All BGRI Abstracts

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Genetic Improvement in Quality, Grain Yield and Yield Associated Traits of Durum wheat (Triticum turgidum var.durum L.) in Ethiopia

BGRI 2018 Poster Abstract
Mekuria Dejene Ethiopian Institute of Agricultural Research

Information about changes associated with advances in crop breeding is essential for understanding yield-limiting factors and developing new strategies for future breeding programmes. Thirty-six durum wheat varieties released since 1966 were evaluated in three replications of the Randomized Complete Design at Debre Zeit and Akaki, Ethiopia during the 2016 cropping season to estimate the amount of genetic gain made over time in grain yield potential, yield-associated traits and in protein content. Analysis of variance revealed significant differences among varieties for all 16 quantitative traits, protein content and protein harvest in Kg ha-1 at each of the locations. Grain yield varied between 1.66t ha-1 for Arendato released in 1966 to 3.90t ha-1 for Megenagna released in 2012 with mean of 2.952t ha-1 at Debre Zeit. At Akaki yield range was between 2.45 and 5.04t ha-1 with mean of 3.992t ha-1. 25 varieties surpassed Arendato (3.754t ha-1) at this location. In the combined ANOVA significant difference between the varieties was observed only for spike length, spikelets spike-1, grains spikelet, grains spike-1, plant height, days to flowering, thousand grain weight and hectoliter weight. Varieties specifically adapted to only one of the locations, widely adapted varieties and varieties not adapted to any of the locations were identified. Regression analysis revealed that grain yield has increased by 22kg ha-1 year-1 since 1966; an increase of 40.6% over yield in 1966. This was accompanied with a significant decline of 11.4% in spike length, 6.7% in spikelets spike-1, 17.9% in protein content and 31.2% in protein yield ha-1 and a significant increase of 41.1% in grains spikelet-1, 32.9% in number of grains spike-1, 22.3% in thousand grain weight, 17.8% in grain filling period, 23.9% in seed growth rate, 40.1% in grain yield production rate, 7.9% in harvest index.

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Epidemics of yellow and stem rust in Southern Italy 2016-2017

BGRI 2018 Poster Abstract
Mehran Patpour Global Rust Reference Center (GRRC), Aarhus University, Denmark
Mogens Støvring Hovmøller, Jens Grønbech Hansen, Annemarie Fejer Justesen, Tine Thach, Julian Rodriguez-Algab, Dave Hodson, Biagio Randazzo

In 2016, severe epidemics of yellow (stripe) rust were observed on durum and bread wheat in European regions where the diseases in the past were insignificant or absent. Stem rust was also observed at epidemic levels for the first time in more than 50 years in Europe. On Sicily, both yellow and stem rust caused epidemics on cultivated durum and bread wheat and numerous breeding lines. In 2017, surveys in farmer fields and trial monitoring were carried out in Southern Italy during April-June. A total of 61 farmer fields and 9 experimental plots were inspected and rust samples collected. Despite unfavourable weather conditions for rust development, stem rust, yellow rust and leaf rust were detected on 86%, 50% and 14% of the surveyed sites, respectively. The surveys on Sicily covered approximately 70% of the durum wheat area, and data uploaded and visualised on the Wheat Rust Toolbox. On mainland Italy and Sardinia, yellow rust was observed, and sampled from nine fields in Sardinia and two in Puglia, whereas stem rust was detected and sampled in experimental plots in Sicily, Sardinia, Puglia, Lazio and Emilia Romagna. A total of 94 samples of stem rust, 30 samples of yellow rust, and 3 rust samples from Berberis aetnensis were sent to GRRC. Preliminary results of yellow rust genotyping and race phenotyping showed prevalence of race Triticale2015. Warrior(-) and a new race (Pst'New'- First detected in 2016) were also detected. For stem rust, TTTTF and TTRTF were detected in Sicily and mainland Italy and TKTTF was identified in Sardinia. Susceptibility of major commercial durum cultivars and breeding lines suggests the need for both durable resistance breeding and systematic surveys coupled to an early warning system.

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Evaluation of durum wheat landraces to yellow rust (Puccinia striiformis Westendorf f. sp. tritici)

BGRI 2018 Poster Abstract
Reza Mohammadi Dryland Agricultural Research Institute, Sararood branch, AREEO, Kermanshah, Iran
Ehsan,Lorestani, Reza, Haghparast, Mohammad Reza, Jalal Kamali, Ahmed, Amri, , , , , , , , , , , , , , , , , , , , , ,

Yellow rust (Puccinia striiformis Westendorf f. sp. tritici) is an important disease on wheat worldwide and especially in the highlands of West and Central Asia. Wheat landraces are composed of complex, variable, genetically dynamic and diverse populations, in equilibrium with both biotic and abiotic stresses prevailing in their environment. A germplasm collection consisting of 380 durum wheat accessions conserved at National Plant Gene Bank (Seed and Plant Improvement Institute, Iran) with worldwide origins, along with four check varieties were screened for resistance to yellow rust, and were also evaluated for several drought adaptative traits under rainfed conditions during 2009-10 cropping season at Sararood agricultural research station, Kermanshah, Iran. The study was conducted to quantify the phenotypic diversity and exploring durum accessions for yellow rust resistance, and to characterize the agronomic profile of different subsets of accessions for reaction to local yellow rust races. High natural infection, caused by the predominant virulent races of 6E8A+ and Yr27+, was experienced as shown by the 100 S reaction of the check bread wheat ?Sardari? and several highly susceptible accessions. The tested accessions exhibited significant variation in yellow rust severity, ranging from highly resistant to highly susceptible. Approximately 12.1% of accessions were found to be resistant to yellow rust, 9.5% were moderately resistant, 10.5% were moderately susceptible and 67.9% were susceptible. The germplasm showed a relatively modest response to yellow rust as expressed by a decrease in 1000-kernel weight (TKW) and a lower yield of the susceptible vs. resistant subsets by 11.4% and 19.9%, respectively. A comparison of foreign vs. Iranian resistant accessions, revealed higher yield productivity, higher TKW, and shorter plant height for the foreign accessions. Durum germplasm may constitute valuable genetic material for breeding new durum varieties characterized by high yield productivity under rainfed conditions and with adequate resistance to yellow rust.

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Race analysis of Puccinia striiformis f.sp. tritici in Iran-2017

BGRI 2018 Poster Abstract
Farzad Afshari Seed and Plant Improvement Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran.
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Stripe rust of wheat, caused by Puccinia striiformis f. sp. trirtici (Pst) is an important disease in many parts of Iran. Over last two decades several epidemics have occurred in Iran causing the breakdown of widely utilized sources of resistance in wheat cultivars. Fifty isolates were collected from different parts of Iran during 2017. Eight isolates of Pst. from 2017 have been processed to date for race analysis. Infection types were assessed on a 0-9 scale 16 and 18 days after inoculation using a scale similar to that described by McNeal et al. (1971). Infection types (ITs) 7 to 9 were regarded as virulent (susceptible) and lower than 7 were avirulent. Pathotypes 102E158A+,Yr27; 6E158A+,Yr27; 102E158A+,Yr27; 166E154A+,Yr27; 38E174A+; 38E158A+,Yr27; 238E190A+,Yr27 and 38E190A+,Yr27 were identified. Pathotype 238E190A+,Yr27+ (from West of Iran) was more aggressive during this study. Plants with Yr1, Yr4, Yr5, Yr10, Yr15, Yr24 and YrSP were resistant to all pathotypes. Pathotypes with virulence on plant with gene/s Yr2, Yr6, Yr7, Yr8, Yr9, Yr25, Yr26, Yr27, Yr32, YrSD, YrSU, YrND and YrA were more common. Seedling tests of Iranian wheat cultivars to race 238E190A+,Yr27+ showed that the new released cultivars that included Parsi, Baharan, Bahar, Pishgam, Zareh, Urom, Maihan, Dena, Haydarei and Shabrang were resistant to the new aggressive race with virulence on plants with Yr27.

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Linkage Mapping of Stem Rust Resistance Gene(s) in Spring Wheat Line CI14275

BGRI 2018 Poster Abstract
Zennah Kosgey University of Minnesota, St. Paul, MN 55108, U.S.A
Ruth Dill-Macky, Ruth Wanyera, Sridhar Bhavani, Worku Bulbula, Matthew Rouse

Stem rust caused by Puccinia graminis f.sp. tritici (Pgt) is one of the major constraints to wheat (Triticum aestivum) production worldwide. Pgt races have rapidly evolved in several geographical regions due to the deployment of single resistance genes resulting in boom and bust cycles, hence combinations of resistance genes through pyramiding ensures durability of resistance in wheat varieties. Spring wheat line CI14275 displayed high levels of field resistance to stem rust in Kenya and USA compared to the parents in its pedigree (Thatcher, Kenya Farmer & Lee). To understand the genetics of resistance in CI14275, 114 Recombinant Inbred lines (RILs) were developed from the cross CI14275/LMPG-6 and screened for seedling response to Pgt races TTTTF, TPMKC, TRTTF, TTKSK & RTQQC. Chi-square goodness of fit tests suggested one-gene, three-genes, and four-genes segregated for response to races TTTTF, TPMKC and RTQQC, respectively. The RILs were all susceptible to races TTKSK and TRTTF. CI14275 showed intermediate low infection types only against races TPMKC (23-) and TTTTF (1+3C). Field screening of the population was completed in Kenya, Ethiopia and St. Paul where CI14275 showed high levels of resistance TMR (Kenya), 5MS (Ethiopia) and 5RMR (St. Paul) against the prevalent races in the stem rust screening platforms. LMPG-6 displayed susceptible responses ranging from 70S-90S in the three locations. 90K wheat Single Nucleotide Polymorphism (SNP) marker platform will be used to genotype parents and the population.

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TaWRKY79, from a wheat variety with adult resistance, negatively confers wheat resistance to stripe rust at seedling stage

BGRI 2018 Poster Abstract
Xiaojie Wang Northwest A&F University
Yanping,Fu, kang, Wang, Yingbin, Hao, Zhensheng, Kang, , , , , , , , , , , , , , , , , , , , , ,

Wheat adult plant resistance (APR) to stripe rust, a non-race-specific and durable resistance, is ideal for breeding. However, the knowledge concerning APR mechanism is largely limited. In order to further investigate the molecular basics of APR to provide guidance for wheat breeding, we conducted the transcriptome sequencing of wheat XZ9104 infected by Puccinia striiformis f. sp. tritici (Pst) at seeding and adult stages, respectively. Comparative analysis revealed that many WRKY transcription factors (TFs) may participate in the APR to stripe rust, of which, TaWRKY79 transcript levels were sharply elevated at the early infection stage in seedling plants. To dissect the relationship between TaWRKY79 and APR, we further studied the function of TaWRKY79. Subcellular localization showed that TaWRKY79 is located in the nuclear, and TaWRKY79 protein contains a separated region for mediating transcriptional activation at the C-terminus (246-328 aa) by yeast one-hybrid analysis. When TaWRKY79 was silenced by virus-induced gene silencing (VIGS) in seedling plants, the Pst growth was attenuated, with shortened hyphae, reduced hyphal branches and colony size. Meanwhile, the expression of TaWRKY79 was highly suppressed by salicylic acid (SA) but induced by jasmonic acid (JA) in seedling of wheat, and the transcription levels of LOX2 and PDF2.2 were significantly reduced, but the expression of PR1.1 was enhanced in TaWRKY79 knocking-down seedlings of wheat. Hence, these findings suggested that TaWRKY79, as a SA/JA cross talk, might play a negative role in resistance defence response to Pst infection at seeding stage by simultaneously activating the JA-dependent pathway and suppressing the SA-dependent pathway.

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Building upon past successes for a continued impact on production and food security through breeding high yielding climate change resilient durum wheat varieties

BGRI 2018 Poster Abstract
Mohamed Salah Gharbi National Institute of Agriculture Research, Tunisia

Meeting food security challenges is a high priority in many developing countries. North African countries are among those with the highest per capita wheat consumption in the world and chronic grain deficits. Climate change scenarios predict decrease of rainfall and increase of temperature with negative impact on crop production and hence food security. Along with adoption of modern technologies, breeding higher yielding and more climate change resilient wheat varieties is widely seen as a tool that can sustain past yield gains and food production increases. Durum wheat production in Tunisia greatly benefited from the green revolution ingredients. Continued breeding lead to replacement of the early semi dwarf varieties with higher yielding, better disease resistant and more drought tolerant ones that have positively impacted yield at farmer and national level. Monitoring gains from increased yield potential and resistance to the most damaging foliar diseases, mainly septoria leaf blotch, leaf rust and stripe rust, showed that grain yield of recently released varieties is up to four times that of the tall late maturing landraces grown before the 1970's and up to 2.5 times that of varieties of the early years of the green revolution. Chlorophyll content, green leaf duration, deeper root development from diverse donors including wild wheat relatives and grain yield are being integrated in the breeding program for the selection of more drought and heat stress tolerant durum cultivars

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Global network for precision field-based wheat phenotyping

BGRI 2018 Poster Abstract
Carolina Saint Pierre CIMMYT
Michel E. Ghanem, Sarrah Ben M'Barek, Gustavo Azzimonti, Silvia Pereyra, Silvia Germán, Felix Marza, Amor Yahyaoui, Pawan Singh, Michael Baum, Hans-Joachim Braun

Based on a global network of wheat partners, precision field-based wheat phenotyping platforms are being developed with the support of the CGIAR Research Program on Wheat and co-investing national agricultural research institutes. This collaboration strategy aims to i) strengthen the quality of phenotypic data to fully exploit the potential of genomic data, ii) strategic prioritization of activities based on trait screening capacities and regional needs, iii) sharing knowledge and germplasm to accelerate superior germplasm development and dissemination, iv) development of capacities. Phenotyping activities are being conducted for wheat blast (Magnaporthe oryzae) in Bolivia, Septoria tritici blotch (STB) in durum wheat in Tunisia, and for multiple diseases (leaf rust, Fusarium head blight, and STB) in bread wheats in Uruguay. Subject to further funding, additional platforms will be implemented, to contribute to a faster development of broad genetic based resistant, high yielding wheat varieties, and complementing evaluations currently performed for diseases and heat, drought and yield potential (Kenya, Ethiopia, Turkey, Mexico).

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A large nested association mapping population to map agronomic QTL and smallholder farmers preference in Ethiopian durum wheat

BGRI 2018 Poster Abstract
Matteo Dell'Acqua Scuola Superiore Sant'Anna
Yosef G.,Kidane, Cherinet, Alem, Bogale, Nigir, Dejene, Mengistu, Carlo, Fadda, , , , , , , , , , , , , , , , , , , ,

The Ethiopian plateau hosts thousands of durum wheat landraces cultivated in low input agriculture conducted by an estimated 70 million smallholder farmers. Having thoroughly characterized the phenotypic and molecular uniqueness of Ethiopian durum wheat landraces, we produced a large nested association mapping (NAM) population harnessing their mostly untapped diversity in a set of recombinant inbred lines (RIL). The NAM founders are 50 landraces providing valuable traits such as drought tolerance and resistance to pests, and maximizing molecular diversity. Each selected landrace was crossed to a durum wheat line with an international background (Asassa), establishing independent interconnected bi-parental families, for a total of 6,280 RILs currently in F8. The Ethiopian NAM is at once i) a powerful QTL mapping tool that will side the increasing availability of genomic tools in wheat towards high-throughput candidate genes identification, and ii) a large pre-breeding panel closing the gap between local and international materials. Here we discuss the molecular and phenotypic characterization of twelve NAM families, represented by 100 RILs each. The 1,200 NAM RIL showed elevated allelic variation and a genetic structure reminiscent of the breeding design followed. The NAM RILs were phenotyped for ten agronomic and five disease traits in multiple locations in the Ethiopian highlands. A quantitative method eliciting smallholder farmers traditional knowledge was used to record local farmers appreciation of NAM RILs in all phenotyping locations. We report that the superior genetic properties of the NAM can be used to map QTL for both agronomic and farmer traits with unprecedented precision. The most promising NAM RILs can be identified combining farmers appreciation and agronomic measures, and prioritized for introgression of Ethiopian landraces traits in breeding pipelines aiming at higher uptake and productivity in local agriculture.

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Genetic variability of drought sdaptive traits in nepalese wheat (Triticum aestivum L.) germplasm

BGRI 2018 Poster Abstract
Dipendra Pokharel Department of Agriculture, Sunsari, Nepal

Wheat (Triticum aestivum L.) is one of the major cereal crops vital for global food supply. Most of the wheat crop in developing world including that of Nepal is either grown with limited irrigation or under rainfed conditions and thus face moisture stress at one or more growth stages limiting grain yield. An experiment was carried out at the Institute of Agriculture and Animal Science, Rampur to evaluate the genetic variability of selected drought adaptive traits in Nepalese wheat germplasm. The wheat genotypes evaluated comprised of Nepalese landraces and commercial cultivars, CIMMYT (International Center for Maize and Wheat Improvement) derived advanced introduction lines and three checks with differential drought adaptability. The wheat genotypes were grown in pots (single plant) arranged in a replicated split plot design in greenhouse under two contrasting moisture regimes, optimum and moisture stressed. The genotypes were evaluated for water use, water use efficiency, relative leaf water content and biomass production. The ANOVA (Analysis of Variance) revealed significant variation between environments and among the wheat genotypes for most of the traits studied. A wide range of variability was observed for water use, water use efficiency, biomass yield and relative leaf water content in moisture stressed and non-stressed environments. Nepalese cultivar Gautam showed a number of favorable drought adaptive traits, whereas, Bhrikuti was average in this respect. Based on the scores of drought adaptive traits recently released Cultivar (cv). Vijay was characterized as drought sensitive. A number of landraces and advanced breeding lines showed high level of water use efficiency and other positive traits for drought adaptation.

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