sib), the most widely grown wheat cultivar in India. The number of KB-free and KB-affected plants in BC1, BC2, BC3 and BC4 as well the F2 was recorded after artificial inoculations. The segregation pattern in these generations clearly indicated two independently segregating, dominant genes which jointly confer the KB-free attribute. The importance of the KB-free line generated in this experiment is discussed. [ABSTRACT FROM AUTHOR]