ICAR-Indian Institute of Wheat and Barley Research
Sudheer,Kumar, P.L., Kashyap, Gyanendra Pratap, Singh, , , , , , , , , , , , , , , , , , , , , , , ,
Yellow rust of wheat caused by Puccinia striiformis Westend. is one of the important diseases of wheat in India. In north Indian states it spreads quite fast due to favourable temperature and moisture prevailing in these states during major part of crop growth (November-mid March). In spite of favourable weather, proactive survey and surveillance and advisories issued in time resulted successful management of yellow rust in India during past four decades. Even large scale cultivation of varieties like HD 2967 in about 12 million ha past two years did not result any losses. Three spots of initial foci near foot hills in Punjab have been identified and are monitored regularly. Any sign of yellow rust is controlled effectively with the foliar sprays of fungicides like propiconazole @ 0.1%. Use of mobiles phones and internet services is regularly done for transfer of information on wheat crop health and suggestions for proper management. Strategic planting and sowing of wheat in which newly released high yielding yellow rust varieties helped in reducing the yellow rust inculum build up. Regular monitoring of wheat health via weather forecasts take place after every fortnight from December to March. During 2016-17 crop season, yellow rust was effectively managed and its occurrence was delayed in Punjab, Haryana and Uttarakhand states. Two new pathotypes, 110S 119 and 110S 84 developed recently were used for evaluation of entries of wheat yield trials during 2016-17 at hot spot locations. The new varieties in pipe line of identification and release are tested against yellow rust. The most critical period for yellow rust management remained from December till mid February.
Agriculture & Agri-Food Canada
Colin,Hiebert, , , , , , , , , , , , , , , , , , , , , , , , , , , ,
Wheat cultivar McNair 701 carries resistance gene SrMcN and is used as a differential line to identify Pgt races using the international letter code nomenclature. The inheritance and location of the resistance gene has not been characterized. We developed a doubled haploid (DH) population from cross LMPG/McNair 701 to study the genetics and chromosomal location of SrMcN. A DH population inoculated with race QCCJB segregated 100 resistant : 94 susceptible, a 1:1 ratio (?2=0.186, P=0.666, NS) indicative of segregation at a single locus. This gene was mapped to chromosome 2DL using the Infinium 90k platform. The map position of SrMcN was similar to that of Sr54, one of two genes previously found in Norin 40. Comparison of stem rust seedling reactions using 12 diverse Pgt races indicated that McNair 701 and an Sr54 line derived from Norin 40 had an identical pattern of responses and similar low infection types (IT=12-) to races LCBNB and QCCJB. Based on the chromosomal location on 2DL and identical seedling responses to Sr54, it is likely that the resistance gene in McNair 701 formerly known as SrMcN is Sr54. This finding will be confirmed by a test of allelism.
Laboratory of Molecular Plant Physiology, Biotechnology Center of Borj Cedria (CBBC) P.O. Box 901, 2050 Hammam-Lif, Tunisia
Mahmoud,Gargouri, Hesham A.Y, Gibriel, Richard B., Todd, Michael F., Seidl, Gerrit H.J, Kema, , , , , , , , , , , , , , , , , , , ,
Septoria tritici blotch disease, caused by the fungus Zymoseptoria tritici, is a major threat to global wheat production. With the recent advances in high-throughput DNA-based technologies, Z. tritici has become a powerful model system for the discovery of candidate determinants that underlie virulence and host specialization. Although a few important virulence/regulatory genes have been identified, a global understanding of the larger regulatory network has not been developed.
Therefore, to uncover the transcriptional regulatory networks of the infection cycle and most particularly the regulatory hubs that control the switch between the biotrophic and necrotrophic phases, we applied an integrated approach combining transcriptomics, proteomics, and metabolomics analyses based on the identification of plant and fungal transcription factors and regulators, which we characterized from the newly annotated genome sequence of the reference isolate IPO323 (Grandaubert et al., 2015) and using datasets from Rudd et al. (2015). Bread wheat transcription factors and regulators were identified by querying the proteome and subsequent categorization from the Plant Transcription Factor database (PTFDB). Similarly, Z. tritici transcription factors and regulators were identified and categorized using the PFAM TF family databases, and following fungal transcription factor rules as outlined by Todd et al. (2014) and rules we developed for fungal transcription regulators. Insights into transcription factors and regulators will enable synthetic biology approaches to alter the Z. tritici-wheat interaction and lead to rewiring of the regulatory networks thereby turning off the fungal infection process. Beyond providing insights into the regulatory systems-levels involved in Z. tritici-wheat interaction, we believe that our dataset and approach sets the stage for an emerging series of studies that will decipher the dynamic regulatory networks in other plant-pathogen interactions.
Panjab University Chandigarh
Pradeep,Sharma, , , , , , , , , , , , , , , , , , , , , , , , , , , ,
Sterol 14?-Demethylase Cytochrome P450 (CYP51) protein involved in ergosterol biosynthesis pathways is a crucial target for efficient fungicidal compounds. However, the recognition mechanism and dynamic behavior of CYP51 in wheat leaf rust pathogen, Puccinia triticina is still obscure. Previously, a mutation at codon 134 (Y134F) was reported in five European isolates of P. triticina, the structural basis of this mutation remain unclear. To address this problem, CYP51 wild type protein and its variant proteins were successfully modeled using I-TASSER, an ab initio based structure prediction pipeline. To gain valuable insights into structure-function behavior for the binding wild-type and mutant-type proteins, individually generated protein models was subjected to 50ns molecular dynamics (MD) simulations run. Observably, this comparative protein-ligand interaction analysis and binding free energy results revealed that impact of mutation on the thermodynamics and conformational stability of the CYP51 protein is negligible. In present study, we carried out structure-based molecular docking and identified potent novel fungicidal compounds from four different databases and libraries. Consequently through MD simulation and thermodynamic integration, four novel compounds such as CoCoCo54211 (CoCoCo database),ZINC04089470(ZINC database), Allyl pyrocatechol 3,4 diacetate (Natural compound library) and 9-octadecenoic acid (Traditional Chinese Medicine database) has been predicted as potent fungicidal compound against CYP51 with XPGlidedocking score of -11.41, -12.52, -7.40 and -7.55 kcal/mol, respectively. These compounds were found to directly bond to heme group of CYP51, subsequently disturbing the stability and survival of fungus and can be used to control leaf rust in wheat.
Instituto Nacional de Investigaci?n Agropecuaria (INIA) La Estanzuela
Paula,Silva, Clara, Pritsch, Miguel, Raffo, Silvia, Pereyra, Silvia, Germ?n, , , , , , , , , , , , , , , , , , , ,
Wheat stem rust (SR), caused by Puccinia graminis f. sp. tritici, (Pgt) is considered one of the most destructive diseases of the wheat crop. As Sr24 and Sr31 are the most widely used resistance genes in the Southern Cone of America, wheat crops in this region is under threat of SR outbreaks posed by the potential migration of virulent Pgt Ug99-lineage races (Ug99+). Efforts have to be made to develop adapted lines resistant to Ug99+. Genes Sr26, Sr32 and Sr39 are effective to both Ug99+ and local races of the pathogen. This work is aimed to pyramid two and three of the resistance genes in two locally adapted wheat cultivars (G?nesis 2375 and G?nesis 6.87). Donor lines of Sr26, Sr32 and Sr39 (developed by I. Dundas, University of Adelaide, Australia) and molecular markers Sr26#43, csSr32#1 and Sr39#22r (developed by R. Mago et al., University of Adelaide) were used. Lines with two-gene combinations were developed in two steps. First, tree-way crosses were made by crossing heterozygous F1 plants (derived from crossings donor lines) to either one of the two adapted wheat cultivars. Subsequently, tree-way F1 plants were genotyped and only those with two-gene combinations were backcrossed (BC) twice to the adapted cultivars. Among three-way F1 plants, two-genes combinations were confirmed for Sr26+Sr32 (8 out of 31), Sr26+Sr39 (2 of 115) and Sr32+Sr39 (26 out of 103). In the BC1F1 generation, Sr26+Sr32, Sr26+Sr39 and Sr32+Sr39 combinations corresponded with 9, 9 and 45 out of 99, 27 and 241 plants, respectively. In 2017, 1345 BC2F1 plants are being grown to obtain BC2F2. We plan to intercross plants with two-gene combinations to obtain lines with the three genes which will be used as sources of resistance to develop cultivars with presumably longer lasting resistance to wheat SR.
Institute of Evolution and the Department of Evolutionary and Environmental Biology, University of Haifa, Israel
Dina,Raats, Lin, Huang, Valeria, Bocharova, Jorge, Dubcovsky, Abraham, Korol, Tzion, Fahima, , , , , , , , , , , , , , , , , ,
Wild emmer wheat (Triticum dicoccoides, (DIC)) is an important source of resistance to stripe rust due to presence of Puccinia striiformis in its natural habitats with high humidity and relatively low temperatures that are favorable for stripe rust development. Previously, we showed that DIC accessions from northern Israel were highly resistant to stripe rust. According to the rust responses of three DIC accessions (G25, H52, G303) and mapping of the resistance to relatively close, but different, genetic positions on chromosome 1BS, three different resistance genes were assumed to be present. However, the development of additional critical recombinants and new higher resolution genetic maps for these three genes in subsequent work led us to place YrH52 and YrG303 in the same genetic interval as Yr15, suggesting that the three putative genes are allelic or identical. The recent cloning of Yr15 allowed us to test this hypothesis using an EMS mutagenesis approach. We sequenced the Yr15 locus in five yrH52 and three yrG303 susceptible mutants and identified missense point mutations associated with the susceptible phenotype in each one. Thus, YrH52 and YrG303 may not be new genes. Further work is under way to determine if these genes are allelic or identical.
ICAR- Indian Institute of Wheat & Barley Research, Karnal-132001, India
Vinod,Tiwari, DP, Singh, RP, Gangwar, GP, Singh, , , , , , , , , , , , , , , , , , , , , ,
The changing climatic conditions are affecting wheat production in major agro-ecological zones in India, namely, north western plains(NWPZ), north eastern plains(NEPZ), central (CZ) and peninsular zone(PZ) where the reproductive phase has to endure higher temperatures. Also, the prevalence and virulence of rust pathotypes and other diseases are affected. To address such challenges, development of wheat for climate resilience was initiated following shuttle breeding approach for incorporating heat stress tolerance as well as resistance to wheat rusts. During 2010-16, a total of 583 elite lines were evaluated against prevalent pathotypes of stripe rust 78S84, 110S119, 110S84 and 46S119; leaf rust 12-2(1R5), 12-5(29R45), 77-2(109R31-1), 77-5(121R63-1), 77-9(121R60-1) and 104-2 (21R55) and stem rust 11(79G31), 40A(62G29), 42(19G35), 122(7G11) and 117-6(37G19) of which 108 promising entries were identified. These lines were evaluated for disease response in multilocational Initial Plant Pathological Screening Nursery (IPPSN) against prevalent races of all three rusts. Based on average coefficient of infection (15.0 ACI), 42 (39%), 104 (96%) and 90(83%) entries were found resistant to different races of stripe, leaf and stem rusts, respectively. Based on performance in multiplication yield trials, 29 entries were contributed in national coordinated evaluation system on Wheat & Barley which resulted in release of four wheat cultivars DBW71(Yr9+27+,Lr26+,Sr2+5+31+), DBW107(Yr9+,Lr26+3+,Sr31+), DBW110(Yr2+, Lr13+10+,Sr13+11+) and DBW93(Yr9+, Lr26+23+, Sr31+) for commercial cultivation in NWPZ, NEPZ, CZ and PZ, respectively. These cultivars are becoming popular among farmers due to their yield advantage, resistance to diseases, tolerance to high temperature and better quality traits. Also, DBW 129 was screened in multiple disease screening nursery (MDSN) and observed resistant to all rusts, leaf blight, powdery mildew, flag smut and shoot fly. The adoption of the newly developed cultivars for deployment of differential genes for resistance would lead to reduction in disease pressure and bring higher profitability to farmers in different agro-ecological zones in India.
James,Winans, Julian, Garcia, Kellie, Damann, Gary, Bergstrom, , , , , , , , , , , , , , , , , , , , , ,
In addition to causing Fusarium head blight of wheat and other cereals, Fusarium graminearum is associated with dozens of wild or weedy grass species. Their role in the disease cycle and evolution of the pathogen has not been established despite their widespread distribution. A three-year survey of wild grasses in New York (USA) found that inflorescences and overwintered stems were frequently colonized by F. graminearum. Through a series of controlled laboratory experiments, wheat and five common grass species were compared for their potential to support inoculum production. Artificially infested stem tissue from several grasses both retained F. graminearum at higher rates through a single winter and supported greater ascospore production per dry gram than wheat. Susceptibility of these species to root and crown rot was measured with a modified seed germination assay and a diverse panel of F. graminearum isolates. Differences were seen between host species, and some grasses were resistant to infection. Our results indicate that wild grass species may support significant F. graminearum inoculum production while differing in their suitability for root and crown colonization. Studying interactions between F. graminearum and alternative host plants can improve our understanding of evolution in a broad host range pathogen and our ability to predict the risk of crop epidemics. We are currently evaluating isolates collected from wild grasses for mycotoxin production and aggressiveness on wheat.
National Institute of Agricultural Research
Nsarellah,Nasserlhaq, Wuletaw, Tadesse, Ahmed, Birouk, , , , , , , , , , , , , , , , , , , , , , , ,
In the context of climate change, drought is one of the most important and complex abiotic stresses affecting crop production worldwide. The adoption of an appropriate technological package, principally drought tolerant varieties, may overcome these challenges to meet global food security needs for the rapidly growing human population, particularly in developing countries. Therefore, this research was carried out to identify efficient phenotypic and genetic selection criteria to identify drought tolerant wheat varieties. In this perspective, 200 diverse elite bread wheat lines from ICARDA and CIMMYT were evaluated under four Moroccan environments during the 2015 and 2016 seasons for yield and 15 agro-physiological traits. The same set of genotypes was genotyped using 15k SNPs. Significant environment and genotype environment interaction effects were observed for yield. Average yield reached 3.18t/ha and ranged from 2.45 to 4.27t/ha. The secondary traits were mostly dominated by the environment effect (p<0.001). Based on correlation and regression analysis between grain yield and phenotypic data, the biomass, grain number per m<sup>2</sup> and to a lesser extent fertile spikes number and thousand kernel weights (depending of drought scenarios) can be more reliable traits than yield for the identification of drought tolerant genotypes. Moreover, the ground cover and canopy temperature depression can be used as supplementary criteria for more accurate selection. Slow selection on the basis of phenotypic traits may be accelerated and improved by using molecular markers. The genetic analysis highlighted significant SNPs and identified new QTLs linked to yield and the most efficient phenotypic traits under drought conditions. These findings could be useful for breeding drought-resistant wheat cultivars using marker-assisted selection to accumulate these favorable alleles of SNPs associated with yield-related traits to increase grain yield.
Sathguru Management Consultants
Kanan,Vijayaraghavan, Venugopal, Chintada, Rituparna, Majumder, Richa, Kapur, Aishwariya, Varadan K, , , , , , , , , , , , , , , , , , , ,
South Asia has the highest "wheat dependent" low income community in the world. Stem rust and blast are recognized as the most damaging disease of wheat in the region producing 19% of the world's wheat. In order to combat the potential threat the national research centers were geared up to track the real time movement of wheat diseases, generate disease incidence data and create an enabling environment to boost wheat research in the region through streamlined efforts and enhanced SAARC tool box deployed six years ago.
Recent data (2016-17) from the tool box has shown a significant increase in the data records captured in this region compared to previous years. This has been possible because of heightened awareness amongst the scientists and with the continuous capacity building through pre-season and in-season surveillance trainings organized by Sathguru in collaboration with National Wheat Research Institutes at various levels.
The model is helping partner institutes to be self-sufficient for generating, maintaining wheat disease surveillance data in national and global databases and exchanging real time information with stakeholders. The application have been widely deployed and competently being used by 95% of rust surveillance teams in the wheat fields of SAARC region.
The study will focus on how national research center's judicious decision of carrying out diligent surveillance during the season contributed to safeguarding wheat crops in their respective nations through increased vigilance on emergence of new races and targeted introduction of regionally resistant varieties. Further using this data scientist's can aim to strategize their wheat research for identification of resistant varieties and eventually resulting in increased productivity addressing food security of the region.