Tel Hadya Research Articles

Impacts of bracteole removal and seeding rate on seedling emergence of halophyte shrubs: implications for rangeland rehabilitation in arid environments

Direct seeding techniques often result in unsatisfactory outcomes in rangeland rehabilitation, primarily because of low seedling emergence and poor establishment. Seed processing techniques aimed at improving seedling emergence have gained interest by pasture managers. The purpose of this study was to investigate the combined effects of bracteole removal and seeding rate on seedling emergence in seven halophytic species: Atriplex halimus, A. canescens, A. leucoclada, A. nummularia, A. lentiformis, Salsola vermiculata and Haloxylon aphyllum under semi-arid conditions in Tel Hadya (Syria). Each of these species was evaluated for seedling emergence under two seed treatments (bracteoles removed and non-removed bracteoles) with three seeding rates (10, 30 and 60 seeds per pot), in a completely randomised block design. The results showed a positive effect of seed treatment on seedling emergence for all studied species. The native A. halimus had the highest emergence percentages whereas the introduced A. mummularia, had the lowest. However, there were no significant effects of seeding rates on seedling emergence. These results showed that bracteole removal could improve germination and seedling emergence, and potentially increase the rate of establishment of the species studied. Therefore, when implementing rangeland rehabilitation projects, bracteole removal needs to be considered. The native S. vermiculata should be recommended for direct seeding in the West Asia and North Africa region given its high seedling emergence, known high palatability, nutritive value, and high auto-regeneration performance.

Managerial Use of Factor Analysis for Identifying Stability of Yield Parameters and Morphological Characters in Barley Trials

This paper aims to demonstrate the usefulness of factor analysis for managing barley trials. It shows whether the relationship between barley yield parameters and morphological characters were affected by genotype and environment. The objectives of this study were to determine whether or not the interrelationship between barley yield parameters (total plant yield, grain yield, straw yield and thousand grain weight), and the morphological characters (vegetative duration, plant height, length of growing season and leafiness) was stable in each hybrid (hybrid 1, hybrid 2 and hybrid 3) and each of two areas in Syria by using factor analysis. The study also aimed to ascertain whether the relationship between yield parameters and morphological characters was affected by genotype environment interaction. There were three hybrids in each of the two Syrian areas: Tel Hadya and Breda. Each hybrid had 102 families. Correlation and factor analysis indicated that the interrelationship for yield parameters, except TGW, was stable, while the interrelationship between morphological characters was not stable. Factor analysis was applied to barley breeding data to determine the relationships between yield parameters and morphological characters. The results demonstrate that this relationship was stable in Tal Hadya, but not stable in Breda. The genotype and the environment influenced the relationship between yield parameters and morphological characters. Consequently, the relationship between yield parameters and morphological characters will not be suitable for forecasting yield.

Characterization of grass pea (Lathyrus sativus L.) germplasm collections for the beneficial agronomic traits

At ICARDA, germplasm collections obtained from five countries namely, Bangladesh, Ethiopia, Syria, Nepal and Pakistan were grouped in to seven sets of trials (BANG1, BANG2, ICARDA, ETH1, ETH2, NEP, PAK) and evaluated in two experimental locations, Tel Hadya and Breda over eight years. Characterization was done for the most desirable agronomic traits such as days to first flowering, days to 95 % maturity, biological yield, seed yield, hundred seed weight and Harvest index. Significant genotypic and interaction effect were found for the expression of the traits. Substantial amount of variability was revealed in the germplasm collections for most of the traits. High broad sense heritability was observed for days to first flowering and hundred seed weight indicating early phenotypic selection of these two traits. The stability over years for the seed yield (in terms of the CV), identified promising accessions such as ILG2178 in BANG1 and ILG1721, ILG1632, ILG1624, ILG1540 and ILG1501 for future breeding.

Intraspecific classification of durum wheat: new botanical varieties and forms

The Wheat Genetic Resources Department of VIR treats Triticum durum Desf. as a separate species. It contains 2 subspecies: subsp. durum and subsp. horanicum. Subsp. horanicum Vav. shows the highest spike density. Subsp. durum – the durum wheat proper – is characterized by a major variation of spike density, grain size and form. The subspecies also has liguleless forms and those with strongly pubescent leaves. The subsp. durum is represented by 6 groups of botanical varieties (convarieties): durum, durocompactum, aglossicon, villosum, falcatum, and caucasicum. Convar. durum has three subconvarieties: durum, muticum and duroramosum. At the time of the development of the classification 121 botanical varieties were described within T. durum. They were identified by a combination of characteristics such as the presence or absence of pubescent straw under the spike, pubescent or glabrous glumes, the roughness of awns (smooth or rough), glume color (white, red, gray, smoked-grayish or black on white or red background), awn color (same color as that of glumes or black), kernel color (white, red or purple). The principle of selection of botanical varieties is based on the combination of a large number of signs, giving a large number of possible options. It is very likely that most of them are not found in nature, but the probability of finding a new botanical variety or the presence of various forms can be increased as the research of polymorphism in accessions of the durum wheat collection in different ecological and geographical conditions. The objects of research were about 6000 accessions from the VIR durum wheat genetic collection, which had been grown in different ecological and geographical conditions during for 15 years. Identification of the accessions was carried out in accordance with the classification used by the Wheat GR department in its work with the collection. As a result of their own field research in ICARDA (Syria, Tel Hadya) and identification of accessions obtained after reproduction on the VIR experimental station, we have identified 10 new botanical varieties and 12 forms of T. durum to supplement the classification. For each of them the diagnosis is given, the type is defined, a herbarium (autotype) and photos are provided.

Intraspecific classification of durum wheat: New botanical varieties and forms

The Wheat Genetic Resources Department at Vavilov All Russia Institute of Plant Genetic Resources (VIR) treats Triticum durum Desf. as a separate species. It contains 2 subspecies: subsp. durum and subsp. horanicum. Subsp. horanicum Vav. shows the highest spike density. Subsp. durum—the durum wheat—is characterized by a major variation of spike density, grain size, and form. The subspecies also has liguleless forms and those with strongly pubescent leaves. The subsp. durum is represented by six groups of botanical varieties (convarieties): durum, durocompactum, aglossicon, villosum, falcatum, and caucasicum. Convar. durum has three subconvarieties: durum, muticum and duroramosum. At the time of the development of the classification, 121 botanical varieties were described within T. durum. They were identified by a combination of characteristics such as the presence or absence of pubescent straw under the spike, pubescent or glabrous glumes, the roughness of the awns (smooth or rough), glume color (white, red, gray, smoked-grayish, or black on a white or red background), awn color (same color as that of glumes or black), and kernel color (white, red, or purple). The principle of selecting botanical varieties is based on the combination of a large number of signs, giving a large number of possible options. It is very likely that most of them are not found in nature, but the probability of finding a new botanical variety or the presence of various forms can be increased as the research of polymorphism in accessions of the durum wheat collection in different ecological and geographical conditions. The objects of research were about 6000 accessions from the VIR durum wheat genetic collection, which had been grown in different ecological and geographical conditions for 15 years. The accessions were identified in accordance with the classification used by the Wheat Genetic Resources Department in its work with the collection. As a result of their own field research in ICARDA (Syria, Tel Hadya) and the identification of accessions obtained after reproduction at the VIR experimental station, we have identified 10 new botanical varieties and 12 forms of T. durum to supplement the classification. For each of them the diagnosis is given, the type is defined, and a herbarium (autotype) and photographs are provided.

Germplasm evaluation of heat tolerance in bread wheat in Tel Hadya, Syria

Breeding for heat tolerance in bread wheat (Triticum aestivum L.) is a serious global concern due to the increasing threats of high temperature. Thus, 189 wheat genotypes coded from 1 to 189 were evaluated for heat tolerance in normal and late seasons in the International Centre for Agricultural Research in Dry Areas (ICARDA), Tel Hadya, Syria, from 2010 to 2012. The experiments were laid out in alpha lattice designs with two replicates. Data collected on the grain yield, days to heading and maturity, grain filling duration and plant height were subjected to restricted maximum likelihood (REML) analysis for generation of the best linear unbiased estimates (BLUEs). Very highly significant effects (p ≤ 0.001) of genotype, season, and genotype by season interaction on grain yield and other traits were obtained. The grain yield and other traits performance of the wheat genotypes were significantly (p ≤ 0.05) higher in the normal season than in the late season. Genotype 148 was among the 30 top grain yielding genotypes in all the environments, while genotypes 172 and 124 were among the top yielding genotypes in all the environments except in late season 2. The relative heat tolerance of the genotypes ranged from -33.69% to -77.95% in late season 1 vs. normal season 1 and -65.28% to -95.83% in late season 2 vs. normal season 2. The high variability obtained in the germplasm underlies sufficient genetic variability for improving heat tolerance in bread wheat.

Genetic variation in winter barley and selection of high yielding lines

Barley (<italic>Hordeum vulgare</italic> L.) is an important crop with excellent nutritious feed and food grain. Winter barley, in particular, is predominantly grown in highland under rainfed systems due to its ability to tolerate cold. However, it has low productivity due to complex genetic mechanisms and limitations in determining an optimal environment for its selection and evaluation. This study evaluated the genetic variability, heritability and genetic gain for yield in barley, using preliminary un-replicated yield trials in 2011 at two locations and followed by replicated sets of yield trials in 2012, all in Syria. Significant genotypic variability was found at both stages of the evaluation/selection. During 2011, the best linear unbiased predictor means of test genotypes adjusted for spatial variability were found in the range of 1.75–3.75 t/ha at Tel Hadya and 0.03–1.58 t/ha at Breda. A set of 22 advanced yield trials comprising a total of 601 lines at Tel Hadya in 2012 yielded in the range of 1.85–3.13 t/ha. Based on the mean over these set of trials, the highest heritable trait was days to heading (broad-sense heritability on mean-basis= 0.64) followed by yield (the heritability = 0.30). The yield gain due to selection, at 20% intensity of selection, was 5.66% at Tel Hadya and 27.1% at Breda in 2011 using un-replicated genetic material, while it was 7.01 % for the replicated trials at Tel Hadya in 2012. We recommend use of the best lines selected in 2012 at Tel Hadya for further exploitation in genotype × environment interaction studies for high yield and specific and broad adaptation.

Genome-Wide Association Mapping of Yield and Grain Quality Traits in Winter Wheat Genotypes.

The main goal of this study was to investigate the genetic basis of yield and grain quality traits in winter wheat genotypes using association mapping approach, and identify linked molecular markers for marker assisted selection. A total of 120 elite facultative/winter wheat genotypes were evaluated for yield, quality and other agronomic traits under rain-fed and irrigated conditions for two years (2011–2012) at the Tel Hadya station of ICARDA, Syria. The same genotypes were genotyped using 3,051 Diversity Array Technologies (DArT) markers, of which 1,586 were of known chromosome positions. The grain yield performance of the genotypes was highly significant both in rain-fed and irrigated sites. Average yield of the genotypes ranged from 2295 to 4038 kg/ha and 4268 to 7102 kg/ha under rain-fed and irrigated conditions, respectively. Protein content and alveograph strength (W) ranged from 13.6–16.1% and 217.6–375 Jx10-4, respectively. DArT markers wPt731910 (3B), wPt4680 (4A), wPt3509 (5A), wPt8183 (6B), and wPt0298 (2D) were significantly associated with yield under rain-fed conditions. Under irrigated condition, tPt4125 on chromosome 2B was significantly associated with yield explaining about 13% of the variation. Markers wPt2607 and wPt1482 on 5B were highly associated with protein content and alveograph strength explaining 16 and 14% of the variations, respectively. The elite genotypes have been distributed to many countries using ICARDA’s International system for potential direct release and/or use as parents after local adaptation trials by the NARSs of respective countries. The QTLs identified in this study are recommended to be used for marker assisted selection after through validation using bi-parental populations.

Evaluation of faba bean breeding lines for spectral indices, yield traits and yield stability under diverse environments

Drought is a major limiting factor in faba bean (Vicia faba L.) production in the Mediterranean region, which is known for its irregular water distribution and moderate moisture levels (~500 mm rainfall). In this study, faba bean genotypes were evaluated for spectral indices, yield traits, rhizobium nodulation and yield stability under diverse environments, and their relationships. Eleven faba bean genotypes were evaluated under two water regimes, rainfed and supplemental irrigation (SI), in 2008–09; and under three water regimes (rainfed, 50% and 100% soil water capacity irrigation) for three consecutive growing seasons (2009–10, 2010–11, 2011–12), at Tel Hadya in Syria. They were also evaluated at Terbol in Lebanon for one season (2011–12) in a split-plot experiment with three irrigation treatments and at Kfardan in Lebanon for two seasons, 2008–09 (rainfed) and 2010–11 (rainfed and SI). The genotypes included three cultivars and eight drought-tolerant breeding lines selected at <300 mm annual rainfall. Phenological and morphological traits were recorded, as well as nodule weight per plant, grain yield, biological yield and spectral reflectance indices. Data were statistically analysed for each year. There were significant genotypic differences for seed yield under SI and rainfed conditions in 2008–09, and full irrigation in 2009–10 and 2011–12. Days to flowering and maturity were significantly different among genotypes for rainfed and irrigated conditions. There were significant differences between water regimes and genotypes, but their interactions were not significant. FLIP06-010FB was the highest yielding and most stable among the tested genotypes across different environments. Days to flowering and days to maturity were positively correlated with grain yield. The spectral indices structure-insensitive pigment index and normalised pheophytinisation index were found to correlate positively with grain yield and could therefore be used for selection under drought-prone environments.

Association Mapping of Resistance to Yellow Rust in Winter Wheat Cultivars and Elite Genotypes

ABSTRACTYellow (stripe) rust, caused by Puccinia striiformis f.sp. tritici (Pst), is a destructive disease of wheat (Triticum aestivum L.) all over the world, particularly in the Central and West Asia and North Africa (CWANA) region. Host plant resistance is the most economical and environment friendly approach to combating wheat rusts through the deployment of resistant cultivars. In this study, we report findings from an association mapping (AM) study of resistance to Pst in 167 facultative/winter elite wheat genotypes. The genotypes were evaluated for resistance to yellow rust (YR) at the adult plant stage and other agronomic traits for 2 yr (2011–2012) at ICARDA field station, Tel Hadya, Syria. The same genotypes were genotyped using 3051 diversity array technology (DArT) markers of which 1586 were of known chromosome positions. Out of the 167 genotypes evaluated for YR resistance, 65 genotypes (38.9%) were resistant, 20 genotypes (12%) were moderately resistant, 30 genotypes (18%) were moderately susceptible, and 52 genotypes (31.1%) were susceptible. Elite genotypes with high yield potential and YR resistance were identified and have been distributed to the National Agricultural Research System (NARS) for potential direct release and/or use as parents after local adaptation trials by the respective countries. Further, AM analysis using a mixed linear model (MLM), corrected for population structure and kinship relatedness and adjusted for false discovery rate (FDR), identified five genomic regions located on wheat chromosomes 2BL, 4BS, 6AS, 6BL, and 7BL which are significantly associated with genes conferring resistance to YR. The loci located on chromosome 4BS appeared to be a novel quantitative trait loci (QTL). These loci may be useful for choosing parents and incorporating new YR resistance genes into locally adapted wheat cultivars.

Combined effect of tillage system, supplemental irrigation and genotype on bread wheat yield and water use in the dry Mediterranean region

Approaches that can help reduce future water shortages and increase food production in the Mediterranean region include the capture of more rainwater and better use of scarce irrigation water. The objective of this study is to evaluate the additive effect of combining zero tillage, supplemental irrigation and adapted varieties of bread wheat on yield and water use. For this purpose, a trial was conducted at the International Center for Agricultural Research in the Dry Areas’ (ICARDA) research station in Tel Hadya, Aleppo, Syria in 2008/2009 and 2011/2012 under two tillage systems: zero tillage (ZT) vs. conventional tillage (CT); two water regimes: rainfed (RD) vs supplemental irrigation (SI); and five genotypes. Results showed that in 2008/2009, grain yield increased on average, from 4515 kg ha-1, under CT in the rainfed regime, to 5929 kg ha-1 when ZT and SI were combined. ZT and SI increased respectively, the yield by 548 and 729 kg ha-1 as compared to CT under rainfed condition. The combination of ZT and SI increased water use by 110 mm as compared to CT under rainfed condition. In year 2011/2012, ZT tended to have no effect on yield and a negative influence on water use. Irrigation increased yields from 5055 to 5927 kg ha-1 under CT tillage and from 4996 to 5448 kg ha-1 under zero tillage. The genotypes Cham 6, Cham 8 and Shuha were the most responsive to SI and ZT in year 1. In year 2, Shuha and Cham 10 tended to be in general, more performing. The preliminary results showed that in dry year, the combination of the two technologies, zero tillage and supplemental irrigation, increased water use and yield. In wetter year, the effect of SI was still positive; but that of ZT was not significant on yield and negative on water use. Further studies are needed, for a longer period, to consolidate the obtained results using more diversified genetic material. Key words: Wheat, zero tillage, irrigation, genotype, yield, evapotranspiration, productivity.

Tillage system and genotype effects on early vigor and water use in bread wheat in the Mediterranean region

The southern part of the Mediterranean basin is among the regions that are characterized by recurrent droughts and it is threatened by the effects of climate change. To deal with these problems in wheat, improved techniques of rain water conservation and adapted varieties need to be developed. Combining zero tillage and varieties with early vigor can reduce evaporation and improve transpiration and water productivity and hence increase yields. To test this hypothesis, a field trial was conducted at ICARDA’s research station at Tel Hadya, Aleppo, Syria in 2008/2009 and 2011/2012. The treatments tested were “zero tillage vs. conventional tillage” and five genotypes of bread wheat. In 2008/2009, results showed that zero tillage improved leaf area index, specific leaf area, above ground biomass production and actual evapotranspiration at the beginning of stem elongation. The values increased, respectively for these parameters, from 2.34 to 3.25, 202.9 to 226.5 cm2 g-1, 1799 to 2333 kg ha-1 and from 91 to 101 mm. Water productivity was improved by 15%, on average. In year 2011/2012, the effect of tillage system on all the parameters was not statistically significant. In general, all genotypes responded positively to zero tillage for these measured variables. From this study, we can conclude that zero tillage under dry conditions is a technique that can improve the early vigor of the seedlings. This enhanced early growth can ensure a good canopy cover that reduces the loss of rainwater by evaporation and increases transpiration in relatively early dry years. The non disturbance of soil by tillage reduces water loss by evaporation. However, under wet conditions due to high rainfall, the positive effect of zero tillage on soil moisture and plant growth disappears. Key words: Wheat, zero tillage, genotype, leaf area, biomass, evapotranspiration.

Identifying High Yielding, Stable Chickpea Genotypes for Spring Sowing: Specific Adaptation to Locations and Sowing Seasons in the Mediterranean Region

ABSTRACTSuperior genotypes are needed to give farmers a choice of improved cultivars of chickpea (Cicer arietinum L.) suitable for traditional spring sowing. From 1997 to 2010, 68 experiments comprising 404 elite chickpea lines were conducted for two seasons per year (spring and winter) at two locations—Tel Hadya, Syria (TH), and Terbol, Lebanon (TR). Genotypic differences were significant (P < 0.05) in 65 of 68 experiments. Genotype × season interaction was more important than the genotype × location. The predicted means in the two growing seasons were significantly correlated, implying the possibility of conducting yield trials in only one of the seasons, such as at TH. Stability analyses showed that S95082 (FLIP95‐78C), with a predicted yield of 1725 kg ha−1, was the top yielding genotype at the TH spring sowing, with a temporal stability rank of 14. The line S95419 ranked second for yield (1633 kg ha−1) followed by S95335 (FLIP95‐147C) with the spring yield at TH of 1583 kg ha−1. The genotype main effect plus genotype × environment interaction (GGE) biplot analyses showed that the FLIP95‐78C and S95335 genotypes were high yielding at TH while FLIP98‐91C and FLIP98‐162C did better at TR in both seasons. Three lines, FLIP01‐06C, FLIP01‐30C, and FLIP01‐49C, having high yields across locations and seasons and being tolerant to drought, were identified for dual season sowing. The findings show the potential to improve chickpea for spring sowing. The ICARDA breeding program is enriching the germplasm base with elite chickpea genotypes benefiting regional and international chickpea improvement programs.

Spatial Variation in Soil Organic Matter, Available Phosphorus, and Potassium under Semi-arid Conditions: Research Station Management Implications

Natural ecosystems are characterized by variability in space and, to a lesser extent, in time. Soil types and properties vary on landscape and field scales. Such variability is either inherent or human-induced and influences crop management. Variability at the plot level impinges on field experimentation. In this study at the main station, Tel Hadya, of the International Center for Agricultural Research in the Dry Areas (ICARDA), we intensively sampled four large field plots and analyzed the samples for soil organic matter (SOM), available Olsen phosphorus (P), and extractable potassium (K). Variability parameters were established for each property, as well as semivariograms. Contour maps for each plot were drawn by kriging. Despite the history of uniform management in each plot, large residual spatial variability was evident for each parameter. Although such variability is generally disregarded by agronomists and crop scientists and is generally believed to be eliminated by an alternate year of uniform cropping (i.e., “homogenization”), the residual persistent variability in these parameters cause variation in crop growth and need to be considered in designing experimental treatments, especially with regard to plot size and orientation. Although P and K variability can be masked by uniform fertilizer application, the effects of SOM persist for several years and thus can influence nutrient availability and soil moisture under such dryland conditions. Systematic soil sampling can help in reducing variability at trial sites, but background variability cannot be eliminated completely in natural bodies such as soils.

Sources of resistance in primary synthetic hexaploid wheat (Triticum aestivum L.) to insect pests: Hessian fly, Russian wheat aphid and Sunn pest in the fertile crescent

Hessian fly, Mayetiola destructor (Say), Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), and Sunn pest, Eurygaster integriceps (Puton), are among the most important insect pests of wheat in North Africa, West and Central Asia. Host plant resistance is the most economical, environmentally friendly and practical means of controlling insect pests. Through field and greenhouse screening, several sources of resistance to Hessian fly, RWA and Sunn pest have been identified in wheat and its wild relatives. To further broaden the genetic base of resistance to these pests, 914 fixed lines of synthetic hexaploid wheat (SHW) commonly designated as primary synthetic wheat were evaluated for resistance to Hessian fly, RWA and Sunn pest. The initial screenings for RWA and Sunn pest were carried out in the field at Tel Hadya, Aleppo, Syria, and for Hessian fly in the greenhouse at Tel Hadya during the 2009 and 2010 seasons. Promising accessions from the initial screening for Hessian fly, RWA and Sunn pest were evaluated for confirmation in replicated trials in the greenhouse and field. Fifteen SHWs showed high levels of resistance to Hessian fly and four showed moderate resistance. A wheat line derived from the cross (Triticum turgidum/T. dicoccoides) also showed a high level of resistance to Hessian fly. The level of resistance to RWA in SHW was considerably lower; only one SHW and one durum wheat ‘Altar 84’ exhibited a high level of resistance, while four SHW were moderately resistant. There were 21 SHW genotypes and one durum wheat ‘Langdon’ found resistant to Sunn pest feeding at the vegetative stage. Crosses between these potentially novel resistance sources and elite bread wheat were initiated. Genetic and genomic studies using these accessions are ongoing to identify and characterize the resistance genes and reveal potentially new resistance genes, which will be useful in breeding programs to develop wheat germplasm with multiple resistances to these pests.

Water and land productivities of wheat and food legumes with deficit supplemental irrigation in a Mediterranean environment

Selecting appropriate crops and applying deficit irrigation can help increase water productivity in water-limited regions such as the Mediterranean. The objective of this study was to develop water production functions of major cereal and legume crops under the same environmental and management conditions. Bread and durum wheat, faba bean, chickpea, and lentil were grown under full supplemental irrigation (FSI), two deficit irrigations levels of 2/3 of FSI (2/3SI) and 1/3 of FSI (1/3SI), and under rainfed conditions (no irrigation). In average, the actual evapotranspirations (ETs) under FSI were 549, 552, 365, 451 and 297mm, for bread wheat, durum wheat, faba bean, chickpea and lentil, respectively. For the same crops, they were 463, 458, 330, 393 and 277mm for the treatment 2/3SI and 357, 351, 265, 318 and 244mm for the treatment 1/3SI, respectively. In the case of the rainfed treatment, ETs for the mentioned crops were 250, 251, 227, 237 and 215mm, respectively. The experiment was conducted at the ICARDA experimental station at Tel Hadya, near Aleppo, Syria, over three growing seasons from 2007 to 2010.Results showed that, in general, the treatment with 1/3 of FSI gave the highest rate of increase in grain yield and water productivity. The mean grain yield from rainfed, 1/3SI, 2/3SI, and FSI were 1.36, 3.82, 5.18, and 5.70t/ha for bread wheat; 1.24, 3.80, 5.10, and 5.75t/ha for durum wheat; 1.57, 2.35, 2.86, and 3.54t/ha for faba bean, 1.36, 2.63, 3.36, and 3.74t/ha for chickpea, and 0.64, 1.16, 1.42, and 1.58t/ha for lentil respectively. Grain yield reductions due to the application of 2/3SI were around 10, 5, 15.6, and 10.2% of FSI on average for wheat, chickpea, faba bean, and lentils, respectively. Deficit irrigation at 2/3SI increased water productivity compared to rainfed treatments, by 200, 223, 126, 148 and 190% for bread wheat, durum wheat, faba bean, chickpea, and lentils, respectively. However, differences in total water productivity of crops grown under full irrigation compared to deficit irrigation were not significant. Irrigation water productivity ranged from 25kgha−1mm−1 in wheat with 1/3SI to 10kgha−1mm−1 for legumes under the FSI treatment. Unlike legumes, maximizing wheat grain yield caused a decline in water productivity.

Dietary supplementation with nonconventional feeds from the Middle East: Assessing the effects on physicochemical and organoleptic properties of Awassi sheep milk and yogurt

Increased feed costs affect the livelihoods of dairy sheep farmers in the Middle East. Farmers endure high risks with large fluctuations in the price of grain used as animal feed, which is further affected by drought and declining range productivity. Using agricultural by-products and treated straw or vetch grazing for supplementing sheep diets would provide resource-poor dairy farmers with increased options to reduce feed costs, but the effects of such feeds on the quality of yogurt (the main product) need to be better understood. Two experiments were conducted to evaluate these effects. The first trial evaluated alternative diets using locally available feedstuffs, including agricultural by-products, compared with traditional diets used by dairy sheep farmers, and was conducted on-station at the International Center for Agricultural Research in Dry Areas (ICARDA, Tel Hadya, Aleppo, Syria). Milking Awassi ewes (n=56) were used to test 6 alternative diets against a traditional control diet containing barley, wheat bran, and barley straw. The 6 alternative diets contained 4 or more of the following ingredients: barley, sugar beet pulp, molasses, cotton seed cake, wheat bran, urea-treated wheat straw, and barley straw. Ewes on one of the alternative diets grazed vetch pasture, whereas ewes on the control diet and the 5 alternative diets grazed native range pasture. The milk fat content was higher in diets containing urea-treated straw. Yogurt firmness and adhesiveness were significantly lower in energy-rich diets (e.g., the control diet) and in the diets rich in soluble sugar (molasses). The effects of diet on yogurt color and on citric and succinic acid contents were significant. A yogurt produced from the milk of the group grazing on vetch was the most yellowish in color, which is appealing to Syrian consumers. The content of citric acid tended to be higher in yogurts produced from diets containing molasses. The second trial was conducted on 3 farms in northern Syria to assess an alternative diet (1 of the 6 tested in the first trial) on 15 milking ewes compared with the farmer's traditional diet (control). The alternative diet increased yogurt firmness and adhesiveness by 7 to 9% and 10 to 16%, respectively. The use of nonconventional feeds available in the region enhances yogurt quality, may reduce requirements for expensive grains, and thus, increase farmers’ livelihoods by targeting expanding markets with better quality products.

Genome wide association analyses for drought tolerance related traits in barley ( Hordeum vulgare L .)

Genome wide association (GWA) analysis of yield, yield components, developmental, physiological and anatomical traits was conducted for a barley germplasm collection consisting of 185 cultivated ( Hordeum vulgare L.) and 38 wild ( Hordeum spontaneum L.) genotypes, originating from 30 countries of four continents. Phenotypic evaluations were performed at a dry (Breda) and wet (Tel Hadya) location in Syria. Genome wide association study was done with 816 markers comprised of 710 diversity array technology (DArT), 61 single nucleotide polymorphism (SNP) and 45 microsatellite or simple sequence repeat (SSR) markers. Diversity analysis revealed 5 groups of germplasm, related to origin (Middle East, North Africa), structural information (two-rows), and domestication (wild versus domesticated). Linkage disequilibrium (LD) decayed after 3 cM with a few exceptions at 10 and 15 cM. Although a few QTLs were identified that differed between the dry and wet site, these QTLs explained low phenotypic variation and could not unequivocally be related to drought tolerance when compared to earlier linkage mapping based QTL analysis studies. Therefore, GWA analysis seems to be not very effective for identification of major QTLs for complex traits like drought tolerance in highly structured germplasm collections.

Relationship between carbon isotope discrimination (Δ), yield and water use efficiency of durum wheat in Northern Syria

► Six durum wheat genotypes varying in grain carbon isotope discrimination (CID) were used in a field experiments. ► This study is to relate wheat yields of the different genotypes with CID and other plant traits. ► CID was measured in the grain and the 4th fully expanded leaf together with soil water content . ► Leaf CID was higher compared with grain CID, positive correlations were found between CID and yields of grain and biomass. ► Water use efficiency did not differ between genotypes. CID was correlated to grain ash and protein content. Field experiments were conducted over two seasons (2005–06 and 2006–07) using six durum wheat genotypes varying in grain carbon isotope discrimination ( Δ ) but similar in phenology. Experimental sites at Tel Hadya, Breda, Muslmieh and Yahmoul across rainfall zones in Northern Syria were used. The main objective of this study is to relate the wheat yields of the different genotypes with Δ and other plant traits. Plant growth was monitored throughout the growing season. Δ was measured for every plot in the grain (Δ G ) and the 4th fully expanded leaf (Δ L ). Also, ash and protein contents of grain were analyzed. Soil water content throughout the growing season was measured at some sites to calculate water use. Yield variability between sites was mostly due to rainfall, with variability between cultivars within a site being due to season. Δ L was higher, with no stress evident at this stage, compared with Δ G . Δ L , ranging from 19.97 to 22.76‰, was lower at the drier sites and higher at the wettest site, which changed to the opposites for Δ G ranging from 12.88 to 16.62‰. Positive correlations were found between Δ and yields of grain and biomass. The stronger correlations were at the drier sites, whilst at the wettest site there was no significant relationship. Δ L for the different genotypes was more stable between sites and seasons than Δ G . Water use efficiency did not differ between genotypes, unlike Δ . Δ was also correlated to grain ash and protein content. This suggests to use these cheap and easily obtainable plant traits as surrogate if Δ was unavailable.

Mapping QTL Associated with Traits Affecting Grain Yield in Chickpea (Cicer arietinum L.) under Terminal Drought Stress

The aim of this study was to evaluate a set of recombinant inbred lines (RILs) for agronomic and physiological traits under drought conditions and to locate quantitative trait loci (QTL) associated with them. This study used a RIL population derived from a cross between drought tolerant (ILC 588) and susceptible (ILC 3279) genotypes. The population consisting of 155 RILs was grown under drought conditions in the field at Tel Hadya, Syria, in 2006 and 2007 and at Breda, Syria, in 2007. A genetic map consisting of eight linkage groups was developed using 97 simple sequence repeat (SSR) markers. The results revealed that high harvest index (HI), early flowering, and early maturity were the important attributes contributing to higher grain yield under drought. Higher stomatal conductance (gs) and cooler canopies (canopy temperature minus air temperature [Tc–Ta]) can also lead to better performance under drought conditions. Quantitative trait locus analysis identified 15 genomic regions significantly associated with various traits affecting drought tolerance in chickpea. Important QTL detected in this study included two QTL for HI explaining 38% of the total phenotypic variability of the trait, four QTL for flowering explaining 45%, and three QTL for maturity explaining 52% on a cumulative basis. Three QTL for gs and six QTL for Tc–Ta also detected explained 7 to 15% phenotypic variability individually. Two QTL (Q3‐1 and Q1‐1) on linkage group 3 (LG3) and LG1 showed effects on many traits related to drought. Hence, these regions can be further explored in future drought studies.