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Yehoshua Saranga - One of the best experts on this subject based on the ideXlab platform.
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Genetic diversity for grain nutrients in wild Emmer wheat: potential for wheat improvement.
Annals of botany, 2010Co-Authors: Merav Chatzav, Zvi Peleg, Tzion Fahima, Atilla Yazici, Levent Ozturk, Ismail Cakmak, Yehoshua SarangaAbstract:Genetic diversity for grain nutrients in wild Emmer wheat – A potential for wheat improvement Merav Chatzav1‡, Zvi Peleg1‡, Tzion Fahima2, Ismail Cakmak3, Yehoshua Saranga1* Abstract • Background and Aims - Mineral nutrient malnutrition, and particularly deficiency in zinc (Zn) and iron (Fe), afflicts over three billion people worldwide. In the current study wild Emmer wheat (Triticum turgidum ssp. dicoccoides (Korn.) Thell.), the progenitor of domesticated wheats, was tested for (i) genetic diversity in grain nutrient concentrations, (ii) the associations among grain nutrients and their relationships with plant productivity, and (iii) their association with the ecogeographical origin of wild Emmer accessions. • Methods - A Total of 154 genotypes, including wild Emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this two-year field study for grain protein (GPC), micronutrients (Zn, Fe, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulphur) concentrations. • Key Results - A wide genetic diversity was found among the wild Emmer accessions for all grain nutrients. The concentrations of grain Zn, Fe and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed a significant genetic variation between and within populations for all minerals. Association between soil characterise of the site of collection and grain nutrient concentrations showed negative associations between soil clay and GPC and between Zn in soil and in grain, the latter suggesting that the greatest potential for grain nutrient mineral is expected in populations from mineral deficient soils. • Conclusions – Wild Emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat genepool. Key words: Triticum turgidum ssp. dicoccoides, grain quality, protein, zinc, iron, wheat improvement, micronutrients, macronutrients
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part of a special issue on plant nutrition genetic diversity for grain nutrients in wild Emmer wheat potential for wheat improvement
2010Co-Authors: Merav Chatzav, Zvi Peleg, Tzion Fahima, Atilla Yazici, Levent Ozturk, Ismail Cakmak, Yehoshua SarangaAbstract:†Background and Aims Micronutrient malnutrition, particularly zinc and iron deficiency, afflicts over three billion people worldwide due to low dietary intake. In the current study, wild Emmer wheat (Triticum turgidum ssp. dicoccoides), the progenitor of domesticated wheat, was tested for (1) genetic diversity in grain nutrient concentrations, (2) associations among grain nutrients and their relationships with plant productivity, and (3) the association of grain nutrients with the eco-geographical origin of wild Emmer accessions. †Methods A total of 154 genotypes, including wild Emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this 2-year field study for grain protein, micronutrient (zinc, iron, copper and manganese) and macronutrient (calcium, magnesium, potassium, phosphorus and sulphur) concentrations. †Key Results Wide genetic diversity was found among the wild Emmer accessions for all grain nutrients. The concentrations of grain zinc, iron and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity, suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed significant genetic variation between and within populations for all minerals. Association between soil characteristics at the site of collection and grain nutrient concentrations showed negative associations between soil clay content and grain protein and between soil-extractable zinc and grain zinc, the latter suggesting that the greatest potential for grain nutrient minerals lies in populations from micronutrient-deficient soils. †Conclusions Wild Emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat gene pool.
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grain zinc iron and protein concentrations and zinc efficiency in wild Emmer wheat under contrasting irrigation regimes
Plant and Soil, 2008Co-Authors: Zvi Peleg, Tzion Fahima, Yehoshua Saranga, Atilla Yazici, Levent Ozturk, Ismail CakmakAbstract:Micronutrient malnutrition, and particularly deficiency in zinc (Zn) and iron (Fe), afflicts over three billion people worldwide, and nearly half of the world’s cereal-growing area is affected by soil Zn deficiency. Wild Emmer wheat [Triticum turgidum ssp. dicoccoides (Korn.) Thell.], the progenitor of domesticated durum wheat and bread wheat, offers a valuable source of economically important genetic diversity including grain mineral concentrations. Twenty two wild Emmer wheat accessions, representing a wide range of drought resistance capacity, as well as two durum wheat cultivars were examined under two contrasting irrigation regimes (well-watered control and water-limited), for grain yield, total biomass production and grain Zn, Fe and protein concentrations. The wild Emmer accessions exhibited high genetic diversity for yield and grain Zn, Fe and protein concentrations under both irrigation regimes, with a considerable potential for improvement of the cultivated wheat. Grain Zn, Fe and protein concentrations were positively correlated with one another. Although irrigation regime significantly affected ranking of genotypes, a few wild Emmer accessions were identified for their advantage over durum wheat, having consistently higher grain Zn (e.g., 125 mg kg−1), Fe (85 mg kg−1) and protein (250 g kg−1) concentrations and high yield capacity. Plants grown from seeds originated from both irrigation regimes were also examined for Zn efficiency (Zn deficiency tolerance) on a Zn-deficient calcareous soil. Zinc efficiency, expressed as the ratio of shoot dry matter production under Zn deficiency to Zn fertilization, showed large genetic variation among the genotypes tested. The source of seeds from maternal plants grown under both irrigation regimes had very little effect on Zn efficiency. Several wild Emmer accessions revealed combination of high Zn efficiency and drought stress resistance. The results indicate high genetic potential of wild Emmer wheat to improve grain Zn, Fe and protein concentrations, Zn deficiency tolerance and drought resistance in cultivated wheat.
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Physiological-genetic Dissection of Drought Resistance in wild Emmer wheat
2008Co-Authors: Yehoshua Saranga, Zvi Peleg, Tzion FahimaAbstract:Wild Emmer wheat (Triticum turgidum ssp. dicoccoides (Korn.) Thell.), the allo-tetraploid (BBAA) progenitor of cultivated wheats, offers a valuable source of allelic diversity for various economically important traits, including drought resistance. A total of 160 wild Emmer accessions, consisting of 25 populations, and three control durum wheat cultivars were examined under two irrigation regimes, well-watered control (~650 mm) and water-limited (~250 mm). Principal component analysis, supported by photosynthetic rate measurements, revealed a variety of drought adaptive strategies among the wild accessions. A wide phenotypic variation was found both between and within the wild Emmer populations in most morpho-physiological traits, with a considerable advantage in drought resistance over cultivated genotypes. Microsatellite markers revealed a wide allelic diversity between and within the wild Emmer populations, confirming the patterns of phenotypic variation. The greatest drought resistance capacity corresponded with the highest allelic diversity and found in populations from intermediate aridity level. Physiological responses to drought were further dissected by quantitative trait loci (QTLs) mapping of yield and drought related traits under contrasting irrigation regimes, using 152 F6 recombinant inbred lines derived from a cross between durum wheat and wild Emmer wheat from drought-prone environment. A total of 102 QTLs were mapped for 10 productivity and morpho-physiological traits. Several QTLs exhibited GxE interaction and accounted for productivity and related physiological traits under either the well watered or water-limited conditions. The identified genetic resources and QTLs detected, shed new light on drought adaptive complexes in wheat and expected to facilitate the improvement of drought resistance in elite wheat cultivars.
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Genetic diversity for drought resistance in wild Emmer wheat and its ecogeographical associations
Plant Cell and Environment, 2005Co-Authors: Zvi Peleg, Tzion Fahima, Shahal Abbo, Tamar Krugman, E. Nevo, Dan Yakir, Yehoshua SarangaAbstract:Wild Emmer wheat ( Triticum turgidum spp. dicoccoides (Korn.) Thell.), the tetraploid progenitor of cultivated wheat, is a potential source for various agronomical traits, including drought resistance. The objectives of this study were to characterize (1) the genetic diversity for drought resistance in wild Emmer wheat, and (2) the relationship between drought responses of the wild Emmer germplasm and the ecogeographical parameters of its collection sites. A total of 110 wild Emmer accessions consisting of 25 populations and three control durum wheat cultivars were examined under two irrigation regimes, well-watered (’wet’) and water-limited (’dry’). Wide genetic diversity was found both between and within the wild Emmer populations in most variables under each treatment. A considerable number of the wild Emmer accessions exhibited an advantage in productivity (spike and total dry matter) over their cultivated counterparts. Most wild Emmer wheat accessions exhibited a greater carbon isotope ratio ( d d d 13 C, indicating higher water-use efficiency) under the dry treatment and higher plasticity of d d d 13 C relative to the cultivated controls, which may have contributed to the drought adaptations in the former. The most outstanding drought-tolerance capacity (in term of productivity under the dry treatment and susceptibility indices) was detected in wild Emmer populations originated from hot dry locations. The results suggest that wild Emmer has the potential to improve drought resistance in cultivated wheat.
Zvi Peleg - One of the best experts on this subject based on the ideXlab platform.
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gni a1 mediates trade off between grain number and grain weight in tetraploid wheat
Theoretical and Applied Genetics, 2019Co-Authors: Guy Golan, Assaf Distelfeld, Idan Ayalon, Aviad Perry, Gil Zimran, Toluwanimi Adeajayi, Assaf Mosquna, Zvi PelegAbstract:KEY MESSAGE: Wild Emmer allele of GNI-A1 ease competition among developing grains through the suppression of floret fertility and increase grain weight in tetraploid wheat. Grain yield is a highly polygenic trait determined by the number of grains per unit area, as well as by grain weight. In wheat, grain number and grain weight are usually negatively correlated. Yet, the genetic basis underlying trade-off between the two is mostly unknown. Here, we fine-mapped a grain weight QTL using wild Emmer introgressions in a durum wheat background and showed that grain weight is associated with the GNI-A1 gene, a regulator of floret fertility. In-depth characterization of grain number and grain weight indicated that suppression of distal florets by the wild Emmer GNI-A1 allele increases weight of proximal grains in basal and central spikelets due to alteration in assimilate distribution. Re-sequencing of GNI-A1 in tetraploid wheat demonstrated the rich allelic repertoire of the wild Emmer gene pool, including a rare allele which was present in two gene copies and contained a nonsynonymous mutation in the C-terminus of the protein. Using an F2 population generated from a cross between wild Emmer accessions Zavitan, which carries the rare allele, and TTD140, we demonstrated that this unique polymorphism is associated with grain weight, independent of grain number. Moreover, we showed, for the first time, that GNI-A1 proteins are transcriptional activators and that selection targeted compromised activity of the protein. Our findings expand the knowledge of the genetic basis underlying trade-off between key yield components and may contribute to breeding efforts for enhanced grain yield.
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Genetic diversity for grain nutrients in wild Emmer wheat: potential for wheat improvement.
Annals of botany, 2010Co-Authors: Merav Chatzav, Zvi Peleg, Tzion Fahima, Atilla Yazici, Levent Ozturk, Ismail Cakmak, Yehoshua SarangaAbstract:Genetic diversity for grain nutrients in wild Emmer wheat – A potential for wheat improvement Merav Chatzav1‡, Zvi Peleg1‡, Tzion Fahima2, Ismail Cakmak3, Yehoshua Saranga1* Abstract • Background and Aims - Mineral nutrient malnutrition, and particularly deficiency in zinc (Zn) and iron (Fe), afflicts over three billion people worldwide. In the current study wild Emmer wheat (Triticum turgidum ssp. dicoccoides (Korn.) Thell.), the progenitor of domesticated wheats, was tested for (i) genetic diversity in grain nutrient concentrations, (ii) the associations among grain nutrients and their relationships with plant productivity, and (iii) their association with the ecogeographical origin of wild Emmer accessions. • Methods - A Total of 154 genotypes, including wild Emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this two-year field study for grain protein (GPC), micronutrients (Zn, Fe, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulphur) concentrations. • Key Results - A wide genetic diversity was found among the wild Emmer accessions for all grain nutrients. The concentrations of grain Zn, Fe and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed a significant genetic variation between and within populations for all minerals. Association between soil characterise of the site of collection and grain nutrient concentrations showed negative associations between soil clay and GPC and between Zn in soil and in grain, the latter suggesting that the greatest potential for grain nutrient mineral is expected in populations from mineral deficient soils. • Conclusions – Wild Emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat genepool. Key words: Triticum turgidum ssp. dicoccoides, grain quality, protein, zinc, iron, wheat improvement, micronutrients, macronutrients
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part of a special issue on plant nutrition genetic diversity for grain nutrients in wild Emmer wheat potential for wheat improvement
2010Co-Authors: Merav Chatzav, Zvi Peleg, Tzion Fahima, Atilla Yazici, Levent Ozturk, Ismail Cakmak, Yehoshua SarangaAbstract:†Background and Aims Micronutrient malnutrition, particularly zinc and iron deficiency, afflicts over three billion people worldwide due to low dietary intake. In the current study, wild Emmer wheat (Triticum turgidum ssp. dicoccoides), the progenitor of domesticated wheat, was tested for (1) genetic diversity in grain nutrient concentrations, (2) associations among grain nutrients and their relationships with plant productivity, and (3) the association of grain nutrients with the eco-geographical origin of wild Emmer accessions. †Methods A total of 154 genotypes, including wild Emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this 2-year field study for grain protein, micronutrient (zinc, iron, copper and manganese) and macronutrient (calcium, magnesium, potassium, phosphorus and sulphur) concentrations. †Key Results Wide genetic diversity was found among the wild Emmer accessions for all grain nutrients. The concentrations of grain zinc, iron and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity, suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed significant genetic variation between and within populations for all minerals. Association between soil characteristics at the site of collection and grain nutrient concentrations showed negative associations between soil clay content and grain protein and between soil-extractable zinc and grain zinc, the latter suggesting that the greatest potential for grain nutrient minerals lies in populations from micronutrient-deficient soils. †Conclusions Wild Emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat gene pool.
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grain zinc iron and protein concentrations and zinc efficiency in wild Emmer wheat under contrasting irrigation regimes
Plant and Soil, 2008Co-Authors: Zvi Peleg, Tzion Fahima, Yehoshua Saranga, Atilla Yazici, Levent Ozturk, Ismail CakmakAbstract:Micronutrient malnutrition, and particularly deficiency in zinc (Zn) and iron (Fe), afflicts over three billion people worldwide, and nearly half of the world’s cereal-growing area is affected by soil Zn deficiency. Wild Emmer wheat [Triticum turgidum ssp. dicoccoides (Korn.) Thell.], the progenitor of domesticated durum wheat and bread wheat, offers a valuable source of economically important genetic diversity including grain mineral concentrations. Twenty two wild Emmer wheat accessions, representing a wide range of drought resistance capacity, as well as two durum wheat cultivars were examined under two contrasting irrigation regimes (well-watered control and water-limited), for grain yield, total biomass production and grain Zn, Fe and protein concentrations. The wild Emmer accessions exhibited high genetic diversity for yield and grain Zn, Fe and protein concentrations under both irrigation regimes, with a considerable potential for improvement of the cultivated wheat. Grain Zn, Fe and protein concentrations were positively correlated with one another. Although irrigation regime significantly affected ranking of genotypes, a few wild Emmer accessions were identified for their advantage over durum wheat, having consistently higher grain Zn (e.g., 125 mg kg−1), Fe (85 mg kg−1) and protein (250 g kg−1) concentrations and high yield capacity. Plants grown from seeds originated from both irrigation regimes were also examined for Zn efficiency (Zn deficiency tolerance) on a Zn-deficient calcareous soil. Zinc efficiency, expressed as the ratio of shoot dry matter production under Zn deficiency to Zn fertilization, showed large genetic variation among the genotypes tested. The source of seeds from maternal plants grown under both irrigation regimes had very little effect on Zn efficiency. Several wild Emmer accessions revealed combination of high Zn efficiency and drought stress resistance. The results indicate high genetic potential of wild Emmer wheat to improve grain Zn, Fe and protein concentrations, Zn deficiency tolerance and drought resistance in cultivated wheat.
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Physiological-genetic Dissection of Drought Resistance in wild Emmer wheat
2008Co-Authors: Yehoshua Saranga, Zvi Peleg, Tzion FahimaAbstract:Wild Emmer wheat (Triticum turgidum ssp. dicoccoides (Korn.) Thell.), the allo-tetraploid (BBAA) progenitor of cultivated wheats, offers a valuable source of allelic diversity for various economically important traits, including drought resistance. A total of 160 wild Emmer accessions, consisting of 25 populations, and three control durum wheat cultivars were examined under two irrigation regimes, well-watered control (~650 mm) and water-limited (~250 mm). Principal component analysis, supported by photosynthetic rate measurements, revealed a variety of drought adaptive strategies among the wild accessions. A wide phenotypic variation was found both between and within the wild Emmer populations in most morpho-physiological traits, with a considerable advantage in drought resistance over cultivated genotypes. Microsatellite markers revealed a wide allelic diversity between and within the wild Emmer populations, confirming the patterns of phenotypic variation. The greatest drought resistance capacity corresponded with the highest allelic diversity and found in populations from intermediate aridity level. Physiological responses to drought were further dissected by quantitative trait loci (QTLs) mapping of yield and drought related traits under contrasting irrigation regimes, using 152 F6 recombinant inbred lines derived from a cross between durum wheat and wild Emmer wheat from drought-prone environment. A total of 102 QTLs were mapped for 10 productivity and morpho-physiological traits. Several QTLs exhibited GxE interaction and accounted for productivity and related physiological traits under either the well watered or water-limited conditions. The identified genetic resources and QTLs detected, shed new light on drought adaptive complexes in wheat and expected to facilitate the improvement of drought resistance in elite wheat cultivars.
Tzion Fahima - One of the best experts on this subject based on the ideXlab platform.
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Variation in Stripe Rust Resistance and Morphological Traits in Wild Emmer Wheat Populations
Agronomy, 2019Co-Authors: Lin Huang, Tzion Fahima, Tamar Krugman, Lihua Feng, Zizhong Tang, Hanan Sela, Dengcai LiuAbstract:Wild Emmer wheat (Triticum dicoccoides), the tetraploid progenitor of cultivated wheats, is indigenous to the Near East Fertile Crescent. An important center of distribution is found today in and around the catchment area of the upper Jordan Valley in Israel and surrounding regions. In the current study, the field stripe rust resistance and morphological traits were analyzed using 98 sample accessions that represented the geographical distribution of wild Emmer populations in Israel and its vicinity. The resistance tests at two field locations revealed that the majority of the wild Emmer accessions possess quantitative resistance against stripe rust. This could be due to the high frequency of Yr36 in the wild Emmer populations. The identification of potentially novel stripe rust resistance in this set of germplasm is highly significant. In total, 11 morphological traits were examined in this study. Wide range of natural variation was revealed in the tested morphological traits. Most of the morphological traits had significant correlations with climate variables, indicating that the local environmental conditions have a profound effect on shaping the genetic structure of wild Emmer wheat. Our results suggest that wild Emmer wheat has the enormous potential to improve stripe rust resistance and various important agronomical traits in wheat.
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Distribution and haplotype diversity of WKS resistance genes in wild Emmer wheat natural populations
TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik, 2016Co-Authors: Lin Huang, Tamar Krugman, Lihua Feng, Hanan Sela, Qijiao Chen, Jun Yan, Jorge Dubcovsky, Tzion FahimaAbstract:The wheat stripe rust resistance gene Yr36 ( WKS1 ) with a unique kinase-START domain architecture is highly conserved in wild Emmer wheat natural populations. Wild Emmer wheat (Triticum dicoccoides) populations have developed various resistance strategies against the stripe rust pathogen Puccinia striiformis f. sp. tritici (Pst). The wild Emmer gene, Yr36 (WKS1), which confers partial resistance to a broad spectrum of Pst races, is composed of a kinase and a START lipid-binding domain, a unique gene architecture found only in the Triticeae tribe. The analysis of 435 wild Emmer accessions from a broad range of natural habitats revealed that WKS1 and its paralogue WKS2 are present only in the southern distribution range of wild Emmer in the Fertile Crescent, supporting the idea that wheat domestication occurred in the northern populations. An analysis of full-length WKS1 sequence from 54 accessions identified 15 different haplotypes and very low-nucleotide diversity (π = 0.00019). The high level of WKS1 sequence conservation among wild Emmer populations is in contrast to the high level of diversity previously observed in NB-LRR genes (e.g., Lr10 and Pm3). This phenomenon may reflect the different resistance mechanisms and different evolutionary pathways that shaped these genes, and may shed light on the evolution of genes that confer partial resistance to stripe rust. Only five WKS1 coding sequence haplotypes were revealed among all tested accessions, encoding four different putative WKS1 proteins (designated P0, P1, P2, and P3). Infection tests showed that P0, P1, and P3 haplotypes display a resistance response, while P2 displayed a susceptible response. These results show that the WKS1 proteins (P0, P1, and P3) can be useful to improve wheat resistance to stripe rust.
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Genetic diversity for grain nutrients in wild Emmer wheat: potential for wheat improvement.
Annals of botany, 2010Co-Authors: Merav Chatzav, Zvi Peleg, Tzion Fahima, Atilla Yazici, Levent Ozturk, Ismail Cakmak, Yehoshua SarangaAbstract:Genetic diversity for grain nutrients in wild Emmer wheat – A potential for wheat improvement Merav Chatzav1‡, Zvi Peleg1‡, Tzion Fahima2, Ismail Cakmak3, Yehoshua Saranga1* Abstract • Background and Aims - Mineral nutrient malnutrition, and particularly deficiency in zinc (Zn) and iron (Fe), afflicts over three billion people worldwide. In the current study wild Emmer wheat (Triticum turgidum ssp. dicoccoides (Korn.) Thell.), the progenitor of domesticated wheats, was tested for (i) genetic diversity in grain nutrient concentrations, (ii) the associations among grain nutrients and their relationships with plant productivity, and (iii) their association with the ecogeographical origin of wild Emmer accessions. • Methods - A Total of 154 genotypes, including wild Emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this two-year field study for grain protein (GPC), micronutrients (Zn, Fe, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulphur) concentrations. • Key Results - A wide genetic diversity was found among the wild Emmer accessions for all grain nutrients. The concentrations of grain Zn, Fe and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed a significant genetic variation between and within populations for all minerals. Association between soil characterise of the site of collection and grain nutrient concentrations showed negative associations between soil clay and GPC and between Zn in soil and in grain, the latter suggesting that the greatest potential for grain nutrient mineral is expected in populations from mineral deficient soils. • Conclusions – Wild Emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat genepool. Key words: Triticum turgidum ssp. dicoccoides, grain quality, protein, zinc, iron, wheat improvement, micronutrients, macronutrients
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part of a special issue on plant nutrition genetic diversity for grain nutrients in wild Emmer wheat potential for wheat improvement
2010Co-Authors: Merav Chatzav, Zvi Peleg, Tzion Fahima, Atilla Yazici, Levent Ozturk, Ismail Cakmak, Yehoshua SarangaAbstract:†Background and Aims Micronutrient malnutrition, particularly zinc and iron deficiency, afflicts over three billion people worldwide due to low dietary intake. In the current study, wild Emmer wheat (Triticum turgidum ssp. dicoccoides), the progenitor of domesticated wheat, was tested for (1) genetic diversity in grain nutrient concentrations, (2) associations among grain nutrients and their relationships with plant productivity, and (3) the association of grain nutrients with the eco-geographical origin of wild Emmer accessions. †Methods A total of 154 genotypes, including wild Emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this 2-year field study for grain protein, micronutrient (zinc, iron, copper and manganese) and macronutrient (calcium, magnesium, potassium, phosphorus and sulphur) concentrations. †Key Results Wide genetic diversity was found among the wild Emmer accessions for all grain nutrients. The concentrations of grain zinc, iron and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity, suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed significant genetic variation between and within populations for all minerals. Association between soil characteristics at the site of collection and grain nutrient concentrations showed negative associations between soil clay content and grain protein and between soil-extractable zinc and grain zinc, the latter suggesting that the greatest potential for grain nutrient minerals lies in populations from micronutrient-deficient soils. †Conclusions Wild Emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat gene pool.
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molecular identification of a new powdery mildew resistance gene pm41 on chromosome 3bl derived from wild Emmer triticum turgidum var dicoccoides
Theoretical and Applied Genetics, 2009Co-Authors: Tzion Fahima, Eviatar Nevo, Tilin Fang, Hongtao Zhang, Chaojie Xie, Tsomin Yang, Qixin Sun, Zhiyong LiuAbstract:Powdery mildew caused by Blumeria graminis f. sp. tritici is an important wheat disease in China and other parts of the world. Wild Emmer (Triticum turgidum var. dicoccoides) is the immediate progenitor of cultivated tetraploid and hexaploid wheats and thus an important resource for wheat improvement. Wild Emmer accession IW2 collected from Mount Hermon, Israel, is highly resistant to powdery mildew at the seedling and adult plant stages. Genetic analysis using an F2 segregating population and F2:3 families, derived from a cross between susceptible durum cultivar Langdon and wild Emmer accession IW2, indicated that a single dominant gene was responsible for the resistance of IW2. Bulked segregant and molecular marker analyses detected that six polymorphic SSR, one ISBP, and three EST-STS markers on chromosome 3BL bin 0.63–1.00 were linked to the resistance gene. Allelic variations of resistance-linked EST-STS marker BE489472 revealed that the allele was present only in wild Emmer but absent in common wheat. Segregation distortion was observed for the powdery mildew resistance allele and its linked SSR markers with preferential transmission of Langdon alleles over IW2 alleles. The resistance gene was introgressed into common wheat by backcrossing and marker-assisted selection. Since no designated powdery mildew resistance gene has been found on chromosome 3BL, the resistance gene derived from wild Emmer accession IW2 appears to be new one and was consequently designated Pm41.
Richard Trethowan - One of the best experts on this subject based on the ideXlab platform.
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The impact of Emmer genetic diversity on grain protein content and test weight of hexaploid wheat under high temperature stress
Journal of Cereal Science, 2020Co-Authors: Smi Ullah, Helen Bramley, Tariq Mahmood, Richard TrethowanAbstract:Abstract High temperature has a negative impact on wheat grain quality and reduces market value. Emmer wheat (Triticum dicoccon Schrank), one of the earliest domesticated wheat species, is a source of genetic diversity for the improvement of heat and drought tolerance in modern wheat. However, the potential of Emmer wheat for the improvement of grain physical quality under high temperature stress is little studied. A diverse set of 184 Emmer-based hexaploid lines were developed by crossing Emmer wheat with hexaploid wheat and backcrossing once to hexaploid wheat. These materials, seven hexaploid recurrent parents and seven commercial cultivars, were evaluated at two times of sowing (E1 and E2) in the field, in 2015–2016. The materials were genotyped using a 90 K SNP platform and these data were used to estimate the contribution of Emmer wheat to the progeny. Significant phenotypic and genetic variation for grain physical quality traits including protein content and test weight was observed. High temperature significantly increased protein content and decreased test weight. Large scale field phenotyping identified Emmer progenies with improved grain characteristic compared to their respective parents and commercial cultivars in both environments. A few families consistently produced higher trait means across environments compared to their recurrent parents. The Emmer wheat parent contributed between 1 and 37% of the genome in Emmer-based genotypes. Selected Emmer derived lines with superior protein content and test weight, tended to have a greater genetic contribution from the Emmer parent, ranging from 12 to 37% and 7–37% in E1 and E2, respectively. It was concluded that new genetic variation for seed traits, such as protein content and test weight, can be introduced to hexaploid wheat from Emmer wheat. The newly developed Emmer derivatives identified with enhanced grain quality under high temperature stress can potentially be used to improve grain quality through breeding.
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Implications of Emmer (Triticum dicoccon Schrank) introgression on bread wheat response to heat stress
Plant Science, 2020Co-Authors: Smi Ullah, Helen Bramley, Tariq Mahmood, Richard TrethowanAbstract:Abstract Wheat is sensitive to heat stress, particularly during grain filling, and this reduces grain yield. Ancestral wheat species, such as Emmer wheat (Triticum dicoccon Schrank), represent potential sources of new genetic diversity for traits that may impact wheat responses to heat stress. However, the diversity available in Emmer wheat has only been explored superficially. Recently developed Emmer derived hexaploid wheat genotypes were evaluated for physiological, phenological and agronomic traits in a multi-environment, multi-season strategy. The Emmer-based hexaploid lines were developed from crosses and backcrosses to 9 hexaploid recurrent parents and these genotypes and 7 commercial cultivars were evaluated under two times of sowing (E1 and E2) in the field for three consecutive years (2014-2016). The materials were genotyped using a 90 K SNP platform and these data used to estimate the contribution of Emmer wheat to the progeny. Significant phenotypic and genetic variation for traits were observed. Higher temperature during reproductive development and grain filling reduced trait expression. Emmer progeny with greater trait values than their recurrent parents and commercial cultivars in both environments were found. Derivatives with higher physiological trait values yielded well in both environments; as indicated by the clustering of genotypes. The Emmer wheat parent contributed between 1 and 43% of the genome of the Emmer-based hexaploid progeny, and progeny with greater Emmer contribution had superior trait values in both environments. These results showed a positive effect of direct Emmer introgression on wheat performance under heat stress. Mitigation of high temperature stress through the introgression of favorable alleles from wheat close relatives into modern wheat cultivars is possible.
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Emmer wheat (Triticum dicoccon Schrank) improves water use efficiency and yield of hexaploid bread wheat.
Plant science : an international journal of experimental plant biology, 2019Co-Authors: Rohayu Ma’arup, Helen Bramley, Richard Trethowan, Nizam U. Ahmed, Peter J. SharpAbstract:Emmer wheat (Triticum dicoccon Schrank) is a potential source of new genetic diversity for the improvement of hexaploid bread wheat. Emmer wheat was crossed and backcrossed to bread wheat and 480 doubled haploids (DHs) were produced from BC1F1 plants with hexaploid appearance derived from 19 crossses. These DHs were screened under well-watered conditions (E1) in 2013 to identify high-yielding materials with similar phenology. One-hundred and eighty seven DH lines selected on this basis, 4 commercial bread wheat cultivars and 9 bread wheat parents were then evaluated in extensive field experiments under two contrasting moisture regimes in north-western NSW in 2014 and 2015. A significant range in the water-use-efficiency of grain production (WUEGrain) was observed among the Emmer derivatives. Of these, 8 hexaploid lines developed from 8 different Emmer wheat parents had significantly improved intrinsic water-use-efficiency (WUEintr) and instantaneous water-use-efficiency (WUEi) compared to their bread wheat recurrent parents. Accurate and large scale field-based phenotyping was effective in identifying Emmer wheat derived lines with superior performance to their hexaploid bread wheat recurrent parents under moisture stress.
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Genetic contribution of Emmer wheat (Triticum dicoccon Schrank) to heat tolerance of bread wheat
Frontiers in plant science, 2018Co-Authors: Smi Ullah, Helen Bramley, Tariq Mahmood, Hans D. Daetwyler, Rebecca. J. Thistlethwaite, Richard TrethowanAbstract:Rising global temperatures cause substantial yield losses in many wheat growing environments. Emmer wheat (Triticum dicoccon Schrank), one of the first wheat species domesticated, carries significant variation for tolerance to abiotic stresses. This study identified new genetic variability for high-temperature tolerance in hexaploid progeny derived from crosses with Emmer wheat. Eight hexaploid and 11 tetraploid parents were recombined in 43 backcross combinations using the hexaploid as the recurrent parent. A total of 537 Emmer-based hexaploid lines were developed by producing approximately 10 doubled haploids on hexaploid like BC1F1 progeny and subsequent selection for hexaploid morphology. These materials and 17 commercial cultivars and hexaploid recurrent parents were evaluated under two times of sowing in the field, in 2014-2016. The materials were genotyped using a 90K SNP platform and these data were used to estimate the contribution of Emmer wheat to the progeny. Significant phenotypic and genetic variation for key agronomical traits including grain yield, TKW and screenings was observed. Many of the Emmer derived lines showed improved performance under heat stress (delayed sowing) compared with parents and commercial cultivars. Emmer derived lines were the highest yielding material in both sowing dates. The Emmer wheat parent contributed between 1 and 44% of the genome of the derived lines. Emmer derived lines with superior kernel weight and yield generally had a greater genetic contribution from the Emmer parent compared to those with lower trait values. The study showed that new genetic variation for key traits such as yield, kernel weight and screenings can be introduced to hexaploid wheat from Emmer wheat. These genetic resources should be explored more systematically to stabilize grain yield and quality in a changing climate.
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Molecular genetic diversity analysis in Emmer wheat (Triticum dicoccon Schrank) from India
Genetic Resources and Crop Evolution, 2012Co-Authors: Arvindkumar Shivaji Salunkhe, Richard Trethowan, Maria Zaharieva, S. A. Tamhankar, Sujata Tetali, David Bonnett, S. C. MisraAbstract:Emmer wheat (Triticum dicoccon Schrank) is still largely cultivated in India, and highly appreciated for the preparation of traditional dishes. Moreover, its nutritional characteristics could justify a development of its cultivation. The perspective of genetic improvement however requires a good knowledge of the genetic diversity existing within the eco-geographic group of Indian Emmer wheats. A set of 48 Emmer wheat accessions from India including 28 from a local collection and 20 Indian accessions obtained from CIMMYT, Mexico, was assessed for genetic variability using 47 microsatellite (SSR) markers, distributed over all the 14 chromosomes. The number of alleles per locus ranged from 2 to 9, with an average of 3.87 alleles per locus. A total of 201 alleles were detected at 52 loci with average polymorphic information content of 0.35 per locus and a mean resolving power of 1. The pair-wise similarity coefficients calculated from binary data matrix based on presence or absence of alleles varied from 0.15 to 0.98, but was greater than 0.5 for most accessions, indicating a high level of similarity. A cluster analysis based on the similarity matrix identified nine distinct accessions and three clusters. All the recently developed commercial varieties were distinctly different from the clusters. Based on the analysis, it appears that Indian Emmer wheats are not very diverse. Consequently, there is a need to increase the diversity within the Indian Emmer wheat eco-geographic group, by introducing diversity from other eco-geographic groups, or even from other wheat species.
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Genome-wide association mapping reveals a rich genetic architecture of stripe rust resistance loci in Emmer wheat (Triticum turgidum ssp. dicoccum)
Theoretical and Applied Genetics, 2017Co-Authors: Marco Maccaferri, Xianming Chen, Gaetano Laghetti, Domenico Pignone, Michael O Pumphrey, Roberto TuberosaAbstract:Key message SNP-based genome scanning in worldwide domesticated Emmer germplasm showed high genetic diversity, rapid linkage disequilibrium decay and 51 loci for stripe rust resistance, a large proportion of which were novel. Abstract Cultivated Emmer wheat ( Triticum turgidum ssp. dicoccum ), one of the oldest domesticated crops in the world, is a potentially rich reservoir of variation for improvement of resistance/tolerance to biotic and abiotic stresses in wheat. Resistance to stripe rust ( Puccinia striiformis f. sp. tritici ) in Emmer wheat has been under-investigated. Here, we employed genome-wide association (GWAS) mapping with a mixed linear model to dissect effective stripe rust resistance loci in a worldwide collection of 176 cultivated Emmer wheat accessions. Adult plants were tested in six environments and seedlings were evaluated with five races from the United States and one from Italy under greenhouse conditions. Five accessions were resistant across all experiments. The panel was genotyped with the wheat 90,000 Illumina iSelect single nucleotide polymorphism (SNP) array and 5106 polymorphic SNP markers with mapped positions were obtained. A high level of genetic diversity and fast linkage disequilibrium decay were observed. In total, we identified 14 loci associated with field resistance in multiple environments. Thirty-seven loci were significantly associated with all-stage (seedling) resistance and six of them were effective against multiple races. Of the 51 total loci, 29 were mapped distantly from previously reported stripe rust resistance genes or quantitative trait loci and represent newly discovered resistance loci. Our results suggest that GWAS is an effective method for characterizing genes in cultivated Emmer wheat and confirm that Emmer wheat is a rich source of stripe rust resistance loci that can be used for wheat improvement.
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genome wide association mapping reveals a rich genetic architecture of stripe rust resistance loci in Emmer wheat triticum turgidum ssp dicoccum
Theoretical and Applied Genetics, 2017Co-Authors: Weizhen Liu, Marco Maccaferri, Xianming Chen, Gaetano Laghetti, Domenico Pignone, Michael O Pumphrey, Roberto TuberosaAbstract:SNP-based genome scanning in worldwide domesticated Emmer germplasm showed high genetic diversity, rapid linkage disequilibrium decay and 51 loci for stripe rust resistance, a large proportion of which were novel. Cultivated Emmer wheat (Triticum turgidum ssp. dicoccum), one of the oldest domesticated crops in the world, is a potentially rich reservoir of variation for improvement of resistance/tolerance to biotic and abiotic stresses in wheat. Resistance to stripe rust (Puccinia striiformis f. sp. tritici) in Emmer wheat has been under-investigated. Here, we employed genome-wide association (GWAS) mapping with a mixed linear model to dissect effective stripe rust resistance loci in a worldwide collection of 176 cultivated Emmer wheat accessions. Adult plants were tested in six environments and seedlings were evaluated with five races from the United States and one from Italy under greenhouse conditions. Five accessions were resistant across all experiments. The panel was genotyped with the wheat 90,000 Illumina iSelect single nucleotide polymorphism (SNP) array and 5106 polymorphic SNP markers with mapped positions were obtained. A high level of genetic diversity and fast linkage disequilibrium decay were observed. In total, we identified 14 loci associated with field resistance in multiple environments. Thirty-seven loci were significantly associated with all-stage (seedling) resistance and six of them were effective against multiple races. Of the 51 total loci, 29 were mapped distantly from previously reported stripe rust resistance genes or quantitative trait loci and represent newly discovered resistance loci. Our results suggest that GWAS is an effective method for characterizing genes in cultivated Emmer wheat and confirm that Emmer wheat is a rich source of stripe rust resistance loci that can be used for wheat improvement.