Ethiopian Institute of Agricultural Research
Bedada,Girma, Endale, Hailu, Fikrte, Yirga, Bekele, Abeyo, Gordon, Cisar, Gina, Brown-Guedira, Erena, Edae, Pablo, Olivera, Matthew, Rouse, , , , , , , , , , , ,
In Ethiopia, breeding resistant wheat varieties is a priority for wheat rust management although new virulent rust races have periodically resulted in losses of R-genes, epidemic outbreaks, and yield losses of up to 100%. During 2014 and 2015, 160 wheat varieties and lines including five checks and 12 differential lines with known resistance genes were evaluated against four stem rust pathogen races at both seedling and adult plant stages. In the field at Kulumsa, Ethiopia, the lines were evaluated in four separate nurseries in an augmented design where each nursery was inoculated with a different Puccinia graminis f. sp. tritici race: TTKSK, TKTTF, TRTTF, and JRCQC. Kingbird, a check variety, displayed low average Area Under the Disease Progress Curve (AUDPC) (67 to 238) and Average Coefficient of Infection (ACI) (1.1 to 9.7) in response to the four races. Effect of lines possessing Sr24+Sr36 and Sr31+Sr36 resistance genes on rust development was comparable to Kingbird or even better. Likewise, 48, 34, 19 and 28 varieties and lines had lower or comparable AUDPC for TTKSK, TKTTF, TRTTF and JRCQC compared to Kingbird. Commercial bread wheat varieties Shorima, Huluka, Hogana, and advanced lines CIMMYT 14, ETBW7058, ETBW7101 and ETBW7258 for which Sr24/Lr24 was postulated, possessed AUDPC and ACI lower than Kingbird. However, all these lines possessed susceptible or intermediate seedling reactions to Sr24-virulent race TTKTT from Kenya at the seedling stage. CIMMYT 18 showed susceptibility to 3 races at seedling stage, but lower AUDPC and ACI than the checks except Kingbird, indicating adult plant resistance. However, this adult plant resistance was marginal in effect to race TKTTF. Resistance genes Sr2, Sr57/Lr34, Sr24/Lr24, Sr25/Lr19, Sr38/Lr37 and SrTmp were postulated at various frequencies in this germplasm. Seedling and adult plant resistance sources identified can be used for rust resistance breeding in Ethiopia.
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.
Maize Research Institute Zemun Polje
Dragana,Ran?i?, Vesna, Kandi?, Biljana, Vuceli?-Radovi?, Jasna, Savi?, Miroslav, Zori?, , , , , , , , , , , , , , , , , , , ,
When environmental stress develops during reproductive phases of growth, wheat plants have to rely increasingly on remobilisation of previously stored assimilates to maintain grain filling. The present study was undertaken to determine the effect of several peduncle (the uppermost stem internode) morpho-anatomical and biochemical traits on grain weight, and to assess the contribution of the peduncle water-soluble carbohydrate (WSC) reserves shortly after anthesis to its variation. In 2-year field trials, 61 wheat genotypes were used (27 F4:5 families, 17 parents used for the crosses and the 17 current best standards) comparing intact control plants (CP) with plants that were defoliated (DP) by cutting off all leaf blades 10 days after anthesis to simulate terminal stress. Estimated contributions of peduncle assimilate reserves to grain weight/spike were from 0.06 to 0.31% and from 0.11 to 0.45% in CP and DP plants, respectively. High peduncle reserve mobilization efficiency, a longer exposed part of the peduncle and larger peduncle storage capacity (through higher parenchyma and/or lower lignified area) were of specific benefit for maintaining grain weight in defoliated plants. There was a large difference in compensation of grain yield loss by dry matter remobilization within studied genotypes (in average 1.2-36.1%). Although compensation of yield loss might be improved through breeding process (our F4:5 families had slightly higher mean compensation effect than their parents under moderate stress), it does not mitigate the effect of post-anthesis drought in great extent (up to 38.4%).
Faculty of Agriculture, The University of Jordan
Moneer,Mansour, Nasab, Rawashdah, Rabei, Sayaydeh, , , , , , , , , , , , , , , , , , , , , , , ,
Durum wheat (Triticum turgidum subsp. durum) landraces are rapidly disappearing from the main wheat production areas in the Fertile Crescent. Such local landraces are most likely contain geographically specific, ectopically adapted alleles or gene complexes for their harsh environments. A panel of 156 durum wheat landraces and released varieties were assembled from historical collections deposited in national and international gene banks and from a recent active collection mission from selected areas across Jordan. The panel were evaluated under field conditions in two different locations for one growing season. Data for days to heading, plant height, peduncle length, number of spikes spike length, spike weight, grains number, grains weight, number of kernels per spike and thousand-kernel weight were recorded. Results indicate the existence of a wide variation between the tested genotypes for all tested agronomical traits. For heading date, the Jordanian landrace "JDu103" was the earliest under dry environment conditions. Regarding grains weight and spike weight, the Jordanian landrace "JDu105" produced the highest mean value under humid conditions. Another landrace "JDu46" produced the longest spikes and the highest TKW mean value, while the Jordanian landrace "JDu105" produced the heaviest spikes weight mean value, while "JDu100" produced the highest grains number. For molecular analysis, total genomic DNA was extracted from each genotype and then used for SNP genotyping using Illumina iSelect wheat 90k SNP chip. Structure analysis showed that the analyzed durum wheat panel can be divided into three genetically distinct subgroups. The GWAS analysis identified 93 significant markers-traits associations for multiple traits with two QTLs located at 7A and 7B, which seems important for TKW in durum wheat under dry environments. In conclusion, the Jordanian landraces used in this study showed wide genotypic and phenotypic variability, which can be considered by plant breeders for their future use in breeding programs.
Rosemary,Shrestha, Kate, Dreher, Victor, Jun Ulat, Luis A., Pubela Luna, Susanne, Dresigacker, , , , , , , , , , , , , , , , , , , ,
The Global Wheat Program of CIMMYT is one of the largest public breeding programs in the world consisting of millions of lines/ genotypes derived from thousands of crosses evaluated under using a shuttle breeding cycle and multi-environment testing. The germplasm is phenotyped for conventional (such as yield and grain quality) as well as non-conventional traits (physiological traits) in field and greenhouse conditions. The breeding germplasm is also screened with genome-wide markers (using Illumina SNP array, genotyping-by-sequencing, or DArTseq platforms) and/or multiple gene/QTL region-specific molecular markers (using KASP platform). All genotyped samples are registered in the "DNA SampleTracker," a software system for tracking DNA samples developed at CIMMYT. In collaboration with High Throughput Genotyping Platform project, the plant sample and data collection methods are optimized. Meanwhile, the extensive wheat genealogies and phenotypic information have been maintained in the International Wheat Information System and will be transferred to a new Enterprise Breeding System. Furthermore, several bioinformatics/statistical genetics methods with the objectives of gene discovery and genomic prediction have been developed and utilized for optimizing genomics-assisted selection. The wheat team is a member of "Genomic Open-source Breeding Informatics Initiative (GOBII)" which aims to develop and implement genomic data management systems to enhance the capacity of breeding programs. Under this initiative, a new genomics database has been built and a pilot wheat version is being tested at CIMMYT. Several decision support tools are also under collaborative development, such as a Genomic Selection Pipeline based on Galaxy, Flapjack-based F1/line verification, and marker assisted backcrossing tools. Additional tools are envisioned for the future including a Cross-Assistor and Selection-Assistor. The ultimate aim is to seamlessly connect the genomic database, phenotypic database, and decision support tools to support the breeding selection process and to lead to the development of cultivars with increased rates of genetic gain.
ICAR Indian Institute of Wheat and Barley Research, Karnal
Satish Kumar, Rekha Malik, Garima Singhroha, Vinod Tiwari, Gyanendra Pratap Singh
Breeding rust resistant cultivars using conventional methods is time-consuming, complex and slow, but molecular markers offer a rapid alternative for developing cultivars with improved disease resistance. Three wheat cultivars, DBW88, DBW107, and DBW110, from different production zones were used as recipients for incorporation of resistance genes using a marker-assisted backcross (MAB) breeding approach. Leaf rust resistance gene Lr32 is being incorporated into all the three varieties, stripe rust resistance gene Yr15 is being incorporated into DBW88 and DBW107, and stem rust resistance gene Sr26 is being added to variety DBW110. Lines PBW703 (Yr15), FLW15 (Lr32) and Avocet (Sr26) were used as donors. Six cross combinations viz., DBW88/PBW703, DBW107/PBW703, DBW88/FLW15, DBW107/FLW15, DBW110/FLW15 and DBW110/Sr26 were made at Karnal during 2015-16 and the crosses were grown at IIWBR-RS, Dalang Maidan for backcrossing. BC1F1 plants were raised at Karnal during 2016-17. Both foreground and background selections were practiced in each combination. SSR markers gwm264 and barc135 were used for foreground selection of Lr32, marker barc8 was used for selection of Yr15, and markers Sr26#43 and BE518379 were used to detect presence and absence of Sr26. From 90 to 127 polymorphic SSR markers chosen for each cross from an initial set of 800 screened on the parents are being used for background selection.
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.
Muhammad,Noor, Makhdoom, Hussain, Majid, Nadeem, Monsif, ur Rehman, Jesse, Poland, Ravi, Prakash Singh, Matthew, Reynolds,, , , , , , , , , , , , , , , ,
Drought and heat along with rusts are the most common biotic and abiotic stresses that affect growth, development and yield of wheat crop in Pakistan. CIMMYT in partnership with Wheat Research Institute Faisalabad (WRI-Fsd), USDA, and Kansas State University initiated an effort to develop heat tolerant, high yielding, and farmer-accepted rusts resistant wheat varieties for Pakistan. A set of 1656 wheat lines received in the form of EPCBW and SABWGPYT nurseries were tested in 2013-14 and 2014-15 wheat season, respectively. Testing of the materials at (WRI-Fsd), Pakistan under normal and late planting conditions resulted in the selection of 55 lines with higher grain yield and resistant to both leaf (LR) and yellow (YR) rusts. Among these lines, the line no. 1027 produced maximum yield (5.78 ton/ha) under normal and line no. 5030 produced maximum yield (3.38t/ha) under late planting conditions with resistance to both LR and YR. Further evaluation of the selected 55 lines as HYT-60 in 2015-16 showed the average grain yield ranged from 4.98 to 2.51 ton/ha under normal and 1.74 to 0.73 t/ha under late planting. Three lines HYT-60-57, HYT-60-7 and HYT-60-5 were included in the first year advanced yield trials to test for their potential as commercial cultivars while another seventeen lines were distributed as HYT-20 to six national wheat breeding programs for yield testing at key location which will enable national partners to combine yield potential with resistance to biotic and abiotic stresses.
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.
Wheat Disease Research Department, Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt
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Stripe rust (Puccinia striiformis f. sp tritici) (Pst) infected wheat samples collected from three Egyptian Governorates (Alexandria, Beheira and Kafr-El Sheikh) were processed for race analysis to determine the race identity among the current populations of the stripe rust fungus. Single uredinial isolates were inoculated to a core set of the 17 World/European differential hosts along with wheat lines with Yr17, Yr25, Yr32. Based on virulence phenotyping, the data revealed that the current populations of Pst belong to three races: Triticale aggressive (virulent to Yr2, Yr6, Yr7, Yr8, Yr10); PstS3 (virulent to Yr2, Yr6, Yr7, Yr8, Yr25); and PstS2 (virulent to Yr2, Yr6, Yr7, Yr8, Yr9, Yr25, Yr27). No collections were found with the Warrior race, that has virulence to Yr1, Yr2, Yr3, Yr4, Yr6, Yr7, Yr9, Yr17, Yr25, Yr32, YrSp).