Cereal Crops Research Institute (CCRI), Pirsabak Nowshera Khyber Pakhtunkhwa-Pakistan
Gulzar,Ahmad, Imtiaz, Muhammad, Khilwat, Afridi, , , , , , , , , , , , , , , , , , , , , , , ,
In the current scenario of climatic change, exploration and development of new stable genotypes performing better under stressed and non stressed environmental conditions is the priority of wheat breeders for exploiting genetic variability to improve stress tolerant cultivars. Late planting is one of the major abiotic stresses, seriously influencing wheat production. In the current study, twenty eight bread wheat genotypes were evaluated independently under normal (optimal) and late (stress) planting conditions at Cereal Crops Research Institute (CCRI), Pirsabak Nowshera Khyber Pakhtunkhwa Pakistan during 2013-14. Analysis of variance revealed highly significant (P < 0.01) differences among the genotypes, planting (sowing dates), and genotype ? sowing dates interactions effects for the studied traits. Generally, reduction in plant height (0.41 to 10.91%) and grain yield (0.36 to 53.35%) was observed among the tested genotypes under late planting as compared to normal (optimal) planting. Least % reduction in grain yield was recorded for genotypes BWL-23 (0.36%), BWL-4(0.76%), BWL-16(1.22%) and BWL-13 (1.78%) and were found tolerant to late planting stress as compared to check (Pirsabak-2008). Eight stress selection indices i.e. Mean productivity (MP), Tolerance (TOL), Geometric Mean Productivity (GMP), Harmonic mean (HM), Stress selection Indices(SSI), Stress Tolerance Index (STI), Yield Index (YI) and Yield Stability Index (YSI) were determined based on mean performance of genotypes evaluated under normal and late planting conditions. Analysis of correlation revealed that plant height and grain yield under normal and late planting conditions, had significant positive correlation with stress selection indices i.e. GM, HM, SSI and YI. These selection indices could be effective in identification of lines/ genotypes to late planting stress tolerant conditions. Based on MP, GMP, HM, STI and YI genotypes i.e. Pirsabak-2008, BWL-23 and BWL-27 were found late planting stress tolerant and could be recommended for sowing in both normal and late planting.
Panjab University Chandigarh
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.
Department of Plant Sciences, University of the Free State, South Africa
Marcel Meyer, Robert Park, Christopher Gilligan, Laura Burgin, Matthew Hort, David Hodson, Zacharias Pretorius
Despite being 10,000 km apart, the current study emphasizes the potential vulnerability of Australia to wind-borne Puccinia graminis f. sp. tritici (Pgt) spore introductions from southern Africa. Of four Pgt introductions into Australia since 1925, at least two (races 326-1,2,3,5,6 and 194-1,2,3,5,6) are thought to have originated from southern Africa. Microsatellite analysis of 29 Australian and South African Pgt races confirmed close genetic relationships between the majority of races in these two geographically separated populations, thus supporting previously reported phenotypic similarities. Using Lagrangian Particle Dispersion Model simulations with finely-resolved global meteorological data over a 14-year period and a three-day urediniospore survival time, the study showed that long distance dispersal of Pgt from southern Africa to Australia is possible, albeit rare. Transmission events occurred most frequently from central South Africa, but were also possible from southern South Africa and Zimbabwe; while none occurred from a representative source-location in Tanzania. Direct dispersal incursions into both the western and eastern Australian wheat belts were feasible. Together, the genetic and simulation data strongly support the hypothesis that earlier introductions of Pgt into Australia occurred through long-distance wind-dispersal across the Indian Ocean. The study thus acts as a warning of possible future Pgt dispersal events to Australia which could include members of the Ug99 race group. This emphasizes the continued need for Pgt surveillance on both continents.
University of Delhi South Campus, New Delhi
Towards understanding the molecular mechanisms of heat stress tolerance, we have analyzed heat stressed substractive cDNA libraries and undertaken genome-wide transcriptome exploration for genes associated with spike photosynthetic efficiency during thermal stress. The photosynthetic efficiencies of Aegilops tauschii and Ae. speltoides were also compared. While the former displayed nearly complete recovery of PSII, the adverse effect was more pronounced in the latter. Functional characterization of heat stress-associated transcription factors and thermal stress-associated proteins was also undertaken e.g. TaHSF, TabZIP, TaZnF and TaMIPS, and TaLTPs in the Indian wheat germplasm. Functional characterization of the three heat stress transcription factors was upregulated under high temperatures and other abiotic stresses. They also showed early flowering and better performance with respect to their growth and yield after heat stress. Additionally, we have identified various interacting components associated with thermal stress-mediated plant signaling partners during thermal stress.
P. triticina has a biotrophic relationship with wheat and needs certain elements from the wheat host for a successful life cycle. In recent years, several long lasting, minor resistance genes have been cloned, and their function suggests that the resistance is not due to a classic NB-LRR gene, but a gene that functions in a biotrophic pathway. The hypothesis was proposed that modification of a susceptibility gene can provide broad, long lasting resistance. To test this hypothesis, Thatcher was treated with EMS and screened for changes in susceptibility. M5 lines were evaluated in the greenhouse with BBBD Race 1 and 5 lines were identified. Also, M5 lines were planted in the field to verify the resistance and test the resistance effectiveness to natural infections of P. triticina. The same five lines were resistant in the field. Resistance ranged from few pustules, a race specific-like reaction, lesion mimics with few or no pustules, and near immunity. These lines were backcrossed to Thatcher, and resistant F2 plants were bulked and sequenced. Gene candidates will be identified and discussed.
Laboratory of Molecular Plant Physiology, Biotechnology Center of Borj Cedria (CBBC)
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.
Mohamed 5 university/ICARDA
Amadou tidiane sall, meryem zaim, Ayed Al-abdallat, Gregor Gorjanc, Jesse Poland, Miloudi Nachit, Abdel karim Filali Maltouf, Bouchra Belkadi, Rodomiro Ortiz, Filippo Bassi
Durum wheat production is globally important, but grain yield has been stagnating in recent decades. In order to ensure that its production maintains the pace with increasing demand, breeding for high grain yield must be supported by molecular-based methods. Genomic estimated breeding values for selection and genome scan were assessed as molecular tools holding maximum potential for durum wheat breeding. Four recombinant inbred line populations bred by inter-mating elite were sown in yield trials at five sites. All progenies were characterized using "genotyping by sequencing" method. A consensus map was developed, and missing genotypes were imputed using a Hidden Markov model to reach a total of 1987 polymorphic markers. Models accounting for genotype environment interactions were used to estimate the genetic component of each measured trait. Hence, Bayesian ridge regression was used to determine the predicted values and their relative accuracy in several combinations, testing full-sibs and half-sibs as training population for grain yield and 1,000 kernel weight. The high level of accuracy achieved suggests that GEBV for selection holds great potential for durum wheat breeding, as long as full-sibs are used as training populations, in combination with statistical models that account for G?E. In order to test the exploitability of genome scan to guide breeding crosses, a separate genome-wide association study was conducted. 288 elite were sown in the south of Morocco and at two sites along the Senegal River for two years. These sites show a temperature differential of 10?C. Implementing a GE model facilitated identifying the most heat tolerant among the tested entries. 8,173 polymorphic SNPs were inquired, and several associations could be identified between markers and the ability to withstand the heat gradient. Hence, GWAS holds great potential to increase genetic gain in breeding via increased accuracy in determining the crosses to be made.
Sathguru Management Consultants
Kanan Vijayaraghavan, Venugopal Chintada, Rituparna Majumder, Richa Kapur, K. Aishwariya Varadan
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.
All Russian Research Institute of Biological Plant Protection
Irina Petrovna Matveeva
Yellow rust caused by Puccinia striiformis West. is a harmful and dangerous disease in the south of Russia. Yield losses under optimum conditions on highly susceptible varieties can vary from 10 to 100%. During the growing season of 2017, cool weather with constant precipitation from the third decade of April to the first decade of June contributed to the intensive development of the pathogen. Surveys of the main winter wheat production areas in five agroclimatic zones of the region revealed that yellow rust was prevalent in all areas. The maximum development of P.striiformis was observed in southern submontane and western Priazovsky agroclimatic zones. Some varieties such as Grom, Yuka, Tanya, Anka had losses to yellow rust of up to 30-40 %. In the central and northern agroclimatic zones, the losses averaged 5%, whereas in the dry eastern steppe zone losses were only up to 1%. The build up of yellow rust inoculum in the region raises concerns that in 2018, under favorable weather conditions in spring, winter wheat crops could be infected with the disease, especially in the wetter agroclimatic zones.
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.