Genetic diversity in Ethiopian Durum wheat ( Triticum turgidum var durum ) inferred from phenotypic variations

The valorization of genetic diversities of major crops like wheat may help substantially to feed the world Population. Durum heat genotypes consisting of 265 farmers’ varieties (FVs), which have been cultivated for many centuries in Ethiopia, as well as 24 improved varieties (IMVs) have been recently evaluated in northern Ethiopia. The evaluation has been carried out at two different locations for 2 consecutive years to verify the inherited diversity in FVs for important phenological and agronomic traits; with the intention to provide refined information to breeders and genebank managers. As a result of a careful evaluation, a very significant variation was observed between the FVs and IMVs. A large number of the former have demonstrated superior performance to the latter in terms of mean values of the major traits within the stipulated years and locations. The best perform- ing FV has shown a gain of 20% grain yield over the best IMV. Multivariate analyses revealed that FVs displayed larger genetic diversity than in those IMVs. FVs could therefore be used as donor of useful alleles in durum wheat breeding for improvement of yield per se and other traits of agronomic and phenological importance. The identified stable superior FVs include: 8208, 226834A, 238567, 222426, 226282 could be best candidates for farmers in marginal environments. Genotypes that have shown stable performance for spatial variation such as 204493A, 214357 and 238567; and temporal variation such as 8208, 208479, 214357 and 226834A could be the best candidates for exploitation in future breeding programs

Which wheat for smallholder Ethiopian farmers? Joining traditional knowledge with metric phenotypes

Africa hosts approximately 33 million smallholder farms, which account for 80% of the continent's farming system. Subsistence farming systems face highly variable climatic conditions that threaten locally-adapted, low-input agriculture. For the near future, they are among the most seriously affected by changing climatic conditions, posing additional risks to these systems. The benefits of modern breeding benefits may fail to reach small farming communities when broadly adapted material does not address specific local requirements. To date, participatory variety selection has only scratched the surface of the exploitability of farmers' knowledge in breeding. Yet, considering that over 80% of the farmers receive seeds from informal systems, making sure that well adapted material is available in production systems, seems to be a reasonable solution to quickly affect a large populations. Ethiopia is one of the most populous countries in Africa, with more than 96 million inhabitants, 80% of whom are engaged in small-scale agriculture, and often subsistence farming. We involved 60 smallholder farmers in two locations in Ethiopia to evaluate traits of their interest in 400 wheat accessions, producing 230,400 data points. We couple this information with metric measurements of 10 agronomic traits, breaking down farmers' preferences on quantitative phenotypes. We found that the relative importance of wheat traits is gender- and locality- dependent, and produced a ranking of the 400 varieties identifying the combination of traits most desired by farmers. The study scale and methods lead to a better understanding of smallholder farmer needs, broadening the discussion for the future of local, sustainable breeding efforts accommodating farmers' knowledge

A crowdsourcing approach to detect farmers’ preferences: evidences from Ethiopia for adapting to climate change

Climate change is severely affecting production systems all over Africa. Ethiopia will face an increase in temperature and changes in rainfall patterns. One solution for long term management of climate related risks is to introduce new traits into production systems. We present an approach to quickly deliver to farmers a selected number of preferred accessions of durum wheat using a crowdsourcing approach. After having completed a phenotypic and genotypic characterisation of 400 accessions of Ethiopian landraces and asked farmers to evaluate them, we distributed seeds of preferred varieties to a large number of farmers using a crowdsourcing approach. In two sites representing different agroecological zones, we distributed 20 superior varieties and one check, an improved variety very common in both areas to 200 farmers in 12 villages per site, covering an area of roughly 350 km 2. We repeated the experiment for 2 years. Each farmer was given 3 blind varieties and the check, each variety being equally represented in the sample. In addition, in each village we included 2 i-buttons, measuring temperature and humidity every 3 hours throughout the growing season. This allowed to analyse the data on critical climatic parameters. Results clearly indicate farmers’ preferences: a) Landraces were preferred over improved varieties for their multiple uses; b) By considering farmers as citizen scientists, we have a better understanding of the criteria farmers use to select their preferred varieties (in our case straw and grain yield, drought tolerance, uniformity, long and dense spikes). In conclusion: • This process has been very effective in quickly disseminating seeds that match farmers’ needs. After 2 years several hundred farmers can use better adapted material. • It shows the potential of landraces to provide immediate option for managing climate related risks and calls for broader use of material conserved in gene banks. • It indicates the need to strengthen local seed systems to better manage these resources. • It indicates how farmers can provide very valuable scientific information that can be translated into research as well as development potential in other areas of research

Genome wide association study to identify the genetic base of smallholder farmer preferences of Durum wheat traits

Smallholder agriculture involves millions of farmers worldwide. A methodical utilization of their traditional knowledge in modern breeding efforts may help the production of locally adapted varieties better addressing their needs. In this study, a combination of participatory approaches, genomics, and quantitative genetics is used to trace the genetic basis of smallholder farmer preferences of durum wheat traits. Two smallholder communities evaluated 400 Ethiopian wheat varieties, mostly landraces, for traits of local interest in two locations in the Ethiopian highlands. For each wheat variety, farmers provided quantitative evaluations of their preference for flowering time, spike morphology, tillering capacity, and overall quality. Ten agronomic and phenology traits were simultaneously measured on the same varieties, providing the means to compare them with farmer traits. The analysis of farmer traits showed that they were partially influenced by gender and location but were repeatable and heritable, in some cases more than metric traits. The durum wheat varieties were genotyped for more than 80,000 SNP markers, and the resulting data was used in a genome wide association (GWA) study providing the molecular dissection of smallholder farmers' choice criteria

A large nested association mapping population for breeding and quantitative trait locus mapping in Ethiopian durum wheat

The Ethiopian plateau hosts thousands of durum wheat (Triticum turgidum subsp. durum) farmer varieties (FV) with high adaptability and breeding potential. To harness their unique allelic diversity, we produced a large nested association mapping (NAM) population intercrossing fifty Ethiopian FVs with an international elite durum wheat variety (Asassa). The Ethiopian NAM population (EtNAM) is composed of fifty interconnected bi-parental families, totalling 6280 recombinant inbred lines (RILs) that represent both a powerful quantitative trait loci (QTL) mapping tool, and a large pre-breeding panel. Here, we discuss the molecular and phenotypic diversity of the EtNAM founder lines, then we use an array featuring 13 000 single nucleotide polymorphisms (SNPs) to characterize a subset of 1200 EtNAM RILs from 12 families. Finally, we test the usefulness of the population by mapping phenology traits and plant height using a genome wide association (GWA) approach. EtNAM RILs showed high allelic variation and a genetic makeup combining genetic diversity from Ethiopian FVs with the international durum wheat allele pool. EtNAM SNP data were projected on the fully sequenced AB genome of wild emmer wheat, and were used to estimate pairwise linkage disequilibrium (LD) measures that reported an LD decay distance of 7.4 Mb on average, and balanced founder contributions across EtNAM families. GWA analyses identified 11 genomic loci individually affecting up to 3 days in flowering time and more than 1.6 cm in height. We argue that the EtNAM is a powerful tool to support the production of new durum wheat varieties targeting local and global agriculture

Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory

Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius $A$. Also the events detected simultaneously by the surface and fluorescence detectors (the `hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.Comment: Matches published versio

Crop variety management for climate adaptation supported by citizen science

Crop adaptation to climate change requires accelerated crop variety introduction accompanied by recommendations to help farmers match the best variety with their field contexts. Existing approaches to generate these recommendations lack scalability and predictivity in marginal production environments. We tested if crowdsourced citizen science can address this challenge, producing empirical data across geographic space that, in aggregate, can characterize varietal climatic responses. We present the results of 12,409 farmer-managed experimental plots of common bean (Phaseolus vulgaris L.) in Nicaragua, durum wheat (Triticum durum Desf.) in Ethiopia, and bread wheat (Triticum aestivum L.) in India. Farmers collaborated as citizen scientists, each ranking the performance of three varieties randomly assigned from a larger set. We show that the approach can register known specific effects of climate variation on varietal performance. The prediction of variety performance from seasonal climatic variables was generalizable across growing seasons. We show that these analyses can improve variety recommendations in four aspects: reduction of climate bias, incorporation of seasonal climate forecasts, risk analysis, and geographic extrapolation. Variety recommendations derived from the citizen science trials led to important differences with previous recommendations

An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources

A new analysis of the data set from the Pierre Auger Observatory provides evidence for anisotropy in the arrival directions of ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative of excess arrivals from strong, nearby sources. The data consist of 5514 events above 20 EeV with zenith angles up to 80 degrees. recorded before 2017 April 30. Sky models have been created for two distinct populations of extragalactic gamma-ray emitters: active galactic nuclei from the second catalog of hard Fermi-LAT sources (2FHL) and starburst galaxies from a sample that was examined with Fermi-LAT. Flux-limited samples, which include all types of galaxies from the Swift-BAT and 2MASS surveys, have been investigated for comparison. The sky model of cosmic-ray density constructed using each catalog has two free parameters, the fraction of events correlating with astrophysical objects, and an angular scale characterizing the clustering of cosmic rays around extragalactic sources. A maximum-likelihood ratio test is used to evaluate the best values of these parameters and to quantify the strength of each model by contrast with isotropy. It is found that the starburst model fits the data better than the hypothesis of isotropy with a statistical significance of 4.0 sigma, the highest value of the test statistic being for energies above 39 EeV. The three alternative models are favored against isotropy with 2.7 sigma-3.2 sigma significance. The origin of the indicated deviation from isotropy is examined and prospects for more sensitive future studies are discussed

A Targeted Search for Point Sources of EeV Photons with the Pierre Auger Observatory

Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p-values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. These limits significantly constrain predictions of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region