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.
Anvar,Jalilov, Zubaida, Kavrakova, Menu, Mamadyusufova, Botirov, Muhiddin, , , , , , , , , , , , , , , , , , , , , ,
The wild relatives of wheat, the genus Aegilops is of great interest for breeding. Many species of the genus Aegilops are distinguished by such valuable properties as resistance to rust diseases, drought resistance, and salt tolerance.
The evaluation of local wheat varieties on resistance to yellow rust showed that local varieties showed high resistance to the pathogen and were amazed from 0 to 10 %. Evaluation of Aegilops species for resistance to yellow and brown rust, showed that the species Aegilops triunciales showed high resistance to yellow and brown rust, except Ae. triunciales, collected in the Rudaki district and showed moderate resistance to brown rust - 20%. The view of the Aegilops cylindrical collected in the Rudakinsky district showed a moderate resistance to yellow rust and a high resistance to brown rust. View Aegilops tauschii, collected in the Rudakinsky district had a high resistance to yellow and brown rust. Species Aegilops crassa to yellow and brown rust showed a reaction from moderate resistance - 30% to moderate susceptibility - 40%. As a result of the studies to assess the resistance of wheat varieties in Central Tajikistan, the cultivars Jaldak, Safedaki Gorchivin and Viyod, which had high resistance to yellow and brown rust, as well as Pamir and Surkhak varieties, showed moderate resistance.
Distinct varieties of wheat with high and moderate resistance to the pathogen of yellow rust can be used as parental forms for breeding new varieties of wheat. Studies on assessing the resistance of Aegilops species have shown that the species Aegilops triunciales has a high resistance to the pathogen of yellow rust. Species of Aegilops tauschii and Aegilops crassa, collected from the Hissar salt source, had moderate resistance to the pathogen. These species of Aegilops can be used in the selection of new varieties of wheat.
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.
La Trobe University
Antony Gendall, Hans Daetwyler, Matthew Hayden
Wheat stem (Sr), leaf (Lr) and stripe (Yr) rust pathogens are among the most destructive fungal diseases threatening global wheat production. We utilized 2300 wheat accession including worldwide landraces, cultivars, breeding materials and 341 synthetic accessions backcrossed with three widely grown Australian cultivars (Annuello, Yitpi and Correll) to investigate rust resistance under wide environmental conditions. The germplasm was genotyped with 90K SNP chip, and was phenotyped for two seasons in three different environments against Sr and Lr and in four different environments against Yr. Different environments for each trait showed significant correlation with mean r values of 0.53, 0.23 and 0.66 for Lr, Sr and Yr; respectively. Single-trait genome wide association (GWAS) revealed several environment-specific QTL and multi-environmental QTL distributed on all chromosomes except 6D. Multi-trait GWAS confirmed a cluster of Yr QTL on chromosome 3B (within 8.3 cM) as well as a QTL for Sr and Lr on chromosome 3D. Linkage disequilibrium and comparative mapping showed that at least three Yr QTL exists within the 3B cluster including the durable rust resistance gene Sr2/Yr30. The same region was effective against Sr resistance but did not pass the stringent significant threshold in two environments. The 3D QTL was found mainly in the synthetic germplasm with Annuello background which is known to carry the Ag. elongatum 3D translocation carrying Sr24/Lr24 resistance gene. Interestingly, estimating the SNP effect using BayesR method showed that the correlation among the highest 5% QTL effects across environments were lower than that for the small effect QTL with differences in r values of 0.25 and 0.2 for Lr and Yr respectively. These results indicate the importance of small effect QTL that cannot be captured using GWAS in achieving durable rust resistance. The detected QTL in this study are useful resources for improving bread wheat resistance to rust diseases.
International Center for Agricultrural Research in Dry Areas
Wuletaw,Tadesse, Najib, Bendaou, , , , , , , , , , , , , , , , , , , , , , , , , ,
Hybrid wheat is a promising technology to increase yields worldwide. High seed production costs and low heterosis are the main constraints for the development of hybrid wheats. Maximizing heterosis, and selection and utilization of appropriate morphological, floral and flowering traits to optimize outcrossing are important for hybrid seed production. For an efficient hybrid wheat seed production, high anther extrusion is required to promote cross fertilization and to ensure a high level of pollen availability. A pool of 200 elite spring bread wheat male parental lines was visually assessed for anther extrusion in the plastic-house and field environments. Genome-wide association studies (GWAS) for anther extrusion was carried out using a total of 12725 SNP markers. A wide genotypic variance was observed. Several significant (|log10(P)| > 3.0) marker trait associations (MTAs) were detected. Both genotypes and environment influenced the magnitude of the anther of extrusion. The consistently significant markers could be helpful to introduce anther extrusion trait in high yielding varieties and consequently improve hybrid-seed production in wheat.
Research Center of Agricultural and Development in Northwest Semi-arid regions of Tunisia
Afef,OTHMANI, Olfa, SLAMA-AYED, Hajer, SLIM-AMARA, Mongi, BEN YOUNES, , , , , , , , , , , , , , , , , , , , , ,
Eleven durum wheat (Triticum durum Desf.) genotypes were screened to select for drought-tolerance under in vitro immature embryos culture. Drought stress is induced by using five PEG concentrations (0, 200, 270, 295 and 310 g/l of PEG 6000). Results showed, for all studied traits, significant differences among PEG treatments and genotypes. In fact, increasing PEG concentration decreases relative growth rate, callus water content, relative water content, in vitro tolerance and relative tolerance. Biplot analysis indicated that the first two PCs (principal components 1 and 2) explain 70.5 % and showed that Karim, Mahmoudi and Om Rabiaa are respectively the most drought tolerant varieties tested, however, Ben Bechir, Maghrbi and Nasr were the most sensitive.
Aleppo University, Aleppo , Syria
Bassam,Souliman, Naem, Al-Housien, Mohammad Shafick, Hakiem, Miloudi.M, Nachit, , , , , , , , , , , , , , , , , , , , , ,
Wheat yellow rust, caused by Puccinia triticina f. sp. tritici, is the major problem in wheat production in most parts of West Asia. Monitoring of the pathogen virulence factors and their changes provides basic information for the development of an early warning system. Wheat yellow rust has become increasingly important in the Syrian central and coastal areas during the last three years, The objective of this study was to identify races of the pathogen. Yellow rust samples collected at sites in the central and the coastal plains, were analyzed on differential host genotypes with known seedling resistance genes. According to the results of race determination, races 230E150, 166E150, 230E142 and 462E128 were identified. The race 462E128 designated the Warrior race, was identified at several sites across the Syrian central plains at the end of the 2017 growing season (early and Mid-May) when yellow rust exploded suddenly on a number of varieties, despite their previous high resistance ratings. The infections rapidly reached significant levels, in spite of the high temperature (up to 33?C) and the absence of rainfall or irrigation. This new virulent race (462E128) has been able to attack wheat lines with several major resistance gene(s) including: Spaldings Prolific (SP), Yr 3+4, Triticum spelta (Yr5), which remained effective until 2016 in Syria, Virulence to lthe resistance genes Yr1, Yr2, Yr2+, Yr3V, Yr3ND, Yr4+, Yr6, Yr6+, Yr7, Yr7+, Yr9, Yr9+, Yr11, Yr12, Yr18, Yr24, Yr26 Spaldings Prolific (YrSP), Anza (YrA+) Spaldings Prolific (SP), Yr 3+4, Triticum spelta (Yr5) and Selkirk (YrSK) was also found. Virulence to Carstens V (CV), Yr 15/6* Avocet S and Yr 5/6* Avocet S; was not found. According to our findings, the Warrior race has increased in frequency within the mix of yellow rust races in these areas in Syria . It is expected that the Warrior yellow rust race will cause damage on resistant wheat cultivars in 2018.
Turkey-ICARDA Regional Cereal Rust Research Center (RCRRC), ICARDA, Menemen, Izmir, Turkey
Muhammad Massub Tehseen, Ezgi Kurtulus, Maha Al Ahmed, Ahmed Amri, Mariana Yazbek, Ali Shehadeh
In 2016 the bread wheat (BW) and durum wheat (DW) landrace accessions were evaluated against PstS2 and in 2017 against a mixture of PstS2 and warrior race in field inoculations at Izmir precision stripe rust phenotyping platform. Inoculation was carried out three times during seedling, tillering and booting stages using mixture of fresh spore and talcum powder. Adult-plant responses of tested accessions were recorded according to 0-9 scale once the flag leaf of the susceptible cultivar became fully susceptible. During 2016, out of 3319 BW accessions, 1135 (36%), 871 (28%) and 1133 (36%) were found resistant (1-3 scale), moderately resistant (4-6), and susceptible (7-9) to PstS2, respectively. Amongst the resistant accessions in 2016, 1043 (33%) remained resistant while 786 (25%) showed moderate resistant and 1310 (42%) became susceptible. In 2017, 43% of moderately resistant accessions showed susceptibility to warrior race and 57% remained resistant to moderately resistant. Within the susceptible accessions to PstS2 race in 2016, 22% showed resistance to the warrior race and the remaining were susceptible. In case of DW in 2016, 76% (553) of the accessions were resistant to PstS2, 23% (163) were moderately resistant and only 1% (7) were found susceptible. In 2017, 329 (46%) of the resistant accessions were found resistant, whereas 289 (40%) and 105 (15%) showed moderately resistance and susceptible reaction to Warrior race, respectively. The present data indicated that BW landraces were generally more susceptible to stripe rust than DWs. Susceptibility of both BW and DW accessions to Warrior race indicated that most likely some of the uncharacterized resistance genes which conferred resistance to PstS2 were ineffective against the warrior race. Sources of resistance to both races were identified in both BW and DW. Genetic architecture of identified sources of resistance in present study requires further investigations.
Egerton University Njoro, Kenya
Ruth Wanyera, James Owuoche, Julian Rodriguez, Annemarie Justesen, Lesley Lesley, Sridhar Bhavani, Cristobal Uauy, Mogens Hovmøller
Emergence of new virulent races of Puccinia striiformis f. sp. tritici (Pst) to stripe (yellow) rust resistance genes in wheat (Triticum aestivum L.) has historically resulted in severe yield losses worldwide. We conducted a study to characterize the virulence profiles of Pst races prevalent in Kenya from historic (1970-1992) and recent collections (2009-2014). Pst isolates collected during surveys in Kenya were characterized at the Global Rust Research Centre (GRRC), Denmark. Yellow rust differential sets (wheat lines with known Yr resistance genes), and strain-specific sequence-characterized-amplified-region (SCAR) markers were used to group the Pst isolates as Pst1 or Pst2. Virulence to Yr1, Yr2, Yr3,Yr6, Yr7, Yr8, Yr9, Yr17, Yr25, Yr27, and the seedling resistance in AvocetS were detected. A total of 12 virulence profiles /races were detected in isolates obtained during 1970 to 1992, while six races were detected from samples collected between 2009 to 2014. In both periods, races with virulence profiles Yr2, Yr6, Yr7, Yr8, Yr25, Yr27, Avs and Yr2, Yr6, Yr7, Yr8, Yr17, Yr25, AvS were common. The SCAR results revealed that both Pst1 and Pst2 strains were present in the Pst isolates tested, Pst1 even in isolates from the 1970s. Additional isolates were also identified with neither Pst1 nor Pst2 profiles. From our findings, race analysis is key to understand the race diversity and pre-breeding efforts for effective resistance gene deployment.
Wheat Research Institute, Ayub Agricultural Research Institute,Faisalabad,Pakistan
Mehvish,Makhdoom, Javed, Ahmad, Makhdoom, Hussain, Iqra, Ghafoor, , , , , , , , , , , , , , , , , , , , , ,
Wheat crop is facing immense losses each year owing to climate change, eventually being major threat to global food security. So, the objective of the present study was to screening of advance lines under drought and heat stress conditions. In following study, 30 advance lines of wheat along with four checks(Faislabad-08, Millat-11, Galaxy-13 and ujala16) with three treatments (heat, drought, normal) were tested for different morphological (days to heading, plant height, days to maturity, biomass,1000 grain weight and grain yield) and physiological (canopy temperature at vegetative & reproductive stage, NDVI vegetative & reproductive), parameters. Biplot analysis depicted that V2, V3, V8, V14, V19, V25, and V30 showed the highest OP vector for grain yield in drought environment. Whereas, under heat conditions, V3, V4, V5, V10, V11, and V12 displayed their maximum longest vector for grain yield. Correlation analysis depicted that grain yield had non-significant correlation with canopy temperature (vegetative stage), normalized difference vegetation index (vegetative stage) canopy temperature (reproductive stage), plant height, days to heading and days to maturity under heat stress environment, while it had significant association with biomass and thousand grain weight. Under drought environment, grain yield had positive and significant correlation with biomass while on the other hand it had negative but significant association with normalized difference vegetation index (reproductive stage) and canopy temperature (reproductive stage). Best performing lines could be efficiently exploited in research programs to evade the perilous impact of climate change.