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Sample records for hexaploid wheat genetic

  1. Genetic diversity among synthetic hexaploid wheat accessions with resistance to several fungal diseases

    Science.gov (United States)

    Synthetic hexaploid wheat (SHW) is known to be an excellent vehicle for transferring large genetic variations especially the many useful traits present in the D genome of Aegilops tauschii Coss (2n=2x=14, DD) for improvement of cultivated wheat (Triticum aestivum L., 2n=6x=42, AABBDD). The objectiv...

  2. Detection of Genetic Diversity in Synthetic Hexaploid Wheats Using Microsatellite Markers

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-yue; LI Li-hui

    2007-01-01

    Ninety-five synthetic hexaploid wheats(2n=6x=42,AABBDD)were analyzed using 45 microsatellite markers to investigate the potential genetic diversity in wheat breeding programs.A total of 326 alleles were detected by these microsatellite primer pairs,with an average of 6.65 alleles per locus.The polymorphic information content(PIC),Simpson index(SI),and genetic similarity(GS)coefficient showed that the D genome is of the highest genetic diversity among the A,B,and D genomes in the synthetic hexaploid wheats.The results also indicated that the synthetic hexaploid wheat is an efficient way to enrich wheat genetic backgrounds,especially to use the genetic variations of the D genome from Aegilops squarrosa for wheat improvement.The UPGMA dendogram,based on a similarity matrix by a simple matching coefficient algorithm,delineated the above accessions into 5 major clusters and was in accordance with the available pedigree information.The results demonstrated the utility of microsatellite markers in detecting DNA polymorphism and estimating genetic diversity.

  3. Estimation of Genetic Diversity in Genetic Stocks of Hexaploid Wheat Using Seed Storage Proteins

    OpenAIRE

    Tanweer Kumar; Imtiaz Ahmed Khan; Niaz Ali; Muhammad Amir Zia; Tahir Hameed; Sohaib Roomi; Ali Bahadur; Habib Ahmad

    2014-01-01

    Bread wheat (Triticum aestivum L.) is an allohexaploid specie, consist of three genomes AABBDD having 2n = 6x = 42 chromosomes. The wheat is a staple food of human beings due to its bread making quality which is composed of seed storage proteins of wheat especially High Molecular Weight Glutenins (HMW-GS). During present research, HMW-GS were analyzed in genetic stocks of common wheat consist of Nullisomic- tetrasomic, ditelosomic and deletion lines of group 3 homoeologous chromosomes by Sodi...

  4. Genetic map of Triticum turgidum based on a hexaploid wheat population without genetic recombination for D genome

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    Zhang Li

    2012-08-01

    Full Text Available Abstract Background A synthetic doubled-haploid hexaploid wheat population, SynDH1, derived from the spontaneous chromosome doubling of triploid F1 hybrid plants obtained from the cross of hybrids Triticum turgidum ssp. durum line Langdon (LDN and ssp. turgidum line AS313, with Aegilops tauschii ssp. tauschii accession AS60, was previously constructed. SynDH1 is a tetraploidization-hexaploid doubled haploid (DH population because it contains recombinant A and B chromosomes from two different T. turgidum genotypes, while all the D chromosomes from Ae. tauschii are homogenous across the whole population. This paper reports the construction of a genetic map using this population. Results Of the 606 markers used to assemble the genetic map, 588 (97% were assigned to linkage groups. These included 513 Diversity Arrays Technology (DArT markers, 72 simple sequence repeat (SSR, one insertion site-based polymorphism (ISBP, and two high-molecular-weight glutenin subunit (HMW-GS markers. These markers were assigned to the 14 chromosomes, covering 2048.79 cM, with a mean distance of 3.48 cM between adjacent markers. This map showed good coverage of the A and B genome chromosomes, apart from 3A, 5A, 6A, and 4B. Compared with previously reported maps, most shared markers showed highly consistent orders. This map was successfully used to identify five quantitative trait loci (QTL, including two for spikelet number on chromosomes 7A and 5B, two for spike length on 7A and 3B, and one for 1000-grain weight on 4B. However, differences in crossability QTL between the two T. turgidum parents may explain the segregation distortion regions on chromosomes 1A, 3B, and 6B. Conclusions A genetic map of T. turgidum including 588 markers was constructed using a synthetic doubled haploid (SynDH hexaploid wheat population. Five QTLs for three agronomic traits were identified from this population. However, more markers are needed to increase the density and resolution of

  5. The pangenome of hexaploid bread wheat.

    Science.gov (United States)

    Montenegro, Juan D; Golicz, Agnieszka A; Bayer, Philipp E; Hurgobin, Bhavna; Lee, HueyTyng; Chan, Chon-Kit Kenneth; Visendi, Paul; Lai, Kaitao; Doležel, Jaroslav; Batley, Jacqueline; Edwards, David

    2017-02-23

    There is an increasing understanding that gene presence absence variation plays an important role in the heritability of agronomic traits, however there have been relatively few studies on gene presence absence variation in crop species. Hexaploid wheat is one of the most important food crops in the world and intensive breeding has reduced the genetic diversity of elite cultivars. Major efforts have produced draft genome assemblies for the cultivar Chinese Spring, but it is unknown how well this represents the genome diversity found in current modern elite cultivars. In this study we build an improved reference for Chinese Spring and explore gene diversity across 18 wheat cultivars. We predict a pangenome size of 140,500 +/- 102 genes, a core genome of 81,070 +/- 1,631 genes, and an average of 128,656 genes in each cultivar. Functional annotation of the variable gene set suggests that it is enriched for genes that may be associated with important agronomic traits. In addition to gene presence variation, more than 36 million intervarietal SNPs were identified across the pangenome. This study of the wheat pangenome provides insight into elite wheat genome diversity as a basis for genomics based improvement of this important crop. A wheat pangenome Gbrowse is available at http://appliedbioinformatics.com.au/cgi-bin/gb2/gbrowse/WheatPan/, and data is available for download from http://wheatgenome.info/wheat_genome_databases.php. This article is protected by copyright. All rights reserved.

  6. Genetic Analysis and Molecular Tagging a Novel Yellow Rust Resistance Gene Derived from Synthetic Hexaploid Wheat Germplasm M08

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-yue; LI Li-hui

    2008-01-01

    Yellow rust of wheat(caused by Puccinia striiformis Westend.f sp.tritici Eriks.)has been periodically epidemic and severely damaged wheat production in China.The development of resistant cultivars could be an effective way to reduce yield losses of wheat caused by yellow rust.Rust reaction tests and genetic analysis indicated that M08,the synthetic hexaploid wheat derived from hybridization between Triticum durum(2n=6X=28;genome AABB)and Aegilops tauschii (2n=2X=14;genome DD),showed resistance to current prevailing yellow rust races at seedling stage,which was controlled by a single dominant gene,designated as YrAm.Bulked segregant analysis was used to identify microsatellite markers linked to gene YrAm in an F2 population derived from cross M08(resistant)×Jinan 17(susceptible).Three microsatellite marker loci Xgwm77,Xgwm285,and Xgwm131 located on chromosome 3B were mapped to the YrAm locus. Xgwm131 was the closest marker locus and showed a linkage distance of 7.8 cM to the resistance locus.Thus,it is assumed that YrAm for resistance to yellow rust may be derived from Triticum durum and is located on the long arm of chromosome 3B.

  7. [Development and study of spring bread wheat variety Pamyati Maystrenko with introgression of genetic material from synthetic hexaploid Triticum timopheevii zhuk. x Aegilops tauschii Coss].

    Science.gov (United States)

    Laikova, L I; Belan, I A; Badaeva, E D; Posseeva, L P; Shepelev, S S; Shumny, V K; Pershina, L A

    2013-01-01

    Synthetic hexaploids are bridges for transferring new genes that determine resistance to stress factors from wild-type species to bread wheat. In the present work, the method of developing the spring bread wheat variety Pamyati Maystrenko and the results of its study are described. This variety was obtained using one of the immune lines produced earlier via the hybridization of the spring bread wheat variety Saratovskaya 29 with the synthetic hexaploid T. timopheevii Zhuk. x Ae. tauschii Coss. The C-staining of chromosomes in the Pamyati Maystrenko variety revealed substitutions of 2B and 6B chromosomes by the homeologous chromosomes of the G genome of T. timopheevii and the substitution of chromosome 1D by an orthologous chromosome ofAe. tauschii. It was found that this variety is characterized by resistance to leaf and stem rust, powdery mildew, and loose smut as well as by high grain and bread-making qualities. The role of the alien genetic material introgressed into the bread-wheat genome in the expression of adaptive and economically valuable traits in the Pamyati Maystrenko variety is discussed.

  8. Association analysis of grain traits with SSR markers between Aegilops tauschii and hexaploid wheat (Triticum aestivumL.)

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jing-lan; WANG Hong-wei; ZHANG Xiao-cun; DU Xu-ye; LI An-fei; KONG Ling-rang

    2015-01-01

    Seven important grain traits, including grain length (GL), grain width (GW), grain perimeter (GP), grain area (GA), grain length/width ratio (GLW), roundness (GR), and thousand-grain weight (TGW), were analyzed using a set of 139 simple sequence repeat (SSR) markers in 130 hexaploid wheat varieties and 193Aegilops tauschiaccessions worldwide. In total, 1612 aleles inAe. tauschiand 1360 aleles in hexaploid wheat (Triticum aestivumL.) were detected throughout the D genome. 197 marker-trait associations inAe. tauschi were identiifed with 58 different SSR loci in 3 environments, and the average phenotypic variation value (R2) ranged from 0.68 to 15.12%. In contrast, 208 marker-trait associations were identiifed in wheat with 66 different SSR markers in 4 environments and the average phenotypicR2ranged from 0.90 to 19.92%. Further analysis indicated that there are 6 common SSR loci present in bothAe. tauschi and hexaploid wheat, which are signiifcantly associated with the 5 investigated grain traits (i.e., GA, GP, GR, GL, and TGW) and in total, 16 aleles derived from the 6 aforementioned SSR loci were shared byAe. tauschi and hexaploid wheat. These preliminary data suggest the existence of common aleles may explain the evolutionary process and the selection betweenAe. tauschi and hexaploid wheat. Furthermore, the genetic differentiation of grain shape and thousand-grain weight were observed in the evolutionary developmental process fromAe. tauschi to hexaploid wheat.

  9. Spontaneous and divergent hexaploid triticales derived from common wheat × rye by complete elimination of D-genome chromosomes.

    Directory of Open Access Journals (Sweden)

    Hao Li

    Full Text Available Hexaploid triticale could be either synthesized by crossing tetraploid wheat with rye, or developed by crossing hexaploid wheat with a hexaploid triticale or an octoploid triticale.Here two hexaploid triticales with great morphologic divergence derived from common wheat cultivar M8003 (Triticum aestivum L. × Austrian rye (Secale cereale L. were reported, exhibiting high resistance for powdery mildew and stripe rust and potential for wheat improvement. Sequential fluorescence in situ hybridization (FISH and genomic in situ hybridization (GISH karyotyping revealed that D-genome chromosomes were completely eliminated and the whole A-genome, B-genome and R-genome chromosomes were retained in both lines. Furthermore, plentiful alterations of wheat chromosomes including 5A and 7B were detected in both triticales and additionally altered 5B, 7A chromosome and restructured chromosome 2A was assayed in N9116H and N9116M, respectively, even after selfing for several decades. Besides, meiotic asynchrony was displayed and a variety of storage protein variations were assayed, especially in the HMW/LMW-GS region and secalins region in both triticales.This study confirms that whole D-genome chromosomes could be preferentially eliminated in the hybrid of common wheat × rye, "genome shock" was accompanying the allopolyploidization of nascent triticales, and great morphologic divergence might result from the genetic variations. Moreover, new hexaploid triticale lines contributing potential resistance resources for wheat improvement were produced.

  10. Combining ability and heterosis effect in hexaploid wheat group

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    Titan Primož

    2012-01-01

    Full Text Available The main goal of hybrid wheat breeding is the identification of parents with high specific combining ability for grain yield and other agronomic traits. This kind of data facilitate the development of hybrid combinations with high level of heterosis in first filial generation (F1 generation. The use of species from the hexaploid wheat group (e.g. Triticum spelta L. Triticum compactum HOST... is representing an opportunity for the increase of heterosis level in the germplasm of common wheat (Triticum aestivum L.. The study of combining ability and heterosis effect in hexaploid wheat group was carried out using crosses between thirteen inbred lines of common wheat (6 lines x 7 testers and inter-species crosses (T. aestivum L. × T. spelta L., T. aestivum L. × T. compactum HOST, T. aestivum L. × T. sphaerococcum PERCIV., T. aestivum L. × T. macha DEKAPR. et MENABDE, T. aestivum L. × T. petropavlovskyi UDACZ. et MIGUSCH, T. aestivum L. × T. vavilovii (THUM. JAKUBZ.. The 42 common wheat F1 hybrids were tested during two seasons (2010/11 and 2011/12 on the Selection center Ptuj. The experiment was carried out in a randomized block design with four replications. The 43 interspecies F1 hybrids were tested on the same location in the season 2011/12 and the experiment was designed as an randomized block with three replications. The results were analyzed using statistical package AGROBASE generation II and STATGRAPHICS Centurion XVI. The analysis of variance was significant for both, GCA and SCA variances (P < 0,01. Generally, SCA variances were lower than GCA variances. We could state, that the improvement of heterosis level in the common wheat germplasm through the use of relatives with the same genome (genome BAD is possible. As an example we can point out the interspecies F1 hybrid between common wheat variety Garcia and an accession of the Triticum sphaerococcum PERCIV. species (accession number 01C0201227.

  11. High Transferability of Homoeolog-Specific Markers between Bread Wheat and Newly Synthesized Hexaploid Wheat Lines

    Science.gov (United States)

    Zeng, Deying; Luo, Jiangtao; Li, Zenglin; Chen, Gang; Zhang, Lianquan; Ning, Shunzong; Yuan, Zhongwei; Zheng, Youliang; Hao, Ming; Liu, Dengcai

    2016-01-01

    Bread wheat (Triticum aestivum, 2n = 6x = 42, AABBDD) has a complex allohexaploid genome, which makes it difficult to differentiate between the homoeologous sequences and assign them to the chromosome A, B, or D subgenomes. The chromosome-based draft genome sequence of the ‘Chinese Spring’ common wheat cultivar enables the large-scale development of polymerase chain reaction (PCR)-based markers specific for homoeologs. Based on high-confidence ‘Chinese Spring’ genes with known functions, we developed 183 putative homoeolog-specific markers for chromosomes 4B and 7B. These markers were used in PCR assays for the 4B and 7B nullisomes and their euploid synthetic hexaploid wheat (SHW) line that was newly generated from a hybridization between Triticum turgidum (AABB) and the wild diploid species Aegilops tauschii (DD). Up to 64% of the markers for chromosomes 4B or 7B in the SHW background were confirmed to be homoeolog-specific. Thus, these markers were highly transferable between the ‘Chinese Spring’ bread wheat and SHW lines. Homoeolog-specific markers designed using genes with known functions may be useful for genetic investigations involving homoeologous chromosome tracking and homoeolog expression and interaction analyses. PMID:27611704

  12. A modified TILLING approach to detect induced mutations in tetraploid and hexaploid wheat

    Directory of Open Access Journals (Sweden)

    Tsai Helen

    2009-08-01

    Full Text Available Abstract Background Wheat (Triticum ssp. is an important food source for humans in many regions around the world. However, the ability to understand and modify gene function for crop improvement is hindered by the lack of available genomic resources. TILLING is a powerful reverse genetics approach that combines chemical mutagenesis with a high-throughput screen for mutations. Wheat is specially well-suited for TILLING due to the high mutation densities tolerated by polyploids, which allow for very efficient screens. Despite this, few TILLING populations are currently available. In addition, current TILLING screening protocols require high-throughput genotyping platforms, limiting their use. Results We developed mutant populations of pasta and common wheat and organized them for TILLING. To simplify and decrease costs, we developed a non-denaturing polyacrylamide gel set-up that uses ethidium bromide to detect fragments generated by crude celery juice extract digestion of heteroduplexes. This detection method had similar sensitivity as traditional LI-COR screens, suggesting that it represents a valid alternative. We developed genome-specific primers to circumvent the presence of multiple homoeologous copies of our target genes. Each mutant library was characterized by TILLING multiple genes, revealing high mutation densities in both the hexaploid (~1/38 kb and tetraploid (~1/51 kb populations for 50% GC targets. These mutation frequencies predict that screening 1,536 lines for an effective target region of 1.3 kb with 50% GC content will result in ~52 hexaploid and ~39 tetraploid mutant alleles. This implies a high probability of obtaining knock-out alleles (P = 0.91 for hexaploid, P = 0.84 for tetraploid, in addition to multiple missense mutations. In total, we identified over 275 novel alleles in eleven targeted gene/genome combinations in hexaploid and tetraploid wheat and have validated the presence of a subset of them in our seed stock

  13. Applicability of Aegilops tauschii drought tolerance traits to breeding of hexaploid wheat.

    Science.gov (United States)

    Sohail, Quahir; Inoue, Tomoe; Tanaka, Hiroyuki; Eltayeb, Amin Elsadig; Matsuoka, Yoshihiro; Tsujimoto, Hisashi

    2011-12-01

    Few genes are available to develop drought-tolerant bread wheat (Triticum aestivum L.) cultivars. One way to enhance bread wheat's genetic diversity would be to take advantage of the diversity of wild species by creating synthetic hexaploid wheat (SW) with the genomic constitution of bread wheat. In this study, we compared the expression of traits encoded at different ploidy levels and evaluated the applicability of Aegilops tauschii drought-related traits using 33 Ae. tauschii accessions along with their corresponding SW lines under well-watered and drought conditions. We found wide variation in Ae. tauschii, and even wider variation in the SW lines. Some SW lines were more drought-tolerant than the standard cultivar Cham 6. Aegilops tauschii from some regions gave better performing SW lines. The traits of Ae. tauschii were not significantly correlated with their corresponding SW lines, indicating that the traits expressed in wild diploid relatives of wheat may not predict the traits that will be expressed in SW lines derived from them. We suggest that, regardless of the adaptability and performance of the Ae. tauschii under drought, production of SW could probably result in genotypes with enhanced trait expression due to gene interactions, and that the traits of the synthetic should be evaluated in hexaploid level.

  14. New broad-spectrum resistance to septoria tritici blotch derived from synthetic hexaploid wheat

    NARCIS (Netherlands)

    Tabib Ghaffary, M.S.; Faris, J.D.; Friesen, T.L.; Visser, R.G.F.; Lee, van der T.A.J.; Robert, O.; Kema, G.H.J.

    2012-01-01

    Septoria tritici blotch (STB), caused by the ascomycete Mycosphaerella graminicola, is one of the most devastating foliar diseases of wheat. We screened five synthetic hexaploid wheats (SHs), 13 wheat varieties that represent the differential set of cultivars and two susceptible checks with a global

  15. Divergent Development of Hexaploid Triticale by a Wheat - Rye -Psathyrostachys huashanica Trigeneric Hybrid Method.

    Science.gov (United States)

    Kang, Houyang; Wang, Hao; Huang, Juan; Wang, Yujie; Li, Daiyan; Diao, Chengdou; Zhu, Wei; Tang, Yao; Wang, Yi; Fan, Xing; Zeng, Jian; Xu, Lili; Sha, Lina; Zhang, Haiqin; Zhou, Yonghong

    2016-01-01

    Hexaploid triticale is an important forage crop and a promising energy plant. Some forms were previously reported for developing the hexaploid triticale, such as crossing tetraploid wheat or hexaploid wheat with rye, crossing hexaploid triticale and/or hexaploid wheat with octoploid triticale, and spontaneously appearing in the selfed progenies of octoploid triticale. In the present study, we developed an effective method for production of diverse types of hexaploid triticale via wheat-rye-Psathyrostachys huashanica trigeneric hybrid. Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) karyotyping revealed that D genome chromosomes were completely eliminated and the whole A, B, and R genome chromosomes were retained in three lines. More interestingly, the composite genome of the line K14-489-2 consisted of complete A and B genomes and chromosomes 1D, 2R, 3R, 4R, 5R, 6R, and 7R, that of line K14-491-2 was 12 A-genome (1A-6A), 14 B-genome (1B-7B), 12 R-genome (1R-3R, 5R-7R), and chromosomes 1D and 3D, and that of the line K14-547-1 had 26A/B and 14R chromosomes, plus one pair of centric 6BL/2DS translocations. This finding implies that some of D genome chromosomes can be spontaneously and stably incorporated into the hexaploid triticale. Additionally, a variety of high-molecular-weight glutenin subunits (HMW-GS) compositions were detected in the six hexaploid triticale lines, respectively. Besides, compared with its recurrent triticale parent Zhongsi828, these lines showed high level of resistance to stripe rust (Puccinia striiformis f. sp. tritici, Pst) pathogens prevalent in China, including V26/Gui 22. These new hexaploid triticales not only enhanced diversification of triticale but also could be utilized as valuable germplasm for wheat improvement.

  16. Divergent Development of Hexaploid Triticale by a Wheat - Rye -Psathyrostachys huashanica Trigeneric Hybrid Method.

    Directory of Open Access Journals (Sweden)

    Houyang Kang

    Full Text Available Hexaploid triticale is an important forage crop and a promising energy plant. Some forms were previously reported for developing the hexaploid triticale, such as crossing tetraploid wheat or hexaploid wheat with rye, crossing hexaploid triticale and/or hexaploid wheat with octoploid triticale, and spontaneously appearing in the selfed progenies of octoploid triticale. In the present study, we developed an effective method for production of diverse types of hexaploid triticale via wheat-rye-Psathyrostachys huashanica trigeneric hybrid. Genomic in situ hybridization (GISH and fluorescence in situ hybridization (FISH karyotyping revealed that D genome chromosomes were completely eliminated and the whole A, B, and R genome chromosomes were retained in three lines. More interestingly, the composite genome of the line K14-489-2 consisted of complete A and B genomes and chromosomes 1D, 2R, 3R, 4R, 5R, 6R, and 7R, that of line K14-491-2 was 12 A-genome (1A-6A, 14 B-genome (1B-7B, 12 R-genome (1R-3R, 5R-7R, and chromosomes 1D and 3D, and that of the line K14-547-1 had 26A/B and 14R chromosomes, plus one pair of centric 6BL/2DS translocations. This finding implies that some of D genome chromosomes can be spontaneously and stably incorporated into the hexaploid triticale. Additionally, a variety of high-molecular-weight glutenin subunits (HMW-GS compositions were detected in the six hexaploid triticale lines, respectively. Besides, compared with its recurrent triticale parent Zhongsi828, these lines showed high level of resistance to stripe rust (Puccinia striiformis f. sp. tritici, Pst pathogens prevalent in China, including V26/Gui 22. These new hexaploid triticales not only enhanced diversification of triticale but also could be utilized as valuable germplasm for wheat improvement.

  17. Application of Synthetic Hexaploid Wheat Derived from T.Durum, Ae. taushiiin Common Wheat Breeding for FHB Resistance

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The F1 and F4 plants of 'synthetic hexaploid wheat/common wheat'crosses and part of their parents were inoculated with Fusarium graminearum to evaluate FHB resistance.The results showed tht the scab resistance in the F1 varied with the synthetic wheat accessions used as crossing parents.In the F4,some resistant head lines were generated from the crosses,although their parents had different scab resistance levels.It indicated that synthetic hexaploid wheat are useful in wheat breeding for scab resistance.

  18. Variability of leaf Cadmium content in tetraploid and hexaploid wheat

    Directory of Open Access Journals (Sweden)

    Kraljević-Balalić Marija

    2009-01-01

    Full Text Available Cadmium (Cd is a toxic trace metal pollutant for humans, animals, and plants. It is a heavy metal present in soils from natural and anthropogenic sources. Much of the Cd taken up by plants is retained in the root, but a portion is translocated to the aerial portions of the plant and into the seed. The objective of this research was to determine the variability and diversity of Cd content in the leaves of 30 wheat cultivars with different ploidy level, during two years. Analyses of Cd content (ppm in the leaves at heading stage were performed with an atomic absorption spectrometer (AAS. Significant differences between the mean values of the genotypes in Cd content were found. Tetraploid wheat genotypes had higher Cd content than hexaploid genotypes. Cd content was predominantly influenced by the year of growing (73%. The influence of genotype on Cd content amounted 16% and the interaction genotype × year 11%. The cluster of the genotypes consists of four groups. In the groups three and four were some of the genotypes (Kalyan Sona, Partizanka and NS Rana 5 with lowest Cd content in the leaves. They could be chosen as parents in the hybridization for lower cadmium concentration.

  19. Structural and molecular basis of starch viscosity in hexaploid wheat.

    Science.gov (United States)

    Ral, J-P; Cavanagh, C R; Larroque, O; Regina, A; Morell, M K

    2008-06-11

    Wheat starch is considered to have a low paste viscosity relative to other starches. Consequently, wheat starch is not preferred for many applications as compared to other high paste viscosity starches. Increasing the viscosity of wheat starch is expected to increase the functionality of a range of wheat flour-based products in which the texture is an important aspect of consumer acceptance (e.g., pasta, and instant and yellow alkaline noodles). To understand the molecular basis of starch viscosity, we have undertaken a comprehensive structural and rheological analysis of starches from a genetically diverse set of wheat genotypes, which revealed significant variation in starch traits including starch granule protein content, starch-associated lipid content and composition, phosphate content, and the structures of the amylose and amylopectin fractions. Statistical analysis highlighted the association between amylopectin chains of 18-25 glucose residues and starch pasting properties. Principal component analysis also identified an association between monoesterified phosphate and starch pasting properties in wheat despite the low starch-phosphate level in wheat as compared to tuber starches. We also found a strong negative correlation between the phosphate ester content and the starch content in flour. Previously observed associations between internal starch granule fatty acids and the swelling peak time and pasting temperature have been confirmed. This study has highlighted a range of parameters associated with increased starch viscosity that could be used in prebreeding/breeding programs to modify wheat starch pasting properties.

  20. Chromosomal structural changes and microsatellite variations in newly synthesized hexaploid wheat mediated by unreduced gametes

    Indian Academy of Sciences (India)

    HAO LI; YAJUAN WANG; XIAOXUE GUO; YINPENG DU; CHANGYOU WANG; WANQUAN JI

    2016-12-01

    Allohexaploid wheat was derived from interspecific hybridization, followed by spontaneous chromosome doubling. Newly synthesized hexaploid wheat by crossing Triticum turgidum and Aegilops tauschii provides a classical model to understand the mechanisms of allohexaploidization in wheat. However, immediate chromosome level variation and microsatellite level variation of newly synthesized hexaploid wheat have been rarely reported. Here, unreduced gametes were applied to develop synthesized hexaploid wheat, NA0928, population by crossing T. turgidum ssp. dicoccum MY3478 and Ae. tauschii SY41, and further S0–S3 generations of NA0928 were assayed by sequential cytological and microsatellite techniques. We demonstrated that plentiful chromosomal structural changes and microsatellite variations emerged in the early generations of newlysynthesized hexaploid wheat population NA0928, including aneuploidy with whole-chromosome loss or gain, aneuploidy with telosome formation, chromosome-specific repeated sequence elimination (indicated by fluorescence in situ hybridization) and microsatellite sequence elimination (indicated by sequencing), and many kinds of variations have not been previously reported. Additionally, we reported a new germplasm, T. turgidum accession MY3478 with excellent unreduced gametes trait, and then succeeded to transfer powdery mildew resistance from Ae. tauschii SY41 to synthesized allohexaploid wheatpopulation NA0928, which would be valuable resistance resources for wheat improvement.

  1. Simultaneous editing of three homoeoalleles in hexaploid bread wheat confers heritable resistance to powdery mildew.

    Science.gov (United States)

    Wang, Yanpeng; Cheng, Xi; Shan, Qiwei; Zhang, Yi; Liu, Jinxing; Gao, Caixia; Qiu, Jin-Long

    2014-09-01

    Sequence-specific nucleases have been applied to engineer targeted modifications in polyploid genomes, but simultaneous modification of multiple homoeoalleles has not been reported. Here we use transcription activator-like effector nuclease (TALEN) and clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9 (refs. 4,5) technologies in hexaploid bread wheat to introduce targeted mutations in the three homoeoalleles that encode MILDEW-RESISTANCE LOCUS (MLO) proteins. Genetic redundancy has prevented evaluation of whether mutation of all three MLO alleles in bread wheat might confer resistance to powdery mildew, a trait not found in natural populations. We show that TALEN-induced mutation of all three TaMLO homoeologs in the same plant confers heritable broad-spectrum resistance to powdery mildew. We further use CRISPR-Cas9 technology to generate transgenic wheat plants that carry mutations in the TaMLO-A1 allele. We also demonstrate the feasibility of engineering targeted DNA insertion in bread wheat through nonhomologous end joining of the double-strand breaks caused by TALENs. Our findings provide a methodological framework to improve polyploid crops.

  2. Meiotic behaviour of tetraploid wheats (Triticum turgidum L.) and their synthetic hexaploid wheat derivates influenced by meiotic restitution and heat stress

    Indian Academy of Sciences (India)

    Masoumeh Rezaei; Ahmad Arzani; Badraldin Ebrahim Sayed-Tabatabaei

    2010-12-01

    Meiotic restitution is considered to be a common mechanism of polyploidization in plants and hence is one of the most important processes in plant speciation. Meiotic behaviour of plant chromosomes is influenced by both genetic and environmental factors. In this study, the meiotic behaviour of cereal crops was investigated, which includes tetraploid wheat genotypes (with and without the meiotic restitution trait) and their derivates (synthetic hexaploid wheats and a doubled haploid (DH) line), grown at two planting dates in the field. In addition, two local landraces of emmer wheat (Triticum turgidum ssp. dicoccum), one wheat cultivar (Chinese spring), one DH triticale cultivar (Eleanor) and one rye accession were included. Immature spikes of mid-autumn and end-winter sowing plants were collected in April and May 2008, respectively, fixed in Carnoy’s solution and stained with hematoxylin. Pollen mother cells (PMCs) from anthers at different stages of meiotic process were analysed for their chromosomal behaviour and irregularities. Meiotic aberrations such as laggards, chromosome bridges, micronuclei, abnormal cytokines, chromatin pulling and meiotic restitution were observed and the studied genotypes were accordingly ranked as follows: triticale > synthetic hexaploid wheats > tetraploid wheats possessing meiotic restitution > tetraploid wheats lacking meiotic restitution > rye. The results indicated that the samples that had been planted in the autumn, thus experiencing an optimum temperature level at the flowering stage, exhibited less meiotic irregularities than winter planting samples that encountered heat stress at the flowering period.

  3. Genomic and genie sequence variation in synthetic hexaploid wheat(AABBDD)as compared to their parental species

    Institute of Scientific and Technical Information of China (English)

    Lihong Nie; Zongfu Han; Lahu Lu; Yingyin Yao; Qixin Sun; Zhongfu Ni

    2008-01-01

    In order to understand the genomic changes during the evolution of hexaploid wheat,two sets of synthetic hexaploid wheat from hybridization between maternal tetraploid wheat (AABB) and paternal diploid goat grass(DD)were used for DNA-AFLP and single strand conformation polymorphism (SSCP) analysis to determine the genomic and genie variation in the synthetic hexaploid wheat.Results indicated that more DNA sequences from paternal diploid species wen eliminated in the synthetic hexaploid wheat than from maternal tetraploid wheat,suggesting that genome from parental species of lower ploidity tends to be eliminated preferentially.However,sequence variation detected by SSCP procedure was much lower than those detected by DNA-AFLP.which indicated that much less variation in the genie regions occurred in the synthetic hexaploid wheat.and sequence variations detected by DNA-AFLP could be derived mostly from non-coding regions and repetitive sequences.Our results also indicated that sequence variation in 4 genes can be detected in hybrid F1.which suggested that this type of sequence variation could be resulted from distant hybridization.It was interesting to note that 3 out of the 4 genes were mapped and clustered on the long alTll of chromosome 2D,which indicated that variation in genic sequences in synthetic hexaploid wheat might not be a randomized process.

  4. Genetic and physiological architecture of early vigor in Aegilops tauschii, the D-genome of hexaploid wheat. A quantitative trait loci analysis

    NARCIS (Netherlands)

    Steege, ter M.W.; Ouden, den F.M.; Lambers, H.; Stam, P.; Peeters, A.J.M.

    2005-01-01

    Plant growth can be studied at different organizational levels, varying from cell, leaf, and shoot to the whole plant. The early growth of seedlings is important for the plant's establishment and its eventual success. Wheat (Triticum aestivum, genome AABBDD) seedlings exhibit a low early growth rate

  5. Evaluation of Aegilops tauschii for Heading Date and Its Gene Location in a Re-synthesized Hexaploid Wheat

    Institute of Scientific and Technical Information of China (English)

    XIANG Zhi-guo; ZHANG Lian-quan; NING Shun-zong; ZHENG You-Liang; LIU Deng-cai

    2009-01-01

    The successful worldwide cultivation of hexaploid wheat in a diverse range of environments is because of, in part, breeding and selection for appropriate heading date. To adjust and fine-tune the heading time of hexaploid wheat to particular geographical regions and specific environment within these, there is an urgent need to evaluate and use alternative alleles for heading time. Aegilops tauschii, the donor species of D-genome of hexaploid wheat, has a wide geographic distribution. The present study revealed a wide variation for heading time among 56 Ae. tauschii accessions. All the accessions with short heading dates belonged to the ssp. tauschii, whereas most of ssp. strangulata accessions showed very long heading date. The heading date was also related to distribution of this species. The monotelosomic and monosomic analysis of a synthetic hexaploid wheat showed that chromosome 2D derived from ssp. tauschii accession AS60 had a major effect on promoting heading time with a reduction of more than 5 days. It is postulated that this Ae. tauschii genotype possess the allele Ppd-Dt1 responsible for the insensitivity to photoperiod. This allele is probably different from Ppd-D1 existing in hexaploid wheat. The new allele Ppd-Dt1 derived from Ae. tauschii might be used as a source for hexaploid wheat breeding on photoperiod response.

  6. Genetically divergent types of the wheat leaf fungus Puccinia triticina in Ethiopia, a center of tetraploid wheat diversity

    Science.gov (United States)

    Collections of Puccinia triticina, the wheat leaf rust fungus, were obtained from tetraploid and hexaploid wheat in the central highlands of Ethiopia, and a smaller number from Kenya from 2011 to 2013, in order to determine the genetic diversity of this wheat pathogen in a center of host diversity. ...

  7. Patterns of homoeologous gene expression shown by RNA sequencing in hexaploid bread wheat.

    KAUST Repository

    Leach, Lindsey J

    2014-04-11

    BACKGROUND: Bread wheat (Triticum aestivum) has a large, complex and hexaploid genome consisting of A, B and D homoeologous chromosome sets. Therefore each wheat gene potentially exists as a trio of A, B and D homoeoloci, each of which may contribute differentially to wheat phenotypes. We describe a novel approach combining wheat cytogenetic resources (chromosome substitution \\'nullisomic-tetrasomic\\' lines) with next generation deep sequencing of gene transcripts (RNA-Seq), to directly and accurately identify homoeologue-specific single nucleotide variants and quantify the relative contribution of individual homoeoloci to gene expression. RESULTS: We discover, based on a sample comprising ~5-10% of the total wheat gene content, that at least 45% of wheat genes are expressed from all three distinct homoeoloci. Most of these genes show strikingly biased expression patterns in which expression is dominated by a single homoeolocus. The remaining ~55% of wheat genes are expressed from either one or two homoeoloci only, through a combination of extensive transcriptional silencing and homoeolocus loss. CONCLUSIONS: We conclude that wheat is tending towards functional diploidy, through a variety of mechanisms causing single homoeoloci to become the predominant source of gene transcripts. This discovery has profound consequences for wheat breeding and our understanding of wheat evolution.

  8. Genome interplay in the grain transcriptome of hexaploid bread wheat.

    Science.gov (United States)

    Pfeifer, Matthias; Kugler, Karl G; Sandve, Simen R; Zhan, Bujie; Rudi, Heidi; Hvidsten, Torgeir R; Mayer, Klaus F X; Olsen, Odd-Arne

    2014-07-18

    Allohexaploid bread wheat (Triticum aestivum L.) provides approximately 20% of calories consumed by humans. Lack of genome sequence for the three homeologous and highly similar bread wheat genomes (A, B, and D) has impeded expression analysis of the grain transcriptome. We used previously unknown genome information to analyze the cell type-specific expression of homeologous genes in the developing wheat grain and identified distinct co-expression clusters reflecting the spatiotemporal progression during endosperm development. We observed no global but cell type- and stage-dependent genome dominance, organization of the wheat genome into transcriptionally active chromosomal regions, and asymmetric expression in gene families related to baking quality. Our findings give insight into the transcriptional dynamics and genome interplay among individual grain cell types in a polyploid cereal genome. Copyright © 2014, American Association for the Advancement of Science.

  9. Synthetic hexaploids derived from under-exploited tetraploids as a new resource for disease resistance in wheat

    Science.gov (United States)

    Synthetic hexaploid wheat (SHW) (2n = 6x = 42, genome AABBDD), which is developed from the hybridization between tetraploid wheat (Triticum turgidum L., 2n = 4x = 28, genome AABB) and Aegilops tauschii Coss. (2n = 2x = 14, genome DD), is a useful bridging germplasm for the introgression of desirable...

  10. Subgenome chromosome walking in wheat: A 450-kb physical contig in Triticum monococcum L. spans the Lr10 resistance locus in hexaploid wheat (Triticum aestivum L.)

    Science.gov (United States)

    Stein, Nils; Feuillet, Catherine; Wicker, Thomas; Schlagenhauf, Edith; Keller, Beat

    2000-01-01

    For many agronomically important plant genes, only their position on a genetic map is known. In the absence of an efficient transposon tagging system, such genes have to be isolated by map-based cloning. In bread wheat Triticum aestivum, the genome is hexaploid, has a size of 1.6 × 1010 bp, and contains more than 80% of repetitive sequences. So far, this genome complexity has not allowed chromosome walking and positional cloning. Here, we demonstrate that chromosome walking using bacterial artificial chromosome (BAC) clones is possible in the diploid wheat Triticum monococcum (Am genome). BAC end sequences were mostly repetitive and could not be used for the first walking step. New probes corresponding to rare low-copy sequences were efficiently identified by low-pass DNA sequencing of the BACs. Two walking steps resulted in a physical contig of 450 kb on chromosome 1AmS. Genetic mapping of the probes derived from the BAC contig demonstrated perfect colinearity between the physical map of T. monococcum and the genetic map of bread wheat on chromosome 1AS. The contig genetically spans the Lr10 leaf rust disease resistance locus in bread wheat, with 0.13 centimorgans corresponding to 300 kb between the closest flanking markers. Comparison of the genetic to physical distances has shown large variations within 350 kb of the contig. The physical contig can now be used for the isolation of the orthologous regions in bread wheat. Thus, subgenome chromosome walking in wheat can produce large physical contigs and saturate genomic regions to support positional cloning. PMID:11078510

  11. Variation in Dehydration Tolerance, ABA Sensitivity and Related Gene Expression Patterns in D-Genome Progenitor and Synthetic Hexaploid Wheat Lines

    Directory of Open Access Journals (Sweden)

    Yumeto Kurahashi

    2009-06-01

    Full Text Available The wild wheat Aegilops tauschii Coss. has extensive natural variation available for breeding of common wheat. Drought stress tolerance is closely related to abscisic acid (ABA sensitivity. In this study, 17 synthetic hexaploid wheat lines, produced by crossing the tetraploid wheat cultivar Langdon with 17 accessions of Ae. tauschii, were used for comparative analysis of natural variation in drought tolerance and ABA sensitivity. Ae. tauschii showed wide natural variation, with weak association between the traits. Drought-sensitive accessions of Ae. tauschii exhibited significantly less ABA sensitivity. D-genome variations observed at the diploid genome level were not necessarily reflected in synthetic wheats. However, synthetic wheats derived from the parental Ae. tauschii accessions with high drought tolerance were significantly more tolerant to drought stress than those from drought-sensitive accessions. Moreover, synthetic wheats with high drought tolerance showed significantly higher ABA sensitivity than drought-sensitive synthetic lines. In the hexaploid genetic background, therefore, weak association of ABA sensitivity with drought tolerance wasobserved. To study differences in gene expression patterns between stress-tolerant and -sensitive lines, levels of two Cor/Lea and three transcription factor gene transcripts were compared. The more tolerant accession of Ae. tauschii tended to accumulate more abundant transcripts of the examined genes than the sensitive accession under stress conditions. The expression patterns in the synthetic wheats seemed to be additive for parental lines exposed to drought and ABA treatments. However, the transcript levels of transcription factor genes in the synthetic wheats did not necessarily correspond to the postulated levels based on expression in parental lines. Allopolyploidization altered the expression levels of the stress-responsive genes in synthetic wheats.

  12. Water and Nutrient Use Efficiency in Diploid, Tetraploid and Hexaploid Wheats

    Institute of Scientific and Technical Information of China (English)

    Ming-Li Huang; Xi-Ping Deng; Yu-Zong Zhao; Sheng-Lu Zhou; Shinobu Inanaga; Satoshi Yamada; Kiyoshi Tanaka

    2007-01-01

    Three diploid (Triticum boeoticum, AA; Aegilops speltoides, BB and Ae. tauschii, DD), two tetraplold (T. dlcoccoides,AABB and T. dicoccon, AABB) and one hexaploid (T. vulgare, AABBDD) varieties of wheat, which are very important in the evolution of wheat were chosen in this study. A pot experiment was carried out on the wheat under different water and nutrient conditions (i) to understand the differences in biomass, yield, water use efficiency (WUE), and nutrient (N, P and K) use efficiency (uptake and utilization efficiency) among ploldles in the evolution of wheat; (ii) to clarify the effect of water and nutrient conditions on water and nutrient use efficiency; and (iii) to assess the relationship of water and nutrient use efficiency in the evolution of wheat. Our results showed that from diploid to tetraploid then to hexaploid during the evolution of wheat, both root biomass and above-ground biomass increased initially and then decreased. Water consumption for transpiration decreased remarkably, correlating with the decline of the growth period, while grain yield, harvest index, WUE, N, P and K uptake efficiency, and N, P and K utilization efficiency increased significantly. Grain yield, harvest index and WUE decreased in the same order: T.vulgare > T. dicoccon > T. dicoccoides > Ae. tauschii > Ae. speltoides > T. boeoticum. Water stress significantly decreased root biomass, above-ground biomass, yield, and water consumption for transpiration by 47-52%, butremarkably increased WUE. Increasing the nutrient supply increased wheat above-ground biomass, grain yield,harvest index, water consumption for transpiration and WUE under different water levels, but reduced root biomass under drought conditions. Generally, water stress and low nutrient supply resulted in the lower nutrientuptake efficiency of wheat. However, water and nutrient application had no significant effects on nutrient utilization efficiency, suggesting that wheat nutrient utilization

  13. Possible origin of Triticum petropavlovskyi based on cytological analyses of crosses between T. petropavlovskyi and tetraploid, hexaploid, and synthetic hexaploid (SHW-DPW wheat accessions

    Directory of Open Access Journals (Sweden)

    Qian Chen

    2016-12-01

    Full Text Available Intraspecific hybridization between Triticum petropavlovskyi Udacz. et Migusch., synthetic hexaploid wheat (SHW-DPW, and tetraploid and hexaploid wheat, was performed to collect data on seed set, fertility of F1 hybrid, and meiotic pairing configuration, aiming to evaluate the possible origin of T. petropavlovskyi. Our data showed that (1 seed set of crosses T. petropavlovskyi × T. polonicum and T. petropavlovskyi × T. aestivum cv. Chinese Spring was significantly high; (2 fertility of hybrids T. petropavlovskyi × T. polonicum and T. petropavlovskyi × T. aestivum ssp. yunnanense was higher than that of the other hybrids; (3 fertility of F1 hybrids SHW-DPW × T. dicoccoides and SHW-DPW×T. aestivum ssp. tibetanum was significantly high; and (4 c-value of T. petropavlovskyi × T. polonicum and T. petropavlovskyi × T. aestivum cv. Changning white wheat was also significantly high. The results indicate that the probable origin of T. petropavlovskyi is divergence from a natural cross between T. aestivum and T. polonicum, via either spontaneous introgression or breeding effort.

  14. Identification and characterization of genes on a single subgenome in the hexaploid wheat (Triticum aestivum L.) genotype 'Chinese Spring'.

    Science.gov (United States)

    Ma, Jian; Zheng, Zhi; Stiller, Jiri; Lan, Xiu-Jin; Liu, Yaxi; Deng, Mei; Wang, Penghao; Pu, Zhien; Chen, Guangdeng; Jiang, Qian-Tao; Wei, Yuming; Zheng, You-Liang

    2017-03-01

    Gene loss during the formation of hexaploid bread wheat has been repeatedly reported. However, our knowledge on genome-wide analysis of the genes present on a single subgenome (SSG) in bread wheat is still limited. In this study, by analysing the 'Chinese Spring' chromosome arm shotgun sequences together with high-confidence gene models, we detected 433 genes on a SSG. Greater gene loss was observed in A and D subgenomes compared with B subgenome. More than 79% of the orthologs for these SSG genes were detected in diploid and tetraploid relatives of hexaploid wheat. Unexpectedly, no bias in expression breadth or in the distribution patterns of GO (gene ontology) terms for these genes was detected among the high-confidence genes. Further, network and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analyses indicated that most of these genes were not functionally related to each other. Interestingly, 30.7% of these SSG genes were most highly expressed in root, showing biased distribution given the distribution of the whole high-confidence genes. Collectively, these results facilitate our understanding of the loss of the genes that were retained in a SSG during the formation of hexaploid wheat.

  15. Transcriptional profiling of hexaploid wheat (Triticum aestivum L.) roots identifies novel, dehydration-responsive genes.

    Science.gov (United States)

    Mohammadi, Mohsen; Kav, Nat N V; Deyholos, Michael K

    2007-05-01

    We used a long-oligonucleotide microarray to identify transcripts that increased or decreased in abundance in roots of dehydration-tolerant hexaploid bread wheat, in response to withholding of water. We observed that the major classes of dehydration-responsive genes (e.g. osmoprotectants, compatible solutes, proteases, glycosyltransferases/hydrolases, signal transducers components, ion transporters) were generally similar to those observed previously in other species and osmotic stresses. More specifically, we highlighted increases in transcript expression for specific genes including those putatively related to the synthesis of asparagine, trehalose, oligopeptide transporters, metal-binding proteins, the gamma-aminobutyric acid (GABA) shunt and transcription factors. Conversely, we noted a decrease in transcript abundance for diverse classes of glutathione and sulphur-related enzymes, specific amino acids, as well as MATE-efflux carrier proteins. From these data, we identified a novel, dehydration-induced putative AP2/ERF transcription factor, which we predict to function as a transcriptional repressor. We also identified a dehydration-induced 'little protein' (LitP; predicted mass: 8 kDa) that is highly conserved across spermatophytes. Using qRT-PCR, we compared the expression patterns of selected genes between two related wheat genotypes that differed in their susceptibility to dehydration, and confirmed that these novel genes were highly inducible by water limitation in both genotypes, although the magnitude of induction differed.

  16. Molecular cloning and characterization of two novel genes from hexaploid wheat that encode double PR-1 domains coupled with a receptor-like protein kinase

    Science.gov (United States)

    Hexaploid wheat (Triticum aestivum L.) contains at least 23 TaPr-1 genes encoding the group 1 pathogenesis-related (PR-1) proteins as identified in our previous work. Here we report the cloning and characterization of TaPr-1-rk1 and TaPr-1-rk2, two novel genes closely related to the wheat PR-1 famil...

  17. Using the Hexaploid Nature of Wheat To Create Variability in Starch Characteristics.

    Science.gov (United States)

    Inokuma, Takayuki; Vrinten, Patricia; Shimbata, Tomoya; Sunohara, Ai; Ito, Hiroyuki; Saito, Mika; Taniguchi, Yoshinori; Nakamura, Toshiki

    2016-02-03

    In hexaploid crops, such as bread wheat, it should be possible to fine-tune phenotypic traits by identifying wild-type and null genes from each of the three genomes and combining them in a calculated manner. Here, we demonstrate this with gene combinations for two starch synthesis genes, SSIIa and GBSSI. Lines with inactive copies of both enzymes show a very dramatic change in phenotype, so to create intermediate phenotypes, we used marker-assisted selection to develop near-isogenic lines (NILs) carrying homozygous combinations of null alleles. For both genes, gene dosage effects follow the order B > D ≥ A; therefore, we completed detailed analysis of starch characteristics for NIL 3-3, which is null for the B-genome copy of the SSIIa and GBSSI genes, and NIL 5-5, which has null mutations in the B- and D-genome-encoded copies of both of these genes. The effects of the combinations on phenotypic traits followed the order expected on the basis of genotype, with NIL 5-5 showing the largest differences from the wild type, while NIL 3-3 characteristics were intermediate between NIL 5-5 and the wild type. Differences among genotypes were significant for many starch characteristics, including percent amylose, chain length distribution, gelatinization temperature, retrogradation, and pasting properties, and these differences appeared to translate into improvements in end-product quality, since bread made from type 5-5 flour showed a 3 day lag in staling.

  18. Quality of synthetic hexaploid wheat containing null alleles at Glu-A1 and Glu-B1 loci

    Indian Academy of Sciences (India)

    Xinkun Hu; Shoufen Dai; Zhien Pu; Dengcai Liu; Zongjun Pu; Jiaqi Jiang; Yuming Wei; Bihua Wu; Xiujin Lan; Youliang Zheng; Zehong Yan

    2013-08-01

    Triticum turgidum ssp. dicoccon PI94668 and PI349045 were identified as containing null alleles at Glu-A1 and Glu-B1 loci in previous investigation. Sequencing of the respective HMW-GS genes Ax, Bx, Ay and By in both accessions indicated equal DNA lengths with gene silencing caused by 1 to 4 in-frame stop codon(s) in the open reading frames. Six synthetic hexaploid wheat lines were produced by crossing PI94668 or PI349045 with six Aegilops tauschii by spontaneous chromosome doubling of unreduced gametes. As expected, these amphiploids had three different HMW-GS: Dx 3.1t + Dy11*t, Dx2.1t +10t and Dx2t + Dy12t in Glu-D1 but double nulls in Glu-A1 and Glu-B1. Quality tests showed that most quality parameters in two T. turgidum ssp. dicoccon parents were very low due to the lack of HMW-GSs. However, incorporation of HMW-GS from Ae. tauschii in six synthetic hexaploid wheat lines significantly increased most quality related parameters. The potential values of these wheat lines in improving the quality of wheat are discussed.

  19. Genetically Divergent Types of the Wheat Leaf Fungus Puccinia triticina in Ethiopia, a Center of Tetraploid Wheat Diversity.

    Science.gov (United States)

    Kolmer, J A; Acevedo, M A

    2016-04-01

    Collections of Puccinia triticina, the wheat leaf rust fungus, were obtained from tetraploid and hexaploid wheat in the central highlands of Ethiopia, and a smaller number from Kenya, from 2011 to 2013, in order to determine the genetic diversity of this wheat pathogen in a center of host diversity. Single-uredinial isolates were derived and tested for virulence phenotype to 20 lines of Thatcher wheat that differ for single leaf rust resistance genes and for molecular genotypes with 10 simple sequence repeat (SSR) primers. Nine virulence phenotypes were described among the 193 isolates tested for virulence. Phenotype BBBQJ, found only in Ethiopia, was predominantly collected from tetraploid wheat. Phenotype EEEEE, also found only in Ethiopia, was exclusively collected from tetraploid wheat and was avirulent to the susceptible hexaploid wheat 'Thatcher'. Phenotypes MBDSS and MCDSS, found in both Ethiopia and Kenya, were predominantly collected from common wheat. Phenotypes CCMSS, CCPSS, and CBMSS were found in Ethiopia from common wheat at low frequency. Phenotypes TCBSS and TCBSQ were found on durum wheat and common wheat in Kenya. Four groups of distinct SSR genotypes were described among the 48 isolates genotyped. Isolates with phenotypes BBBQJ and EEEEE were in two distinct SSR groups, and isolates with phenotypes MBDSS and MCDSS were in a third group. Isolates with CCMSS, CCPSS, CBMSS, TCBSS, and TCBSQ phenotypes were in a fourth SSR genotype group. The diverse host environment of Ethiopia has selected and maintained a genetically divergent population of P. triticina.

  20. ROOT WATER-UPTAKE AND PLANT GROWTH IN TWO SYNTHETIC HEXAPLOID WHEAT GENOTYPES GROWN IN SALINE SOIL UNDER CONTROLLED WATER-DEFICIT STRESS

    Directory of Open Access Journals (Sweden)

    Masanori Inagaki

    2016-02-01

    Full Text Available A key breeding objective for bread wheat grown in the dry regions of Western Asia and North Africa is to enhance its adaptation to drought and its related salinity. Two newly-developed genotypes of synthetic hexaploid wheat, ‘SW-3’ and ‘SW-4’, their parental durum wheat variety ‘Jennah Khetifa’ and a dry-land bread wheat variety ‘Cham 6’, were compared for plant growth in saline hydroponic culture. They were also compared for root water-uptake and growth in soil culture in pots under combined water deficit and salinity stresses. Under saline hydroponic culture for five weeks, ‘SW-3’ developed a larger leaf area than the other genotypes. In saline soils for the period up to maturity, ‘SW-4’ and ‘Cham 6’ had higher root water uptake than the others. Only ‘SW-4’ developed normal grains and was clearly tolerant of soil salinity. ‘Cham 6’ developed normal spikes but ceased to fill the grains after heading. It may be assumed that salinity stress depressed root water-uptake at the early stages of growth, but the toxic effects of salinity stress increased in the later stages. The four wheat genotypes used in this study responded differently to salinity stress whereas water-deficit stress resulted in relatively few genotypic differences. ‘SW-4’ was more tolerant of soil salinity than its durum wheat variety parent ‘Jennah Khetifa’. This could be a useful genetic resource for improving ‘Cham 6’, which was relatively tolerant of water-deficit stress but sensitive to salinity stress after heading.

  1. Quantification of genetic relationships among A genomes of wheats.

    Science.gov (United States)

    Brandolini, A; Vaccino, P; Boggini, G; Ozkan, H; Kilian, B; Salamini, F

    2006-04-01

    The genetic relationships of A genomes of Triticum urartu (Au) and Triticum monococcum (Am) in polyploid wheats are explored and quantified by AFLP fingerprinting. Forty-one accessions of A-genome diploid wheats, 3 of AG-genome wheats, 19 of AB-genome wheats, 15 of ABD-genome wheats, and 1 of the D-genome donor Ae. tauschii have been analysed. Based on 7 AFLP primer combinations, 423 bands were identified as potentially A genome specific. The bands were reduced to 239 by eliminating those present in autoradiograms of Ae. tauschii, bands interpreted as common to all wheat genomes. Neighbour-joining analysis separates T. urartu from T. monococcum. Triticum urartu has the closest relationship to polyploid wheats. Triticum turgidum subsp. dicoccum and T. turgidum subsp. durum lines are included in tightly linked clusters. The hexaploid spelts occupy positions in the phylogenetic tree intermediate between bread wheats and T. turgidum. The AG-genome accessions cluster in a position quite distant from both diploid and other polyploid wheats. The estimates of similarity between A genomes of diploid and polyploid wheats indicate that, compared with Am, Au has around 20% higher similarity to the genomes of polyploid wheats. Triticum timo pheevii AG genome is molecularly equidistant from those of Au and Am wheats.

  2. [Analysis of wheat and rye semidwarfing gene distribution in spring hexaploid triticale (Triticosecale Wittm.) varieties and lines].

    Science.gov (United States)

    Korshunova, A D; Divashchuk, M G; Solov'ev, A A; Karlov, G I

    2015-03-01

    A collection of spring hexaploid triticale varieties and promising breeding lines has been examined for the presence of wheat Rht-B1b, Rht-B1e, and Rht8c semidwarfing genes and the rye Hl semidwarfing gene. It was discovered in spring triticale that these semidwarfing genes are represented by only one, the Rht-B1b wheat gene. The presence of this gene is associated with shortening of spring triticale plants by 28 cm on average, which constituted 26% of their initial height. Rht-B1b was found in all of the studied commercial varieties of spring triticale, which rendered it possible to conclude that plant height reduction is a necessary condition for increasing the competitiveness of this crop culture.

  3. Genotype-dependent Burst of Transposable Element Expression in Crowns of Hexaploid Wheat (Triticum aestivum L. during Cold Acclimation

    Directory of Open Access Journals (Sweden)

    Debbie Laudencia-Chingcuanco

    2012-01-01

    Full Text Available The expression of 1,613 transposable elements (TEs represented in the Affymetrix Wheat Genome Chip was examined during cold treatment in crowns of four hexaploid wheat genotypes that vary in tolerance to cold and in flowering time. The TE expression profiles showed a constant level of expression throughout the experiment in three of the genotypes. In winter Norstar, the most cold-hardy of the four genotypes, a subset of the TEs showed a burst of expression after vernalization saturation was achieved. About 47% of the TEs were expressed, and both Class I (retrotransposons and Class II (DNA transposons types were well represented. Gypsy and Copia were the most represented among the retrotransposons while CACTA and Mariner were the most represented DNA transposons. The data suggests that the Vrn-A1 region plays a role in the stage-specific induction of TE expression in this genotype.

  4. Tetraploid and hexaploid wheat varieties reveal large differences in expression of alpha-gliadins from homoeologous Gli-2 loci

    Directory of Open Access Journals (Sweden)

    Bastien Thomas

    2009-01-01

    Full Text Available Abstract Background Α-gliadins form a multigene protein family encoded by multiple α-gliadin (Gli-2 genes at three genomic loci, Gli-A2, Gli-B2 and Gli-D2, respectively located on the homoeologous wheat chromosomes 6AS, 6BS, and 6DS. These proteins contain a number of important celiac disease (CD-immunogenic domains. The α-gliadins expressed from the Gli-B2 locus harbour fewer conserved CD-epitopes than those from Gli-A2, whereas the Gli-D2 gliadins have the highest CD-immunogenic potential. In order to detect differences in the highly CD-immunogenic α-gliadin fraction we determined the relative expression level from the homoeologous Gli-2 loci in various tetraploid and hexaploid wheat genotypes by using a quantitative pyrosequencing method and by analyzing expressed sequence tag (EST sequences. Results We detected large differences in relative expression levels of α-gliadin genes from the three homoeologous loci among wheat genotypes, both as relative numbers of expressed sequence tag (EST sequences from specific varieties and when using a quantitative pyrosequencing assay specific for Gli-A2 genes. The relative Gli-A2 expression level in a tetraploid durum wheat cultivar ('Probstdorfer Pandur' was 41%. In genotypes derived from landraces, the Gli-A2 frequency varied between 12% and 58%. In some advanced hexaploid bread wheat cultivars the genes from locus Gli-B2 were hardly expressed (e.g., less than 5% in 'Lavett' but in others they made up more than 40% (e.g., in 'Baldus'. Conclusion Here, we have shown that large differences exist in relative expression levels of α-gliadins from the homoeologous Gli-2 loci among wheat genotypes. Since the homoelogous genes differ in the amount of conserved CD-epitopes, screening for differential expression from the homoeologous Gli-2 loci can be employed for the pre-selection of wheat varieties in the search for varieties with very low CD-immunogenic potential. Pyrosequencing is a method that can be

  5. Synthesizing double haploid hexaploid wheat populations based on a spontaneous alloploidization process

    Institute of Scientific and Technical Information of China (English)

    Lianquan Zhang; Youliang Zheng; Dengcai Liu; Yang Yen; Li Zhang; Jiangtao Luo; Wenjie Chen; Ming Hao; Baolong Liu; Zehong Yan; Bo Zhang; Huaigang Zhang

    2011-01-01

    Doubled haploid (DH) populations are useful to scientists and breeders in both crop improvement and basic research. Current methods of producing DHs usually need in vitro culture for extracting haploids and chemical treatment for chromosome doubling. This report describes a simple method for synthesizing DHs (SynDH) especially for allopolyploid species by utilizing meiotic restitution genes. The method involves three steps: hybridization to induce recombination, interspecific hybridization to extract haploids, and spontaneous chromosome doubling by selfing the interspecific F1s. DHs produced in this way contain recombinant chromosomes in the genome(s) of interest in a homogeneous background. No special equipment or treatments are involved in the DH production and it can be easily applied in any breeding and/or genetic program. Triticum turgidum L. and Aegilops tauschii Coss, the two ancestral species of common wheat (Triticum aestivum L.) and molecular markers were used to demonstrate the SynDH method.

  6. Cytogenetics and immature embryo culture at Embrapa Trigo breeding program: transfer of disease resistance from related species by artificial resynthesis of hexaploid wheat (Triticum aestivum L. em. Thell

    Directory of Open Access Journals (Sweden)

    Maria Irene Baggio de Moraes Fernandes

    2000-12-01

    to facilitate gene flow between wheat and related species. Since the environment at the center of origin of wheat in Southern Asia is quite different from subtropical environments, Brazilian breeding programs overcome more challenges to adapt wheat crop to biotic and abiotic stresses than some other countries. The germplasm bank of Embrapa Trigo has about 1000 registered entries of Triticum relatives, Aegilops, Secale and Agropyron species supplied from several germplasm banks distributed over the world which were multiplied and/or selected for naturally occurring or artificially inoculated fungal diseases. Since Aegilops squarrosa L. entries showed very good performance, the genetic variability observed in this species was firstly exploited. It is reported here the strategy used for transferring useful genes from Ae. squarrosa (DD, 2n = 14: crossing with tetraploid species (AABB, 2n = 28, rescue and in vitro culture of immature embryos for regeneration of the trihaploid (ABD, 2n = 21 hybrid, and colchicine treatment for genome duplication resulting in the artificial synthesis of hexaploid wheat lines (AABBDD, 2n = 42. Results of 10,739 artificial pollinations involving 28 cross combinations amongst eight T. durum L., T. dicoccum and T. cartlicum tetraploid entries used as female parents and ten selected Ae. squarrosa sources of resistance as male parents are presented here. Immature embryos from 18 cross combinations were recovered and cultured in vitro. Green plantlets from 13 combinations were regenerated. Fertile amphiploids were recovered only from crosses among entries of tetraploid T. durum and diploid Ae. squarrosa. They originated 11 fertile synthetic amphiploid lines from seven different combinations. Useful stem and leaf rust as well as powdery mildew resistance for future use in breeding programs were obtained.

  7. A splice acceptor site mutation in TaGW2-A1 increases thousand grain weight in tetraploid and hexaploid wheat through wider and longer grains.

    Science.gov (United States)

    Simmonds, James; Scott, Peter; Brinton, Jemima; Mestre, Teresa C; Bush, Max; Del Blanco, Alicia; Dubcovsky, Jorge; Uauy, Cristobal

    2016-06-01

    Across 13 experiments the gw2 - A1 mutant allele shifts grain size distribution consistently across all grains significantly increasing grain weight (6.6 %), width (2.8 %) and length (2.1 %) in tetraploid and hexaploid wheat. There is an urgent need to identify, understand and incorporate alleles that benefit yield in polyploid wheat. The rice OsGW2 gene functions as a negative regulator of grain weight and width and is homologous to the wheat TaGW2 gene. Previously it was shown that transcript levels of the A-genome homoeologue, TaGW2-A1, are negatively associated with grain width in hexaploid wheat. In this study we screened the tetraploid Kronos TILLING population to identify mutants in TaGW2-A1. We identified a G to A transition in the splice acceptor site of exon 5 which leads to mis-splicing in TaGW2-A1. We backcrossed the mutant allele into tetraploid and hexaploid wheat and generated a series of backcross derived isogenic lines which were evaluated in glasshouse and field conditions. Across 13 experiments the GW2-A1 mutant allele significantly increased thousand grain weight (6.6 %), grain width (2.8 %) and grain length (2.1 %) in tetraploid and hexaploid wheat compared to the wild type allele. In hexaploid wheat, this led to an increase in spike yield since no differences were detected for spikelet or grain number between isogenic lines. The increase in grain width and length was consistent across grains of different sizes, suggesting that the effect of the mutation is stable across the ear and within spikelets. Differences in carpel size and weight between alleles were identified as early as 5 days before anthesis, suggesting that TaGW2-A1 acts on maternal tissue before anthesis to restrict seed size. A single nucleotide polymorphism marker was developed to aid the deployment of the mutant allele into breeding programmes.

  8. Characterization of Quantitative Trait Loci for Grain Minerals in Hexaploid Wheat (Triticum aestivum L.)

    Institute of Scientific and Technical Information of China (English)

    SHI Rong-li; TONG Yi-ping; JING Rui-lian; ZHANG Fu-suo; ZOU Chun-qin

    2013-01-01

    Wheat is an important source of essential minerals for human body. Breeding wheat with high grain mineral concentration thus benefits human health. The objective of present study was to identify quantitative trait loci (QTLs) controlling grain mineral concentration and to evaluate the relation between nitrogen (N) and other essential minerals in winter wheat. Wheat grains were harvested from field experiment which conducted in China and analyzed for this purpose. Forty-three QTLs controlling grain mineral concentration and nitrogen-related traits were detected by using a double haploid (DH) population derived from winter wheat varieties Hanxuan 10 and Lumai 14. Chromosomes 4D and 5A might be very important in controlling mineral status in wheat grains. Significant positive correlations were found between grain nitrogen concentration (GNC) and nutrients Fe, Mn, Cu, Mg concentrations (FeGC, MnGC, CuGC, MgGC). Flag leaf N concentration at anthesis (FLNC) significantly and positively correlated with GNC, FeGC, MnGC, and CuGC. The study extended our knowledge on minerals in wheat grains and suggested which interactions between minerals should be considered in future breeding program.

  9. Chromatin modification contributes to the expression divergence of three TaGS2 homoeologs in hexaploid wheat

    Science.gov (United States)

    Zhang, Wei; Fan, Xiaoli; Gao, Yingjie; Liu, Lei; Sun, Lijing; Su, Qiannan; Han, Jie; Zhang, Na; Cui, Fa; Ji, Jun; Tong, Yiping; Li, Junming

    2017-01-01

    Plastic glutamine synthetase (GS2) is responsible for ammonium assimilation. The reason that TaGS2 homoeologs in hexaploid wheat experience different selection pressures in the breeding process remains unclear. TaGS2 were minimally expressed in roots but predominantly expressed in leaves, and TaGS2-B had higher expression than TaGS2-A and TaGS2-D. ChIP assays revealed that the activation of TaGS2-B expression in leaves was correlated with increased H3K4 trimethylation. The transcriptional silencing of TaGS2 in roots was correlated with greater cytosine methylation and less H3K4 trimethylation. Micrococcal nuclease and DNase I accessibility experiments indicated that the promoter region was more resistant to digestion in roots than leaves, which indicated that the closed nucleosome conformation of the promoter region was important to the transcription initiation for the spatial-temporal expression of TaGS2. In contrast, the transcribed regions possess different nuclease accessibilities of three TaGS2 homoeologs in the same tissue, suggesting that nucleosome conformation of the transcribed region was part of the fine adjustment of TaGS2 homoeologs. This study provides evidence that histone modification, DNA methylation and nuclease accessibility coordinated the control of the transcription of TaGS2 homoeologs. Our results provided important evidence that TaGS2-B experienced the strongest selection pressures during the breeding process. PMID:28300215

  10. Genome-wide identification and expression characterization of ABCC-MRP transporters in hexaploid wheat

    Directory of Open Access Journals (Sweden)

    Kaushal Kumar Bhati

    2015-07-01

    Full Text Available The ABCC multidrug resistance associated proteins (ABCC-MRP, a subclass of ABC transporters are involved in multiple physiological processes that include cellular homeostasis, metal detoxification and transport of glutathione-conjugates. Although they are well studied in humans, yeast and Arabidopsis, limited efforts have been made to address their possible role in crop like wheat. In the present work, eighteen wheat ABCC-MRP proteins were identified that showed the uniform distribution with families of rice and Arabidopsis. Organ specific quantitative expression analysis of wheat ABCC genes indicated significantly higher accumulation in roots (TaABCC2, TaABCC3, and TaABCC11 and TaABCC12, stem (TaABCC1, leaves (TaABCC16 and TaABCC17, flag leaf (TaABCC14 and TaABCC15 and seeds (TaABCC6, TaABCC8, TaABCC12, TaABCC13 and TaABCC17 implicating their role in the respective tissues. Differential transcript expression patterns were observed for TaABCC genes during grain maturation speculating their role during seed development. Hormone treatment experiments indicated that some of the ABCC genes could be transcriptionally regulated during seed development. In the presence of Cd or hydrogen peroxide, distinct molecular expression of wheat ABCC genes was observed in the wheat seedlings, suggesting their possible role during heavy metal generated oxidative stress. Functional characterization of the wheat transporter, TaABCC13 a homolog of maize LPA1 confirms its role in glutathione-mediated detoxification pathway and is able to utilize adenine biosynthetic intermediates as a substrate. This is the first comprehensive inventory of wheat ABCC-MRP gene subfamily.

  11. Genome-wide identification and expression characterization of ABCC-MRP transporters in hexaploid wheat.

    Science.gov (United States)

    Bhati, Kaushal K; Sharma, Shivani; Aggarwal, Sipla; Kaur, Mandeep; Shukla, Vishnu; Kaur, Jagdeep; Mantri, Shrikant; Pandey, Ajay K

    2015-01-01

    The ABCC multidrug resistance associated proteins (ABCC-MRP), a subclass of ABC transporters are involved in multiple physiological processes that include cellular homeostasis, metal detoxification, and transport of glutathione-conjugates. Although they are well-studied in humans, yeast, and Arabidopsis, limited efforts have been made to address their possible role in crop like wheat. In the present work, 18 wheat ABCC-MRP proteins were identified that showed the uniform distribution with sub-families from rice and Arabidopsis. Organ-specific quantitative expression analysis of wheat ABCC genes indicated significantly higher accumulation in roots (TaABCC2, TaABCC3, and TaABCC11 and TaABCC12), stem (TaABCC1), leaves (TaABCC16 and TaABCC17), flag leaf (TaABCC14 and TaABCC15), and seeds (TaABCC6, TaABCC8, TaABCC12, TaABCC13, and TaABCC17) implicating their role in the respective tissues. Differential transcript expression patterns were observed for TaABCC genes during grain maturation speculating their role during seed development. Hormone treatment experiments indicated that some of the ABCC genes could be transcriptionally regulated during seed development. In the presence of Cd or hydrogen peroxide, distinct molecular expression of wheat ABCC genes was observed in the wheat seedlings, suggesting their possible role during heavy metal generated oxidative stress. Functional characterization of the wheat transporter, TaABCC13 a homolog of maize LPA1 confirms its role in glutathione-mediated detoxification pathway and is able to utilize adenine biosynthetic intermediates as a substrate. This is the first comprehensive inventory of wheat ABCC-MRP gene subfamily.

  12. Rmg8, a New Gene for Resistance to Triticum Isolates of Pyricularia oryzae in Hexaploid Wheat.

    Science.gov (United States)

    Anh, Vu Lan; Anh, Nguyen Tuan; Tagle, Analiza Grubanzo; Vy, Trinh Thi Phuong; Inoue, Yoshihiro; Takumi, Shigeo; Chuma, Izumi; Tosa, Yukio

    2015-12-01

    Blast, caused by Pyricularia oryzae, is one of the major diseases of wheat in South America. We identified a new gene for resistance to Triticum isolates of P. oryzae in common wheat 'S-615', and designated it "resistance to Magnaporthe grisea 8" (Rmg8). Rmg8 was assigned to chromosome 2B through molecular mapping with simple-sequence repeat markers. To identify an avirulence gene corresponding to Rmg8, Triticum isolate Br48 (avirulent on S-615) was crossed with 200R29 (virulent on S-615), an F1 progeny derived from a cross between an Eleusine isolate (MZ5-1-6) and Br48. Segregation analysis of their progeny revealed that avirulence of Br48 on S-615 was conditioned by a single gene, which was designated AVR-Rmg8. AVR-Rmg8 was closely linked to AVR-Rmg7, which corresponded to Rmg7 located on chromosome 2A of tetraploid wheat.

  13. Mapping-by-sequencing in complex polyploid genomes using genic sequence capture: a case study to map yellow rust resistance in hexaploid wheat.

    Science.gov (United States)

    Gardiner, Laura-Jayne; Bansept-Basler, Pauline; Olohan, Lisa; Joynson, Ryan; Brenchley, Rachel; Hall, Neil; O'Sullivan, Donal M; Hall, Anthony

    2016-08-01

    Previously we extended the utility of mapping-by-sequencing by combining it with sequence capture and mapping sequence data to pseudo-chromosomes that were organized using wheat-Brachypodium synteny. This, with a bespoke haplotyping algorithm, enabled us to map the flowering time locus in the diploid wheat Triticum monococcum L. identifying a set of deleted genes (Gardiner et al., 2014). Here, we develop this combination of gene enrichment and sliding window mapping-by-synteny analysis to map the Yr6 locus for yellow stripe rust resistance in hexaploid wheat. A 110 MB NimbleGen capture probe set was used to enrich and sequence a doubled haploid mapping population of hexaploid wheat derived from an Avalon and Cadenza cross. The Yr6 locus was identified by mapping to the POPSEQ chromosomal pseudomolecules using a bespoke pipeline and algorithm (Chapman et al., 2015). Furthermore the same locus was identified using newly developed pseudo-chromosome sequences as a mapping reference that are based on the genic sequence used for sequence enrichment. The pseudo-chromosomes allow us to demonstrate the application of mapping-by-sequencing to even poorly defined polyploidy genomes where chromosomes are incomplete and sub-genome assemblies are collapsed. This analysis uniquely enabled us to: compare wheat genome annotations; identify the Yr6 locus - defining a smaller genic region than was previously possible; associate the interval with one wheat sub-genome and increase the density of SNP markers associated. Finally, we built the pipeline in iPlant, making it a user-friendly community resource for phenotype mapping.

  14. Rapid changes of microsatellite flanking sequence in the allopolyploidization of new synthesized hexaploid wheat

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lianquan; LIU Dengcai; YAN Zehong; LAN Xiujin; ZHENG Youliang; ZHOU Yonghong

    2004-01-01

    It was suggested that the rapid changes of DNA sequence and gene expression occurred at the early stages of allopolyploid formation. In this study, we revealed the microsatellite (SSR) differences between newly formed allopolyploids and their donor parents by using 21 primer sets specific for D genome of wheat. It was indicated that rapid changes had occurred in the "shock" process of the allopolyploid formation between tetraploid wheat and Aegilops tauschii. The changes of SSR flanking sequence resulted in appearance of novel bands or disappearance of parental bands. The disappearance of the parental bands showed much higher frequencies in comparison with that of appearance of novel bands. Disappearance of the parental bands was not random. The frequency of disappearance in tetraploid wheat was much higher than in Ae. tauschii, i. e. the disappearance frequency in AABB genome was much higher than in D genome. Changes of SSR flanking sequence occurred at the early stage of F1 hybrid or just after chromosome doubling. From the above results, it can be inferred that SSR flanking sequence region was very active and was amenable to change in the process of polyploidization. This suggested that SSR flanking sequence probably had special biological function at the early stage of ployploidization. The rapid and directional changes at the early stage of polyploidization might contribute to the rapid evolution of the newly formed allopolyploid and allow the divergent genomes to act in harmony.

  15. A comparison of the levels of hydroxamic acids in Aegilops speltoides and a hexaploid wheat and effects on Rhopalosiphum padi behaviour and fecundity.

    Science.gov (United States)

    Elek, Henriett; Smart, Lesley; Ahmad, S; Anda, Angéla; Werner, C P; Pickett, J A

    2014-03-01

    Hydroxamic acids (HAs) are plant secondary metabolites produced by certain cereals, which have been found to be toxic to pest aphids in artificial diet assays. Previous studies have shown that tetraploid and hexaploid wheat varieties, the leaf tissues of which contained higher levels of these compounds than used in artificial diets, did not reduce aphid settling or fecundity. This current study reports findings on a high HA producing B genome accession of the diploid ancestor of wheat, Aegilops speltoides. We found that this accession does have a negative impact on aphid host selection and substantially reduces nymph production. Whole leaf tissue assays showed very high levels of HAs, well in excess of the toxic level determined in the artificial diet assays. Extraction of the apoplast fluid (AF) from this accession showed that the HA level is much lower than that of the whole tissue, but is still close to the artificial diet toxic level. Furthermore the HA level in the AF increases in response to aphid feeding. These observations could explain why hexaploid wheat remains susceptible to aphids, despite having whole leaf tissue HA levels in excess of the toxic levels determined in artificial diets.

  16. Genetic diversity revealed by genomic-SSR and EST-SSR markers among common wheat, spelt and compactum

    Institute of Scientific and Technical Information of China (English)

    YANG Xinquan; LIU Peng; HAN Zongfu; NI Zhongfu; SUN Qixin

    2005-01-01

    In this study, two SSR molecular markers, named genomic-SSR and EST-SSR, are used to measure the genetic diversity among three hexaploid wheat populations, which include 28 common wheat ( Triticum aestivum L. ), 13 spelt ( Triticum spelta L. ),and 11 compactum ( Triticum compactum Host. ). The results show that common wheat has the highest genetic polymorphism, followed by spelt and then compactum. The mean genetic distance between the populations is higher than that within a population, and similar tendency is detected for individual genomes A, B and D. Therefore, spelt and compactum can be used as potential germplasms for wheat breeding, especially for enriching the genetic variation in genome D. As compared with spelt, the genetic diversity between common wheat and compactum is much smaller, indicating a closer consanguine relationship between these two species. Although the polymorphism revealed by EST-SSR is lower than that by genomic-SSR, it can effectively differentiate diverse genotypes as well. Together with our present results, it is concluded that EST-SSR marker is an ideal marker for assessing the genetic diversity in wheat. Meanwhile, the origin and evolution of hexaploid wheat is also analyzed and discussed.

  17. Mapping of quantitative trait loci determining agronomic important characters in hexaploid wheat ( Triticum aestivum L.).

    Science.gov (United States)

    Börner, A.; Schumann, E.; Fürste, A.; Cöster, H.; Leithold, B.; Röder, S.; Weber, E.

    2002-11-01

    A set of 114 recombinant inbred lines of the 'International Triticeae Mapping Initiative' mapping population was grown during the seasons 1997, 1998, 1999 and 2000 under several environments. Twenty morphological (glume colour, awn colour, waxiness, leaf erectness, peduncle length), agronomical (ear emergence time, flowering time, grain filling time, ear length, plant height, lodging, grain number, thousand-grain-weight, grain weight per ear, grain protein content, winter hardiness) and disease resistance (powdery mildew, yellow rust, leaf rust, fusarium) traits were studied. Not all traits were scored in each experiment. In total 210 QTLs with a LOD threshold of >2.0 (minor QTLs) were detected of which 64 reached a LOD score of >3.0 (major QTLs). Often QTLs were detected in comparable positions in different experiments. Homologous and homoeologous relationships of the detected QTLs, and already described major genes or QTLs determining the same traits in wheat or other Triticeae members, are discussed.

  18. Genetic Variance in Cadmium Tolerance and Accumulation in Wheat Materials Differing in Ploidy and Genome at Seedling Stage

    DEFF Research Database (Denmark)

    Ci, D; Jiang, D; Wollenweber, B;

    2010-01-01

    Cadmium (Cd) tolerance and accumulation in wheat varieties differing in ploidy and genome were investigated at seedling stage under controlled environmental conditions. The wheat varieties included six diploid, eight tetraploid, seven hexaploid and three octoploid species together with wheat rela...

  19. Genetic diversity of the African hexaploid species Solanum scabrum Mill. and S. nigrum L. (Solanaceae)

    NARCIS (Netherlands)

    Manoko, M.L.K.; Berg, van den R.G.; Feron, R.M.C.; Weerden, van der G.M.; Mariani, C.

    2008-01-01

    Two hexaploid species of Solanum sect. Solanum are present in Africa: Solanum scabrum and S. nigrum. Solanum scabrum is a widely cultivated species and is used as a leafy vegetable, as a source of medicine and as a source of ink dye. In previous studies a wide range of morphological diversity has be

  20. Presence of celiac disease epitopes in modern and old hexaploid wheat varieties: wheat breeding may have contributed to increased prevalence of celiac disease

    NARCIS (Netherlands)

    Broeck, van den H.C.; Jong, de H.C.; Salentijn, E.M.J.; Dekking, L.; Bosch, H.J.; Hamer, R.J.; Gilissen, L.J.W.J.; Meer, van der I.M.; Smulders, M.J.M.

    2010-01-01

    Gluten proteins from wheat can induce celiac disease (CD) in genetically susceptible individuals. Specific gluten peptides can be presented by antigen presenting cells to gluten-sensitive T-cell lymphocytes leading to CD. During the last decades, a significant increase has been observed in the preva

  1. Comparative high-resolution mapping of the wax inhibitors Iw1 and Iw2 in hexaploid wheat.

    Directory of Open Access Journals (Sweden)

    Haibin Wu

    Full Text Available The wax (glaucousness on wheat leaves and stems is mainly controlled by two sets of genes: glaucousness loci (W1 and W2 and non-glaucousness loci (Iw1 and Iw2. The non-glaucousness (Iw loci act as inhibitors of the glaucousness loci (W. High-resolution comparative genetic linkage maps of the wax inhibitors Iw1 originating from Triticum dicoccoides, and Iw2 from Aegilops tauschii were developed by comparative genomics analyses of Brachypodium, sorghum and rice genomic sequences corresponding to the syntenic regions of the Iw loci in wheat. Eleven Iw1 and eight Iw2 linked EST markers were developed and mapped to linkage maps on the distal regions of chromosomes 2BS and 2DS, respectively. The Iw1 locus mapped within a 0.96 cM interval flanked by the BE498358 and CA499581 EST markers that are collinear with 122 kb, 202 kb, and 466 kb genomic regions in the Brachypodium 5S chromosome, the sorghum 6S chromosome and the rice 4S chromosome, respectively. The Iw2 locus was located in a 4.1 to 5.4-cM interval in chromosome 2DS that is flanked by the CJ886319 and CJ519831 EST markers, and this region is collinear with a 2.3 cM region spanning the Iw1 locus on chromosome 2BS. Both Iw1 and Iw2 co-segregated with the BF474014 and CJ876545 EST markers, indicating they are most likely orthologs on 2BS and 2DS. These high-resolution maps can serve as a framework for chromosome landing, physical mapping and map-based cloning of the wax inhibitors in wheat.

  2. Molecular cloning and characterization of two novel genes from hexaploid wheat that encode double PR-1 domains coupled with a receptor-like protein kinase.

    Science.gov (United States)

    Lu, Shunwen; Faris, Justin D; Edwards, Michael C

    2017-04-01

    Hexaploid wheat (Triticum aestivum L.) contains at least 23 TaPr-1 genes encoding the group 1 pathogenesis-related (PR-1) proteins as identified in our previous work. Here, we report the cloning and characterization of TaPr-1-rk1 and TaPr-1-rk2, two novel genes closely related to the wheat PR-1 family. The two TaPr-1-rk genes are located on homoeologous chromosomes 3D and 3A, respectively, and each contains a large open reading frame (7385 or 6060 bp) that is interrupted by seven introns and subjected to alternative splicing (AS) with five or six isoforms of mRNA transcripts. The deduced full-length TaPR-1-RK1 and TaPR-1-RK2 proteins (95% identity) contain two repeat PR-1 domains, the second of which is fused via a transmembrane helix to a serine/threonine kinase catalytic (STKc) domain characteristic of receptor-like protein kinases. Phylogenetic analysis indicated that the two PR-1 domains of the TaPR-1-RK proteins form sister clades with their homologues identified in other monocot plants and are well separated from stand-alone PR-1 proteins, whereas the STKc domains may have originated from cysteine-rich receptor-like kinases (CRKs). Reverse-transcriptase-PCR analysis revealed that the TaPr-1-rk genes are predominantly expressed in wheat leaves and their expression levels are elevated in response to pathogen attack, such as infection by barley stripe mosaic virus (BSMV), and also to stress conditions, most obviously, to soil salinity. This is the first report of PR-1-CRK hybrid proteins in wheat. The data may shed new insights into the function/evolutionary origin of the PR-1 family and the STKc-mediated defense/stress response pathways in plants.

  3. Chromosome Based Strategies to Decipher the Structure and Evolution of the Hexaploid Wheat Genome: Chromosome 3B, a Case Study

    Institute of Scientific and Technical Information of China (English)

    E. Paux; P. Sourdille; J. Salse; P. Leroy; J. Dolezel; M. Bernard; C. Feuillet

    2007-01-01

    @@ With 17% of all crop area, wheat is the staple food for 40% of the world's population. Improvement in bread wheat quality and yield in the context of sustainable agriculture is needed in the next decades to meet human needs by 2050.

  4. Genetic transformation of Indian bread (T. aestivum) and pasta (T. durum) wheat by particle bombardment of mature embryo-derived calli

    OpenAIRE

    Khurana Paramjit; Patnaik Debasis

    2003-01-01

    Abstract Background Particle bombardment has been successfully employed for obtaining transgenics in cereals in general and wheat in particular. Most of these procedures employ immature embryos which are not available throughout the year. The present investigation utilizes mature seeds as the starting material and the calli raised from the hexaploid Triticum aestivum and tetraploid Triticum durum display a high regeneration response and were therefore used as the target tissue for genetic tra...

  5. A highly conserved gene island of three genes on chromosome 3B of hexaploid wheat: diverse gene function and genomic structure maintained in a tightly linked block

    Directory of Open Access Journals (Sweden)

    Ma Wujun

    2010-05-01

    Full Text Available Abstract Background The complexity of the wheat genome has resulted from waves of retrotransposable element insertions. Gene deletions and disruptions generated by the fast replacement of repetitive elements in wheat have resulted in disruption of colinearity at a micro (sub-megabase level among the cereals. In view of genomic changes that are possible within a given time span, conservation of genes between species tends to imply an important functional or regional constraint that does not permit a change in genomic structure. The ctg1034 contig completed in this paper was initially studied because it was assigned to the Sr2 resistance locus region, but detailed mapping studies subsequently assigned it to the long arm of 3B and revealed its unusual features. Results BAC shotgun sequencing of the hexaploid wheat (Triticum aestivum cv. Chinese Spring genome has been used to assemble a group of 15 wheat BACs from the chromosome 3B physical map FPC contig ctg1034 into a 783,553 bp genomic sequence. This ctg1034 sequence was annotated for biological features such as genes and transposable elements. A three-gene island was identified among >80% repetitive DNA sequence. Using bioinformatics analysis there were no observable similarity in their gene functions. The ctg1034 gene island also displayed complete conservation of gene order and orientation with syntenic gene islands found in publicly available genome sequences of Brachypodium distachyon, Oryza sativa, Sorghum bicolor and Zea mays, even though the intergenic space and introns were divergent. Conclusion We propose that ctg1034 is located within the heterochromatic C-band region of deletion bin 3BL7 based on the identification of heterochromatic tandem repeats and presence of significant matches to chromodomain-containing gypsy LTR retrotransposable elements. We also speculate that this location, among other highly repetitive sequences, may account for the relative stability in gene order and

  6. Source-Sink Relationship in Wheat (Triticum aestivum and T. durum and Triticale (Triticale hexaploid Lart. Genotypes under Ahvaz Conditions

    Directory of Open Access Journals (Sweden)

    A Modhej

    2012-02-01

    Full Text Available In order to study the sink-source physiological relationship, current photosynthesis, contribution and remobilization of assimilates to grain yield in wheat and triticale genotypes, a field experiment was conducted in Iran, Ahvaz area on 2003-4. Treatments were two bread wheat (Simareh and Tawer, one durum wheat (Showa and two triticale (Juvanillo92 and Line 45 genotypes. Grain weight changes determined with removal of 50% spikelet from one spike side in main stem and tillers. Results indicated that the highest and the lowest grain yield were in Juvanilo92 and Line 45 genotypes. Higher grain yield in Juvanillo92 genotype was due to higher biological yield (1500 g.m-2, grain number per spike (65 floret per spikelet (2.3 and spikelet number per spike (28. In average, source limitation was 22 and 30.7% in wheat and triticale genotypes, respectively. Increase in grain weight in spikelet removal treatments compared to unmanipulated spike was 22.2 and 29% for main stem and tillers, respectively. It seems that this reaction was due to remobilization of assimilates from main stems to tillers by spikelets removal from main spikes. However, in desirable conditions, high yielding genotypes of wheat and triticale could be selected on the basis of the higher spike number and grain yield which are related to increase of source limitation.

  7. Genetic mapping of flavor loci in wheat

    Science.gov (United States)

    Flavor is an essential aspect of consumer acceptance, especially with whole-wheat foods. However, little if any selection is performed during breeding of new wheat cultivars for flavor, and little is known regarding the genetics of flavor. Our research is aimed at identifying genes that impart eithe...

  8. Genome-wide association mapping for resistance to leaf and stripe rust in winter-habit hexaploid wheat landraces

    Science.gov (United States)

    Leaf rust, caused by Puccinia triticina (Pt), and stripe rust, caused by P. striiformis f. sp. tritici (Pst), are destructive foliar diseases of wheat worldwide. Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst re...

  9. Tetraploid and hexaploid wheat varieties reveal large differences in expression of alpha-gliadins from homoelogous Gli-loci

    NARCIS (Netherlands)

    Salentijn, E.M.J.; Goryunova, S.V.; Bas, N.; Meer, van der I.M.; Broeck, van den H.C.; Bastien, T.A.; Gilissen, L.J.W.J.; Smulders, M.J.M.

    2009-01-01

    Background - A-gliadins form a multigene protein family encoded by multiple ¿-gliadin (Gli-2) genes at three genomic loci, Gli-A2, Gli-B2 and Gli-D2, respectively located on the homoeologous wheat chromosomes 6AS, 6BS, and 6DS. These proteins contain a number of important celiac disease (CD)-immunog

  10. Genetic transformation of mature embryos of bread (T. aestivum) and pasta (T. durum) wheat genotypes.

    Science.gov (United States)

    Moghaieb, Reda E A; El-Arabi, Nagwa I; Momtaz, Osama A; Youssef, Sawsan S; Soliman, Mohamed H

    2010-01-01

    The objective of the present study is to develop an efficient protocol for regeneration of transgenic wheat plants using Agrobacterium- mediated transformation of mature embryos of hexaploid bread wheat (Triticum aestivum) and tetraploid pasta wheat (Triticum durum). The data indicated that embryogenic calli were formed within 7 days in the presence of 2 mgl-1 2,4-D. Adventitious shoots emerged from the embryonic calli in the presence of 2 mgl-1 BA. Shoot regeneration frequency varied between wheat cultivars according to their genetic background differences. Regeneration frequency was higher in the cultivar Gemmiza 10 (95 %) compared with the other cultivars tested. Mature embryos derived callus of the cultivars Gemmiza 10 and Gemmiza 9 were co-cultivated with A. tumefaciens strain LBA4404 harboring a binary vector pBI-121 containing the neomycin phosphotransferase-II gene (npt-II). The resulted putative transgenic plantlets were able to grow on kanamycin containing medium. A successful integration of the transgene was confirmed by analyzing the T0 plantlets using Southern hybridization and PCR amplification. The gus gene expression can be detected only in the transgenic plants. The reported protocol is reproducible and can be used to regenerate transgenic wheat plants expressing the genes present in A. tumifaciens binary vectors.

  11. mlo-based powdery mildew resistance in hexaploid bread wheat generated by a non-transgenic TILLING approach.

    Science.gov (United States)

    Acevedo-Garcia, Johanna; Spencer, David; Thieron, Hannah; Reinstädler, Anja; Hammond-Kosack, Kim; Phillips, Andrew L; Panstruga, Ralph

    2017-03-01

    Wheat is one of the most widely grown cereal crops in the world and is an important food grain source for humans. However, wheat yields can be reduced by many abiotic and biotic stress factors, including powdery mildew disease caused by Blumeria graminis f.sp. tritici (Bgt). Generating resistant varieties is thus a major effort in plant breeding. Here, we took advantage of the non-transgenic Targeting Induced Lesions IN Genomes (TILLING) technology to select partial loss-of-function alleles of TaMlo, the orthologue of the barley Mlo (Mildew resistance locus o) gene. Natural and induced loss-of-function alleles (mlo) of barley Mlo are known to confer durable broad-spectrum powdery mildew resistance, typically at the expense of pleiotropic phenotypes such as premature leaf senescence. We identified 16 missense mutations in the three wheat TaMlo homoeologues, TaMlo-A1, TaMlo-B1 and TaMlo-D1 that each lead to single amino acid exchanges. Using transient gene expression assays in barley single cells, we functionally analysed the different missense mutants and identified the most promising candidates affecting powdery mildew susceptibility. By stacking of selected mutant alleles we generated four independent lines with non-conservative mutations in each of the three TaMlo homoeologues. Homozygous triple mutant lines and surprisingly also some of the homozygous double mutant lines showed enhanced, yet incomplete, Bgt resistance without the occurrence of discernible pleiotropic phenotypes. These lines thus represent an important step towards the production of commercial non-transgenic, powdery mildew-resistant bread wheat varieties.

  12. Genome-Wide Association Mapping for Resistance to Leaf and Stripe Rust in Winter-Habit Hexaploid Wheat Landraces.

    Directory of Open Access Journals (Sweden)

    Albert Kertho

    Full Text Available Leaf rust, caused by Puccinia triticina (Pt, and stripe rust, caused by P. striiformis f. sp. tritici (Pst, are destructive foliar diseases of wheat worldwide. Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst requires a constant search for new sources of resistance. Here we report a genome-wide association analysis of 567 winter wheat (Triticum aestivum landrace accessions using the Infinium iSelect 9K wheat SNP array to identify loci associated with seedling resistance to five races of Pt (MDCL, MFPS, THBL, TDBG, and TBDJ and one race of Pst (PSTv-37 frequently found in the Northern Great Plains of the United States. Mixed linear models identified 65 and eight significant markers associated with leaf rust and stripe rust, respectively. Further, we identified 31 and three QTL associated with resistance to Pt and Pst, respectively. Eleven QTL, identified on chromosomes 3A, 4A, 5A, and 6D, are previously unknown for leaf rust resistance in T. aestivum.

  13. Does Seed Priming Induce Changes in the Levels of Some Endogenous Plant Hormones in Hexaploid Wheat Plants Under Salt Stress?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to assess whether salt tolerance could be improved in spring wheat (Triticum aestivum L.), the present study was performed by soaking the seeds of two cultivars, namely MH-97 (salt sensitive) and Inqlab91 (salt tolerant), for 12 h in distilled water or 100 mol/m3 CaCl2, KCl, or NaCl. Primed seeds from each treatment group and non-primed seeds were sown in a field in which NaCl salinity of 15 dS/m was developed. Priming of seeds with CaCl2, followed by priming with KCl and NaCl, was found to be effective in alleviating the adverse effects of salt stress on both wheat cultivars in terms of shoot fresh and dry weights and grain yield. Priming with CaCl2 alleviated the adverse effects of salt stress on hormonal balance in plants of both cultivars. In MH-97plants, CaCl2 pretreatment considerably reduced leaf abscisic acid (ABA) concentrations and increased leaf free salicylic acid (SA) concentrations under both saline and non-saline conditions. In contrast, in the Inqlab-91plant, CaCl2 increased free indoleacetic acid (IAA) and indolebutyric acid (IBA) content. However, priming of seeds with CaCl2 did not alter free polyamine levels in either cultivar, although spermidine levels were considerably lower in plants raised from seeds treated with CaCl2 for both cultivars under saline conditions. Priming with KCl increased growth in Inqlab-91 plants, but not in MH-97 plants, under saline conditions. The salinity induced reduction in auxins (IAA and IBA) was alleviated by NaCl priming in both cultivars under saline conditions.However, NaCl increased leaf free ABA content and lowered leaf SA and putrescine levels in Inqlab-91 plants under saline conditions. In conclusion, although all three priming agents (i.e. CaCl2, KCl, and NaCI) were effective in alleviating the adverse effects of salt stress on wheat plants, their effects on altering the levels of different plant hormones were different in the two cultivars.

  14. A genetic linkage map of hexaploid naked oat constructed with SSR markers

    Institute of Scientific and Technical Information of China (English)

    Gaoyuan; Song; Pengjie; Huo; Bin; Wu; Zongwen; Zhang

    2015-01-01

    Naked oat is a unique health food crop in China. Using 202 F2 individuals derived from a hybrid between the variety 578 and the landrace Sanfensan, we constructed a genetic linkage map consisting of 22 linkage groups covering 2070.50 c M and including 208 simple sequence repeat(SSR) markers. The minimum distance between adjacent markers was0.01 c M and the average was 9.95 c M. Each linkage group contained 2–22 markers. The largest linkage group covered 174.40 c M and the shortest one covered 36.80 c M, with an average of 94.11 c M. Thirty-six markers(17.3%) showing distorted segregation were distributed across linkage groups LG5 to LG22. This map complements published oat genetic maps and is applicable for quantitative trait locus analysis, gene cloning and molecular marker-assisted selection.

  15. Chromosome engineering techniques for targeted introgression of rust resistance from wild wheat relatives

    Science.gov (United States)

    Hexaploid wheat has relatively narrow genetic diversity due to its evolution and domestication processes compared to its wild relatives that often carry agronomically important traits including resistance to biotic and abiotic stresses. Many genes have been introgressed into wheat from wild relative...

  16. Evidence for stable transformation of wheat by floraldip in Agrobacterium tumefaciens

    Science.gov (United States)

    Hexaploid wheat is one of the world’s most important staple crops but genetic transformation is still challenging. We have developed a floral transformation protocol that does not utilize tissue culture. Three T-DNA wheat transformants have been produced in the germplasm line, Crocus, using this p...

  17. Genetic diversity, population structure and marker-trait associations for agronomic and grain traits in wild diploid wheat Triticum urartu.

    Science.gov (United States)

    Wang, Xin; Luo, Guangbin; Yang, Wenlong; Li, Yiwen; Sun, Jiazhu; Zhan, Kehui; Liu, Dongcheng; Zhang, Aimin

    2017-07-01

    Wild diploid wheat, Triticum urartu (T. urartu) is the progenitor of bread wheat, and understanding its genetic diversity and genome function will provide considerable reference for dissecting genomic information of common wheat. In this study, we investigated the morphological and genetic diversity and population structure of 238 T. urartu accessions collected from different geographic regions. This collection had 19.37 alleles per SSR locus and its polymorphic information content (PIC) value was 0.76, and the PIC and Nei's gene diversity (GD) of high-molecular-weight glutenin subunits (HMW-GSs) were 0.86 and 0.88, respectively. UPGMA clustering analysis indicated that the 238 T. urartu accessions could be classified into two subpopulations, of which Cluster I contained accessions from Eastern Mediterranean coast and those from Mesopotamia and Transcaucasia belonged to Cluster II. The wide range of genetic diversity along with the manageable number of accessions makes it one of the best collections for mining valuable genes based on marker-trait association. Significant associations were observed between simple sequence repeats (SSR) or HMW-GSs and six morphological traits: heading date (HD), plant height (PH), spike length (SPL), spikelet number per spike (SPLN), tiller angle (TA) and grain length (GL). Our data demonstrated that SSRs and HMW-GSs were useful markers for identification of beneficial genes controlling important traits in T. urartu, and subsequently for their conservation and future utilization, which may be useful for genetic improvement of the cultivated hexaploid wheat.

  18. Study on genetic diversity in Pakistani wheat varieties using simple ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-01

    Sep 1, 2009 ... genetic diversity of 10 varieties of wheat (T. aestivum) were analyzed using 14 simple sequence repeat. (SSR) primer sets ... wheat every year. To increase .... All PCR reactions were carried out in 25 µl reaction containing 50 -.

  19. New insights into the origin of the B genome of hexaploid wheat: Evolutionary relationships at the SPA genomic region with the S genome of the diploid relative Aegilops speltoides

    Directory of Open Access Journals (Sweden)

    Charmet Gilles

    2008-11-01

    Full Text Available Abstract Background Several studies suggested that the diploid ancestor of the B genome of tetraploid and hexaploid wheat species belongs to the Sitopsis section, having Aegilops speltoides (SS, 2n = 14 as the closest identified relative. However molecular relationships based on genomic sequence comparison, including both coding and non-coding DNA, have never been investigated. In an attempt to clarify these relationships, we compared, in this study, sequences of the Storage Protein Activator (SPA locus region of the S genome of Ae. speltoides (2n = 14 to that of the A, B and D genomes co-resident in the hexaploid wheat species (Triticum aestivum, AABBDD, 2n = 42. Results Four BAC clones, spanning the SPA locus of respectively the A, B, D and S genomes, were isolated and sequenced. Orthologous genomic regions were identified as delimited by shared non-transposable elements and non-coding sequences surrounding the SPA gene and correspond to 35 268, 22 739, 43 397 and 53 919 bp for the A, B, D and S genomes, respectively. Sequence length discrepancies within and outside the SPA orthologous regions are the result of non-shared transposable elements (TE insertions, all of which inserted after the progenitors of the four genomes divergence. Conclusion On the basis of conserved sequence length as well as identity of the shared non-TE regions and the SPA coding sequence, Ae speltoides appears to be more evolutionary related to the B genome of T. aestivum than the A and D genomes. However, the differential insertions of TEs, none of which are conserved between the two genomes led to the conclusion that the S genome of Ae. speltoides has diverged very early from the progenitor of the B genome which remains to be identified.

  20. Impact of the D genome and quantitative trait loci on quantitative traits in a spring durum by spring bread wheat cross

    Science.gov (United States)

    Desirable agronomic traits are similar for common hexaploid (6X) bread wheat (Triticum aestivum, 2n = 6x = 42, genome, AABBDD) and tetraploid (4X) durum wheat (Triticum turgidum durum, 2n = 4x = 28, genome, AABB). However, they are genetically isolated from each other due to an unequal number of ge...

  1. Allelic Variation and Genetic Diversity at HMW Glutenin Subunits Loci in Yunnan,Tibetan and Xinjiang Wheat

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-yan; WANG Xiu-e; CHEN Pei-du; LIU Da-jun

    2004-01-01

    Allelic variation and genetic diversity at HMW glutenin subunits loci, Glu-A1, Glu-B1and Glu-D1 were investigated in 64 accessions of three unique wheats of western China using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Two HMW glutenin patterns (i.e., "null, 7+8, 2+12" and "null, 7, 2+12") in 34 Yunnan wheat accessions, 3 HMW glutenin patterns (i.e., "null, 7+8, 2+12"; "null, 6+8, 2+12" and "null, 7+8, 2") in 24 Tibetan accessions and 1 HMW glutenin pattern ("null, 7, 2+12") in 6 Xinjiang wheat accessions were found. The Tibetan accession TB18 was found to be with a rare subunit 2 encoded by Glu-D1. A total of 4 (i.e., Glu-A1c, Glu-B1a, Glu-B1b and Glu-D1a), 5 (i.e., Glu-A1c, Glu-B1d, Glu-B1b, Glu-D1a and Glu-D1) and 3 alleles (i.e.,Glu-A1c, Glu-B1a and Glu-D1a) at Glu-1 locus were identified among Yunnan, Tibetan and Xinjiang unique wheat accessions, respectively. For Yunnan wheat, Tibetan wheat and Xinjiang wheat, the Nei′s mean genetic variation indexes were 0.1574, 0.1366 and 0,respectively, which might indicate the higher genetic diversity at HMW glutenin subunits loci of Yunnan and Tibetan wheat accessions as compared to that of Xinjiang wheat accessions. Among the three genomes of hexaploid wheats of western China, the highest Nei′s genetic variation index was appeared in B genome with the mean value of 0.2674,while the indexes for genomes A and D were 0 and 0.0270, respectively. It might be reasonable to indicate that Glu-B1 showed the highest, Glu-D1 the intermediate and GluA1 always the lowest genetic diversity.

  2. Effect of Allelic Variation at the Glu-3/Gli-1 Loci on Breadmaking Quality Parameters in Hexaploid Wheat (Triticum aestivum L.).

    Science.gov (United States)

    Bonafede, Marcos D; Tranquilli, Gabriela; Pflüger, Laura A; Peña, Roberto J; Dubcovsky, Jorge

    2015-03-01

    Low molecular weight glutenin subunits (LMW-GS) encoded by the Glu-3 loci are known to contribute to wheat breadmaking quality. However, the specific effect of individual Glu-3 alleles is not well understood due to their complex protein banding patterns in SDS-PAGE and tight linkage with gliadins at the Gli-1 locus. Using DNA markers and a backcross program we developed a set of nine near isogenic lines (NILs) including different Glu-A3/GliA-1 or Glu-B3/Gli-B1 alleles in the genetic background of the Argentine variety ProINTA Imperial. The nine NILs and the control were evaluated in three different field trials in Argentina. Significant genotype-by-environment interactions were detected for most quality parameters indicating that the effects of the Glu-3/Gli-1 alleles are modulated by environmental differences. None of the NILs showed differences in total flour protein content, but relative changes in the abundance of particular classes of proteins cannot be ruled out. On average, the Glu-A3f, Glu-B3b, Glu-B3g and Glu-B3iMan alleles were associated with the highest values in gluten strength-related parameters, while Glu-A3e, Glu-B3a and Glu-B3iChu were consistently associated with weak gluten and low quality values. The value of different Glu3/Gli-1 allele combinations to improve breadmaking quality is discussed.

  3. Effect of Allelic Variation at the Glu-3/Gli-1 Loci on Breadmaking Quality Parameters in Hexaploid Wheat (Triticum aestivum L.)

    Science.gov (United States)

    Bonafede, Marcos D.; Tranquilli, Gabriela; Pflüger, Laura A.; Peña, Roberto J.; Dubcovsky, Jorge

    2016-01-01

    Low molecular weight glutenin subunits (LMW-GS) encoded by the Glu-3 loci are known to contribute to wheat breadmaking quality. However, the specific effect of individual Glu-3 alleles is not well understood due to their complex protein banding patterns in SDS-PAGE and tight linkage with gliadins at the Gli-1 locus. Using DNA markers and a backcross program we developed a set of nine near isogenic lines (NILs) including different Glu-A3/GliA-1 or Glu-B3/Gli-B1 alleles in the genetic background of the Argentine variety ProINTA Imperial. The nine NILs and the control were evaluated in three different field trials in Argentina. Significant genotype-by-environment interactions were detected for most quality parameters indicating that the effects of the Glu-3/Gli-1 alleles are modulated by environmental differences. None of the NILs showed differences in total flour protein content, but relative changes in the abundance of particular classes of proteins cannot be ruled out. On average, the Glu-A3f, Glu-B3b, Glu-B3g and Glu-B3iMan alleles were associated with the highest values in gluten strength-related parameters, while Glu-A3e, Glu-B3a and Glu-B3iChu were consistently associated with weak gluten and low quality values. The value of different Glu3/Gli-1 allele combinations to improve breadmaking quality is discussed. PMID:27818572

  4. A diploid wheat TILLING resource for wheat functional genomics

    Directory of Open Access Journals (Sweden)

    Rawat Nidhi

    2012-11-01

    Full Text Available Abstract Background Triticum monococcum L., an A genome diploid einkorn wheat, was the first domesticated crop. As a diploid, it is attractive genetic model for the study of gene structure and function of wheat-specific traits. Diploid wheat is currently not amenable to reverse genetics approaches such as insertion mutagenesis and post-transcriptional gene silencing strategies. However, TILLING offers a powerful functional genetics approach for wheat gene analysis. Results We developed a TILLING population of 1,532 M2 families using EMS as a mutagen. A total of 67 mutants were obtained for the four genes studied. Waxy gene mutation frequencies are known to be 1/17.6 - 34.4 kb DNA in polyploid wheat TILLING populations. The T. monococcum diploid wheat TILLING population had a mutation frequency of 1/90 kb for the same gene. Lignin biosynthesis pathway genes- COMT1, HCT2, and 4CL1 had mutation frequencies of 1/86 kb, 1/92 kb and 1/100 kb, respectively. The overall mutation frequency of the diploid wheat TILLING population was 1/92 kb. Conclusion The mutation frequency of a diploid wheat TILLING population was found to be higher than that reported for other diploid grasses. The rate, however, is lower than tetraploid and hexaploid wheat TILLING populations because of the higher tolerance of polyploids to mutations. Unlike polyploid wheat, most mutants in diploid wheat have a phenotype amenable to forward and reverse genetic analysis and establish diploid wheat as an attractive model to study gene function in wheat. We estimate that a TILLING population of 5, 520 will be needed to get a non-sense mutation for every wheat gene of interest with 95% probability.

  5. Transferring a Gene Expression Cassette Lacking the Vector Backbone Sequences of the 1Ax1 High Molecular Weight Glutenin Subunit into Two Chinese Hexaploid Wheat Genotypes

    Institute of Scientific and Technical Information of China (English)

    SHI Nong-nong; HE Guang-yuan; LI Ke-xiu; WANG Hui-zhong; CHEN Guan-ping; XU Ying

    2007-01-01

    1Ax1 high molecular weight glutenin subunit (HMW-GS) gene expression cassette (GEC) lacking vector backbone sequences together with selectable marker Bar GEC were co-transformed into Chinese hexaploid cultivars Een 1 and Emai 12 to test the feasibility and the efficiency of explant regeneration, transformation frequency and transgene expression comparing with whole vector transformation by the approaches of plasmid extraction and excision, immature embryo isolation, particle co-bombardment, tissue culture, DNA extraction, PCR amplification, southern hybridization, leaf-painting test and SDS-PAGE etc. No significant difference was shown in tissue culture response of the proportion of embryogenic calli, somatic embryogenesis and regeneration frequency between GEC and whole plasmid bombarded embryos, but both regenerated less well than non-bombarded control. Total 56 plantlets that survived PPT selection had insertion of at least the Bar gene, 18 were from the GEC treatment and 38 from the whole plasmid treatment, the escape ratio averaged 0.23. Six independent transplants f230 - f235 with GEC transformation from genotype Emai 12 presented clear PCR amplification bands of Bar and 1Ax1 gene. The transformation and co-transformation frequency were 3.51 and 100% respectively. PCR amplification using a primer-pair specific for ampicillin resistant gene indicated the existence of AmpR gene in whole vectors but the removal in GECs and transplants. Southern blot of total DNA and PCR products from transgenic plants of 1Ax1 GEC confirmed the integration of the transgene 1Ax1 and the absence of the EcoR Ⅰ recognition site at both ends of the 1Ax1 GEC when integrated. SDS-PAGE showed the expression of 1Ax1 GEC and un-expression of whole plasmid. The length of integrated fragment, the proportion of the gene of interest (GOI) and the selectable marker (MG), bombardment pressure and genotypes are vital for the expression of a transformed GEC.

  6. A genome-wide association study of resistance to stripe rust (Puccinia striiformis f. sp. tritici) in a worldwide collection of hexaploid spring wheat (Triticum aestivum L.).

    Science.gov (United States)

    Maccaferri, Marco; Zhang, Junli; Bulli, Peter; Abate, Zewdie; Chao, Shiaoman; Cantu, Dario; Bossolini, Eligio; Chen, Xianming; Pumphrey, Michael; Dubcovsky, Jorge

    2015-01-20

    New races of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, show high virulence to previously deployed resistance genes and are responsible for large yield losses worldwide. To identify new sources of resistance we performed a genome-wide association study (GWAS) using a worldwide collection of 1000 spring wheat accessions. Adult plants were evaluated under field conditions in six environments in the western United States, and seedlings were tested with four Pst races. A single-nucleotide polymorphism (SNP) Infinium 9K-assay provided 4585 SNPs suitable for GWAS. High correlations among environments and high heritabilities were observed for stripe rust infection type and severity. Greater levels of Pst resistance were observed in a subpopulation from Southern Asia than in other groups. GWAS identified 97 loci that were significant for at least three environments, including 10 with an experiment-wise adjusted Bonferroni probability resistance genes and QTL, and likely represent new resistance loci. The other seven QTL mapped close to known resistance genes and allelism tests will be required to test their relationships. In summary, this study provides an integrated view of stripe rust resistance resources in spring wheat and identifies new resistance loci that will be useful to diversify the current set of resistance genes deployed to control this devastating disease.

  7. GENETIC DIVERSITY OF WHEAT CULTIVARS ESTIMATED BY SSR MARKERS

    Directory of Open Access Journals (Sweden)

    K. Dvojković

    2008-09-01

    Full Text Available Presence and utilization of the genetic variability in the breeding programmes is prerequisite for their successfulness. Important factor for crop improvement is knowledge about the genetic diversity which providing a basis for the precise selection of parental combinations. Since beginning of 20th century, generation of wheat breeders and scientists in Croatia developed numerous advanced and successful wheat cultivars. Previous researches aimed to genetic diversity evaluation in Croatia were conducted by means of morphological traits, pedigree data (coefficients of parentage, proteins (glutenins and gliadins and RAPD DNA markers. DNA markers detect directly variation of DNA sequence for particular loci and they are not under influence of environment, epistatic and pleiotropic effects. Microsatellite markers (Simple Sequence Repeats; SSRs, as highly polymorphic, informative and codominant DNA marker system, have been extensively used for genetic diversity studies on wheat world wide. A set of 98 wheat cultivars released in Croatia during the period 1905-2007, and 24 foreign cultivar (included because of their ancestral significance or as standards, were screened by 45 microsatellite markers, covering all three wheat genomes. The objectives of this study were to evaluate the microsatellites-based genetic diversity with emphasize on cultivars created at the Agricultural Institute Osijek, as well as to investigate SSR application for selection of genetically the most distant parental pairs. Preliminary data obtained by means of SSR markers showed a satisfactory level of genetic diversity and usefulness of microsatellites for parental selection.

  8. CHROMOSOME LOCATION OF GENETIC FACTORS DETERMINIG PHYSIOLOGICAL AND BIOCHEMICAL PROCESSES ASSOCIATED WITH DROUGHT TOLERANCE IN WHEAT TRITICUM AESTIVUM L.

    Directory of Open Access Journals (Sweden)

    Osipova S.

    2012-08-01

    Full Text Available Drought tolerance is characterized as the most recalcitrant trait to improve for its complexity and considered target for genomic-assisted improvement. A profitable genetic strategy lies in the discovery and exploitation of quantitative trait loci (QTL involved in determining tolerance to water deficit at the cellular level. Enzymes of the antioxidant system participating in detoxification of reactive oxygen species accumulating under stress are the essential component of the common protective systems in cell. The same is lipoxygenase – a key enzyme of jasmonate-dependent signaling pathway initiating the development of adaptive programs in cell. Understanding of the genetic basis of wheat drought tolerance as a polygenic trait and identification of the QTL is facilitated by the availability of a number of sets of inter-varietal single chromosome substitution lines (ISCSLs in bread wheat Triticum aestivum L. Two sets of bread wheat ISCSLs were used in this study. In the first set, 'Saratovskaya' 29 (S29 / 'Janetzkis Probat' (JP, the recipient was a drought tolerant cultivar and the donor of individual pairs of homologous chromosomes was a sensitive one. In the second set, 'Chinese Spring' (CS / 'Synthetic 6x' (Syn 6x, the donor of separate chromosomes was a synthetic hexaploid wheat (T. dicoccoides X Ae. tauschii. In the set S29/JP the chromosomes of the second homoeological group and 4D chromosome were found to be critical for drought tolerance. A decrease of tolerance correlated with decreasing of antioxidant enzymes cumulative activity in leaves. In the set CS/Syn, chromosomes 4B and 4D were found to be critical for drought tolerance. The levels of LOX activity in leaves of both sets differently correlated with grain productivity but influenced positively on retaining a grain size under drought. Besides the structural genes for LOX biosynthesis situated on chromosomes of 4 and 5 homoeological groups, in both sets, the genetic factors on

  9. Genetic Potential of Winter Wheat Grain Quality in Central Asia

    Science.gov (United States)

    Abugaliyeva, Aigul I.; Morgounov, Alexey I.

    2016-01-01

    The grain quality of winter wheat varies significantly by cultivars and growing region, not previously differentiated by end-use (baking, confectionery, etc.) in the national breeding programs. In these conditions it is advisable to determine the genetic potential and analyze the actual grain quality. Determining the genetic potential requires the…

  10. Genetic analysis of wheat domestication and evolution under domestication.

    Science.gov (United States)

    Peleg, Zvi; Fahima, Tzion; Korol, Abraham B; Abbo, Shahal; Saranga, Yehoshua

    2011-10-01

    Wheat is undoubtedly one of the world's major food sources since the dawn of Near Eastern agriculture and up to the present day. Morphological, physiological, and genetic modifications involved in domestication and subsequent evolution under domestication were investigated in a tetraploid recombinant inbred line population, derived from a cross between durum wheat and its immediate progenitor wild emmer wheat. Experimental data were used to test previous assumptions regarding a protracted domestication process. The brittle rachis (Br) spike, thought to be a primary characteristic of domestication, was mapped to chromosome 2A as a single gene, suggesting, in light of previously reported Br loci (homoeologous group 3), a complex genetic model involved in spike brittleness. Twenty-seven quantitative trait loci (QTLs) conferring threshability and yield components (kernel size and number of kernels per spike) were mapped. The large number of QTLs detected in this and other studies suggests that following domestication, wheat evolutionary processes involved many genomic changes. The Br gene did not show either genetic (co-localization with QTLs) or phenotypic association with threshability or yield components, suggesting independence of the respective loci. It is argued here that changes in spike threshability and agronomic traits (e.g. yield and its components) are the outcome of plant evolution under domestication, rather than the result of a protracted domestication process. Revealing the genomic basis of wheat domestication and evolution under domestication, and clarifying their inter-relationships, will improve our understanding of wheat biology and contribute to further crop improvement.

  11. Distribution of Grain Hardness in Chinese Wheats and Genetic Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yan-hua; HE Zhong-hu; YAN Jun; ZHANG Yan; WANG De-sen; ZHOU Gui-ying

    2002-01-01

    A hundred winter wheat and 41 spring wheat cultivars and advanced lines were used to investigate the distribution of grain hardness in Chinese wheats and correlations between grain hardness and other kernel traits. P1, P2, F1, F2 and F3 from three crosses, i. e. , Liken2/Yumai2, 85Zhong33/Wenmai6 and 85Zhong33/95Zhong459 were sown to study the genetics of grain hardness. Significant correlation was observed between hardness measured by Single Kernel Characteristic System 4100 (SKCS 4100) and Near Infrared (NIR) Spectroscopy, r ranging from 0. 85 to 0.94. Chinese wheat is a mixed population in terms of hardness, ranging from very soft to very hard. For autumn-sown wheat, on average, grain hardness decreases from north to south and spring-sown wheat is dominant with hard type. Hardness is negatively associated with flour color, and its associations with flour yield and ash content differ in winter and spring wheats. Grain hardness is controlled by a major gene and several minor genes with additive effect mostly, but dominant effect is also observed, with heritability of 0.78.

  12. Molecular and genetic study of wheat rusts

    African Journals Online (AJOL)

    Nicholas Le Maitre

    Wheat rusts can cause losses as high as 70%. The rusts ability to ... Rotation of genes, that is, where different major resis- tance genes are ... and generate accurate results the same day (Brown,. 1996 ..... More work is required to assign these ...

  13. Evolution of polyploid triticum wheats under cultivation: the role of domestication, natural hybridization and allopolyploid speciation in their diversification.

    Science.gov (United States)

    Matsuoka, Yoshihiro

    2011-05-01

    The evolution of the polyploid Triticum wheats is distinctive in that domestication, natural hybridization and allopolyploid speciation have all had significant impacts on their diversification. In this review, I outline the phylogenetic relationships of cultivated wheats and their wild relatives and provide an overview of the recent progress and remaining issues in understanding the genetic and ecological factors that favored their evolution. An attempt is made to view the evolution of the polyploid Triticum wheats as a continuous process of diversification that was initiated by domestication of tetraploid emmer wheat and driven by various natural events ranging from interploidy introgression via hybridization to allopolyploid speciation of hexaploid common wheat, instead of viewing it as a group of discrete evolutionary processes that separately proceeded at the tetraploid and hexaploid levels. This standpoint underscores the important role of natural hybridization in the reticulate diversification of the tetraploid-hexaploid Triticum wheat complex and highlights critical, but underappreciated, issues that concern the allopolyploid speciation of common wheat.

  14. Wheat Production and Wheat Rust Management in Canada

    Institute of Scientific and Technical Information of China (English)

    Xue Allen G; Chi Dawn T; Zhang Shu-zhen; Li Zuo-fu

    2012-01-01

    Wheat is Canada's the largest crop with most of the production in the western Canadian Prairie Provinces of Manitoba, Saskatchewan and Alberta. There were approximately 10 million (M) hectares (hm2) seeded to wheat in Canada, including 7 M hm2 of hexaploid spring wheat (Triticum aestivum L.), 2 M hm2 of durum wheat (T. turgidum L. ssp. durum (Desf.) Husn.), and 1 M hm2 of winter wheat (T. aestivum). Within hexaploid wheat there has been diversification into a number of market classes based on different end-use quality criteria. The predominant spring bread wheat class has been the Canada Western Red Spring (CWRS) class. Historically, the disease of major concern in wheat was stem rust, caused by Puccinia graminis f. sp. tritici. The first significant stem rust resistant cultivar in Canada was Thatcher, grown extensively from 1939 until the early 1970s. Thatcher, however, was very susceptible to leaf rust, caused by Puccinia triticina. Over years, improved resistance to both stem and leaf rust was achieved with the release of cultivars with additional genes for resistance, primarily Sr2, Sr6, Sr7a, Sr9b, Lr13, Lr14a, Lr16, and Lr34. The genetic resistance has adequately controlled stem rust but leaf rust continues to cause significant loss, partially due to changes in the P. triticina population which reduced the effectiveness of resistance genes such as Lr13 and Lr16. Stripe rust on wheat, caused by Puccinia striiformis f. sp. tritici, was historically a problem under irrigation in southern Alberta, but since 2000, it has been found annually in the central Canadian prairies and southern Ontario. The genetic basis of resistance to stripe rust in most Canadian wheat cultivars has not been determined, although Yr18 provides partial resistance in many cultivars. In the future, other rust diseases, such as wheat stripe rust, or highly virulent new pathotypes of current rust pathogens, such as P. graminis f. sp. tritici race Ug-99, may pose

  15. Molecular Diversity and Genetic Structure of Durum Wheat Landraces

    Directory of Open Access Journals (Sweden)

    GULNAR SHIKHSEYIDOVA

    2015-06-01

    Full Text Available To determine the genetic diversity of durum wheat, 41 accessions from Morocco, Ethiopia, Turkey, Lebanon, Kazakhstan, China, and Mongolia were analyzed through Inter-Simple Sequence Repeats (ISSR molecular markers. Out of the used twenty primers, 15 primers that included a considerable polymorphism were selected for the analyses. Among the genotypes under study, 163 fragments (73.7% were polymorph. Several indexes were used to determine the most appropriate primers. While UBC812, UBC864, UBC840, and UBC808 primers were among those markers which produced the highest number of bands and polymorphic bands, they also dedicated the highest rate of polymorphic index content (PIC. These primers also possessed the highest amounts of effective multiplex ratio (EMR and marker index (MI. Therefore, these primers can be recommended for genetic evaluation of the durum wheat. The results of cluster analysis and principle component analysis indicated that the observed genetic diversity in wheat materials under study is geographically structured. The results also indicated that the genetic diversity index based on ISSR markers was higher for Turkey, Lebanon, Morocco, and Ethiopia accessions than for other countries. The high level of polymorphism in this collections durum wheat would agree with the suggestion that Fertile Crescent and parts of Africa are first possible diversity center of this crop.

  16. Identification and Phylogenetic Analysis of a CC-NBS-LRR Encoding Gene Assigned on Chromosome 7B of Wheat

    Directory of Open Access Journals (Sweden)

    Xiangqi Zhang

    2013-07-01

    Full Text Available Hexaploid wheat displays limited genetic variation. As a direct A and B genome donor of hexaploid wheat, tetraploid wheat represents an important gene pool for cultivated bread wheat. Many disease resistant genes express conserved domains of the nucleotide-binding site and leucine-rich repeats (NBS-LRR. In this study, we isolated a CC-NBS-LRR gene locating on chromosome 7B from durum wheat variety Italy 363, and designated it TdRGA-7Ba. Its open reading frame was 4014 bp, encoding a 1337 amino acid protein with a complete NBS domain and 18 LRR repeats, sharing 44.7% identity with the PM3B protein. TdRGA-7Ba expression was continuously seen at low levels and was highest in leaves. TdRGA-7Ba has another allele TdRGA-7Bb with a 4 bp deletion at position +1892 in other cultivars of tetraploid wheat. In Ae. speltoides, as a B genome progenitor, both TdRGA-7Ba and TdRGA-7Bb were detected. In all six species of hexaploid wheats (AABBDD, only TdRGA-7Bb existed. Phylogenic analysis showed that all TdRGA-7Bb type genes were grouped in one sub-branch. We speculate that TdRGA-7Bb was derived from a TdRGA-7Ba mutation, and it happened in Ae. speltoides. Both types of TdRGA-7B participated in tetraploid wheat formation. However, only the TdRGA-7Bb was retained in hexaploid wheat.

  17. Evaluation of Genetic Diversity in Wild Diploid Wheat Triticum boeoticum from Iran Using AFLP Markers

    Institute of Scientific and Technical Information of China (English)

    M.R. Naghavi; M. Malaki; H. Alizadeh; M. Mardi; Fakhre-Tabatabaei

    2007-01-01

    @@ Although Iran is a main center of distribution of wild wheats, but little information is available regarding genetic variation in wild wheat relatives from this country (Tabatabaei and Massoumi, 2001).

  18. Aphid–parasitoid community structure on genetically modified wheat

    OpenAIRE

    2011-01-01

    Since the introduction of genetically modified (GM) plants, one of the main concerns has been their potential effect on non-target insects. Many studies have looked at GM plant effects on single non-target herbivore species or on simple herbivore–natural enemy food chains. Agro-ecosystems, however, are characterized by numerous insect species which are involved in complex interactions, forming food webs. In this study, we looked at transgenic disease-resistant wheat (Triticum aestivum) and it...

  19. Genetic mapping of race-specific stem rust resistance in the synthetic hexaploid W7984 x Opata M85 mapping population

    Science.gov (United States)

    Stem rust (caused by Puccinia graminis f. sp. tritici) has historically caused severe yield losses of wheat (Triticum aestivum) worldwide and has been one of the most feared diseases of wheat and barley (Hordeum vulgare). Stem rust has been controlled successfully through the use of resistant varie...

  20. Tetraploid Wheat Landraces in the Mediterranean Basin: Taxonomy, Evolution and Genetic Diversity

    OpenAIRE

    Oliveira, Hugo R; Campana, Michael G; Huw Jones; Hunt, Harriet V.; Fiona Leigh; Redhouse, David I.; Lister, Diane L.; Jones, Martin K.

    2012-01-01

    The geographic distribution of genetic diversity and the population structure of tetraploid wheat landraces in the Mediterranean basin has received relatively little attention. This is complicated by the lack of consensus concerning the taxonomy of tetraploid wheats and by unresolved questions regarding the domestication and spread of naked wheats. These knowledge gaps hinder crop diversity conservation efforts and plant breeding programmes. We investigated genetic diversity and population st...

  1. Chromosomal Behavior during Meiosis in the Progeny of Triticum timopheevii × Hexaploid Wild Oat.

    Directory of Open Access Journals (Sweden)

    Hongzhou An

    Full Text Available The meiotic behavior of pollen mother cells (PMCs of the F2 and F3 progeny from Triticum timopheevii × hexaploid wild oat was investigated by cytological analysis and sequential C-banding-genomic in situ hybridization (GISH in the present study. A cytological analysis showed that the chromosome numbers of the F2 and F3 progeny ranged from 28 to 41. A large number of univalents, lagging chromosomes, chromosome bridges and micronuclei were found at the metaphase I, anaphase I, anaphase II and tetrad stages in the F2 and F3 progeny. The averages of univalents were 3.50 and 2.73 per cell, and those of lagging chromosomes were 3.37 and 1.87 in the F2 and F3 progeny, respectively. The PMC meiotic indices of the F2 and F3 progeny were 12.22 and 20.34, respectively, indicating considerable genetic instability. A sequential C-banding-GISH analysis revealed that some chromosomes and fragments from the hexaploid wild oat were detected at metaphase I and anaphase I in the progeny, showing that the progeny were of true intergeneric hybrid origin. The alien chromosomes 6A, 7A, 3C and 2D were lost during transmission from F2 to F3. In addition, partial T. timopheevii chromosomes appeared in the form of univalents or lagging chromosomes, which might result from large genome differences between the parents, and the wild oat chromosome introgression interfered with the wheat homologues' normally pairing.

  2. Genetic diversity and structure found in samples of Eritrean bread wheat

    DEFF Research Database (Denmark)

    Desta, Zeratsion Abera; Orabi, Jihad; Jahoor, Ahmed

    2014-01-01

    Genetic diversity and structure plays a key role in the selection of parents for crosses in plant breeding programmes. The aim of the present study was to analyse the genetic diversity and structure of Eritrean bread wheat accessions. We analysed 284 wheat accessions from Eritrea using 30 simple ...

  3. Genetic and comparative genomics mapping reveals that a powdery mildew resistance gene Ml3D232 originating from wild emmer co-segregates with an NBS-LRR analog in common wheat (Triticum aestivum L.).

    Science.gov (United States)

    Zhang, Hongtao; Guan, Haiying; Li, Jingting; Zhu, Jie; Xie, Chaojie; Zhou, Yilin; Duan, Xiayu; Yang, Tsomin; Sun, Qixin; Liu, Zhiyong

    2010-11-01

    Powdery mildew caused by Blumeria graminis f. sp. tritici is one of the most important wheat diseases worldwide and breeding for resistance using diversified disease resistance genes is the most promising approach to prevent outbreaks of powdery mildew. A powdery mildew resistance gene, originating from wild emmer wheat (Triticum turgidum var. dicoccoides) accessions collected from Israel, has been transferred into the hexaploid wheat line 3D232 through crossing and backcrossing. Inoculation results with 21 B. graminis f. sp. tritici races indicated that 3D232 is resistant to all of the powdery mildew isolates tested. Genetic analyses of 3D232 using an F(2) segregating population and F(3) families indicated that a single dominant gene, Ml3D232, confers resistance in the host seedling stage. By applying molecular markers and bulked segregant analysis (BSA), we have identified polymorphic simple sequence repeats (SSR), expressed sequence tags (EST) and derived sequence tagged site (STS) markers to determine that the Ml3D232 is located on chromosome 5BL bin 0.59-0.76. Comparative genetic analyses using mapped EST markers and genome sequences of rice and Brachypodium established co-linearity of the Ml3D232 genomic region with a 1.4 Mb genomic region on Brachypodium distachyon chromosome 4, and a 1.2 Mb contig located on the Oryza sativa chromosome 9. Our comparative approach enabled us to develop new EST-STS markers and to delimit the genomic region carrying Ml3D232 to a 0.8 cM segment that is collinear with a 558 kb region on B. distachyon. Eight EST markers, including an NBS-LRR analog, co-segregated with Ml3D232 to provide a target site for fine genetic mapping, chromosome landing and map-based cloning of the powdery mildew resistance gene. This newly developed common wheat germplasm provides broad-spectrum resistance to powdery mildew and a valuable resource for wheat breeding programs.

  4. Genetic Architecture of Anther Extrusion in Spring and Winter Wheat

    Directory of Open Access Journals (Sweden)

    Quddoos H. Muqaddasi

    2017-05-01

    Full Text Available Hybrid wheat breeding is gaining prominence worldwide because it ensures higher and more static yield than conventionally bred varieties. The cleistogamous floral architecture of wheat (Triticum aestivum L. impedes anthers inside the floret, making it largely an inbreeder. For hybrid seed production, high anther extrusion is needed to promote cross pollination and to ensure a high level of pollen availability for the seed plant. This study, therefore, aimed at the genetic dissection of anther extrusion (AE in panels of spring (SP, and winter wheat (WP accessions by genome wide association studies (GWAS. We performed GWAS to identify the SNP markers potentially linked with AE in each panel separately. Phenotypic data were collected for 3 years for each panel. The average levels of Pearson's correlation (r among all years and their best linear unbiased estimates (BLUEs within both panels were high (r(SP = 0.75, P < 0.0001;r(WP = 0.72, P < 0.0001. Genotypic data (with minimum of 0.05 minor allele frequency applied included 12,066 and 12,191 SNP markers for SP and WP, respectively. Both genotypes and environment influenced the magnitude of AE. In total, 23 significant (|log10(P| > 3.0 marker trait associations (MTAs were detected (SP = 11; WP = 12. Anther extrusion behaved as a complex trait with significant markers having either favorable or unfavorable additive effects and imparting minor to moderate levels of phenotypic variance (R2(SP = 9.75−14.24%; R2 (WP = 9.44−16.98%. All mapped significant markers as well as the markers within their significant linkage disequilibrium (r2 ≥ 0.30 regions were blasted against wheat genome assembly (IWGSC1+popseq to find the corresponding genes and their high confidence descriptions were retrieved. These genes and their orthologs in Hordeum vulgare, Brachypodium distachyon, Oryza sativa, and Sorghum bicolor revealed syntenic genomic regions potentially involved in flowering-related traits. Moreover, the

  5. Genetic transformation of Indian bread (T. aestivum and pasta (T. durum wheat by particle bombardment of mature embryo-derived calli

    Directory of Open Access Journals (Sweden)

    Khurana Paramjit

    2003-09-01

    Full Text Available Abstract Background Particle bombardment has been successfully employed for obtaining transgenics in cereals in general and wheat in particular. Most of these procedures employ immature embryos which are not available throughout the year. The present investigation utilizes mature seeds as the starting material and the calli raised from the hexaploid Triticum aestivum and tetraploid Triticum durum display a high regeneration response and were therefore used as the target tissue for genetic transformation by the biolistic approach. Results Mature embryo-derived calli of bread wheat (Triticum aestivum, cv. CPAN1676 and durum wheat (T. durum, cv. PDW215 were double bombarded with 1.1 gold microprojectiles coated with pDM302 and pAct1-F at a target distance of 6 cm. Southern analysis using the bar gene as a probe revealed the integration of transgenes in the T0 transformants. The bar gene was active in both T0 and T1 generations as evidenced by phosphinothricin leaf paint assay. Approximately 30% and 33% primary transformants of T. aestivum and T. durum, respectively, were fertile. The transmission of bar gene to T1 progeny was demonstrated by PCR analysis of germinated seedlings with primers specific to the bar gene. Conclusions The transformation frequency obtained was 8.56% with T. aestivum and 10% with T. durum. The optimized protocol was subsequently used for the introduction of the barley gene encoding a late embryogenesis abundant protein (HVA1 in T. aestivum and T. durum. The presence of the HVA1 transgene was confirmed by Southern analysis in the T0 generation in case of Triticum aestivum, and T0 and T1 generation in Triticum durum.

  6. Wheat ferritins: Improving the iron content of the wheat grain

    DEFF Research Database (Denmark)

    Borg, Søren; Brinch-Pedersen, Henrik; Tauris, Birgitte

    2012-01-01

    The characterization of the full complement of wheat ferritins show that the modern hexaploid wheat genome contains two ferritin genes, TaFer1 and TaFer2, each represented by three homeoalleles and placed on chromosome 5 and 4, respectively. The two genes are differentially regulated and expresse...

  7. Wheat Landrace Genome Diversity.

    Science.gov (United States)

    Wingen, Luzie U; West, Claire; Leverington-Waite, Michelle; Collier, Sarah; Orford, Simon; Goram, Richard; Yang, Cai-Yun; King, Julie; Allen, Alexandra M; Burridge, Amanda; Edwards, Keith J; Griffiths, Simon

    2017-02-17

    Understanding the genomic complexity of bread wheat (Triticum aestivum L.) is a cornerstone in the quest to unravel the processes of domestication and the following adaptation of domesticated wheat to a wide variety of environments across the globe. Additionally, it is of importance for future improvement of the crop, particularly in the light of climate change. Focussing on the adaptation after domestication, a nested association mapping (NAM) panel of 60 segregating bi-parental populations were developed mainly involving landrace accessions from the core set of the Watkins hexaploid wheat collection optimized for genetic diversity (WINGEN et al. 2014). A modern spring elite variety, 'Paragon,' was used as common reference parent. Genetic maps were constructed following identical rules to make them comparable. In total, 1,611 linkage groups were identified, based on recombination from an estimated 126,300 crossover events over the whole NAM panel. A consensus map, named landrace consensus map (LRC) was constructed and contained 2,498 genetic loci. These newly developed genetics tools were used to investigate the rules underlying genome fluidity or rigidity, e.g. by comparing at marker distances and marker orders. In general, marker order was highly correlated, which provides support for strong synteny between bread wheat accessions. However, many exceptional cases of incongruent linkage groups and increased marker distances were also found. Segregation distortion was detected for many markers, sometimes as hot-spots present in different populations. Furthermore, evidence for translocations in at least 36 of the maps was found. These translocations fell, in general, into many different translocation classes, but a few translocation classes were found in several accessions, the most frequent one being the well known T5B:7B translocation. Loci involved in recombination rate, which is an interesting trait for plant breeding, were identified by QTL analyses using the

  8. Alien DNA introgression and wheat DNA rearrangements in a stable wheat line derived from the early generation of distant hybridization

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lianquan; LIU Dengcai; YAN Zehong; ZHENG Youliang

    2005-01-01

    Polyploidy has been found to be common in plants. Bread or common wheat (Triticum aestivum L., 2n = 42) is a good example of allopolyploid made up of three diploid genomes A, B and D. In recent years, by the study of mimicking the origination of common wheat, it was found that changes of DNA sequence and gene expression occurred at the early stages of artificial allohexaploid between tetraploid wheat and Aegilops tauschii, which was probably favorable to genetic diploidization of new synthetic hexaploid wheat. Common wheat 99L2 is a new line stable in genetic, which was derived from the early self-pollinated generation of wide hybrids between common wheat and rye. In this study, it was found that at least two rye DNA segments had been introgressed into 99L2. This result suggested that a mechanism of alien DNA introgression may exist, which was different from the traditional mechanism of chromosome pairing and DNA recombination between wheat and alien species. Meanwhile, during the introgression process of alien rye DNA segments, the changes in DNA sequences of wheat itself occurred.

  9. Current status and trends of wheat genetic transformation studies in China

    Institute of Scientific and Technical Information of China (English)

    HE Yi; WANG Qiong; ZENG Jian; SUN Tao; YANG Guang-xiao; HE Guang-yuan

    2015-01-01

    More than 20 years have passed since the ifrst report on successful genetic transformation of wheat. With the establishment and improvement of transformation platform, great progresses have been made on wheat genetic transformation both on its fundamental and applied studies in China, especial y driven by the National Major Project for Transgenic Organism Breed-ing, China, initiated in 2008. In this review, wheat genetic transformation platform improvement and transgenic research progresses including new techniques applied and functional studies of wheat quality, yield and stress tolerant related genes and biosafety assessment are summarized. The existing problems and the trends in wheat transformation with traditional methods combined with genomic studies and genome editing technology are also discussed.

  10. Genetic analysis of amino acid content in wheat grain

    Indian Academy of Sciences (India)

    Xiaoling Jiang; Peng Wu; Jichun Tian

    2014-08-01

    Complete diallel crosses with five parents of common wheat (Triticum aestivum L.) were conducted to analyse inheritance of 17 amino acid contents by using the genetic model including seed, cytoplasmic, maternal and environment interaction effects on quantitative traits of seeds in cereal crops. The results showed that inheritance of 17 amino acid contents, except tyrosine, was controlled by several genetic systems including seed, cytoplasmic, and maternal effects, and by significant gene × environment interaction effects. Seed-direct additive and maternal effects constituted a major part of genetic effects for lysine, tyrosine, arginine, methionine, and glutamic acid content. Seed-direct additive effect formed main part in inheritance of isoleucine and serine contents. Threonine content was mainly governed by maternal additive effect. The other nine amino acid contents were almost entirely controlled by dominance effects. High general heritability of tyrosine (36.3%), arginine (45.8%), lysine (24.7%) and threonine (21.4%) contents, revealed that it could be effective to improve them by direct selection in progenies from appropriate crosses. Interaction heritability for phenylalanine, proline, and histidine content, which was 36.1%, 39.5% and 25.7%, respectively, was higher than for the other amino acids.

  11. Immunotoxicological Evaluation of Wheat Genetically Modified with TaDREB4 Gene on BALB/c Mice

    Institute of Scientific and Technical Information of China (English)

    LIANG Chun Lai; ZHANG Xiao Peng; SONG Yan; JIA Xu Dong

    2013-01-01

    Objective To evaluate the immunotoxicological effects of genetically modified wheat with TaDREB4 gene in female BALB/c mice. Methods Female mice weighing 18-22 g were divided into five groups (10 mice/group), which were set as negative control group, common wheat group, parental wheat group, genetically modified wheat group and cyclophosphamide positive control group, respectively. Mice in negative control group and positive control group were fed with AIN93G diet, mice in common wheat group, non-genetically modified parental wheat group and genetically modified wheat group were fed with feedstuffs added corresponding wheat (the proportion is 76%) for 30 days, then body weight, absolute and relative weight of spleen and thymus, white blood cell count, histological examination of immune organ, peripheral blood lymphocytes phenotyping, serum cytokine, serum immunoglobulin, antibody plaque-forming cell, serum half hemolysis value, mitogen-induced splenocyte proliferation, delayed-type hypersensitivity reaction and phagocytic activities of phagocytes were detected. Results No immunotoxicological effects related to the consumption of the genetically modified wheat were observed in BALB/c mice when compared with parental wheat group, common wheat group and negative control group. Conclusion From the immunotoxicological point of view, results from this study demonstrate that genetically modified wheat with TaDREB4 gene is as safe as the parental wheat.

  12. Mapping QTLs for Fusarium Head Blight Resistance in an Interspecific Wheat Population

    Science.gov (United States)

    Giancaspro, Angelica; Giove, Stefania L.; Zito, Daniela; Blanco, A.; Gadaleta, Agata

    2016-01-01

    Fusarium head blight (scab) is one of the most widespread and damaging diseases of wheat, causing grain yield and quality losses and production of harmful mycotoxins. Development of resistant varieties is hampered by lack of effective resistance sources in the tetraploid wheat primary gene pool. Here we dissected the genetic basis of resistance in a new durum wheat (Triticum turgidum ssp. durum) Recombinant inbred lines (RILs) population obtained by crossing an hexaploid resistant line and a durum susceptible cultivar. A total of 135 RILs were used for constituting a genetic linkage map and mapping loci for head blight incidence, severity, and disease-related plant morphological traits (plant height, spike compactness, and awn length). The new genetic map accounted for 4,366 single nucleotide polymorphism markers assembled in 52 linkage groups covering a total length of 4,227.37 cM. Major quantitative trait loci (QTL) for scab incidence and severity were mapped on chromosomes 2AS, 3AL, and 2AS, 2BS, 4BL, respectively. Plant height loci were identified on 3A, 3B, and 4B, while major QTL for ear compactness were found on 4A, 5A, 5B, 6A, and 7A. In this work, resistance to Fusarium was transferred from hexaploid to durum wheat, and correlations between the disease and morphological traits were assessed. PMID:27746787

  13. Herbicide resistance-endowing ACCase gene mutations in hexaploid wild oat (Avena fatua): insights into resistance evolution in a hexaploid species.

    Science.gov (United States)

    Yu, Q; Ahmad-Hamdani, M S; Han, H; Christoffers, M J; Powles, S B

    2013-03-01

    Many herbicide-resistant weed species are polyploids, but far too little about the evolution of resistance mutations in polyploids is understood. Hexaploid wild oat (Avena fatua) is a global crop weed and many populations have evolved herbicide resistance. We studied plastidic acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicide resistance in hexaploid wild oat and revealed that resistant individuals can express one, two or three different plastidic ACCase gene resistance mutations (Ile-1781-Leu, Asp-2078-Gly and Cys-2088-Arg). Using ACCase resistance mutations as molecular markers, combined with genetic, molecular and biochemical approaches, we found in individual resistant wild-oat plants that (1) up to three unlinked ACCase gene loci assort independently following Mendelian laws for disomic inheritance, (2) all three of these homoeologous ACCase genes were transcribed, with each able to carry its own mutation and (3) in a hexaploid background, each individual ACCase resistance mutation confers relatively low-level herbicide resistance, in contrast to high-level resistance conferred by the same mutations in unrelated diploid weed species of the Poaceae (grass) family. Low resistance conferred by individual ACCase resistance mutations is likely due to a dilution effect by susceptible ACCase expressed by homoeologs in hexaploid wild oat and/or differential expression of homoeologous ACCase gene copies. Thus, polyploidy in hexaploid wild oat may slow resistance evolution. Evidence of coexisting non-target-site resistance mechanisms among wild-oat populations was also revealed. In all, these results demonstrate that herbicide resistance and its evolution can be more complex in hexaploid wild oat than in unrelated diploid grass weeds. Our data provide a starting point for the daunting task of understanding resistance evolution in polyploids.

  14. SNP-revealed genetic diversity in wild emmer wheat correlates with ecological factors

    National Research Council Canada - National Science Library

    Ren, Jing; Chen, Liang; Sun, Daokun; You, Frank M; Wang, Jirui; Peng, Yunliang; Nevo, Eviatar; Beiles, Avigdor; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua

    2013-01-01

    .... However, few studies have been performed on the genetic structure and population divergence in wild emmer wheat using a large number of EST-related single nucleotide polymorphism (SNP) markers...

  15. Tetraploid wheat landraces in the Mediterranean basin: taxonomy, evolution and genetic diversity.

    Directory of Open Access Journals (Sweden)

    Hugo R Oliveira

    Full Text Available The geographic distribution of genetic diversity and the population structure of tetraploid wheat landraces in the Mediterranean basin has received relatively little attention. This is complicated by the lack of consensus concerning the taxonomy of tetraploid wheats and by unresolved questions regarding the domestication and spread of naked wheats. These knowledge gaps hinder crop diversity conservation efforts and plant breeding programmes. We investigated genetic diversity and population structure in tetraploid wheats (wild emmer, emmer, rivet and durum using nuclear and chloroplast simple sequence repeats, functional variations and insertion site-based polymorphisms. Emmer and wild emmer constitute a genetically distinct population from durum and rivet, the latter seeming to share a common gene pool. Our population structure and genetic diversity data suggest a dynamic history of introduction and extinction of genotypes in the Mediterranean fields.

  16. DIVERSITY OF EAR CHARACTERISTICS OF CROATIAN WHEAT GERMPLASM

    Directory of Open Access Journals (Sweden)

    Ivana Rukavina

    2013-06-01

    Full Text Available Morphological characteristics of ear were used for estimation of genetic diversity in 50 varieties of hexaploid winter wheat originated from Croatian breeding programs. Field trials were set at two locations in two vegetation years (2008/09 and 2009/10. Observations in field trials and laboratory were done on 13 ear characteristics used in DUS testing. Genetic diversity research of Croatian wheat germplasm according to ear morphological characteristics, showed a high level of dissimilarity (0.625 among the tested varieties. Varieties Super Žitarka and AFZG Karla are pointed out with highest coefficient of dissimilarity (0.94. Application of UPGMA method showed that all varieties in different groups had significant genetic diversity. On the basis of data analysis the most distant varieties with the best morphological characteristics of ear were determined and it will be help in the selection of new parent combinations in future breeding programs.

  17. Transgene x environment interactions in genetically modified wheat.

    Directory of Open Access Journals (Sweden)

    Simon L Zeller

    Full Text Available BACKGROUND: The introduction of transgenes into plants may cause unintended phenotypic effects which could have an impact on the plant itself and the environment. Little is published in the scientific literature about the interrelation of environmental factors and possible unintended effects in genetically modified (GM plants. METHODS AND FINDINGS: We studied transgenic bread wheat Triticum aestivum lines expressing the wheat Pm3b gene against the fungus powdery mildew Blumeria graminis f.sp. tritici. Four independent offspring pairs, each consisting of a GM line and its corresponding non-GM control line, were grown under different soil nutrient conditions and with and without fungicide treatment in the glasshouse. Furthermore, we performed a field experiment with a similar design to validate our glasshouse results. The transgene increased the resistance to powdery mildew in all environments. However, GM plants reacted sensitive to fungicide spraying in the glasshouse. Without fungicide treatment, in the glasshouse GM lines had increased vegetative biomass and seed number and a twofold yield compared with control lines. In the field these results were reversed. Fertilization generally increased GM/control differences in the glasshouse but not in the field. Two of four GM lines showed up to 56% yield reduction and a 40-fold increase of infection with ergot disease Claviceps purpurea compared with their control lines in the field experiment; one GM line was very similar to its control. CONCLUSIONS: Our results demonstrate that, depending on the insertion event, a particular transgene can have large effects on the entire phenotype of a plant and that these effects can sometimes be reversed when plants are moved from the glasshouse to the field. However, it remains unclear which mechanisms underlie these effects and how they may affect concepts in molecular plant breeding and plant evolutionary ecology.

  18. A SNP Genotyping Array for Hexaploid Oat

    Directory of Open Access Journals (Sweden)

    Nicholas A. Tinker

    2014-11-01

    Full Text Available Recognizing a need in cultivated hexaploid oat ( L. for a reliable set of reference single nucleotide polymorphisms (SNPs, we have developed a 6000 (6K BeadChip design containing 257 Infinium I and 5486 Infinium II designs corresponding to 5743 SNPs. Of those, 4975 SNPs yielded successful assays after array manufacturing. These SNPs were discovered based on a variety of bioinformatics pipelines in complementary DNA (cDNA and genomic DNA originating from 20 or more diverse oat cultivars. The array was validated in 1100 samples from six recombinant inbred line (RIL mapping populations and sets of diverse oat cultivars and breeding lines, and provided approximately 3500 discernible Mendelian polymorphisms. Here, we present an annotation of these SNPs, including methods of discovery, gene identification and orthology, population-genetic characteristics, and tentative positions on an oat consensus map. We also evaluate a new cluster-based method of calling SNPs. The SNP design sequences are made publicly available, and the full SNP genotyping platform is available for commercial purchase from an independent third party.

  19. An efficient and reproducible protocol for the production of salt tolerant transgenic wheat plants expressing the Arabidopsis AtNHX1 gene.

    Science.gov (United States)

    Moghaieb, Reda E A; Sharaf, Ahmed N; Soliman, Mohamed H; El-Arabi, Nagwa I; Momtaz, Osama A

    2014-01-01

    We present an efficient method for the production of transgenic salt tolerant hexaploid wheat plants expressing the Arabidopsis AtNHX1 gene. Wheat mature zygotic embryos were isolated from two hexaploid bread wheat (Triticum aestivum) cultivars (namely: Gemmeiza 9 and Gemmeiza 10) and were transformed with the A. tumefaciens LBA4404 harboring the pBI-121 vector containing the AtNHX1 gene. Transgenic wheat lines that express the gus intron was obtained and used as control. The results confirmed that npt-II gene could be transmitted and expressed in the T2 following 3:1 Mendelian segregation while the control plant couldn't. The data indicate that, the AtNHX1 gene was integrated in a stable manner into the wheat genome and the corresponding transcripts were expressed. The transformation efficiency was 5.7 and 7.5% for cultivars Gemmeiza 10 and Gemmeiza 9, respectively. A greenhouse experiment was conducted to investigate the effect of AtNHX1 gene in wheat salt tolerance. The transgenic wheat lines could maintain high growth rate under salt stress condition (350 mM NaCl) while the control plant couldn't. The results confirmed that Na(+)/H(+) antiporter gene AtNHX1 increased salt tolerance by increasing Na(+) accumulation and keeping K+/Na(+) balance. Thus, transgenic plants showed high tolerance to salt stress and can be considered as a new genetic resource in breeding programs.

  20. Genetic evidence for differential selection of grain and embryo weight during wheat evolution under domestication.

    Science.gov (United States)

    Golan, Guy; Oksenberg, Adi; Peleg, Zvi

    2015-09-01

    Wheat is one of the Neolithic founder crops domesticated ~10 500 years ago. Following the domestication episode, its evolution under domestication has resulted in various genetic modifications. Grain weight, embryo weight, and the interaction between those factors were examined among domesticated durum wheat and its direct progenitor, wild emmer wheat. Experimental data show that grain weight has increased over the course of wheat evolution without any parallel change in embryo weight, resulting in a significantly reduced (30%) embryo weight/grain weight ratio in domesticated wheat. The genetic factors associated with these modifications were further investigated using a population of recombinant inbred substitution lines that segregated for chromosome 2A. A cluster of loci affecting grain weight and shape was identified on the long arm of chromosome 2AL. Interestingly, a novel locus controlling embryo weight was mapped on chromosome 2AS, on which the wild emmer allele promotes heavier embryos and greater seedling vigour. To the best of our knowledge, this is the first report of a QTL for embryo weight in wheat. The results suggest a differential selection of grain and embryo weight during the evolution of domesticated wheat. It is argued that conscious selection by early farmers favouring larger grains and smaller embryos appears to have resulted in a significant change in endosperm weight/embryo weight ratio in the domesticated wheat. Exposing the genetic factors associated with endosperm and embryo size improves our understanding of the evolutionary dynamics of wheat under domestication and is likely to be useful for future wheat-breeding efforts.

  1. Identification of three wheat globulin genes by screening a Triticum aestivum BAC genomic library with cDNA from a diabetes-associated globulin

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    MacFarlane Amanda J

    2009-07-01

    Full Text Available Abstract Background Exposure to dietary wheat proteins in genetically susceptible individuals has been associated with increased risk for the development of Type 1 diabetes (T1D. Recently, a wheat protein encoded by cDNA WP5212 has been shown to be antigenic in mice, rats and humans with autoimmune T1D. To investigate the genomic origin of the identified wheat protein cDNA, a hexaploid wheat genomic library from Glenlea cultivar was screened. Results Three unique wheat globulin genes, Glo-3A, Glo3-B and Glo-3C, were identified. We describe the genomic structure of these genes and their expression pattern in wheat seeds. The Glo-3A gene shared 99% identity with the cDNA of WP5212 at the nucleotide and deduced amino acid level, indicating that we have identified the gene(s encoding wheat protein WP5212. Southern analysis revealed the presence of multiple copies of Glo-3-like sequences in all wheat samples, including hexaploid, tetraploid and diploid species wheat seed. Aleurone and embryo tissue specificity of WP5212 gene expression, suggested by promoter region analysis, which demonstrated an absence of endosperm specific cis elements, was confirmed by immunofluorescence microscopy using anti-WP5212 antibodies. Conclusion Taken together, the results indicate that a diverse group of globulins exists in wheat, some of which could be associated with the pathogenesis of T1D in some susceptible individuals. These data expand our knowledge of specific wheat globulins and will enable further elucidation of their role in wheat biology and human health.

  2. Divergence in homoeolog expression of the grain length-associated gene GASR7 during wheat allohexaploidization

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    Dongdong Zhang

    2015-02-01

    Full Text Available Hexaploid wheat has triplicated homoeologs for most of the genes that are located in subgenomes A, B, and D. GASR7, a member of the Snakin/GASA gene family, has been associated with grain length development in wheat. However, little is known about divergence of its homoeolog expression in wheat polyploids. We studied the expression patterns of the GASR7 homoeologs in immature seeds in a synthetic hexaploid wheat line whose kernels are slender like those of its maternal parent (Triticum turgidum, AABB, PI 94655 in contrast to the round seed shape of its paternal progenitor (Aegilops tauschii, DD, AS2404. We found that the B homoeolog of GASR7 was the main contributor to the total expression level of this gene in both the maternal tetraploid progenitor and the hexaploid progeny, whereas the expression levels of the A and D homoeologs were much lower. To understand possible mechanisms regulating different GASR7 homoeologs, we firstly analyzed the promoter sequences of three homoeologous genes and found that all of them contained gibberellic acid (GA response elements, with the TaGASR7B promoter (pTaGASR7B uniquely characterized by an additional predicted transcriptional enhancer. This was confirmed by the GA treatment of spikes where all three homoeologs were induced, with a much stronger response for TaGASR7B. McrBC enzyme assays showed that the methylation status at pTaGASR7D was increased during allohexaploidization, consistent with the repressed expression of TaGASR7D. For pTaGASR7A, the distribution of repetitive sequence-derived 24-nucleotide (nt small interfering RNAs (siRNAs were found which suggests possible epigenetic regulation because 24-nt siRNAs are known to mediate RNA-dependent DNA methylation. Our results thus indicate that both genetic and epigenetic mechanisms may be involved in the divergence of GASR7 homoeolog expression in polyploid wheat.

  3. [Genetics and Genomics of Wheat: Storage Proteins, Ecological Plasticity, and Immunity].

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    Novoselskaya-Dragovich, A Yu

    2015-05-01

    Recent advances in genetics and genetic research methods made it possible to explain the large polymorphism observed among storage proteins of wheat weevil (gliadins and glutenins), to determine their genetic control mechanism, and to develop a system for the identification of wheat genotypes on the basis of multiple allelism. This system has extremely high sensitivity and efficiency, which makes it possible to conduct studies to determine the purity and authenticity of wheat varieties, the dynamics of alleles diversity in time and space, the phylogenetics, etc., through the use of an extensive database on the allelic composition of gliadin loci. An investigation of the molecular structure of genes controlling the synthesis of storage proteins and their organization on chromosomes, as well as an analysis of wheat genome structure, revealed the molecular mechanisms of variability in the wheat genome and its reorganization in response to changes in environmental conditions and cultivation technologies. The multilevel genetic system of protection against pathogens and adverse environmental factors that developed in the course of wheat evolution continues to astound researchers' imagination with new resistance genes and novel types of antimicrobial peptides having been discovered and sequenced in recent years and the diversity of their structures and mechanisms of action in response to pathogens. An analysis of gene sequences involved in wheat domestication, namely, those that define ecological plasticity, i. e. the type of plant development (Vrn genes), and those responsible for spikelet traits (Q genes), which ensured the successful cultivation of wheat by humans, revealed that the basis for these features are specific mutations.

  4. In search of tetraploid wheat accessions reduced in celiac disease-related gluten epitopes.

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    van den Broeck, Hetty; Hongbing, Chen; Lacaze, Xavier; Dusautoir, Jean-Claude; Gilissen, Ludovicus; Smulders, Marinus; van der Meer, Ingrid

    2010-11-01

    Tetraploid wheat (durum wheat) is mainly used for the preparation of pasta. As a result of breeding, thousands of tetraploid wheat varieties exist, but also tetraploid landraces are still maintained and used for local food preparations. Gluten proteins present in wheat can induce celiac disease, a T-cell mediated auto-immune disorder, in genetically predisposed individuals after ingestion. Compared to hexaploid wheat, tetraploid wheat might be reduced in T-cell stimulatory epitopes that cause celiac disease because of the absence of the D-genome. We tested gluten protein extracts from 103 tetraploid wheat accessions (obtained from the Dutch CGN genebank and from the French INRA collection) including landraces, old, modern, and domesticated accessions of various tetraploid species and subspecies from many geographic origins. Those accessions were typed for their level of T-cell stimulatory epitopes by immunoblotting with monoclonal antibodies against the α-gliadin epitopes Glia-α9 and Glia-α20. In the first selection, we found 8 CGN and 6 INRA accessions with reduced epitope staining. Fourteen of the 57 CGN accessions turned out to be mixed with hexaploid wheat, and 5 out of the 8 selected CGN accessions were mixtures of two or more different gluten protein chemotypes. Based on single seed analysis, lines from two CGN accessions and one INRA accession were obtained with significantly reduced levels of Glia-α9 and Glia-α20 epitopes. These lines will be further tested for industrial quality and may contribute to the development of safer foods for celiac patients.

  5. Genetic variation of wheat streak mosaic virus in the United States Pacific Northwest.

    Science.gov (United States)

    Robinson, Megan D; Murray, Timothy D

    2013-01-01

    Wheat streak mosaic virus (WSMV), the cause of wheat streak mosaic, is a widespread and damaging pathogen of wheat. WSMV is not a chronic problem of annual wheat in the United States Pacific Northwest but could negatively affect the establishment of perennial wheat, which is being developed as an alternative to annual wheat to prevent soil erosion. Fifty local isolates of WSMV were collected from 2008 to 2010 near Lewiston, ID, Pullman, WA, and the United States Department of Agriculture Central Ferry Research Station, near Pomeroy, WA to determine the amount of genetic variation present in the region. The coat protein gene from each isolate was sequenced and the data subjected to four different methods of phylogenetic analyses. Two well-supported clades of WSMV were identified. Isolates in clade I share sequence similarity with isolates from Central Europe; this is the first report of isolates from Central Europe being reported in the United States. Isolates in clade II are similar to isolates originating from Australia, Argentina, and the American Pacific Northwest. Nine isolates showed evidence of recombination and the same two well-supported clades were observed when recombinant isolates were omitted from the analysis. More polymorphic sites, parsimony informative sites, and increased diversity were observed in clade II than clade I, suggesting more recent establishment of the virus in the latter. The observed diversity within both clades could make breeding for durable disease resistance in perennial wheat difficult if there is a differential response of WSMV resistance genes to isolates from different clades.

  6. 人工合成六倍体小麦醇溶蛋白遗传多样性分析%Gliadin Genetic Diversity in Artificially Synthesized Hexaploid Wheat

    Institute of Scientific and Technical Information of China (English)

    陈国跃; 李立会

    2006-01-01

    运用酸性聚丙烯酰胺凝胶电泳(A-PAGE)技术,对96份人工合成六倍体小麦的醇溶蛋白多样性进行了分析.结果显示,96份人工合成小麦中,共分离出65条不同的醇溶蛋白谱带,其中ω区22条,β和γ区各17条,α区9条,但各醇溶蛋白在电泳图谱中出现的频率差异较大,其变化范围为1.04%~91.67%.醇溶蛋白遗传多样性指数(H′)及多态性信息含量(PIC)分析结果显示,β、ω两个谱带区醇溶蛋白组成最为丰富,而α区最低;聚类分析结果显示,材料间的平均遗传距离为0.86,在遗传距离为0.83水平上, 96份材料被划分为4个主要类群,类群间的关系基本反映了合成双二倍体的亲缘关系.研究结果表明,人工合成六倍体小麦醇溶蛋白基因位点表现出广泛的遗传变异,具有丰富的遗传多样性.

  7. Genetic variability in common wheat germplasm based on coefficients of parentage

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    Fernanda Bered

    2002-01-01

    Full Text Available The characterization of genetic variability and an estimate of the genetic relationship among varieties are essential to any breeding program, because artificial crosses among less similar parents allow a larger segregation and the combination of different favorable alleles. Genetic variability can be evaluated in different ways, including the Coefficient of Parentage (COP, which estimates the probability of two alleles in two different individuals being identical by descent. In this study, we evaluated the degree of genetic relationship among 53 wheat genotypes, and identified the ancestor genotypes which contributed the most to the current wheat germplasm, as a prediction of the width of the genetic base of this cereal. The results revealed a mean COP of 0.07 and the formation of 22 similarity groups. The ancestor genotypes Ciano 67 and Mentana were those which contributed the most to the current wheat germplasm. According to the COP analyses, the genetic base of wheat rests on a small number of ancestral genotypes.

  8. Genetic rearrangements of six wheat-agropyron cristatum 6P addition lines revealed by molecular markers.

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    Haiming Han

    Full Text Available Agropyron cristatum (L. Gaertn. (2n = 4x = 28, PPPP not only is cultivated as pasture fodder but also could provide many desirable genes for wheat improvement. It is critical to obtain common wheat-A. cristatum alien disomic addition lines to locate the desired genes on the P genome chromosomes. Comparative analysis of the homoeologous relationships between the P genome chromosome and wheat genome chromosomes is a key step in transferring different desirable genes into common wheat and producing the desired alien translocation line while compensating for the loss of wheat chromatin. In this study, six common wheat-A. cristatum disomic addition lines were produced and analyzed by phenotypic examination, genomic in situ hybridization (GISH, SSR markers from the ABD genomes and STS markers from the P genome. Comparative maps, six in total, were generated and demonstrated that all six addition lines belonged to homoeologous group 6. However, chromosome 6P had undergone obvious rearrangements in different addition lines compared with the wheat chromosome, indicating that to obtain a genetic compensating alien translocation line, one should recombine alien chromosomal regions with homoeologous wheat chromosomes. Indeed, these addition lines were classified into four types based on the comparative mapping: 6PI, 6PII, 6PIII, and 6PIV. The different types of chromosome 6P possessed different desirable genes. For example, the 6PI type, containing three addition lines, carried genes conferring high numbers of kernels per spike and resistance to powdery mildew, important traits for wheat improvement. These results may prove valuable for promoting the development of conventional chromosome engineering techniques toward molecular chromosome engineering.

  9. Genetic Nature of Elemental Contents in Wheat Grains and Its Genomic Prediction: Toward the Effective Use of Wheat Landraces from Afghanistan

    Science.gov (United States)

    Yamaoka, Shuhei; Yoshimura, Kazusa; Kondou, Youichi; Onogi, Akio; Matsui, Minami; Iwata, Hiroyoshi; Ban, Tomohiro

    2017-01-01

    Profiling elemental contents in wheat grains and clarifying the underlying genetic systems are important for the breeding of biofortified crops. Our objective was to evaluate the genetic potential of 269 Afghan wheat landraces for increasing elemental contents in wheat cultivars. The contents of three major (Mg, K, and P) and three minor (Mn, Fe, and Zn) elements in wheat grains were measured by energy dispersive X-ray fluorescence spectrometry. Large variations in elemental contents were observed among landraces. Marker-based heritability estimates were low to moderate, suggesting that the elemental contents are complex quantitative traits. Genetic correlations between two locations (Japan and Afghanistan) and among the six elements were estimated using a multi-response Bayesian linear mixed model. Low-to-moderate genetic correlations were observed among major elements and among minor elements respectively, but not between major and minor elements. A single-response genome-wide association study detected only one significant marker, which was associated with Zn, suggesting it will be difficult to increase the elemental contents of wheat by conventional marker-assisted selection. Genomic predictions for major elemental contents were moderately or highly accurate, whereas those for minor elements were mostly low or moderate. Our results indicate genomic selection may be useful for the genetic improvement of elemental contents in wheat. PMID:28072876

  10. Genomics as the key to unlocking the polyploid potential of wheat.

    Science.gov (United States)

    Borrill, Philippa; Adamski, Nikolai; Uauy, Cristobal

    2015-12-01

    Polyploidy has played a central role in plant genome evolution and in the formation of new species such as tetraploid pasta wheat and hexaploid bread wheat. Until recently, the high sequence conservation between homoeologous genes, together with the large genome size of polyploid wheat, had hindered genomic analyses in this important crop species. In the past 5 yr, however, the advent of next-generation sequencing has radically changed the wheat genomics landscape. Here, we review a series of advances in genomic resources and tools for functional genomics that are shifting the paradigm of what is possible in wheat molecular genetics and breeding. We discuss how understanding the relationship between homoeologues can inform approaches to modulate the response of quantitative traits in polyploid wheat; we also argue that functional redundancy has 'locked up' a wide range of phenotypic variation in wheat. We explore how genomics provides key tools to inform targeted manipulation of multiple homoeologues, thereby allowing researchers and plant breeders to unlock the full polyploid potential of wheat.

  11. [Development of commercially valuable traits in hexaploid triticale lines with Aegilops introgressions as dependent on the genome composition].

    Science.gov (United States)

    Adonina, I G; Orlovskaia, O A; Tereshchenko, O Yu; Koren', L V; Khotyleva, L V; Shumnyĭ, V K; Salina, E A

    2011-04-01

    Introgressive hybridization is an efficient means to improve the genetic diversity of cultivated cereals, including triticale. To identify the triticale lines with Aegilops introgressions, genotyping was carried out with ten lines obtained by crossing hexaploid triticale with genome-substitution forms of the common wheat cultivar Avrora: Avrolata (AABBUU), Avrodes (AABBSS), and Avrotika (AABBTT). The genome composition of the triticale lines was studied by in situ hybridization, and recombination events involving Aegilops and/or common wheat chromosomes were assumed for nine out of the ten lines. Translocations involving rye chromosomes were not observed. Substitutions for rye chromosomes were detected in two lines resulting from crosses with Avrolata. Genomic in situ hybridization (GISH) with Ae. umbellulata DNA and molecular genetic analysis showed that chromosome 1R was substituted with Ae. umbellulata chromosome 1U in one of the lines and that 2R(2U) substitution took place in the other line. Fluorescence in situ hybridization (FISH) with the Spelt 1 and pSc119.2 probes revealed a translocation from Ae. speltoides to the long arm of chromosome 1B in one of the two lines resulting from crosses with Avrodes and a translocation in the long arm of chromosome 7B in the other line. In addition, the pSc119.2 probe revealed chromosome 1B rearrangements in four lines resulting from crosses with Avrolata and in a line resulting from crosses with Avrotika. The lines were tested for main productivity parameters. A negative effect on all productivity parameters was demonstrated for Ae. umbellulata chromosome 2U. The overwinter survival in all of the lines was similar to or even higher than in the original triticale cultivars. A substantial increase in winter resistance as compared with the parental cultivar was observed for the line carrying the T7BS-7SL translocation. The line with the 1R(1U) chromosome substitution seemed promising for the baking properties of triticale.

  12. Genetics of end-use quality differences between a modern and historical spring wheat

    Science.gov (United States)

    The goal of this project was to determine the genetic basis for quality differences between a modern semidwarf spring wheat cultivar ‘McNeal’ and a historically important standard height cultivar ‘Thatcher’. McNeal is higher yielding with lower grain protein than Thatcher, yet has stronger gluten p...

  13. Hypersensitive response-like reaction is associated with hybrid necrosis in interspecific crosses between tetraploid wheat and Aegilops tauschii coss.

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    Nobuyuki Mizuno

    Full Text Available BACKGROUND: Hybrid speciation is classified into homoploid and polyploid based on ploidy level. Common wheat is an allohexaploid species that originated from a naturally occurring interploidy cross between tetraploid wheat and diploid wild wheat Aegilops tauschii Coss. Aegilops tauschii provides wide naturally occurring genetic variation. Sometimes its triploid hybrids with tetraploid wheat show the following four types of hybrid growth abnormalities: types II and III hybrid necrosis, hybrid chlorosis, and severe growth abortion. The growth abnormalities in the triploid hybrids could act as postzygotic hybridization barriers to prevent formation of hexaploid wheat. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report on the geographical and phylogenetic distribution of Ae. tauschii accessions inducing the hybrid growth abnormalities and showed that they are widely distributed across growth habitats in Ae. tauschii. Molecular and cytological characterization of the type III necrosis phenotype was performed. The hybrid abnormality causing accessions were widely distributed across growth habitats in Ae. tauschii. Transcriptome analysis showed that a number of defense-related genes such as pathogenesis-related genes were highly up-regulated in the type III necrosis lines. Transmission electron microscope observation revealed that cell death occurred accompanied by generation of reactive oxygen species in leaves undergoing type III necrosis. The reduction of photosynthetic activity occurred prior to the appearance of necrotic symptoms on the leaves exhibiting hybrid necrosis. CONCLUSIONS/SIGNIFICANCE: Taking these results together strongly suggests that an autoimmune response might be triggered by intergenomic incompatibility between the tetraploid wheat and Ae. tauschii genomes in type III necrosis, and that genetically programmed cell death could be regarded as a hypersensitive response-like cell death similar to that observed in Arabidopsis

  14. The effect of wheat-rye translocation 1BL.1RS in a different quality genetic background on biological traits in wheat

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    Dimitrijević Miodrag

    2008-01-01

    Full Text Available A sample of 139 varieties of common wheat (Triticum aestivum L., predominantly Serbian winter wheat varieties originated in the Institute of Field and Vegetable Crops in Novi Sad, has been examined for presence of 1BL/1RS wheat-rye translocation. Two genotype groups consisted of varieties possessing and lacking the translocation have been compared. Stem rust, leaf rust, powdery mildew as well as, winter hardiness were studied. The influence of 1BL/1RS translocation was also studied in a light of wheat seed storage protein (glutenin and gliadin genetic background composition. Genotypes having the translocation appeared to be more tolerant to stem rust, and leaf rust, but more susceptible to powdery mildew. These effects were slightly modified depending on the examined genetic background, but the effect of the rye 1RS translocated chromosome arm was the main cause for the observed differences.

  15. Population genetic analysis and trichothecene profiling of Fusarium graminearum from wheat in Uruguay.

    Science.gov (United States)

    Pan, D; Mionetto, A; Calero, N; Reynoso, M M; Torres, A; Bettucci, L

    2016-03-11

    Fusarium graminearum sensu stricto (F. graminearum s.s.) is the major causal agent of Fusarium head blight of wheat worldwide, and contaminates grains with trichothecene mycotoxins that cause serious threats to food safety and animal health. An important aspect of managing this pathogen and reducing mycotoxin contamination of wheat is knowledge regarding its population genetics. Therefore, isolates of F. graminearum s.s. from the major wheat-growing region of Uruguay were analyzed by amplified fragment length polymorphism assays, PCR genotyping, and chemical analysis of trichothecene production. Of the 102 isolates identified as having the 15-ADON genotype via PCR genotyping, all were DON producers, but only 41 strains were also 15-ADON producers, as determined by chemical analysis. The populations were genotypically diverse but genetically similar, with significant genetic exchange occurring between them. Analysis of molecular variance indicated that most of the genetic variability resulted from differences between isolates within populations. Multilocus linkage disequilibrium analysis suggested that the isolates had a panmictic population genetic structure and that there is significant recombination occurs in F. graminearum s.s. In conclusion, tour findings provide the first detailed description of the genetic structure and trichothecene production of populations of F. graminearum s.s. from Uruguay, and expands our understanding of the agroecology of F. graminearum and of the correlation between genotypes and trichothecene chemotypes.

  16. A Catalog of Regulatory Sequences for Trait Gene for the Genome Editing of Wheat

    Science.gov (United States)

    Makai, Szabolcs; Tamás, László; Juhász, Angéla

    2016-01-01

    Wheat has been cultivated for 10000 years and ever since the origin of hexaploid wheat it has been exempt from natural selection. Instead, it was under the constant selective pressure of human agriculture from harvest to sowing during every year, producing a vast array of varieties. Wheat has been adopted globally, accumulating variation for genes involved in yield traits, environmental adaptation and resistance. However, one small but important part of the wheat genome has hardly changed: the regulatory regions of both the x- and y-type high molecular weight glutenin subunit (HMW-GS) genes, which are alone responsible for approximately 12% of the grain protein content. The phylogeny of the HMW-GS regulatory regions of the Triticeae demonstrates that a genetic bottleneck may have led to its decreased diversity during domestication and the subsequent cultivation. It has also highlighted the fact that the wild relatives of wheat may offer an unexploited genetic resource for the regulatory region of these genes. Significant research efforts have been made in the public sector and by international agencies, using wild crosses to exploit the available genetic variation, and as a result synthetic hexaploids are now being utilized by a number of breeding companies. However, a newly emerging tool of genome editing provides significantly improved efficiency in exploiting the natural variation in HMW-GS genes and incorporating this into elite cultivars and breeding lines. Recent advancement in the understanding of the regulation of these genes underlines the needs for an overview of the regulatory elements for genome editing purposes. PMID:27766102

  17. Ancient DNA from 8400 Year-Old Catalhoyuk Wheat: Implications for the Origin of Neolithic Agriculture.

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    Hatice Bilgic

    Full Text Available Human history was transformed with the advent of agriculture in the Fertile Crescent with wheat as one of the founding crops. Although the Fertile Crescent is renowned as the center of wheat domestication, archaeological studies have shown the crucial involvement of Çatalhöyük in this process. This site first gained attention during the 1961-65 excavations due to the recovery of primitive hexaploid wheat. However, despite the seeds being well preserved, a detailed archaeobotanical description of the samples is missing. In this article, we report on the DNA isolation, amplification and sequencing of ancient DNA of charred wheat grains from Çatalhöyük and other Turkish archaeological sites and the comparison of these wheat grains with contemporary wheat species including T. monococcum, T. dicoccum, T. dicoccoides, T. durum and T. aestivum at HMW glutenin protein loci. These ancient samples represent the oldest wheat sample sequenced to date and the first ancient wheat sample from the Middle East. Remarkably, the sequence analysis of the short DNA fragments preserved in seeds that are approximately 8400 years old showed that the Çatalhöyük wheat stock contained hexaploid wheat, which is similar to contemporary hexaploid wheat species including both naked (T. aestivum and hulled (T. spelta wheat. This suggests an early transitory state of hexaploid wheat agriculture from the Fertile Crescent towards Europe spanning present-day Turkey.

  18. Accumulation of Dry Matter, Canopy Structure and Photosynthesis of Synthetic Hexaploid Wheat-Derived High-Yielding Varieties Grown in Sichuan Basin, China%人工合成小麦衍生品种的物质积累、冠层结构及群体光合特性

    Institute of Scientific and Technical Information of China (English)

    汤永禄; 李朝苏; 吴晓丽; 吴春; 杨武云; 黄钢; 马孝玲

    2014-01-01

    [Objective]Synthetic hexaploid wheat (SHW) has increasingly reported having outstanding tolerance to abiotic and biotic stresses and a great potential in improving wheat yield. The objective of this study was to evaluate the yield performance, accumulation and portioning of dry matter, leaf and canopy photosynthesis of SHW-derived varieties released nationally. [Method]Three SHW-derived varieties (SDVs) were compared with 5 local elite non-synthetic derived varieties (NSVs) in field experiments conducted during the 2010 to 2011, 2011 to 2012, and 2012 to 2013 crop seasons at Guanghan county of Sichuan province, China.[Result]Combined analysis of variance showed that a significant difference in grain yield and dry matter-related traits was detected among genotypes and experimental years, and year effect was higher than both genotype effect and genotype by year interaction. Average grain yield,grain number/m2, and thousand kernel weight of SDVs over three years were 9 163 kg·hm-2, 19133, and 47.5 g, respectively, which were 12.31%, 5.31%, and 7.95%higher than NSVs. SDVs had higher rate of dry matter accumulation, especially at earlier growth stages as showed that the rates of dry matter accumulation during the periods from sowing to tillering and from tillering to jointing were 18.66%and 20.46%higher than NSVs, and consequently higher amount of accumulated dry matter at major growth stages, higher translocated dry matter and contribution to grain than NSVs. With no significant difference in dry matter distribution amongst organs of spike-bearing shoot between SDVs and NSVs at flowering stage, while the proportion of dry matter to leaf, rhachis&glume, and stem&sheath of SDVs was lower than that of NSVs by 15.46%, 7.14%, and 2.65%, respectively. SDVs showed a relative compact type with medium to high plight, shorter but wider upper leaves compared to NSVs, and no significant difference in canopy analyzer parameters between varieties tested at anthesis but SDVs had

  19. Evaluation of Genetic Diversity of Sichuan Common Wheat Landraces in China by SSR Markers

    Institute of Scientific and Technical Information of China (English)

    LI Wei; BIAN Chun-mei; WEI Yu-ming; LIU An-jun; CHEN Guo-yue; PU Zhi-en; LIU Ya-xi; ZHENG You-liang

    2013-01-01

    Genetic diversity of 62 Sichuan wheat landraces accessions of China was investigated by agronomic traits and SSR markers. The landrace population showed the characters of higher tiller capability and more kernels/spike, especially tiller no./plant of six accessions was over 40 and kernels/spike of three accessions was more than 70. A total of 547 alleles in 124 polymorphic loci were detected with an average of 4.76 alleles per locus by 114 SSR markers. Parameters analysis indicated that the genetic diversity ranked as genome A>genome B>genome D, and the homoeologous groups ranked as 5>4>3>1>2>7>6 based on genetic richness (Ri). Furthermore, chromosomes 2A, 1B and 3D had more diversity than that of chromosomes 4A, 7A and 6B. The variation of SSR loci on chromosomes 1B, 2A, 2D, 3B, and 4B implied that, in the past, different selective pressures might have acted on different chromosome regions of these landraces. Our results suggested that Sichuan common wheat landraces is a useful genetic resource for genetic research and wheat improvement.

  20. Allelic Variation and Genetic Diversity at Glu-1 Loci in Chinese Wheat (Triticum aestivum L.) Germplasms

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue-yong; PANG Bin-shuang; YOU Guang-xia; WANG Lan-fen; JIA Ji-zeng; DONG Yu-chen

    2002-01-01

    Wheat processing quality is greatly influenced by the seed proteins especially the high molecular weight glutenin subunit (HMW-GS) components, the low molecular weight glutenin subunit (LMW-GS) components and gliadin components. Genes encoding the HMW-GS and LMW-GS components were located on the long arms and the short arms of homoeologous group 1 chromosomes, respectively. HMW-GS components in 5 129 accessions of wheat germplasms were analyzed systematically, including 3 459 landraces and 1 670 modern varieties. These accessions were chosen as candidate core collections to represent the genetic diversity of Chinese common wheat (Triticum aestivum ) germplasms documented and conserved in the National Gene Bank. These candidate core collections covered the 10 wheat production regions in China. In the whole country, the dominating alleles at the three loci are Glu-A1b (null), Glu-B1b (7 + 8), and Glu- D1a (2 + 12), respectively. The obvious difference between the land race and the modern variety is the dramatic frequency increase of alleles Glu-A1a (1), Glu-B1c (7 + 9), Glu-B1h (14 + 15), Glu-D1d (5 + 10) and allele cording 5 + 12 subunits in the later ones. In the whole view, there is minor difference on the genetic(allelic)richness between the landrace and the modern variety at Glu-1, which is 28 and 30 respectively. However, the genetic dispersion index (Simpson index) based on allelic variation and frequencies at Glu-A1, Glu-B1 and Glu-D1 suggested that the modern varieties had much higher genetic diversity than the landraces. This revealed that various isolating mechanisms (such as auto-gamous nature, low migration because of undeveloped transposition system) limited the gene flow and exchange between populations of the landraces, which led up to some genotypes localized in very small areas. Modern breeding has strongly promoted gene exchanges and introgression between populations and previous isolated populations. In the three loci, Glu-B1 has the highest

  1. Relationships between Genetic Diversity and Fusarium Toxin Profiles of Winter Wheat Cultivars

    Science.gov (United States)

    Góral, Tomasz; Stuper-Szablewska, Kinga; Buśko, Maciej; Boczkowska, Maja; Walentyn-Góral, Dorota; Wiśniewska, Halina; Perkowski, Juliusz

    2015-01-01

    Fusarium head blight is one of the most important and most common diseases of winter wheat. In order to better understanding this disease and to assess the correlations between different factors, 30 cultivars of this cereal were evaluated in a two-year period. Fusarium head blight resistance was evaluated and the concentration of trichothecene mycotoxins was analysed. Grain samples originated from plants inoculated with Fusarium culmorum and naturally infected with Fusarium species. The genetic distance between the tested cultivars was determined and data were analysed using multivariate data analysis methods. Genetic dissimilarity of wheat cultivars ranged between 0.06 and 0.78. They were grouped into three distinct groups after cluster analysis of genetic distance. Wheat cultivars differed in resistance to spike and kernel infection and in resistance to spread of Fusarium within a spike (type II). Only B trichothecenes (deoxynivalenol, 3-acetyldeoxynivalenol and nivalenol) produced by F. culmorum in grain samples from inoculated plots were present. In control samples trichothecenes of groups A (H-2 toxin, T-2 toxin, T-2 tetraol, T-2 triol, scirpentriol, diacetoxyscirpenol) and B were detected. On the basis of Fusarium head blight assessment and analysis of trichothecene concentration in the grain relationships between morphological characters, Fusarium head blight resistance and mycotoxins in grain of wheat cultivars were examined. The results were used to create of matrices of distance between cultivars – for trichothecene concentration in inoculated and naturally infected grain as well as for FHB resistance Correlations between genetic distance versus resistance/mycotoxin profiles were calculated using the Mantel test. A highly significant correlation between genetic distance and mycotoxin distance was found for the samples inoculated with Fusarium culmorum. Significant but weak relationships were found between genetic distance matrix and FHB resistance or

  2. A Whole Genome DArTseq and SNP Analysis for Genetic Diversity Assessment in Durum Wheat from Central Fertile Crescent

    Science.gov (United States)

    Shahid, Muhammad Qasim; Çiftçi, Vahdettin; E. Sáenz de Miera, Luis; Aasim, Muhammad; Nadeem, Muhammad Azhar; Aktaş, Husnu; Özkan, Hakan; Hatipoğlu, Rüştü

    2017-01-01

    Until now, little attention has been paid to the geographic distribution and evaluation of genetic diversity of durum wheat from the Central Fertile Crescent (modern-day Turkey and Syria). Turkey and Syria are considered as primary centers of wheat diversity, and thousands of locally adapted wheat landraces are still present in the farmers’ small fields. We planned this study to evaluate the genetic diversity of durum wheat landraces from the Central Fertile Crescent by genotyping based on DArTseq and SNP analysis. A total of 39,568 DArTseq and 20,661 SNP markers were used to characterize the genetic characteristic of 91 durum wheat land races. Clustering based on Neighbor joining analysis, principal coordinate as well as Bayesian model implemented in structure, clearly showed that the grouping pattern is not associated with the geographical distribution of the durum wheat due to the mixing of the Turkish and Syrian landraces. Significant correlation between DArTseq and SNP markers was observed in the Mantel test. However, we detected a non-significant relationship between geographical coordinates and DArTseq (r = -0.085) and SNP (r = -0.039) loci. These results showed that unconscious farmer selection and lack of the commercial varieties might have resulted in the exchange of genetic material and this was apparent in the genetic structure of durum wheat in Turkey and Syria. The genomic characterization presented here is an essential step towards a future exploitation of the available durum wheat genetic resources in genomic and breeding programs. The results of this study have also depicted a clear insight about the genetic diversity of wheat accessions from the Central Fertile Crescent. PMID:28099442

  3. Acc homoeoloci and the evolution of wheat genomes

    Science.gov (United States)

    We analyzed the DNA sequences of BACs from many wheat libraries containing the Acc-1 and Acc-2 loci, encoding the plastid and cytosolic forms of the enzyme acetyl-CoA carboxylase, to gain understanding of the evolution of these genes and the origin of the three genomes in modern hexaploid wheat. Mor...

  4. Genetic Diversity in Fusarium graminearum from a Major Wheat-Producing Region of Argentina

    Directory of Open Access Journals (Sweden)

    Giuseppina Mulè

    2011-10-01

    Full Text Available The Fusarium graminearum species complex (FGSC is a group of mycotoxigenic fungi that are the primary cause of Fusarium head blight (FHB of wheat worldwide. The distribution, frequency of occurrence, and genetic diversity of FGSC species in cereal crops in South America is not well understood compared to some regions of Asia, Europe and North America. Therefore, we examined the frequency and genetic diversity of a collection of 183 FGSC isolates recovered from wheat grown during multiple growing seasons and across a large area of eastern Argentina, a major wheat producing region in South America. Sequence analysis of the translation elongation factor 1−α and β-tubulin genes as well as Amplified Fragment Length Polymorphism (AFLP analyses indicated that all isolates were the FGSC species F. graminearum sensu stricto. AFLP analysis resolved at least 11 subgroups, and all the isolates represented different AFLP haplotypes. AFLP profile and geographic origin were not correlated. Previously obtained trichothecene production profiles of the isolates revealed that the 15-acetyldeoxynivalenol chemotype was slightly more frequent than the 3-acetyldeoxynivalenol chemotype among the isolates. These data extend the current understanding of FGSC diversity and provide further evidence that F. graminearum sensu stricto is the predominant cause of FHB in the temperate main wheat-growing area of Argentina. Moreover, two isolates of F. crookwellense and four of F. pseudograminearum were also recovered from wheat samples and sequenced. The results also suggest that, although F. graminearum sensu stricto was the only FGSC species recovered in this study, the high level of genetic diversity within this species should be considered in plant breeding efforts and development of other disease management strategies aimed at reducing FHB.

  5. Systematic Investigation of FLOWERING LOCUS T-Like Poaceae Gene Families Identifies the Short-Day Expressed Flowering Pathway Gene, TaFT3 in Wheat (Triticum aestivum L.)

    Science.gov (United States)

    Halliwell, Joanna; Borrill, Philippa; Gordon, Anna; Kowalczyk, Radoslaw; Pagano, Marina L.; Saccomanno, Benedetta; Bentley, Alison R.; Uauy, Cristobal; Cockram, James

    2016-01-01

    To date, a small number of major flowering time loci have been identified in the related Triticeae crops, bread wheat (Triticum aestivum), durum wheat (T. durum), and barley (Hordeum vulgare). Natural genetic variants at these loci result in major phenotypic changes which have adapted crops to the novel environments encountered during the spread of agriculture. The polyploid nature of bread and durum wheat means that major flowering time loci in which recessive alleles confer adaptive advantage in related diploid species have not been readily identified. One such example is the PPD-H2 flowering time locus encoded by FLOWERING LOCUS T 3 (HvFT3) in the diploid crop barley, for which recessive mutant alleles confer delayed flowering under short day (SD) photoperiods. In autumn-sown barley, such alleles aid the repression of flowering over the winter, which help prevent the development of cold-sensitive floral organs until the onset of inductive long day (LD) photoperiods the following spring. While the identification of orthologous loci in wheat could provide breeders with alternative mechanisms to fine tune flowering time, systematic identification of wheat orthologs of HvFT3 has not been reported. Here, we characterize the FT gene families in six Poaceae species, identifying novel members in all taxa investigated, as well as FT3 homoeologs from the A, B and D genomes of hexaploid (TaFT3) and tetraploid wheat. Sequence analysis shows TaFT3 homoeologs display high similarity to the HvFT3 coding region (95–96%) and predicted protein (96–97%), with conservation of intron/exon structure across the five cereal species investigated. Genetic mapping and comparative analyses in hexaploid and tetraploid wheat find TaFT3 homoeologs map to the long arms of the group 1 chromosomes, collinear to HvFT3 in barley and FT3 orthologs in rice, foxtail millet and brachypodium. Genome-specific expression analyses show FT3 homoeologs in tetraploid and hexaploid wheat are upregulated

  6. Quantitative Trait Loci Associated with Micronutrient Concentrations in Two Recombinant Inbred Wheat Lines

    Institute of Scientific and Technical Information of China (English)

    PU Zhi-en; WEI Yu-ming; ZHENG You-liang; YU Ma; HE Qiu-yi; CHEN Guo-yue; WANG Ji-rui; LIU Ya-xi; JIANG Qian-tao; LI Wei; DAI Shou-fen

    2014-01-01

    Micronutrient malnutrition affects over three billion people worldwide, especially women and children in developing countries. Increasing the bioavailable concentrations of essential elements in the edible portions of crops is an effective resolution to address this issue. To determine the genetic factors controlling micronutrient concentration in wheat, the quantitative trait locus (QTL) analysis for iron, zinc, copper, manganese, and selenium concentrations in two recombinant inbred line populations was performed. In all, 39 QTLs for ifve micronutrient concentrations were identiifed in this study. Of these, 22 alleles from synthetic wheat SHW-L1 and seven alleles from the progeny line of the synthetic wheat Chuanmai 42 showed an increase in micronutrient concentrations. Five QTLs on chromosomes 2A, 3D, 4D, and 5B found in both the populations showed signiifcant phenotypic variation for 2-3 micronutrient concentrations. Our results might help understand the genetic control of micronutrient concentration and allow the utilization of genetic resources of synthetic hexaploid wheat for improving micronutrient efifciency of cultivated wheat by using molecular marker-assisted selection.

  7. Morphological, cytological and molecular analyses of a synthetic hexaploid derived from an interspecific hybrid between Gossypium hirsutum and Gossypium anomalum

    Directory of Open Access Journals (Sweden)

    Xia Zhang

    2014-10-01

    Full Text Available Gossypium anomalum represents an inestimable source of genes that could potentially be transferred into the gene pool of cultivated cotton. To resolve interspecific hybrid sterility problems, we previously treated triploid hybrids derived from a cross between Gossypium hirsutum and G. anomalum with 0.15% colchicine and obtained a putative fertile hexaploid. In this study, we performed morphological, molecular and cytological analyses to assess the hybridity and doubled status of putative interspecific hybrid plants. Most of the morphological characteristics of the putative hexaploid plants were intermediate between G. hirsutum and G. anomalum. Analysis of mitotic metaphase plates revealed 78 chromosomes, confirming the doubled hybrid status of the hexaploid. Genome-wide molecular analysis with different genome-derived SSR markers revealed a high level of polymorphism (96.6% between G. hirsutum and G. anomalum. The marker transferability rate from other species to G. anomalum was as high as 98.0%. The high percentage of polymorphic markers with additive banding profiles in the hexaploid indicates the hybridity of the hexaploid on a genome-wide level. A-genome-derived markers were more powerful for distinguishing the genomic differences between G. hirsutum and G. anomalum than D-genome-derived markers. This study demonstrates the hybridity and chromosomally doubled status of the (G. anomalum × G. hirsutum2 hexaploid using morphological, cytological and molecular marker methods. The informative SSR markers screened in the study will be useful marker resources for tracking the flow of G. anomalum genetic material among progenies that may be produced by future backcrosses to G. hirsutum.

  8. Morphological, cytological and molecular analyses of a synthetic hexaploid derived from an interspecific hybrid between Gossypium hirsutum and Gossypium anomalum

    Institute of Scientific and Technical Information of China (English)

    Xia; Zhang; Caijiao; Zhai; Linchi; He; Qi; Guo; Xianggui; Zhang; Peng; Xu; Hongmei; Su; Yuanyong; Gong; Wanchao; Ni; Xinlian; Shen

    2014-01-01

    Gossypium anomalum represents an inestimable source of genes that could potentially be transferred into the gene pool of cultivated cotton. To resolve interspecific hybrid sterility problems, we previously treated triploid hybrids derived from a cross between Gossypium hirsutum and G. anomalum with 0.15% colchicine and obtained a putative fertile hexaploid. In this study, we performed morphological, molecular and cytological analyses to assess the hybridity and doubled status of putative interspecific hybrid plants. Most of the morphological characteristics of the putative hexaploid plants were intermediate between G. hirsutum and G.anomalum. Analysis of mitotic metaphase plates revealed 78 chromosomes, confirming the doubled hybrid status of the hexaploid. Genome-wide molecular analysis with different genome-derived SSR markers revealed a high level of polymorphism(96.6%) between G. hirsutum and G. anomalum. The marker transferability rate from other species to G. anomalum was as high as 98.0%. The high percentage of polymorphic markers with additive banding profiles in the hexaploid indicates the hybridity of the hexaploid on a genome-wide level. A-genome-derived markers were more powerful for distinguishing the genomic differences between G. hirsutum and G. anomalum than D-genome-derived markers. This study demonstrates the hybridity and chromosomally doubled status of the(G. anomalum × G. hirsutum)2hexaploid using morphological, cytological and molecular marker methods. The informative SSR markers screened in the study will be useful marker resources for tracking the flow of G. anomalum genetic material among progenies that may be produced by future backcrosses to G. hirsutum.

  9. Genetic diversity in Chinese modern wheat varieties revealed by microsatellite markers

    Institute of Scientific and Technical Information of China (English)

    HAO; Chenyang; WANG; Lanfen; ZHANG; Xueyong; YOU; Guangxia; DONG; Yushen; JIA; Jizeng; LIU; Xu; SHANG; Xunwu; LIU; Sancai; CAO; Yongsheng

    2006-01-01

    Genetic diversity of 1680 modern varieties in Chinese candidate core collections was analyzed at 78 SSR loci by fluorescence detection system. A total of 1336 alleles were detected, of which 1253 alleles could be annotated into 71 loci. For these 71 loci, the alleles ranged from 4 to 44 with an average of 17.6, and the PIC values changed from 0.19 to 0.89 with an average of 0.69. (1) In the three genomes of wheat, the average genetic richness was B>A>D, and the genetic diversity indexes were B>D>A. (2) Among the seven homoeologous groups, the average genetic richness was 2=7>3>4>6>5>1, and the genetic diversity indexes were 7>3>2>4>6>5>1. As a whole, group 7 possessed the highest genetic diversity, while groups 1 and 5 were the lowest. (3) In the 21 wheat chromosomes, 7A, 3B and 2D possessed much higher genetic diversity, while 2A, 1B, 4D, 5D and 1D were the lowest. (4) The highest average genetic diversity index existed in varieties bred in the 1950s, and then it declined continually. However, the change tendency of genetic diversity among decades was not greatly sharp. This was further illustrated by changes of the average genetic distance between varieties. In the 1950s it was the largest (0.731). Since the 1960s, it has decreased gradually (0.711, 0.706, 0.696, 0.695). The genetic base of modern varieties is becoming narrower and narrower. This should be given enough attention by breeders and policy makers.

  10. Exploiting genetic diversity from landraces in wheat breeding for adaptation to climate change.

    Science.gov (United States)

    Lopes, Marta S; El-Basyoni, Ibrahim; Baenziger, Peter S; Singh, Sukhwinder; Royo, Conxita; Ozbek, Kursad; Aktas, Husnu; Ozer, Emel; Ozdemir, Fatih; Manickavelu, Alagu; Ban, Tomohiro; Vikram, Prashant

    2015-06-01

    Climate change has generated unpredictability in the timing and amount of rain, as well as extreme heat and cold spells that have affected grain yields worldwide and threaten food security. Sources of specific adaptation related to drought and heat, as well as associated breeding of genetic traits, will contribute to maintaining grain yields in dry and warm years. Increased crop photosynthesis and biomass have been achieved particularly through disease resistance and healthy leaves. Similarly, sources of drought and heat adaptation through extended photosynthesis and increased biomass would also greatly benefit crop improvement. Wheat landraces have been cultivated for thousands of years under the most extreme environmental conditions. They have also been cultivated in lower input farming systems for which adaptation traits, particularly those that increase the duration of photosynthesis, have been conserved. Landraces are a valuable source of genetic diversity and specific adaptation to local environmental conditions according to their place of origin. Evidence supports the hypothesis that landraces can provide sources of increased biomass and thousand kernel weight, both important traits for adaptation to tolerate drought and heat. Evaluation of wheat landraces stored in gene banks with highly beneficial untapped diversity and sources of stress adaptation, once characterized, should also be used for wheat improvement. Unified development of databases and promotion of data sharing among physiologists, pathologists, wheat quality scientists, national programmes, and breeders will greatly benefit wheat improvement for adaptation to climate change worldwide. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Assessment of heritability and genetic advance for agronomic traits in durum wheat (Triticum durum Desf.

    Directory of Open Access Journals (Sweden)

    HASSAN NIKKHAHKOUCHAKSARAEI

    2017-09-01

    Full Text Available In order to evaluate the amount of heritability for desirable agronomic characteristics and the genetic progress associated with grain yield of durum wheat (Triticum durum Desf., a split plot experiment was carried out with four replications during three cropping seasons (2009-2012. Three sowing dates (as environmental factor and six durum wheat varieties (as genotypic factor were considered as main and sub factors respectively. Analysis of variance showed interaction effects between genotypes and environments in days to ripening, plant height, spike length, number of grains per spike, number of spikes per unit area, grain mass and grain yield. The grain yield showed the highest positive correlation with number of grains per spike also grain mass (91 % and 85 %, respectively. A relatively high heritability of these traits (82.1 % and 82.2 %, respectively suggests that their genetic improvement is possible. The maximum genetic gain (19.6 % was observed for grain mass, indicating this trait should be a very important indicator for durum wheat breeders, although the climatic effects should not be ignored.

  12. Genetic and epigenetic variations induced by wheat-rye 2R and 5R monosomic addition lines.

    Directory of Open Access Journals (Sweden)

    Shulan Fu

    Full Text Available BACKGROUND: Monosomic alien addition lines (MAALs can easily induce structural variation of chromosomes and have been used in crop breeding; however, it is unclear whether MAALs will induce drastic genetic and epigenetic alterations. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, wheat-rye 2R and 5R MAALs together with their selfed progeny and parental common wheat were investigated through amplified fragment length polymorphism (AFLP and methylation-sensitive amplification polymorphism (MSAP analyses. The MAALs in different generations displayed different genetic variations. Some progeny that only contained 42 wheat chromosomes showed great genetic/epigenetic alterations. Cryptic rye chromatin has introgressed into the wheat genome. However, one of the progeny that contained cryptic rye chromatin did not display outstanding genetic/epigenetic variation. 78 and 49 sequences were cloned from changed AFLP and MSAP bands, respectively. Blastn search indicated that almost half of them showed no significant similarity to known sequences. Retrotransposons were mainly involved in genetic and epigenetic variations. Genetic variations basically affected Gypsy-like retrotransposons, whereas epigenetic alterations affected Copia-like and Gypsy-like retrotransposons equally. Genetic and epigenetic variations seldom affected low-copy coding DNA sequences. CONCLUSIONS/SIGNIFICANCE: The results in the present study provided direct evidence to illustrate that monosomic wheat-rye addition lines could induce different and drastic genetic/epigenetic variations and these variations might not be caused by introgression of rye chromatins into wheat. Therefore, MAALs may be directly used as an effective means to broaden the genetic diversity of common wheat.

  13. Generation of amphidiploids from hybrids of wheat and related species from the genera Aegilops, Secale, Thinopyrum, and Triticum as a source of genetic variation for wheat improvement.

    Science.gov (United States)

    Nemeth, Csilla; Yang, Cai-yun; Kasprzak, Paul; Hubbart, Stella; Scholefield, Duncan; Mehra, Surbhi; Skipper, Emma; King, Ian; King, Julie

    2015-02-01

    We aim to improve diversity of domesticated wheat by transferring genetic variation for important target traits from related wild and cultivated grass species. The present study describes the development of F1 hybrids between wheat and related species from the genera Aegilops, Secale, Thinopyrum, and Triticum and production of new amphidiploids. Amphidiploid lines were produced from 20 different distant relatives. Both colchicine and caffeine were successfully used to double the chromosome numbers. The genomic constitution of the newly formed amphidiploids derived from seven distant relatives was determined using genomic in situ hybridization (GISH). Altogether, 42 different plants were analysed, 19 using multicolour GISH separating the chromosomes from the A, B, and D genomes of wheat, as well as the distant relative, and 23 using single colour GISH. Restructuring of the allopolyploid genome, both chromosome losses and aneuploidy, was detected in all the genomes contained by the amphidiploids. From the observed chromosome numbers there is an indication that in amphidiploids the B genome of wheat suffers chromosome losses less frequently than the other wheat genomes. Phenotyping to realize the full potential of the wheat-related grass germplasm is underway, linking the analyzed genotypes to agronomically important target traits.

  14. Rhizosheaths on wheat grown in acid soils: phosphorus acquisition efficiency and genetic control.

    Science.gov (United States)

    James, Richard A; Weligama, Chandrakumara; Verbyla, Klara; Ryan, Peter R; Rebetzke, Gregory J; Rattey, Allan; Richardson, Alan E; Delhaize, Emmanuel

    2016-06-01

    Rhizosheaths comprise soil bound to roots, and in wheat (Triticum aestivum L.) rhizosheath size correlates with root hair length. The aims of this study were to determine the effect that a large rhizosheath has on the phosphorus (P) acquisition by wheat and to investigate the genetic control of rhizosheath size in wheat grown on acid soil.Near-isogenic wheat lines differing in rhizosheath size were evaluated on two acid soils. The soils were fertilized with mineral nutrients and included treatments with either low or high P. The same soils were treated with CaCO3 to raise the pH and detoxify Al(3+) Genotypic differences in rhizosheath size were apparent only when soil pH was low and Al(3+) was present. On acid soils, a large rhizosheath increased shoot biomass compared with a small rhizosheath regardless of P supply. At low P supply, increased shoot biomass could be attributed to a greater uptake of soil P, but at high P supply the increased biomass was due to some other factor. Generation means analysis indicated that rhizosheath size on acid soil was controlled by multiple, additive loci. Subsequently, a quantitative trait loci (QTL) analysis of an F6 population of recombinant inbred lines identified five major loci contributing to the phenotype together accounting for over 60% of the total genetic variance. One locus on chromosome 1D accounted for 34% of the genotypic variation. Genetic control of rhizosheath size appears to be relatively simple and markers based on the QTL provide valuable tools for marker assisted breeding.

  15. Genetic Architecture of Resistance to Stripe Rust in a Global Winter Wheat Germplasm Collection

    Directory of Open Access Journals (Sweden)

    Peter Bulli

    2016-08-01

    Full Text Available Virulence shifts in populations of Puccinia striiformis f. sp. tritici (Pst, the causal pathogen of wheat stripe rust, are a major challenge to resistance breeding. The majority of known resistance genes are already ineffective against current races of Pst, necessitating the identification and introgression of new sources of resistance. Germplasm core collections that reflect the range of genetic and phenotypic diversity of crop species are ideal platforms for examining the genetic architecture of complex traits such as resistance to stripe rust. We report the results of genetic characterization and genome-wide association analysis (GWAS for resistance to stripe rust in a core subset of 1175 accessions in the National Small Grains Collection (NSGC winter wheat germplasm collection, based on genotyping with the wheat 9K single nucleotide polymorphism (SNP iSelect assay and phenotyping of seedling and adult plants under natural disease epidemics in four environments. High correlations among the field data translated into high heritability values within and across locations. Population structure was evident when accessions were grouped by stripe rust reaction. GWAS identified 127 resistance loci that were effective across at least two environments, including 20 with significant genome-wide adjusted P-values. Based on relative map positions of previously reported genes and QTL, five of the QTL with significant genome-wide adjusted P-values in this study represent potentially new loci. This study provides an overview of the diversity of Pst resistance in the NSGC winter wheat germplasm core collection, which can be exploited for diversification of stripe rust resistance in breeding programs.

  16. Genetic analysis of biomass and photosynthetic parameters in wheat grown in different light intensities

    Institute of Scientific and Technical Information of China (English)

    Hongwei Li; Gui Wang; Qi Zheng; Bin Li; Ruilian Jing; Zhensheng Li

    2014-01-01

    Growth light intensities largely determine photo-synthesis, biomass, and grain yield of cereal crops. To explore the genetic basis of light responses of biomass and photosynthetic parameters in wheat (Triticum aestivum L.), a quantitative trait locus (QTL) analysis was carried out in a doubled haploid (DH) population grown in low light (LL), medium light (ML), and high light (HL), respectively. The results showed that the wheat seedlings grown in HL produced more biomass with lower total chlorophyll content (Chl), carotenoid content, and maximum photochemical efficiency of photosystem II (Fv/Fm) while the wheat seed-lings grown in LL produced less biomass with higher Chl compared with those grown in ML. In total, 48 QTLs were identified to be associated with the investigated parameters in relation to growth light intensities. These QTLs were mapped to 15 chromosomes which individually explained 6.3%-36.0% of the phenotypic variance, of which chromo-somes 3A, 1D, and 6B were specifically involved in LL response, 5D and 7A specifically involved in ML response, and 4B specifically involved in HL response. Several light-responsive QTLs were co-located with QTLs for photosyn-thetic parameters, biomass, and grain weight under various conditions which may provide new hints to uncover the genetic control of photosynthesis, biomass, and grain weight.

  17. Does wheat genetically modified for disease resistance affect root-colonizing pseudomonads and arbuscular mycorrhizal fungi?

    Directory of Open Access Journals (Sweden)

    Joana Beatrice Meyer

    Full Text Available This study aimed to evaluate the impact of genetically modified (GM wheat with introduced pm3b mildew resistance transgene, on two types of root-colonizing microorganisms, namely pseudomonads and arbuscular mycorrhizal fungi (AMF. Our investigations were carried out in field trials over three field seasons and at two locations. Serial dilution in selective King's B medium and microscopy were used to assess the abundance of cultivable pseudomonads and AMF, respectively. We developed a denaturing gradient gel electrophoresis (DGGE method to characterize the diversity of the pqqC gene, which is involved in Pseudomonas phosphate solubilization. A major result was that in the first field season Pseudomonas abundances and diversity on roots of GM pm3b lines, but also on non-GM sister lines were different from those of the parental lines and conventional wheat cultivars. This indicates a strong effect of the procedures by which these plants were created, as GM and sister lines were generated via tissue cultures and propagated in the greenhouse. Moreover, Pseudomonas population sizes and DGGE profiles varied considerably between individual GM lines with different genomic locations of the pm3b transgene. At individual time points, differences in Pseudomonas and AMF accumulation between GM and control lines were detected, but they were not consistent and much less pronounced than differences detected between young and old plants, different conventional wheat cultivars or at different locations and field seasons. Thus, we conclude that impacts of GM wheat on plant-beneficial root-colonizing microorganisms are minor and not of ecological importance. The cultivation-independent pqqC-DGGE approach proved to be a useful tool for monitoring the dynamics of Pseudomonas populations in a wheat field and even sensitive enough for detecting population responses to altered plant physiology.

  18. Genetic dissection of chlorophyll content at different growth stages in common wheat

    Indian Academy of Sciences (India)

    Kunpu Zhang; Zhijun Fang; Yan Liang; Jichun Tian

    2009-08-01

    Quantitative trait loci (QTLs) for chlorophyll content were studied using a doubled haploid (DH) population with 168 progeny lines, derived from a cross between two elite Chinese wheat cultivars Huapei 3 × Yumai 57. Chlorophyll content was evaluated at the maximum tillering stage (MS), the heading stage (HS), and the grain filling stage (GS), at three different environments in 2005 and 2006 cropping seasons. QTL analyses were performed using a mixed linear model approach. A total of 17 additive QTLs and nine pairs of epistatic QTLs were detected. Ten of 17 additive QTLs for chlorophyll content were persistently expressed at more than two growth stages, which suggest developmentally regulated loci controlling genetics for chlorophyll content in different growth stages in wheat. One novel major QTL for chlorophyll content was closely linked with the PCR marker Xwmc215 and was persistently expressed at three growth stages.

  19. Disease Impact on Wheat Yield Potential and Prospects of Genetic Control

    DEFF Research Database (Denmark)

    Singh, Ravi P.; Singh, Pawan K.; Rutkoski, Jessica;

    2016-01-01

    Wheat is grown worldwide in diverse geographical regions, environments, and production systems. Although many diseases and pests are known to reduce grain yield potential and quality, the three rusts and powdery mildew fungi have historically caused major crop losses and continue to remain...... and Bangladesh) have become diseases of major importance in recent years largely because of intensive production systems, the expansion of conservation agriculture, undesirable crop rotations, or increased dependency on fungicides. High genetic diversity for race-specific and quantitative resistance is known...... economically important despite the widespread use of host resistance and fungicides. The evolution and fast spread of virulent and more aggressive race lineages of rust fungi have only worsened the situation. Fusarium head blight, leaf spotting diseases, and, more recently, wheat blast (in South America...

  20. Genetics of resistance to septoria tritici blotch in the Portuguese wheat breeding line TE 9111.

    Science.gov (United States)

    Chartrain, L; Joaquim, P; Berry, S T; Arraiano, L S; Azanza, F; Brown, J K M

    2005-04-01

    We report the genetics of resistance of the Portuguese wheat breeding line TE 9111 to septoria tritici blotch (STB), which is caused by Mycosphaerella graminicola. TE 9111 is the most resistant line known in Europe and combines isolate-non-specific, partial resistance with several isolate-specific resistances. We show that, in addition to high levels of partial resistance to STB, TE 9111 has a new gene for resistance to M. graminicola isolate IPO90012, named Stb11, that maps on chromosome 1BS, the Stb6 gene for resistance to isolate IPO323 and, probably, the Stb7 gene for resistance to isolate IPO87019. All of these genes are closely linked to microsatellite markers, which can be used for marker-assisted selection. TE 9111 may therefore be a valuable source of resistance to STB for wheat breeding, especially in Mediterranean environments.

  1. Breaking wheat yield barriers requires integrated efforts in developing countries

    Institute of Scientific and Technical Information of China (English)

    Saeed Rauf; Maria Zaharieva; Marilyn L Warburton; ZHANG Ping-zhi; Abdullah M AL-Sadi; Farghama Khalil; Marcin Kozak; Sultan A Tariq

    2015-01-01

    Most yield progress obtained through the so cal ed“Green Revolution”, particularly in the irrigated areas of Asia, has reached a limit, and major resistance genes are quickly overcome by the appearance of new strains of disease causing organisms. New plant stresses due to a changing environment are dififcult to breed for as quickly as the changes occur. There is con-sequently a continual need for new research programs and breeding strategies aimed at improving yield potential, abiotic stress tolerance and resistance to new, major pests and diseases. Recent advances in plant breeding encompass novel methods of expanding genetic variability and selecting for recombinants, including the development of synthetic hexaploid, hybrid and transgenic wheats. In addition, the use of molecular approaches such as quantitative trait locus (QTL) and asso-ciation mapping may increase the possibility of directly selecting positive chromosomal regions linked with natural variation for grain yield and stress resistance. The present article reviews the potential contribution of these new approaches and tools to the improvement of wheat yield in farmer’s ifelds, with a special emphasis on the Asian countries, which are major wheat producers, and contain the highest concentration of resource-poor wheat farmers.

  2. Genetic diversity of Brazilian triticales evaluated with genomic wheat microsatellites Diversidade genética de triticales brasileiros avaliada com microssatélites genômicos de trigo

    Directory of Open Access Journals (Sweden)

    Cibele Tesser da Costa

    2007-11-01

    Full Text Available The objective of this work was to determine the genetic variability available for triticale (X Triticosecale Wittmack crop improvement in Brazil. Forty-two wheat genomic microsatellites were used to estimate the molecular diversity of 54 genotypes, which constitute the base of one of the major triticale breeding programs in the country. Average heterozygosity was 0.06 and average and effective number of alleles per locus were 2.13 and 1.61, respectively, with average allelic frequency of 0.34. The set of genomic wheat microsatellites used clustered the genotypes into seven groups, even when the germplasm was originated primarily from only two triticale breeding programs, a fact reflected on the average polymorphic information content value estimated for the germplasm (0.36. The 71.42% transferability achieved for the tested microsatellites indicates the possibility of exploiting these transferable markers in further triticale genetic and breeding studies, even those mapped on the D genome of wheat, when analyzing hexaploid triticales.O objetivo deste trabalho foi determinar a variabilidade disponível para o melhoramento de triticale (X Triticosecale Wittmack no Brasil. Quarenta e dois microssatélites de trigo foram empregados para estimar a diversidade molecular de 54 genótipos, que constituem a base de um dos principais programas de melhoramento da espécie no país. A heterozigosidade média foi 0,06, e os números médio e efetivo de alelos por lócus foram de 2,13 e 1,61, respectivamente, com freqüência alélica média de 0,34. O conjunto de microssatélites de trigo possibilitou reunir os genótipos em sete grupos, mesmo que o germoplasma utilizado seja originado de apenas duas instituições de pesquisa, o que refletiu em baixo índice de polimorfismo médio (0,36. A taxa de transferência dos marcadores testados (71,42% indica a possibilidade de uso desses microssatélites de trigo, até mesmo os mapeados no genoma D da espécie, na

  3. Genetic variation of carotenoids in Chinese bread wheat cultivars and the effect of the 1BL.1RS translocation

    Directory of Open Access Journals (Sweden)

    Wenshuang LI,Shengnan ZHAI,Hui JIN,Weie WEN,Jindong LIU,Xianchun XIA,Zhonghu HE

    2016-06-01

    Full Text Available Carotenoid content of wheat is an important criterion for prediction of the commercial and nutritional value of products made from bread wheat (Triticum aestivum cultivars. The objective of this study was to determine the major components of carotenoids in Chinese wheat using ultra performance liquid chromatography (UPLC including lutein, zeaxanthin, α-carotene and β-carotene. Grain carotenoid content was investigated in 217 cultivars from three major Chinese wheat regions and from seven other countries grown in two environments. Genotype contributed to the majority of variation in carotenoid components. Lutein, zeaxanthin and β-carotene concentrations varied from 18.3 to 100.1, 4.9 to 12.0 and 0.9 to 48.7 μg per 100 g in wheat flour with an average of 40.2, 7.2 and 18.2 μg per 100 g, respectively. Lutein (61.3% was the main carotenoid component, followed by β-carotene (27.7% and zeaxanthin (11.0%. No α-carotene was detected. Total carotenoids, lutein, zeaxanthin and β-carotene were all higher in cultivars with the 1BL.1RS translocation compared to those without the translocation. This is the first report on assay of lutein, zeaxanthin and β-carotene concentrations for a large number of wheat cultivars. These data will be useful for genetic improvement of wheat carotenoid content and for understanding of the carotenoid biosynthetic pathway in wheat.

  4. Genetic architecture of seed longevity in bread wheat (Triticum aestivum L.)

    Indian Academy of Sciences (India)

    MIAN ABDUR REHMAN ARIF; MANUELA NAGEL; ULRIKE LOHWASSER; ANDREAS BÖRNER

    2017-03-01

    The deterioration in the quality of ex situ conserved seed over time reflects a combination of both physical andchemical changes. Intraspecific variation for longevity is, at least in part, under genetic control. Here, the grain of 183bread wheat accessions maintained under low-temperature storage at the IPK-Gatersleben genebank over somedecades have been tested for their viability, along with that of fresh grain subjected to two standard artificial ageingprocedures. A phenotype–genotype association analysis, conducted to reveal the genetic basis of the observedvariation between accessions, implicated many regions of the genome, underling the genetic complexity of the trait.Some, but not all, of these regions were associated with variation for both natural and experimental ageing, implyingsome non-congruency obtains between these two forms of testing for longevity. The genes underlying longevityappear to be independent of known genes determining dormancy and pre-harvest sprouting.

  5. Solar Radiation-Associated Adaptive SNP Genetic Differentiation in Wild Emmer Wheat, Triticum dicoccoides

    Science.gov (United States)

    Ren, Jing; Chen, Liang; Jin, Xiaoli; Zhang, Miaomiao; You, Frank M.; Wang, Jirui; Frenkel, Vladimir; Yin, Xuegui; Nevo, Eviatar; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua

    2017-01-01

    Whole-genome scans with large number of genetic markers provide the opportunity to investigate local adaptation in natural populations and identify candidate genes under positive selection. In the present study, adaptation genetic differentiation associated with solar radiation was investigated using 695 polymorphic SNP markers in wild emmer wheat originated in a micro-site at Yehudiyya, Israel. The test involved two solar radiation niches: (1) sun, in-between trees; and (2) shade, under tree canopy, separated apart by a distance of 2–4 m. Analysis of molecular variance showed a small (0.53%) but significant portion of overall variation between the sun and shade micro-niches, indicating a non-ignorable genetic differentiation between sun and shade habitats. Fifty SNP markers showed a medium (0.05 ≤ FST ≤ 0.15) or high genetic differentiation (FST > 0.15). A total of 21 outlier loci under positive selection were identified by using four different FST-outlier testing algorithms. The markers and genome locations under positive selection are consistent with the known patterns of selection. These results suggested that genetic differentiation between sun and shade habitats is substantial, radiation-associated, and therefore ecologically determined. Hence, the results of this study reflected effects of natural selection through solar radiation on EST-related SNP genetic diversity, resulting presumably in different adaptive complexes at a micro-scale divergence. The present work highlights the evolutionary theory and application significance of solar radiation-driven natural selection in wheat improvement. PMID:28352272

  6. [Genealogical Analysis of the Use of Aegilops (Aegilops L.) Genetic Material in Wheat (Triticum Aestivum L.)].

    Science.gov (United States)

    Martynov, S P; Dobrotvorskaya, T V; Mitrofanova, O P

    2015-09-01

    A genealogical analysis of accessions in the global gene pool of the wheat database GRIS4.0 showed that the use of the genetic material of Aegilops in wheat breeding began about half a century ago. During this time, more than 1350 varieties and 9000 lines, the pedigree of which contains Aegilops species, were created in different regions of the world. The spatial and temporal dynamics of the distribution of wheat varieties containing the genetic material of Aegilops was investigated. Analysis of the data showed that most commercial varieties with a pedigree including Ae. tauschii and/or Ae. umbellulata were created and grown in North America. More than 70% of the varieties were produced with Ae. ventricosa, which is common in western and central Europe. A gradual increase in the proportion of varieties with Aegilops genetic material was recorded from 1962 to 2011. The percentage of varieties created with the involvement of Ae. umbellulata increased from 1-5% in the 1960s to 25-29% in the 2000s. Those created with Ae. tauschii increased from 0% to 14-18%, and those created with Ae. ventricosa increased from 1% to 34-37%. The increases in the number of these varieties indicates that the resistance genes from Aegilops species retain their effectiveness. Genealogical analysis of the varieties in which resistance genes from Aegilops were postulated revealed that varieties or lines that were sources of identified genes were often absent in the pedigree. This may be due to an incorrect pedigree record or errors in the identification of resistance genes by phytopathological testing and/or the use of molecular markers, or confusion in nurseries. Preliminary analysis of pedigrees provides an opportunity to reveal discrepancies between the pedigree and postulated genes.

  7. Bioethanol production using genetically modified and mutant wheat and barley straws

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z. [Washington State Univ., Pullman, WA (US). Dept. of Biological Engineering; East China Univ. of Science and Technology, Shanghai (CN). State Key Laboratory of Bioreactor Engineering; Liu, Y. [Michigan State Univ., East Lansing, MI (US). Biosystems and Agricultural Engineering; Chen, S. [Washington State Univ., Pullman, WA (US). Dept. of Biological Systems Engineering; Zemetra, R.S. [Univ. of Idaho, Moscow, ID (US). Plant, Soil, and Entomological Sciences

    2011-01-15

    To improve the performance of wheat and barley straws as feedstocks for ethanol biorefining, the genetic modifications of down regulating Cinnamoyl-CoA reductase and low phytic acid mutation have been introduced into wheat and barley respectively. In this study, total 252 straw samples with different genetic background and location were collected from the field experiment based on a randomized complete block design. The fiber analysis (neutral detergent fiber, acid detergent fiber, and acid detergent lignin) indicated that there were no significant differences between modified and wild type straw lines in terms of straw compositions. However, the difference did exist among straw lines on fiber utilization. 16 straw samples were further selected to conduct diluted acid pretreatment, enzymatic hydrolysis and fermentation. The data indicated that the phytic acid mutant and transgenic straws have changed the fiber structure, which significantly influences their hydrolysibility. These results may lead to a possible solution of mutant or genetic modified plant species that is capable to increase the hydrolysibility of biomass without changing their compositions and sacrificing their agronomy performance. (author)

  8. A simplified and accurate detection of the genetically modified wheat MON71800 with one calibrator plasmid.

    Science.gov (United States)

    Kim, Jae-Hwan; Park, Saet-Byul; Roh, Hyo-Jeong; Park, Sunghoon; Shin, Min-Ki; Moon, Gui Im; Hong, Jin-Hwan; Kim, Hae-Yeong

    2015-06-01

    With the increasing number of genetically modified (GM) events, unauthorized GMO releases into the food market have increased dramatically, and many countries have developed detection tools for them. This study described the qualitative and quantitative detection methods of unauthorized the GM wheat MON71800 with a reference plasmid (pGEM-M71800). The wheat acetyl-CoA carboxylase (acc) gene was used as the endogenous gene. The plasmid pGEM-M71800, which contains both the acc gene and the event-specific target MON71800, was constructed as a positive control for the qualitative and quantitative analyses. The limit of detection in the qualitative PCR assay was approximately 10 copies. In the quantitative PCR assay, the standard deviation and relative standard deviation repeatability values ranged from 0.06 to 0.25 and from 0.23% to 1.12%, respectively. This study supplies a powerful and very simple but accurate detection strategy for unauthorized GM wheat MON71800 that utilizes a single calibrator plasmid.

  9. Genetic diversity for drought resistance in wild emmer wheat and its ecogeographical associations

    National Research Council Canada - National Science Library

    PELEG, Z; FAHIMA, T; ABBO, S; KRUGMAN, T; NEVO, E; YAKIR, D; SARANGA, Y

    2005-01-01

    Wild emmer wheat ( Triticum turgidum spp. dicoccoides (Körn.) Thell.), the tetraploid progenitor of cultivated wheat, is a potential source for various agronomical traits, including drought resistance...

  10. Flanking sequence determination and event-specific detection of genetically modified wheat B73-6-1

    Institute of Scientific and Technical Information of China (English)

    Junyi Xu; Jijuan Cao; Dongmei Cao; Tongtong Zhao; Xin Huang; Piqiao Zhang; Fengxia Luan

    2013-01-01

    In order to establish a specific identification method for genetically modified (GM) wheat,exogenous insert DNA and flanking sequence between exogenous fragment and recombinant chromosome of GM wheat B73-6-1 were successfully acquired by means of conventional polymerase chain reaction (PCR) and thermal asymmetric interlaced (TAIL)-PCR strategies.Newly acquired exogenous fragment covered the full-length sequence of transformed genes such as transformed plasmid and corresponding functional genes including marker uidA,herbicide-resistant bar,ubiquitin promoter,and high-molecular-weight gluten subunit.The flanking sequence between insert DNA revealed high similarity with Triticum turgidum A gene (GenBank:AY494981.1).A specific PCR detection method for GM wheat B73-6-1 was established on the basis of primers designed according to the flanking sequence.This specific PCR method was validated by GM wheat,GM corn,GM soybean,GM rice,and non-GM wheat.The specifically amplified target band was observed only in GM wheat B73-6-1.This method is of high specificity,high reproducibility,rapid identification,and excellent accuracy for the identification of GM wheat B73-6-1.

  11. Divergence in homoeolog expression of the grain length-associated gene GASR7 during wheat allohexaploidization

    Institute of Scientific and Technical Information of China (English)

    Dongdong; Zhang; Bingnan; Wang; Junmin; Zhao; Xubo; Zhao; Lianquan; Zhang; Dengcai; Liu; Lingli; Dong; Daowen; Wang; Long; Mao; Aili; Li

    2015-01-01

    Hexaploid wheat has triplicated homoeologs for most of the genes that are located in subgenomes A, B, and D. GASR7, a member of the Snakin/GASA gene family, has been associated with grain length development in wheat. However, little is known about divergence of its homoeolog expression in wheat polyploids. We studied the expression patterns of the GASR7 homoeologs in immature seeds in a synthetic hexaploid wheat line whose kernels are slender like those of its maternal parent(Triticum turgidum, AABB, PI 94655) in contrast to the round seed shape of its paternal progenitor(Aegilops tauschii, DD, AS2404). We found that the B homoeolog of GASR7 was the main contributor to the total expression level of this gene in both the maternal tetraploid progenitor and the hexaploid progeny, whereas the expression levels of the A and D homoeologs were much lower. To understand possible mechanisms regulating different GASR7 homoeologs, we firstly analyzed the promoter sequences of three homoeologous genes and found that all of them contained gibberellic acid(GA) response elements, with the TaG ASR7 B promoter(pT aG ASR7B) uniquely characterized by an additional predicted transcriptional enhancer. This was confirmed by the GA treatment of spikes where all three homoeologs were induced, with a much stronger response for TaG ASR7 B. McrB C enzyme assays showed that the methylation status at pT aG ASR7 D was increased during allohexaploidization, consistent with the repressed expression of TaG ASR7 D. For pT aG ASR7 A, the distribution of repetitive sequence-derived 24-nucleotide(nt) small interfering RNAs(siR NAs) were found which suggests possible epigenetic regulation because 24-nt siR NAs are known to mediate RNA-dependent DNA methylation. Our results thus indicate that both genetic and epigenetic mechanisms may be involved in the divergence of GASR7 homoeolog expression in polyploid wheat.

  12. Proteomic and genetic analysis of wheat endosperm albumins and globulins using deletion lines of cultivar Chinese Spring

    DEFF Research Database (Denmark)

    Merlino, Marielle; Bousbata, Sabrina; Svensson, Birte;

    2012-01-01

    Albumins and globulins from the endosperm of Triticum aestivum L. cv Chinese Spring (CS) were analysed to establish a proteome reference map for this standard wheat cultivar. Approximately, 1,145 Coomassie-stained spots were detected by two-dimensional gel electrophoresis (2DE), 410 of which were...... the composition and genetics of a complex tissue, such as the wheat endosperm.......Albumins and globulins from the endosperm of Triticum aestivum L. cv Chinese Spring (CS) were analysed to establish a proteome reference map for this standard wheat cultivar. Approximately, 1,145 Coomassie-stained spots were detected by two-dimensional gel electrophoresis (2DE), 410 of which were...... in endosperm proteins due to chromosomal deletions. This differential analysis of spots allowed structural or regulatory genes, encoding 211 proteins, to be located on segments of the 21 wheat chromosomes. In addition, variance analysis of quantitative variations in spot volume showed that the expression...

  13. Evaluation of the safety of ancient strains of wheat in coeliac disease reveals heterogeneous small intestinal T cell responses suggestive of coeliac toxicity.

    Science.gov (United States)

    Šuligoj, Tanja; Gregorini, Armando; Colomba, Mariastella; Ellis, H Julia; Ciclitira, Paul J

    2013-12-01

    Coeliac disease is a chronic small intestinal immune-mediated enteropathy triggered by dietary gluten in genetically predisposed individuals. Since it is unknown if all wheat varieties are equally toxic to coeliac patients seven Triticum accessions showing different origin (ancient/modern) and ploidy (di-, tetra- hexaploid) were studied. Selected strains of wheat were ancient Triticum monococcum precoce (AA genome) and Triticum speltoides (BB genome), accessions of Triticum turgidum durum (AABB genome) including two ancient (Graziella Ra and Kamut) and two modern (Senatore Cappelli and Svevo) durum strains of wheat and Triticum aestivum compactum (AABBDD genome). Small intestinal gluten-specific T-cell lines generated from 13 coeliac patients were tested with wheat accessions by proliferation assays. All strains of wheat independent of ploidy or ancient/modern origin triggered heterogeneous responses covering wide ranges of stimulation indices. Ancient strains of wheat, although previously suggested to be low or devoid of coeliac toxicity, should be tested for immunogenicity using gluten-specific T-cell lines from multiple coeliac patients rather than gluten-specific clones to assess their potential toxicity. Our findings provide further evidence for the need for a strict gluten-free diet in coeliac patients, including avoidance of ancient strains of wheat. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  14. A chromosome bin map of 2148 expressed sequence tag loci of wheat homoeologous group 7.

    Science.gov (United States)

    Hossain, K G; Kalavacharla, V; Lazo, G R; Hegstad, J; Wentz, M J; Kianian, P M A; Simons, K; Gehlhar, S; Rust, J L; Syamala, R R; Obeori, K; Bhamidimarri, S; Karunadharma, P; Chao, S; Anderson, O D; Qi, L L; Echalier, B; Gill, B S; Linkiewicz, A M; Ratnasiri, A; Dubcovsky, J; Akhunov, E D; Dvorák, J; Miftahudin; Ross, K; Gustafson, J P; Radhawa, H S; Dilbirligi, M; Gill, K S; Peng, J H; Lapitan, N L V; Greene, R A; Bermudez-Kandianis, C E; Sorrells, M E; Feril, O; Pathan, M S; Nguyen, H T; Gonzalez-Hernandez, J L; Conley, E J; Anderson, J A; Choi, D W; Fenton, D; Close, T J; McGuire, P E; Qualset, C O; Kianian, S F

    2004-10-01

    The objectives of this study were to develop a high-density chromosome bin map of homoeologous group 7 in hexaploid wheat (Triticum aestivum L.), to identify gene distribution in these chromosomes, and to perform comparative studies of wheat with rice and barley. We mapped 2148 loci from 919 EST clones onto group 7 chromosomes of wheat. In the majority of cases the numbers of loci were significantly lower in the centromeric regions and tended to increase in the distal regions. The level of duplicated loci in this group was 24% with most of these loci being localized toward the distal regions. One hundred nineteen EST probes that hybridized to three fragments and mapped to the three group 7 chromosomes were designated landmark probes and were used to construct a consensus homoeologous group 7 map. An additional 49 probes that mapped to 7AS, 7DS, and the ancestral translocated segment involving 7BS also were designated landmarks. Landmark probe orders and comparative maps of wheat, rice, and barley were produced on the basis of corresponding rice BAC/PAC and genetic markers that mapped on chromosomes 6 and 8 of rice. Identification of landmark ESTs and development of consensus maps may provide a framework of conserved coding regions predating the evolution of wheat genomes.

  15. Genetic Transformation of Wheat (Triticum aestivum L):A Review%小麦遗传转化研究进展

    Institute of Scientific and Technical Information of China (English)

    Abdul Razzaq; 马峙英; 王海波

    2004-01-01

    Gradual progress made in genetic transformation of wheat is presented in this paper. Information on promoters, antibiotic, herbicide and auxotrophic markers, and various traits of wheat modified through genetic transformation, is provided. In addition the methods used for wheat transformation are discussed. Though significant efforts have been made for genetic transformation of wheat mainly through particle bombardment method but transformation efficiency is still low for mass production of fertile transgenic plants. Studies on the inheritance of transgenes and its incorporation into commercial elite cultivars are not significant. Agrobacterium mediated transformation seems to have better prospects for wheat transformation in future due to its advantages over particle bombardment. In planta transformation of wheat tissues seems possible only with A grobacterium.

  16. Genetic Diversity and Population Structure of Tetraploid Wheats (Triticum turgidum L. Estimated by SSR, DArT and Pedigree Data.

    Directory of Open Access Journals (Sweden)

    Giovanni Laidò

    Full Text Available Levels of genetic diversity and population genetic structure of a collection of 230 accessions of seven tetraploid Triticum turgidum L. subspecies were investigated using six morphological, nine seed storage protein loci, 26 SSRs and 970 DArT markers. The genetic diversity of the morphological traits and seed storage proteins was always lower in the durum wheat compared to the wild and domesticated emmer. Using Bayesian clustering (K = 2, both of the sets of molecular markers distinguished the durum wheat cultivars from the other tetraploid subspecies, and two distinct subgroups were detected within the durum wheat subspecies, which is in agreement with their origin and year of release. The genetic diversity of morphological traits and seed storage proteins was always lower in the improved durum cultivars registered after 1990, than in the intermediate and older ones. This marked effect on diversity was not observed for molecular markers, where there was only a weak reduction. At K >2, the SSR markers showed a greater degree of resolution than for DArT, with their identification of a greater number of groups within each subspecies. Analysis of DArT marker differentiation between the wheat subspecies indicated outlier loci that are potentially linked to genes controlling some important agronomic traits. Among the 211 loci identified under selection, 109 markers were recently mapped, and some of these markers were clustered into specific regions on chromosome arms 2BL, 3BS and 4AL, where several genes/quantitative trait loci (QTLs are involved in the domestication of tetraploid wheats, such as the tenacious glumes (Tg and brittle rachis (Br characteristics. On the basis of these results, it can be assumed that the population structure of the tetraploid wheat collection partially reflects the evolutionary history of Triticum turgidum L. subspecies and the genetic potential of landraces and wild accessions for the detection of unexplored alleles.

  17. Rapid development of PCR-based genome-specific repetitive DNA junction markers in wheat

    Science.gov (United States)

    In hexaploid wheat (Triticum aestivum L.) (AABBDD, C=17,000Mb), repeat DNA accounts for ~ 90% of the genome of which transposable elements (TEs) constitute 60-80 %. Despite the dynamic evolution of TEs, our previous study indicated that the majority of TEs between the homologous wheat genomes are co...

  18. Genetics of flowering time in bread wheat Triticum aestivum: complementary interaction between vernalization-insensitive and photoperiod-insensitive mutations imparts very early flowering habit to spring wheat

    Indian Academy of Sciences (India)

    Sushil Kumar; Vishakha Sharma; Swati Chaudhary; Anshika Tyagi; Poonam Mishra; Anupama Priyadarshini; Anupam Singh

    2011-04-01

    Time to flowering in the winter growth habit bread wheat is dependent on vernalization (exposure to cold conditions) and exposure to long days (photoperiod). Dominant Vrn-1 (Vrn-A1, Vrn-B1 and Vrn-D1) alleles are associated with vernalization-independent spring growth habit. The semidominant Ppd-D1a mutation confers photoperiod-insensitivity or rapid flowering in wheat under short day and long day conditions. The objective of this study was to reveal the nature of interaction between Vrn-1 and Ppd-D1a mutations (active alleles of the respective genes vrn-1 and Ppd-D1b). Twelve Indian spring wheat cultivars and the spring wheat landrace Chinese Spring were characterized for their flowering times by seeding them every month for five years under natural field conditions in New Delhi. Near isogenic Vrn-1 Ppd-D1 and Vrn-1 Ppd-D1a lines constructed in two genetic backgrounds were also phenotyped for flowering time by seeding in two different seasons. The wheat lines of Vrn-A1a Vrn-B1 Vrn-D1 Ppd-D1a, Vrn-A1a Vrn-B1 Ppd-D1a and Vrn-A1a Vrn-D1 Ppd-D1a (or Vrn-1 Ppd-D1a) genotypes flowered several weeks earlier than that of Vrn-A1a Vrn-B1 Vrn-D1 Ppd-D1b, Vrn-A1b Ppd-D1b and Vrn-D1 Ppd-D1b (or Vrn-1 Ppd-D1b) genotypes. The flowering time phenotypes of the isogenic vernalization-insensitive lines confirmed that Ppd-D1a hastened flowering by several weeks. It was concluded that complementary interaction between Vrn-1 and Ppd-D1a active alleles imparted super/very-early flowering habit to spring wheats. The early and late flowering wheat varieties showed differences in flowering time between short day and long day conditions. The flowering time in Vrn-1 Ppd-D1a genotypes was hastened by higher temperatures under long day conditions. The ambient air temperature and photoperiod parameters for flowering in spring wheat were estimated at 25°C and 12 h, respectively.

  19. Evaluation of genetic bases and diversity of Egyptian wheat cultivars released during the last 50 years using coefficient of parentage

    Directory of Open Access Journals (Sweden)

    Bhoja R. Basnet

    2011-04-01

    Full Text Available Discerning the genetic diversity of any crop species provides insight into the strength of an applied breeding program and directs future breeding strategies aimed at long-term genetic gain and minimized genetic vulnerability. The number and abundance of ancestral parents present in the pedigree of crop cultivars can provide an average estimation of the depth of the genetic base of the overall crop improvement program. The objectives of this study were to estimate (1 the genetic similarity among 33 Egyptian wheat (Triticum aestivum L. cultivars and different eras of release (1947-2004 and productivity groups based on COP values, and (2 the relative genetic contribution and abundance of ancestral parents from different geographical origins to the total gene pool of Egyptian wheat cultivars. Broad genetic diversity was observed among 33 Egyptian cultivars with average COP value of 0.11 and large numbers of ancestral parents (155 landraces traced to 31 countries. The genetic base ranged from very low in pre 1960’s cultivars such as ‘Giza 139’ (with only 3 landraces in the background to very high in modern cultivars such as ‘Gemmeiza-7’ (with 73 landraces in the background. ‘Hindi-62’, ‘Red Fife’, ‘Hard Red Calcutta’ and ‘Akagomughi’ were the major ancestors with 6, 5, 4, and 4% of total genetic contribution to the Egyptian wheat gene pool, respectively. Egypt, United States of America, Kenya and Ukraine were the major source countries with 16, 11, 9 and 7% of total genetic contribution to this gene pool, respectively. Though Marquis-Thatcher germplasm from North America has the greatest influence on overall Egyptian cultivars, Mexican-based sources of dwarfing and high yield, derived from ancestors such as ‘Akagomughi’ and ‘Daruma’ and exploited by the International Maize and Wheat Improvement Center (CIMMYT, were very prominent in Egyptian cultivars post 1970’s.

  20. Subgenomic Diversity Patterns Caused by Directional Selection in Bread Wheat Gene Pools

    Directory of Open Access Journals (Sweden)

    Kai Voss-Fels

    2015-07-01

    Full Text Available Genetic diversity represents the fundamental key to breeding success, providing the basis for breeders to select varieties with constantly improving yield performance. On the other hand, strong selection during domestication and breeding have eliminated considerable genetic diversity in the breeding pools of major crops, causing erosion of genetic potential for adaptation to emerging challenges like climate change. High-throughput genomic technologies can address this dilemma by providing detailed knowledge to characterize and replenish genetic diversity in breeding programs. In hexaploid bread wheat ( L., the staple food for 35% of the world’s population, bottlenecks during allopolyploidisation followed by strong artificial selection have considerably narrowed diversity to the extent that yields in many regions appear to be unexpectedly stagnating. In this study, we used a 90,000 single nucleotide polymorphism (SNP wheat genotyping array to assay high-frequency, polymorphic SNP markers in 460 accessions representing different phenological diversity groups from Asian, Australian, European, and North American bread wheat breeding materials. Detailed analysis of subgroup diversity at the chromosome and subgenome scale revealed highly distinct patterns of conserved linkage disequilibrium between different gene pools. The data enable identification of genome regions in most need of rejuvenation with novel diversity and provide a high-resolution molecular basis for genomic-assisted introgression of new variation into chromosome segments surrounding directionally selected metaloci conferring important adaptation and quality traits.

  1. [Comparative cytogenetic analysis of hexaploid Avena L. species].

    Science.gov (United States)

    Badaeva, E D; Shelukhina, O Iu; Dedkova, O S; Loskutov, I G; Pukhal'skiĭ, V A

    2011-06-01

    Using C-banding method and in situ hybridization with the 45S and 5S rRNA gene probes, six hexaploid species of the genus Avena L. with the ACD genome constitution were studied to reveal evolutionary karyotypic changes. Similarity in the C-banding patterns of chromosomal and in the patterns of distribution of the rRNA gene families suggests a common origin of all hexaploid species. Avena fatua is characterized by the broadest intraspecific variation of the karyotype; this species displays chromosomal variants typical of other hexaploid species of Avena. For instance, a translocation with the involvement of chromosome 5C marking A. occidentalis was discovered in many A. fatua accessions, whereas in other representatives of this species this chromosome is highly similar to the chromosome of A. sterilis. Only A. fatua and A. sativa show slight changes in the morphology and in the C-banding pattern of chromosome 2C. These results can be explained either by a hybrid origin of A. fatua or by the fact that this species is an intermediate evolutionary form of hexaploid oats. The 7C-17 translocation was identified in all studied accessions of wild and weedy species (A. sterilis, A. fatua, A. ludoviciana, and A. occidentalis) and in most A. sativa cultivars, but it was absent in A. byzantina and in two accessions of A. sativa. The origin and evolution of the Avena hexaploid species are discussed in context of the results.

  2. Exploring and Mobilizing the Gene Bank Biodiversity for Wheat Improvement

    Science.gov (United States)

    Sehgal, Deepmala; Vikram, Prashant; Sansaloni, Carolina Paola; Ortiz, Cynthia; Pierre, Carolina Saint; Payne, Thomas; Ellis, Marc; Amri, Ahmed; Petroli, César Daniel; Wenzl, Peter; Singh, Sukhwinder

    2015-01-01

    Identifying and mobilizing useful genetic variation from germplasm banks to breeding programs is an important strategy for sustaining crop genetic improvement. The molecular diversity of 1,423 spring bread wheat accessions representing major global production environments was investigated using high quality genotyping-by-sequencing (GBS) loci, and gene-based markers for various adaptive and quality traits. Mean diversity index (DI) estimates revealed synthetic hexaploids to be genetically more diverse (DI= 0.284) than elites (DI = 0.267) and landraces (DI = 0.245). GBS markers discovered thousands of new SNP variations in the landraces which were well known to be adapted to drought (1273 novel GBS SNPs) and heat (4473 novel GBS SNPs) stress environments. This may open new avenues for pre-breeding by enriching the elite germplasm with novel alleles for drought and heat tolerance. Furthermore, new allelic variation for vernalization and glutenin genes was also identified from 47 landraces originating from Iraq, Iran, India, Afghanistan, Pakistan, Uzbekistan and Turkmenistan. The information generated in the study has been utilized to select 200 diverse gene bank accessions to harness their potential in pre-breeding and for allele mining of candidate genes for drought and heat stress tolerance, thus channeling novel variation into breeding pipelines. This research is part of CIMMYT’s ongoing ‘Seeds of Discovery’ project visioning towards the development of high yielding wheat varieties that address future challenges from climate change. PMID:26176697

  3. Exploring and Mobilizing the Gene Bank Biodiversity for Wheat Improvement.

    Science.gov (United States)

    Sehgal, Deepmala; Vikram, Prashant; Sansaloni, Carolina Paola; Ortiz, Cynthia; Pierre, Carolina Saint; Payne, Thomas; Ellis, Marc; Amri, Ahmed; Petroli, César Daniel; Wenzl, Peter; Singh, Sukhwinder

    2015-01-01

    Identifying and mobilizing useful genetic variation from germplasm banks to breeding programs is an important strategy for sustaining crop genetic improvement. The molecular diversity of 1,423 spring bread wheat accessions representing major global production environments was investigated using high quality genotyping-by-sequencing (GBS) loci, and gene-based markers for various adaptive and quality traits. Mean diversity index (DI) estimates revealed synthetic hexaploids to be genetically more diverse (DI= 0.284) than elites (DI = 0.267) and landraces (DI = 0.245). GBS markers discovered thousands of new SNP variations in the landraces which were well known to be adapted to drought (1273 novel GBS SNPs) and heat (4473 novel GBS SNPs) stress environments. This may open new avenues for pre-breeding by enriching the elite germplasm with novel alleles for drought and heat tolerance. Furthermore, new allelic variation for vernalization and glutenin genes was also identified from 47 landraces originating from Iraq, Iran, India, Afghanistan, Pakistan, Uzbekistan and Turkmenistan. The information generated in the study has been utilized to select 200 diverse gene bank accessions to harness their potential in pre-breeding and for allele mining of candidate genes for drought and heat stress tolerance, thus channeling novel variation into breeding pipelines. This research is part of CIMMYT's ongoing 'Seeds of Discovery' project visioning towards the development of high yielding wheat varieties that address future challenges from climate change.

  4. Exploring and Mobilizing the Gene Bank Biodiversity for Wheat Improvement.

    Directory of Open Access Journals (Sweden)

    Deepmala Sehgal

    Full Text Available Identifying and mobilizing useful genetic variation from germplasm banks to breeding programs is an important strategy for sustaining crop genetic improvement. The molecular diversity of 1,423 spring bread wheat accessions representing major global production environments was investigated using high quality genotyping-by-sequencing (GBS loci, and gene-based markers for various adaptive and quality traits. Mean diversity index (DI estimates revealed synthetic hexaploids to be genetically more diverse (DI= 0.284 than elites (DI = 0.267 and landraces (DI = 0.245. GBS markers discovered thousands of new SNP variations in the landraces which were well known to be adapted to drought (1273 novel GBS SNPs and heat (4473 novel GBS SNPs stress environments. This may open new avenues for pre-breeding by enriching the elite germplasm with novel alleles for drought and heat tolerance. Furthermore, new allelic variation for vernalization and glutenin genes was also identified from 47 landraces originating from Iraq, Iran, India, Afghanistan, Pakistan, Uzbekistan and Turkmenistan. The information generated in the study has been utilized to select 200 diverse gene bank accessions to harness their potential in pre-breeding and for allele mining of candidate genes for drought and heat stress tolerance, thus channeling novel variation into breeding pipelines. This research is part of CIMMYT's ongoing 'Seeds of Discovery' project visioning towards the development of high yielding wheat varieties that address future challenges from climate change.

  5. Genetic diversity for Russian wheat aphid resistance as determined by genome-wide association mapping and inheritance in progeny

    Science.gov (United States)

    Russian wheat aphid (RWA) is an increasing problem on barley throughout the world. Genetic resistance has been identified and used to create barley germplasm and cultivars adapted to the US. Several mapping studies have been conducted to identify loci associated with resistance, but questions remain...

  6. Genome merger: from sequence rearrangements in triticale to their elimination in wheat-rye addition lines.

    Science.gov (United States)

    Bento, Miguel; Gustafson, Perry; Viegas, Wanda; Silva, Manuela

    2010-08-01

    Genetic and epigenetic modifications resulting from different genomes adjusting to a common nuclear environment have been observed in polyploids. Sequence restructuring within genomes involving retrotransposon/microsatellite-rich regions has been reported in triticale. The present study uses inter-retrotransposon amplified polymorphisms (IRAP) and retrotransposon microsatellite amplified polymorphisms (REMAP) to assess genome rearrangements in wheat-rye addition lines obtained by the controlled backcrossing of octoploid triticale to hexaploid wheat followed by self-fertilization. The comparative analysis of IRAP and REMAP banding profiles, involving a complete set of wheat-rye addition lines, and their parental species revealed in those lines the presence of wheat-origin bands absent in triticale, and the absence of rye-origin and triticale-specific bands. The presence in triticale x wheat backcrosses (BC) of rye-origin bands that were absent in the addition lines demonstrated that genomic rearrangement events were not a direct consequence of backcrossing, but resulted from further genome structural rearrangements in the BC plant progeny. PCR experiments using primers designed from different rye-origin sequences showed that the absence of a rye-origin band in wheat-rye addition lines results from sequence elimination rather than restrict changes on primer annealing sites, as noted in triticale. The level of genome restructuring events evaluated in all seven wheat-rye addition lines, compared to triticale, indicated that the unbalanced genome merger situation observed in the addition lines induced a new round of genome rearrangement, suggesting that the lesser the amount of rye chromatin introgressed into wheat the larger the outcome of genome reshuffling.

  7. Genetic diversity for gliadin patterns of durum wheat landraces in the Northwest of Iran and Azerbaijan

    Directory of Open Access Journals (Sweden)

    Mohammad Zaefizadeh

    2010-12-01

    Full Text Available The objective of this study was to identify gliadin band patterns and the extent of genetic diversity in durum wheat genotypes from Northwestern Iran and the Republic of Azerbaijan. Gliadins from 46 landraces and four cultivars were evaluated through acid PAGE analyses. Sixty-six polymorphic bands and 81 patterns were identified. Twenty-four different motility bands and 22 patterns were found in the ω gliadin region with 14 polymorph bands and 20 patterns for α and γ gliadins, and 14 bands and 19 different patterns for β gliadins. The combination of these patterns generated 38 and 39 combinations for Gli-1 and Gli-2 loci, respectively. The genetic diversity index (H was higher for α gliadins (0.924, followed by ω and γ gliadins (0.899 and 0.878, respectively, and for β gliadin patterns (0.866. Extensive polymorphism (H = 0.875 was observed in four gliadin pattern regions, with higher genetic diversity in the Iranian landraces than in the Azerbaijani ones. Each genotype had special identifying patterns in the gliadin acid PAGE analysis, and cluster analysis based on Jaccard's similarity coefficients formed six groups. Gliadin has a simple, repeatable and economic analysis, and can be used in genetic studies

  8. Useful genetic sources of economic importance and their utlization in wheat-breeding programs in Pakistan.

    Science.gov (United States)

    Qureshi, S A

    Wheat breeders the world over have been utilizing genetic sources to tailor the varieties to meet ever-changing requirements. In the late 1940s Dr. Borlaug at CIMMYT recognized that further increase in yield would be possible only if lodging in the existing wheat varieties could be avoided, for which he began to look for a suitable source for dwarfness. The Japanese had developed semidwarf Norin strains through a series of crosses involving a local line, Daruma; American soft red winter variety, Fultz; and American hard red winter variety, Turkey Red. One of the Norin strains, Norin-10, was used in the breeding programs, first in Italy and then in the United States where Dr. Orville Vogel developed two to three semidwarf varieties. In 1953 Dr. Vogel supplied some F2 seeds of Norin-10 Brevor to the CIMMYT program in Mexico, where this source was employed extensively in the breeding rogram; a large number of varieties were developed, some of which worth mentioning are Pitic, Penjamo, Lerma, Sonora, Inia, Tobari, and Siete Cerros.

  9. Genetic analysis of fertility restoring genes for AL-type male sterility in wheat

    Institute of Scientific and Technical Information of China (English)

    Liu Xiaofang; Tian Xiaoming; Nie Yingbin; Mu Peiyuan; Han Xinnian; Sang Wei; Cui Fengjuan; Xu Hongjun; Xiang Jishan

    2013-01-01

    In order to screen molecular markers linked to fertility restoring genes and further improve the breeding efficiency of restorer lines,in this study,wheat varieties 18A,18B and 99AR144-1 were used as experimental materials to establish F2 fertility-segregating population. Plant quantitative trait“major gene+polygene mixed mo-del”separation analysis method and simple sequence repeat (SSR) molecular markers were adopted for genetic analysis of four generations,including the parents (P1 and P2),and hybrid (Fl and F2) populations. The results show that AL-type fertility restoring gene is controlled by two pairs of additive-dominant-epistatic genes and addi-tive-dominant polygene;two primers linked to fertility restoring genes were selected by SSR molecular markers, including Xgwm95 on chromosome 2A and Barc61 on chromosome 1B,with the linkage distance of 15.0 cM and 18.0 cM,respectively. Based on verification,these two markers are reliable for distinguishing AL-type wheat ste-rile lines and restorer lines.

  10. Genetic variation and interrelationships of agronomic characteristics in durum wheat under two constructing water regimes

    Directory of Open Access Journals (Sweden)

    Reza Talebi

    2010-08-01

    Full Text Available This work aimed to study the grain yield components and plant characteristics related to grain yield. Twenty-four durum wheat genotypes from the ICARDA durum wheat breeding program were grown during 2006-2007 under rainfed and irrigated conditions using a complete randomized block design with three replicate in west of Iran. Correlation and path analysis were carried out. Results showed that there was strong positive association of grain yield with the number of seed/spike, biomass and harvest index. Grain yield was negatively associated with spike length and plant height in different moisture conditions. Comparatively, high genetic variation was found in grain yield and other characteristics. Hierarchical cluster analysis was used as a tool to classify the genotypes according to their grain yield ability under optimum and drought stress conditions. Among the genotypes, one of three groups of genotypes were characterized by high grain yield in optimum and drought stress conditions. These genotypes could be used as source of germplasm for breeding for drought tolerance.

  11. Genetic and Association Mapping Study of Wheat Agronomic Traits Under Contrasting Water Regimes

    Science.gov (United States)

    Dodig, Dejan; Zoric, Miroslav; Kobiljski, Borislav; Savic, Jasna; Kandic, Vesna; Quarrie, Steve; Barnes, Jeremy

    2012-01-01

    Genetic analyses and association mapping were performed on a winter wheat core collection of 96 accessions sampled from a variety of geographic origins. Twenty-four agronomic traits were evaluated over 3 years under fully irrigated, rainfed and drought treatments. Grain yield was the most sensitive trait to water deficit and was highly correlated with above-ground biomass per plant and number of kernels per m2. The germplasm was structured into four subpopulations. The association of 46 SSR loci distributed throughout the wheat genome with yield and agronomic traits was analyzed using a general linear model, where subpopulation information was used to control false-positive or spurious marker-trait associations (MTAs). A total of 26, 21 and 29 significant (P < 0.001) MTAs were identified in irrigated, rainfed and drought treatments, respectively. The marker effects ranged from 14.0 to 50.8%. Combined across all treatments, 34 significant (P < 0.001) MTAs were identified with nine markers, and R2 ranged from 14.5 to 50.2%. Marker psp3200 (6DS) and particularly gwm484 (2DS) were associated with many significant MTAs in each treatment and explained the greatest proportion of phenotypic variation. Although we were not able to recognize any marker related to grain yield under drought stress, a number of MTAs associated with developmental and agronomic traits highly correlated with grain yield under drought were identified. PMID:22754357

  12. Genetic Fingerprinting of Wheat and Its Progenitors by Mitochondrial Gene orf256

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    Mona M. Elseehy

    2012-04-01

    Full Text Available orf256 is a wheat mitochondrial gene associated with cytoplasmic male sterility (CMS that has different organization in various species. This study exploited the orf256 gene as a mitochondrial DNA marker to study the genetic fingerprint of Triticum and Aegilops species. PCR followed by sequencing of common parts of the orf256 gene were employed to determine the fingerprint and molecular evolution of Triticum and Aegilops species. Although many primer pairs were used, two pairs of orf256 specific primers (5:-94/C: 482, 5:253/C: 482, amplified DNA fragments of 576 bp and 230 bp respectively in all species were tested. A common 500 bp of nine species of Triticum and Aegilops were aligned and showed consistent results with that obtained from other similar chloroplast or nuclear genes. Base alignment showed that there were various numbers of base substitutions in all species compared to S. cereal (Sc (the outgroup species. Phylogenetic relationship revealed similar locations and proximity on phylogenetic trees established using plastid and nuclear genes. The results of this study open a good route to use unknown function genes of mitochondria in studying the molecular relationships and evolution of wheat and complex plant genomes.

  13. Population- and genome-specific patterns of linkage disequilibrium and SNP variation in spring and winter wheat (Triticum aestivum L.

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    Campbell Kim

    2010-12-01

    among populations. The higher extent of LD in the wheat D-genome versus the A- and B-genomes likely reflects the episodes of recent introgression and population bottleneck accompanying the origin of hexaploid wheat. The assessment of LD and population structure in this assembled panel of diverse lines provides critical information for the development of genetic resources for genome-wide association mapping of agronomically important traits in wheat.

  14. ESTIMATION OF PHENOTYPIC AND GENETIC CORRELATIONS FOR QUALITY TRAITS IN A WHEAT POPULATION

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    Dario Novoselović

    2012-06-01

    Full Text Available The objective of this paper was to estimate phenotypic and genetic correlations in order to improve existing wheat quality breeding methodology in early generations. For this purpose, one-year trial with population of 143 recombinant inbred lines from crossing combination Bezostaja/Klara was carried out on Osijek and Slavonski Brod locations in 2008/09 year. Among analyzed traits (grain protein content, wet gluten content, gluten index, mid-line peak time -MPT, mid-line peak height -MPH and mid-line tail width -MTW consistent positive phenotypic and genetic pattern of correlations was found between grain protein content and wet gluten content, negative between gluten index with grain protein content and wet gluten content, and positive between grain protein content and wet gluten content with MPT and MPH. Conformity of the phenotypic and genetic correlations was confirmed by Mantel test on both locations (for Osijek r=0.81** and for Slavonski Brod r=0.88**.

  15. Genetic structure of wild emmer wheat populations as reflected by transcribed versus anonymous SSR markers.

    Science.gov (United States)

    Peleg, Zvi; Fahima, Tzion; Abbo, Shahal; Krugman, Tamar; Saranga, Yehoshua

    2008-03-01

    Simple sequence repeat (SSR) markers have become a major tool in population genetic analyses. The anonymous genomic SSRs (gSSRs) have been recently supplemented with expressed sequence tag (EST) derived SSRs (eSSRs), which represent the transcribed regions of the genome. In the present study, we used 8 populations of wild emmer wheat (Triticum turgidum subsp. dicoccoides) to compare the usefulness of the two types of SSR markers in assessing allelic diversity and population structure. gSSRs revealed significantly higher diversity than eSSRs in terms of average number of alleles (14.92 vs. 7.4, respectively), polymorphic information content (0.87 vs. 0.68, respectively), and gene diversity (He; 0.55 vs. 0.38, respectively). Despite the overall differences in the level of diversity, Mantel tests for correlations between eSSR and gSSR pairwise genetic distances were found to be significant for each population as well as for all accessions jointly (RM=0.54, p=0.01). Various genetic structure analyses (AMOVA, PCoA, STRUCTURE, unrooted UPGMA tree) revealed a better capacity of eSSRs to distinguish between populations, while gSSRs showed a higher proportion of intrapopulation (among accessions) diversity. We conclude that eSSR and gSSR markers should be employed in conjunction to obtain a high inter- and intra-specific (or inter- and intra-varietal) distinctness.

  16. Molecular, physicochemical and rheological characteristics of introgressive Triticale/Triticum monococcum ssp. monococcum lines with wheat 1D/1A chromosome substitution.

    Science.gov (United States)

    Salmanowicz, Bolesław P; Langner, Monika; Wiśniewska, Halina; Apolinarska, Barbara; Kwiatek, Michał; Błaszczyk, Lidia

    2013-07-26

    Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat) genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8). Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW) glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number) of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax), and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement.

  17. Molecular, Physicochemical and Rheological Characteristics of Introgressive Triticale/Triticum monococcum ssp. monococcum Lines with Wheat 1D/1A Chromosome Substitution

    Directory of Open Access Journals (Sweden)

    Lidia Błaszczyk

    2013-07-01

    Full Text Available Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8. Genomic in situ hybridization (GISH and fluorescence in situ hybridization (FISH confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE, capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax, and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement.

  18. Application of real-time PCR-based SNP detection for mapping of Net2, a causal D-genome gene for hybrid necrosis in interspecific crosses between tetraploid wheat and Aegilops tauschii.

    Science.gov (United States)

    Matsuda, Ryusuke; Iehisa, Julio C M; Takumi, Shigeo

    2012-01-01

    Available information on genetically assigned molecular markers is not sufficient for efficient construction of a high-density linkage map in wheat. Here, we report on application of high resolution melting (HRM) analysis using a real-time PCR apparatus to develop single nucleotide polymorphism (SNP) markers linked to a hybrid necrosis gene, Net2, located on wheat chromosome 2D. Based on genomic information on barley chromosome 2H and wheat expressed sequence tag libraries, we selected wheat cDNA sequences presumed to be located near the Net2 chromosomal region, and then found SNPs between the parental Ae. tauschii accessions of the synthetic wheat mapping population. HRM analysis of the PCR products from F(2) individuals' DNA enabled us to assign 44.4% of the SNP-representing cDNAs to chromosome 2D despite the presence of the A and B genomes. In addition, the designed SNP markers were assigned to chromosome 2D of Ae. tauschii. The order of the assigned SNP markers in synthetic hexaploid wheat was confirmed by comparison with the markers in barley and Ae. tauschii. Thus, the SNP-genotyping method based on HRM analysis is a useful tool for development of molecular markers at target loci in wheat.

  19. Identification and Validation of a Major Quantitative Trait Locus for Slow-rusting Resistance to Stripe Rust in Wheat

    Institute of Scientific and Technical Information of China (English)

    Xiaohua Cao; Jianghong Zhou; Xiaoping Gong; Guangyao Zhao; Jizeng Jia; Xiaoquan Qi

    2012-01-01

    Stripe (yellow) rust,caused by Puccinia striiformis Westend.f.sp.tritici Eriks (Pst),is one of the most important wheat (Triticum aestivum L.) diseases and causes significant yield losses.A recombinant inbred (RI) population derived from a cross between Yanzhan 1 and Xichang 76-9 cultivars was evaluated for resistance to wheat stripe rust strain CYR32 at both the seedling and adult plant stages.Four resistance quantitative trait loci (QTLs) were detected in this population,in which the major one,designated as Yrq1,was mapped on chromosome 2DS.The strategy of using the Brachypodium distachyon genome,wheat expressed sequence tags and a draft DNA sequences (scaffolds) of the D-genome (Aegilops tauschii Coss.) for the development of simple sequence repeat (SSR) markers was successfully used to identify 147 SSRs in hexaploid wheat.Of the 19 polymorphic SSRs in the RI population,17 SSRs were mapped in the homeologous group 2 chromosomes near Yrq1 region and eight SSRs were genetically mapped in the 2.7 cM region of Yrq1,providing abundant DNA markers for fine-mapping of Yrq1 and marker-assisted selection in wheat breeding program.The effectiveness of Yrq1 was validated in an independent population,indicating that this resistance QTL can be successfully transferred into a susceptible cultivar for improvement of stripe rust resistance.

  20. Genetic compensation abilities of Aegilops speltoides chromosomes for homoeologous B-genome chromosomes of polyploid wheat in disomic S(B) chromosome substitution lines

    Science.gov (United States)

    The S genome of Aegilops speltoides is closely related to the B and G genomes of polyploid wheats. However, little work has been reported on the genetic relationships between the S-genome and B-genome chromosomes of polyploid wheat. Here we report the isolation of a set of disomic substitutions (DS)...

  1. Genetic and molecular bases of yield-associated traits: a translational biology approach between rice and wheat.

    Science.gov (United States)

    Valluru, Ravi; Reynolds, Matthew P; Salse, Jerome

    2014-07-01

    Transferring the knowledge bases between related species may assist in enlarging the yield potential of crop plants. Being cereals, rice and wheat share a high level of gene conservation; however, they differ at metabolic levels as a part of the environmental adaptation resulting in different yield capacities. This review focuses on the current understanding of genetic and molecular regulation of yield-associated traits in both crop species, highlights the similarities and differences and presents the putative knowledge gaps. We focus on the traits associated with phenology, photosynthesis, and assimilate partitioning and lodging resistance; the most important drivers of yield potential. Currently, there are large knowledge gaps in the genetic and molecular control of such major biological processes that can be filled in a translational biology approach in transferring genomics and genetics informations between rice and wheat.

  2. Breeding Value of Primary Synthetic Wheat Genotypes for Grain Yield

    Science.gov (United States)

    Jafarzadeh, Jafar; Bonnett, David; Jannink, Jean-Luc; Akdemir, Deniz; Dreisigacker, Susanne; Sorrells, Mark E.

    2016-01-01

    To introduce new genetic diversity into the bread wheat gene pool from its progenitor, Aegilops tauschii (Coss.) Schmalh, 33 primary synthetic hexaploid wheat genotypes (SYN) were crossed to 20 spring bread wheat (BW) cultivars at the International Wheat and Maize Improvement Center. Modified single seed descent was used to develop 97 populations with 50 individuals per population using first back-cross, biparental, and three-way crosses. Individuals from each cross were selected for short stature, early heading, flowering and maturity, minimal lodging, and free threshing. Yield trials were conducted under irrigated, drought, and heat-stress conditions from 2011 to 2014 in Ciudad Obregon, Mexico. Genomic estimated breeding values (GEBVs) of parents and synthetic derived lines (SDLs) were estimated using a genomic best linear unbiased prediction (GBLUP) model with markers in each trial. In each environment, there were SDLs that had higher GEBVs than their recurrent BW parent for yield. The GEBVs of BW parents for yield ranged from -0.32 in heat to 1.40 in irrigated trials. The range of the SYN parent GEBVs for yield was from -2.69 in the irrigated to 0.26 in the heat trials and were mostly negative across environments. The contribution of the SYN parents to improved grain yield of the SDLs was highest under heat stress, with an average GEBV for the top 10% of the SDLs of 0.55 while the weighted average GEBV of their corresponding recurrent BW parents was 0.26. Using the pedigree-based model, the accuracy of genomic prediction for yield was 0.42, 0.43, and 0.49 in the drought, heat and irrigated trials, respectively, while for the marker-based model these values were 0.43, 0.44, and 0.55. The SYN parents introduced novel diversity into the wheat gene pool. Higher GEBVs of progenies were due to introgression and retention of some positive alleles from SYN parents. PMID:27656893

  3. Genome-wide genetic dissection of supernumerary spikelet and related traits in common wheat

    Science.gov (United States)

    Branched spike or supernumerary spikelet (SS) is a naturally occurring variant in wheat and holds great potential for increasing the number of grains per spike, and ultimately, increasing wheat yield. However, detailed knowledge of the molecular basis of spike branching in common wheat is lacking. I...

  4. Registration of ‘NE05548’ (husker genetics brand panhandle) hard red winter wheat

    Science.gov (United States)

    Western Nebraska wheat producers and those in adjacent areas want taller wheat (Triticum aestivum L.) cultivars that retain their height under drought for better harvestability. ‘NE05548’ (Reg. No. CV-1117, PI 670462) hard red winter wheat was developed cooperatively by the Nebraska Agricultural Exp...

  5. End-use quality of CIMMYT-derived soft kernel durum wheat germplasm. II. Dough strength and pan bread quality

    Science.gov (United States)

    Durum wheat (Triticum turgidum ssp. durum) is considered unsuitable for the majority of commercial bread production because its weak gluten strength combined with flour particle size and flour starch damage after milling are not commensurate with hexaploid wheat flours. Recently a new durum cultivar...

  6. Comparative cytogenetic analysis of diploid and hexaploid Chenopodium album Agg

    Directory of Open Access Journals (Sweden)

    Bożena Kolano

    2011-01-01

    Full Text Available Two cytotypes of Chenopodium album, diploid (2n=2x=18 and hexaploid (2n=6x=54, were analysed using flow cytometry and a FISH experiment. The genome size was indicated as 1.795 pg for the diploid and 3.845 pg for the hexaploid plants which suggested genome downsizing in the evolution of hexaploid cytotype. Double FISH with 25S rDNA and 5S rDNA allowed three to five homologue chromosome pairs to be distinguished depending on the cytotype. The Variation in size and number of rDNA sites between the polyploid C. album and its putative diploid ancestor indicated that rDNA loci underwent rearrangements after polyploidization. Flow cytometry measurements of the relative nuclear DNA content in the somatic tissue of C. album revealed extensive endopolyploidization resulting in tissues comprising a mixture of cells with a different DNA content (from 2C to 32C in varying proportions. The pattern of endopolyploidy was characteristic for the developmental stage of the plant and for the individual organ. Polysomaty was not observed in the embryo tissues however endopolyploidization had taken place in most tested organs of seedlings. The endopolyploidy in diploid and hexaploid C. album was compared to find any relationship between the pattern of polysomaty and polyploidy level in this species. This revealed that polyploid plants showed a decline in the number of endocycles as well as in the frequency of endopolyploidy cells compared to diploid plants.

  7. Collinearity Analysis and High-Density Genetic Mapping of the Wheat Powdery Mildew Resistance Gene Pm40 in PI 672538.

    Science.gov (United States)

    Zhong, Shengfu; Ma, Lixia; Fatima, Syeda Akash; Yang, Jiezhi; Chen, Wanquan; Liu, Taiguo; Hu, Yuting; Li, Qing; Guo, Jingwei; Zhang, Min; Lei, Li; Li, Xin; Tang, Shengwen; Luo, Peigao

    2016-01-01

    The wheat powdery mildew resistance gene Pm40, which is located on chromosomal arm 7BS, is effective against nearly all prevalent races of Blumeria graminis f. sp tritici (Bgt) in China and is carried by the common wheat germplasm PI 672538. A set of the F1, F2 and F2:3 populations from the cross of the resistant PI 672538 with the susceptible line L1034 were used to conduct genetic analysis of powdery mildew resistance and construct a high-density linkage map of the Pm40 gene. We constructed a high-density linkage genetic map with a total length of 6.18 cM and average spacing between markers of 0.48 cM.Pm40 is flanked by Xwmc335 and BF291338 at genetic distances of 0.58 cM and 0.26 cM, respectively, in deletion bin C-7BS-1-0.27. Comparative genomic analysis based on EST-STS markers established a high level of collinearity of the Pm40 genomic region with a 1.09-Mbp genomic region on Brachypodium chromosome 3, a 1.16-Mbp genomic region on rice chromosome 8, and a 1.62-Mbp genomic region on sorghum chromosome 7. We further anchored the Pm40 target intervals to the wheat genome sequence. A putative linear index of 85 wheat contigs containing 97 genes on 7BS was constructed. In total, 9 genes could be considered as candidates for the resistances to powdery mildew in the target genomic regions, which encoded proteins that were involved in the plant defense and response to pathogen attack. These results will facilitate the development of new markers for map-based cloning and marker-assisted selection of Pm40 in wheat breeding programs.

  8. Collinearity Analysis and High-Density Genetic Mapping of the Wheat Powdery Mildew Resistance Gene Pm40 in PI 672538

    Science.gov (United States)

    Fatima, Syeda Akash; Yang, Jiezhi; Chen, Wanquan; Liu, Taiguo; Hu, Yuting; Li, Qing; Guo, Jingwei; Zhang, Min; Lei, Li; Li, Xin; Tang, Shengwen; Luo, Peigao

    2016-01-01

    The wheat powdery mildew resistance gene Pm40, which is located on chromosomal arm 7BS, is effective against nearly all prevalent races of Blumeria graminis f. sp tritici (Bgt) in China and is carried by the common wheat germplasm PI 672538. A set of the F1, F2 and F2:3 populations from the cross of the resistant PI 672538 with the susceptible line L1034 were used to conduct genetic analysis of powdery mildew resistance and construct a high-density linkage map of the Pm40 gene. We constructed a high-density linkage genetic map with a total length of 6.18 cM and average spacing between markers of 0.48 cM.Pm40 is flanked by Xwmc335 and BF291338 at genetic distances of 0.58 cM and 0.26 cM, respectively, in deletion bin C-7BS-1-0.27. Comparative genomic analysis based on EST-STS markers established a high level of collinearity of the Pm40 genomic region with a 1.09-Mbp genomic region on Brachypodium chromosome 3, a 1.16-Mbp genomic region on rice chromosome 8, and a 1.62-Mbp genomic region on sorghum chromosome 7. We further anchored the Pm40 target intervals to the wheat genome sequence. A putative linear index of 85 wheat contigs containing 97 genes on 7BS was constructed. In total, 9 genes could be considered as candidates for the resistances to powdery mildew in the target genomic regions, which encoded proteins that were involved in the plant defense and response to pathogen attack. These results will facilitate the development of new markers for map-based cloning and marker-assisted selection of Pm40 in wheat breeding programs. PMID:27755575

  9. Genetic Diversity and Genome Wide Association Study of β-Glucan Content in Tetraploid Wheat Grains.

    Science.gov (United States)

    Marcotuli, Ilaria; Houston, Kelly; Schwerdt, Julian G; Waugh, Robbie; Fincher, Geoffrey B; Burton, Rachel A; Blanco, Antonio; Gadaleta, Agata

    2016-01-01

    Non-starch polysaccharides (NSPs) have many health benefits, including immunomodulatory activity, lowering serum cholesterol, a faecal bulking effect, enhanced absorption of certain minerals, prebiotic effects and the amelioration of type II diabetes. The principal components of the NSP in cereal grains are (1,3;1,4)-β-glucans and arabinoxylans. Although (1,3;1,4)-β-glucan (hereafter called β-glucan) is not the most representative component of wheat cell walls, it is one of the most important types of soluble fibre in terms of its proven beneficial effects on human health. In the present work we explored the genetic variability of β-glucan content in grains from a tetraploid wheat collection that had been genotyped with a 90k-iSelect array, and combined this data to carry out an association analysis. The β-glucan content, expressed as a percentage w/w of grain dry weight, ranged from 0.18% to 0.89% across the collection. Our analysis identified seven genomic regions associated with β-glucan, located on chromosomes 1A, 2A (two), 2B, 5B and 7A (two), confirming the quantitative nature of this trait. Analysis of marker trait associations (MTAs) in syntenic regions of several grass species revealed putative candidate genes that might influence β-glucan levels in the endosperm, possibly via their participation in carbon partitioning. These include the glycosyl hydrolases endo-β-(1,4)-glucanase (cellulase), β-amylase, (1,4)-β-xylan endohydrolase, xylanase inhibitor protein I, isoamylase and the glycosyl transferase starch synthase II.

  10. Genetic Diversity and Genome Wide Association Study of β-Glucan Content in Tetraploid Wheat Grains.

    Directory of Open Access Journals (Sweden)

    Ilaria Marcotuli

    Full Text Available Non-starch polysaccharides (NSPs have many health benefits, including immunomodulatory activity, lowering serum cholesterol, a faecal bulking effect, enhanced absorption of certain minerals, prebiotic effects and the amelioration of type II diabetes. The principal components of the NSP in cereal grains are (1,3;1,4-β-glucans and arabinoxylans. Although (1,3;1,4-β-glucan (hereafter called β-glucan is not the most representative component of wheat cell walls, it is one of the most important types of soluble fibre in terms of its proven beneficial effects on human health. In the present work we explored the genetic variability of β-glucan content in grains from a tetraploid wheat collection that had been genotyped with a 90k-iSelect array, and combined this data to carry out an association analysis. The β-glucan content, expressed as a percentage w/w of grain dry weight, ranged from 0.18% to 0.89% across the collection. Our analysis identified seven genomic regions associated with β-glucan, located on chromosomes 1A, 2A (two, 2B, 5B and 7A (two, confirming the quantitative nature of this trait. Analysis of marker trait associations (MTAs in syntenic regions of several grass species revealed putative candidate genes that might influence β-glucan levels in the endosperm, possibly via their participation in carbon partitioning. These include the glycosyl hydrolases endo-β-(1,4-glucanase (cellulase, β-amylase, (1,4-β-xylan endohydrolase, xylanase inhibitor protein I, isoamylase and the glycosyl transferase starch synthase II.

  11. Production of multiple wheat-rye 1RS translocation stocks and genetic analysis of LMW subunits of glutenin and gliadins in wheats using these stocks.

    Science.gov (United States)

    Gupta, R B; Shepherd, K W

    1993-02-01

    A triple (1AL.1RS/1BL.1RS/1DL.1RS) and three double (1AL.1RS/1BL.1RS, 1AL.1RS/1DL.1RS, 1BL.1RS/1DL.1RS) wheat-rye 1RS translocation stocks were isolated from a segregating population using the Gli-1, Tri-1 and Sec-1 seed proteins as genetic markers. These stocks carried 42 chromosomes and formed the expected multivalents (frequency of 14-25%) at metaphase 1. They gave floret fertility ranging from 40-60%. These stocks were subsequently used to determine the genetic control of low-molecular-weight (LMW) glutenin subunits in 'Chinese Spring' and 'Gabo' by means of two-step one-dimensional SDS-PAGE. All of the B subunits and most of the C subunits of glutenin were shown to be controlled by genes on the short arms of group-1 chromosomes in these wheats. The other C subunits were not controlled by group-1 chromosomes. The triple translocation line served as a suitable third parent in producing test-cross seeds for studying the inheritance of the LMW glutenin subunits and gliadins in wheat cultivars, e.g. 'Chinese Spring' and 'Orca'. The segregation patterns of the LMW glutenin subunits in these cultivars revealed that the subunits were inherited in clusters and that their controlling genes (Glu-3) were tightly linked with those controlling gliadins (Gli-1). The LMW glutenin patterns d, d and e in 'Orca' segregated as alternatives to the patterns a, a and a in 'Chinese Spring' controlled by Glu-A3, Glu-B3 and Glu-D3 loci on chromosome arms 1AS, 1BS and 1DS, respectively, thus indicating that these patterns were controlled by allelic genes at these loci.

  12. The role of seed size in the non-genetic variation exhibited in salt tolerance studies involving the bread wheat cv. chinese spring

    Directory of Open Access Journals (Sweden)

    P. K. Martin

    2014-01-01

    Full Text Available The intention of this study was to confirm the role of seed size in the non-genetic variation exhibited during salinity tolerance experiments involving the bread wheat cv. Chinese Spring. The nutrient film/rockwool hydroponics technique was utilised. This study concluded that seed size does not play a significant role in the non-genetic variation generated during a study of salinity tolerance of the bread wheat cv. Chinese Spring.

  13. Nucleotide diversity maps reveal variation in diversity among wheat genomes and chromosomes

    Directory of Open Access Journals (Sweden)

    McGuire Patrick E

    2010-12-01

    Full Text Available Abstract Background A genome-wide assessment of nucleotide diversity in a polyploid species must minimize the inclusion of homoeologous sequences into diversity estimates and reliably allocate individual haplotypes into their respective genomes. The same requirements complicate the development and deployment of single nucleotide polymorphism (SNP markers in polyploid species. We report here a strategy that satisfies these requirements and deploy it in the sequencing of genes in cultivated hexaploid wheat (Triticum aestivum, genomes AABBDD and wild tetraploid wheat (Triticum turgidum ssp. dicoccoides, genomes AABB from the putative site of wheat domestication in Turkey. Data are used to assess the distribution of diversity among and within wheat genomes and to develop a panel of SNP markers for polyploid wheat. Results Nucleotide diversity was estimated in 2114 wheat genes and was similar between the A and B genomes and reduced in the D genome. Within a genome, diversity was diminished on some chromosomes. Low diversity was always accompanied by an excess of rare alleles. A total of 5,471 SNPs was discovered in 1791 wheat genes. Totals of 1,271, 1,218, and 2,203 SNPs were discovered in 488, 463, and 641 genes of wheat putative diploid ancestors, T. urartu, Aegilops speltoides, and Ae. tauschii, respectively. A public database containing genome-specific primers, SNPs, and other information was constructed. A total of 987 genes with nucleotide diversity estimated in one or more of the wheat genomes was placed on an Ae. tauschii genetic map, and the map was superimposed on wheat deletion-bin maps. The agreement between the maps was assessed. Conclusions In a young polyploid, exemplified by T. aestivum, ancestral species are the primary source of genetic diversity. Low effective recombination due to self-pollination and a genetic mechanism precluding homoeologous chromosome pairing during polyploid meiosis can lead to the loss of diversity from large

  14. Genetic analysis and SSR mapping of stem rust resistance gene from wheat mutant D51

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Wheat (Triticum aestivum L.) stem rust caused by Puccinia graminis f.sp.tritici is one of the main diseases of wheat worldwide.Wheat mutant line D51,which forms a highly susceptive cultivar 'L6239' to the three races notated and cultured with immature embryos,shows resistance to prevailing races 21C3CPH,21C3CKH,and 21C3CTR of P.graminis f.sp.tritici in China.In this study,the number and the expression stages of the resistance genes in mutant D51 were studied using inoculation identification and microsatellite (SSR) marker analysis.Two F1 populations from the crosses of D51×L6239 (60 individuals) and D51 × Chinese Spring (60 individuals),their F2 populations (185 and 175 individuals respectively) at the seedling stage,and one F2 population derived from the cross of D51×L6239 (194 individuals) at the adult stage were inoculated with pathogen race 21C3CPH to test for resistance.All F1 individuals of the two crosses were immune to stem rust at both seedling and adult stages.The response pattern of the three F2 populations showed that the R:S segregation ratio was 3:1,suggesting that the stem rust resistance of D51 is controlled by a single dominant gene,and is expressed during the entire growth period.The identification of the stem rust resistance by the F3 progeny test confirmed the credibility of the F2 population test.Segregating populations and small population analyses were used to identify chromosomal regions and molecular markers linked to the gene by the SSR marker method.A total of 675 SSR markers and 185 individuals of the D51 x L6239 F2 population were used to search genetically linked markers to the target gene.Using Mapmaker 3.0 and Map-draw with Kosambi's function and other options set at default values,molecular mapping revealed that the gene was located on chromosome 5DS,linked with and flanked by two SSR markers,Xgwml90 and Xwmc150,at 18.58 and 21.33 cM,respectively.It has been reported that only one stem rust resistant gene,Sr30,is located on the

  15. Genetic variation for glutenin and gliadins associated with quality in durum wheat (Triticum turgidum L. ssp. turgidum) landraces from Spain

    Energy Technology Data Exchange (ETDEWEB)

    Aguiriano, E.; Ruiz, M.; Fite, R.; Carrillo, J. M.

    2008-07-01

    The allelic variation at seven prolamin loci involved in quality has been studied in a set of durum wheat land races from all the Spanish regions where this crop has been traditionally cultivated. The genetic variability was higher than that found in other germplasm collections. All the loci, except Glu-B2, displayed a genetic variability higher than 0.62, with Glu-3 the most polymorphic. In total, five alleles were studied at Glu-A1, nine at Glu-B1, 15 at Glu-A3, 18 at Glu-B3, two at Glu- B2, and eight at Gli-A1 and Gli-B1. New allelic variants not previously identified in durum wheat were detected. The 30 different genotypes of B low-molecular-weight (B-LMW) glutenin subunits analysed, of which 25 are novel, provide an important source of genetic variability for quality breeding. Protein patterns for convars. durum and turgidum, and for the North and South of Spain were identified for the loci with significant influence on quality. Higher variability was observed in convar. turgidum and in the North zone than in convar. durum and the South, respectively, mainly for the Glu-B1 and Glu-B3. Also, convar. turgidum appeared to be a valuable source for new alleles for the LMW glutenin subunits. Wheats from the South were, however, more diverse for prolamins encoded at Glu-A3. (Author) 33 refs.

  16. Genetic characterization of Lophopyrum elongatum salt tolerance and associated ion regulation as expressed in bread wheat. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-07

    Lophopyrum elongatum is a highly salt-tolerant relative of wheat. Its salt tolerance is partially expressed in the amphiploid from a cross between wheat cv. Chinese Spring and L. elongatum. Genetic studies showed that the tolerance of gradually imposed salt stress is controlled by L. elongatum chromosomes 3E, 4E, 5E, and 7E and the tolerance of suddenly imposed salt stress by chromosomes 3E, 5E, 6E, and 7E. In wheat, rye, barley, and Dasypyrum, chromosomes of the same homoeologous groups, 3, 5, 6, and 7, were found to control the tolerance of these stress regimes. To gain insight into the physiological mechanisms of salt tolerance by wheat and L. elongatum, accumulation of Na and K, 20 protein amino acids, glycinebetaine, aminobutyrate, all TCA cycle intermediates, oxalate, glycerol-3-P, glyceraldehyde-3-P, pyruvate, lactate, ornithine, taurine, glucose, sucrose and other sugars was examined in the amphiploid and Chinese Spring by gas chromatography and H-NMR.

  17. Considering causal genes in the genetic dissection of kernel traits in common wheat.

    Science.gov (United States)

    Mohler, Volker; Albrecht, Theresa; Castell, Adelheid; Diethelm, Manuela; Schweizer, Günther; Hartl, Lorenz

    2016-11-01

    Genetic factors controlling thousand-kernel weight (TKW) were characterized for their association with other seed traits, including kernel width, kernel length, ratio of kernel width to kernel length (KW/KL), kernel area, and spike number per m(2) (SN). For this purpose, a genetic map was established utilizing a doubled haploid population derived from a cross between German winter wheat cultivars Pamier and Format. Association studies in a diversity panel of elite cultivars supplemented genetic analysis of kernel traits. In both populations, genomic signatures of 13 candidate genes for TKW and kernel size were analyzed. Major quantitative trait loci (QTL) for TKW were identified on chromosomes 1B, 2A, 2D, and 4D, and their locations coincided with major QTL for kernel size traits, supporting the common belief that TKW is a function of other kernel traits. The QTL on chromosome 2A was associated with TKW candidate gene TaCwi-A1 and the QTL on chromosome 4D was associated with dwarfing gene Rht-D1. A minor QTL for TKW on chromosome 6B coincided with TaGW2-6B. The QTL for kernel dimensions that did not affect TKW were detected on eight chromosomes. A major QTL for KW/KL located at the distal tip of chromosome arm 5AS is being reported for the first time. TaSus1-7A and TaSAP-A1, closely linked to each other on chromosome 7A, could be related to a minor QTL for KW/KL. Genetic analysis of SN confirmed its negative correlation with TKW in this cross. In the diversity panel, TaSus1-7A was associated with TKW. Compared to the Pamier/Format bi-parental population where TaCwi-A1a was associated with higher TKW, the same allele reduced grain yield in the diversity panel, suggesting opposite effects of TaCwi-A1 on these two traits.

  18. Identifying genetic markers of wheat (Triticum aestivum) associated with flavor preference using a mouse model

    Science.gov (United States)

    Whole wheat products provide critical nutrients for human health, though differences in wheat flavor are not well understood. Using the house mouse as a model system, flavor was examined using a two-choice feeding system and the Student’s t statistic. To eliminate the confounding effect of processin...

  19. Genetic markers of wheat (Triticum aestivum) associated with flavor preference using a mouse (Mus musculus) model

    Science.gov (United States)

    Whole wheat products provide critical nutrients for human health, differences in wheat flavor are not well understood. Using the house mouse as a model system, flavor preference and discrimination were examined using a two-choice feeding system and 24-h trials and the Student’s t statistic. To elimi...

  20. Discovery and mapping of single feature polymorphisms in wheat using Affymetrix arrays

    Directory of Open Access Journals (Sweden)

    Hu Shengwa

    2009-05-01

    Full Text Available Abstract Background Wheat (Triticum aestivum L. is a staple food crop worldwide. The wheat genome has not yet been sequenced due to its huge genome size (~17,000 Mb and high levels of repetitive sequences; the whole genome sequence may not be expected in the near future. Available linkage maps have low marker density due to limitation in available markers; therefore new technologies that detect genome-wide polymorphisms are still needed to discover a large number of new markers for construction of high-resolution maps. A high-resolution map is a critical tool for gene isolation, molecular breeding and genomic research. Single feature polymorphism (SFP is a new microarray-based type of marker that is detected by hybridization of DNA or cRNA to oligonucleotide probes. This study was conducted to explore the feasibility of using the Affymetrix GeneChip to discover and map SFPs in the large hexaploid wheat genome. Results Six wheat varieties of diverse origins (Ning 7840, Clark, Jagger, Encruzilhada, Chinese Spring, and Opata 85 were analyzed for significant probe by variety interactions and 396 probe sets with SFPs were identified. A subset of 164 unigenes was sequenced and 54% showed polymorphism within probes. Microarray analysis of 71 recombinant inbred lines from the cross Ning 7840/Clark identified 955 SFPs and 877 of them were mapped together with 269 simple sequence repeat markers. The SFPs were randomly distributed within a chromosome but were unevenly distributed among different genomes. The B genome had the most SFPs, and the D genome had the least. Map positions of a selected set of SFPs were validated by mapping single nucleotide polymorphism using SNaPshot and comparing with expressed sequence tags mapping data. Conclusion The Affymetrix array is a cost-effective platform for SFP discovery and SFP mapping in wheat. The new high-density map constructed in this study will be a useful tool for genetic and genomic research in wheat.

  1. Isolation and identification of Triticeae chromosome 1 receptor-like kinase genes (Lrk10) from diploid, tetraploid, and hexaploid species of the genus Avena.

    Science.gov (United States)

    Cheng, D W; Armstrong, K C; Drouin, G; McElroy, A; Fedak, G; Molnar, S D

    2003-02-01

    The DNA sequence of an extracellular (EXC) domain of an oat (Avena sativa L.) receptor-like kinase (ALrk10) gene was amplified from 23 accessions of 15 Avena species (6 diploid, 6 tetraploid, and 3 hexaploid). Primers were designed from one partial oat ALrk10 clone that had been used to map the gene in hexaploid oat to linkage groups syntenic to Triticeae chromosome 1 and 3. Cluster (phylogenetic) analyses showed that all of the oat DNA sequences amplified with these primers are orthologous to the wheat and barley sequences that are located on chromosome 1 of the Triticeae species. Triticeae chromosome 3 Lrk10 sequences were not amplified using these primers. Cluster analyses provided evidence for multiple copies at a locus. The analysis divided the ALrk EXC sequences into two groups, one of which included AA and AABB genome species and the other CC, AACC, and CCCC genome species. Both groups of sequences were found in hexaploid AACCDD genome species, but not in all accessions. The C genome group was divided into 3 subgroups: (i) the CC diploids and the perennial autotetraploid, Avena macrostachya (this supports other evidence for the presence of the C in this autotetraploid species); (ii) a sequence from Avena maroccana and Avena murphyi and several sequences from different accessions of A. sativa; and (iii) A. murphyi and sequences from A. sativa and Avena sterilis. This suggests a possible polyphyletic origin for A. sativa from the AACC progenitor tetraploids or an origin from a progenitor of the AACC tetraploids. The sequences of the A genome group were not as clearly divided into subgroups. Although a group of sequences from the accession 'SunII' and a sequence from line Pg3, are clearly different from the others, the A genome diploid sequences were interspersed with tetraploid and hexaploid sequences.

  2. Metabolite profiling of a diverse collection of wheat lines using ultraperformance liquid chromatography coupled with time-of-flight mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Shawna B Matthews

    Full Text Available Genetic differences among major types of wheat are well characterized; however, little is known about how these distinctions affect the small molecule profile of the wheat seed. Ethanol/water (65% v/v extracts of seed from 45 wheat lines representing 3 genetically distinct classes, tetraploid durum (Triticum turgidum subspecies durum (DW and hexaploid hard and soft bread wheat (T. aestivum subspecies aestivum (BW were subjected to ultraperformance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-TOF-MS. Discriminant analyses distinguished DW from BW with 100% accuracy due to differences in expression of nonpolar and polar ions, with differences attributed to sterol lipids/fatty acids and phospholipids/glycerolipids, respectively. Hard versus soft BW was distinguished with 100% accuracy by polar ions, with differences attributed to heterocyclic amines and polyketides versus phospholipid ions, respectively. This work provides a foundation for identification of metabolite profiles associated with desirable agronomic and human health traits and for assessing how environmental factors impact these characteristics.

  3. Analysis of DNA methylation variation in wheat genetic background after alien chromatin introduction based on methylation-sensitive amplification polymorphism

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    During the process of alien germplasm introduced into wheat genome by chromosome engineering,extensive genetic variations of genome structure and gene expression in recipient could be induced.In this study,we performed GISH(genome in situ hybridization)and AFLP(amplified fragment length polymorphism) on wheat-rye chromosome transIocation lines and their parents to detect the identity in genomic structure of different translocation lines.The results showed that the genome primary structure variations were not obviously detected in different translocation lines except the same 1RS chromosome translocation.Methylation sensitive amplification polymorphism(MSAP)analyses on genomic DNA showed that the ratios of fully-methylated sites were significantly increased in translocation lines(CN12,20.15%;CN17,20.91%;CN18,22.42%),but the ratios of hemimethylated sites were significantly lowered(CN12,21.41%;CN17,23.43%;CN18,22.42%),whereas 16.37%were fully-methylated and 25.44%were hemimethylated in case of their wheat parent.Twenty-nine classes of methylation patterns were identified in a comparative assay of cytosine methylation patterns between wheat-rye translocation lines and their wheat parent,including 13 hypermethylation patterns(33.74%),9 demethylation patterns(22.76%)and 7 uncertain patterns(4.07%).In further sequence analysis,the alterations of methylation pattern affected both repetitive DNA sequences,such as retrotransposons and tandem repetitive sequences,and low-copy DNA.

  4. No adverse effect of genetically modified antifungal wheat on decomposition dynamics and the soil fauna community--a field study.

    Directory of Open Access Journals (Sweden)

    Caroline Duc

    Full Text Available The cultivation of genetically modified (GM plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C∶N ratio, lignin, cellulose, hemicellulose were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina, springtails (Isotomidae, annelids (Enchytraeidae and Diptera (Cecidomyiidae larvae. Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM

  5. Fine mapping and genetic association analysis of Net2, the causative D-genome locus of low temperature-induced hybrid necrosis in interspecific crosses between tetraploid wheat and Aegilops tauschii.

    Science.gov (United States)

    Sakaguchi, Kouhei; Nishijima, Ryo; Iehisa, Julio Cesar Masaru; Takumi, Shigeo

    2016-10-01

    Hybrid necrosis has been observed in many interspecific hybrids from crosses between tetraploid wheat and the wheat D-genome donor Aegilops tauschii. Type II necrosis is a kind of hybrid incompatibility that is specifically characterized by low-temperature induction and growth suppression. Two complementary genes, Net1 on the AB genome and Net2 on the D genome, putatively control type II necrosis in ABD triploids and synthetic hexaploid wheat. Toward map-based cloning of Net2, a fine map around the Net2 region on 2DS was constructed in this study. Using the draft genome sequence of Ae. tauschii and the physical map of the barley genome, the Net2 locus was mapped within a 0.6 cM interval between two closely linked markers. Although local chromosomal rearrangements were observed in the Net2-corresponding region between the barley/Brachypodium and Ae. tauschii genomes, the two closely linked markers were significantly associated with type II necrosis in Ae. tauschii. These results suggest that these markers will aid efficient selection of Net2 non-carrier individuals from the Ae. tauschii population and intraspecific progeny, and could help with introgression of agriculturally important genes from Ae. tauschii to common wheat.

  6. Accelerated Senescence and Enhanced Disease Resistance in Hybrid Chlorosis Lines Derived from Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii

    OpenAIRE

    Hiroki Nakano; Nobuyuki Mizuno; Yukio Tosa; Kentaro Yoshida; Pyoyun Park; Shigeo Takumi

    2015-01-01

    Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlyin...

  7. Genetic analysis and location of gene for resistance to stripe rust in wheat international differential host Strubes Dickkopf

    Indian Academy of Sciences (India)

    Feng Jing; Xu Jiao-Jiao; Lin Rin-Ming; He Yue-Qiu; Xu Shi-Chang

    2013-08-01

    Strubes Dickkopf is the sixth differential in the world set for wheat stripe (yellow) rust. It is very important to clarify its genetic character of resistance to stripe rust and to develop the molecular markers linked to resistance genes. The NIL Taichung 29*6/Strubes Dickkopf, which was obtained by Strubes Dickkopf as the gene donor and Taichung 29 as the genetic background through backcross breeding, was crossed with the recurrent parent Taichung 29, inbred, and backcrossed to obtain the F1, F2 and BC1 population. The genetic analysis of the cross Taichung 29/(Taichung 29*6/Strubes Dickkopf) was assessed by inoculating the rust race CYR26 at seedling stage. Bulked segregant analysis (BSA) and F2 segregation analysis were used for detecting polymorphic primers to locate the gene. The resistance of the NIL Taichung 29*6/Strubes Dickkopf to CYR26 was controlled by a single dominant gene, named YrSD. The primer pair Xbarc59 on 5B was linked to YrSD and the genetic distance between Xbarc59 and YrSD was 2.4 cM. The molecular marker Xbarc59 closely linked to the gene YrSD could be used in marker-assisted selection for resistance to stripe rust in wheat breeding programmes.

  8. Physical mapping of a large plant genome using global high-information-content-fingerprinting: the distal region of the wheat ancestor Aegilops tauschii chromosome 3DS

    Directory of Open Access Journals (Sweden)

    You Frank M

    2010-06-01

    Full Text Available Abstract Background Physical maps employing libraries of bacterial artificial chromosome (BAC clones are essential for comparative genomics and sequencing of large and repetitive genomes such as those of the hexaploid bread wheat. The diploid ancestor of the D-genome of hexaploid wheat (Triticum aestivum, Aegilops tauschii, is used as a resource for wheat genomics. The barley diploid genome also provides a good model for the Triticeae and T. aestivum since it is only slightly larger than the ancestor wheat D genome. Gene co-linearity between the grasses can be exploited by extrapolating from rice and Brachypodium distachyon to Ae. tauschii or barley, and then to wheat. Results We report the use of Ae. tauschii for the construction of the physical map of a large distal region of chromosome arm 3DS. A physical map of 25.4 Mb was constructed by anchoring BAC clones of Ae. tauschii with 85 EST on the Ae. tauschii and barley genetic maps. The 24 contigs were aligned to the rice and B. distachyon genomic sequences and a high density SNP genetic map of barley. As expected, the mapped region is highly collinear to the orthologous chromosome 1 in rice, chromosome 2 in B. distachyon and chromosome 3H in barley. However, the chromosome scale of the comparative maps presented provides new insights into grass genome organization. The disruptions of the Ae. tauschii-rice and Ae. tauschii-Brachypodium syntenies were identical. We observed chromosomal rearrangements between Ae. tauschii and barley. The comparison of Ae. tauschii physical and genetic maps showed that the recombination rate across the region dropped from 2.19 cM/Mb in the distal region to 0.09 cM/Mb in the proximal region. The size of the gaps between contigs was evaluated by comparing the recombination rate along the map with the local recombination rates calculated on single contigs. Conclusions The physical map reported here is the first physical map using fingerprinting of a complete

  9. Analysis of Breeding Systems, Ploidy, and the Role of Hexaploids in Three Hypericum perforatum L. Populations

    Science.gov (United States)

    Hexaploid seeds are produced by predominantly tetraploid populations of Hypericum perforatum, but the fate of hexaploid seedlings and their reproductive behavior have not been closely examined. We used flow cytometry to analyze single seeds and individual plant samples of three accessions of H. per...

  10. Spontaneous wheat-Aegilops biuncialis, Ae. geniculata and Ae. triuncialis amphiploid production, a potential way of gene transference

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, I.; Escorial, C.; Garcia-Baudin, J. M.; Chueca, M. C.

    2009-07-01

    Some F1 hybrid plants between three species of the Aegilops genus and different hexaploid wheat Triticum aestivum cultivars show certain self-fertility, with averages of F{sub 1} hybrids bearing F{sub 2} seeds of 8.17%, 5.12% and 48.14% for Aegilops biuncialis, Aegilops geniculata and Aegilops triuncialis respectively. In the Ae. triuncialis-wheat combination with Astral wheat cultivar, the fertility was higher than that found in the other combinations. All the F2 seeds studied were spontaneous amphiploids (2n=10x=70). The present study evidences the possibility of spontaneous formation of amphiploids between these three Aegilops species and hexaploid wheat and discusses their relevance for gene transference. Future risk assessment of transgenic wheat cultivars needs to evaluate the importance of amphiploids as a bridge for transgene introgression and for gene escape to the wild. (Author)

  11. Genetic variability and fumonisin production by Fusarium proliferatum isolated from durum wheat grains in Argentina.

    Science.gov (United States)

    Palacios, S A; Susca, A; Haidukowski, M; Stea, G; Cendoya, E; Ramírez, M L; Chulze, S N; Farnochi, M C; Moretti, A; Torres, A M

    2015-05-18

    Fusarium proliferatum is a member of the Fusarium fujikuroi species complex (FFSC) involved in the maize ear rot together with Fusarium verticillioides, which is a very closely related species. Recently, different studies have detected natural fumonisin contamination in wheat kernels and most of them have shown that the main species isolated was F. proliferatum. Fusarium strains obtained from freshly harvested durum wheat samples (2008 to 2011 harvest seasons) from Argentina were characterized through a phylogenetic analysis based on translation elongation factor-1 alpha (EF-1α) and calmodulin (CaM) genes, determination of mating type alleles, and evaluation of fumonisin production capability. The strains were identified as F. proliferatum (72%), F. verticillioides (24%) and other Fusarium species. The ratio of mating type alleles (MAT-1 and MAT-2) obtained for both main populations suggests possible occurrence of sexual reproduction in the wheat fields, although this seems more frequent in F. proliferatum. Phylogenetic analysis revealed greater nucleotide variability in F. proliferatum strains than in F. verticillioides, however this was not related to origin, host or harvest year. The fumonisin-producing ability was detected in 92% of the strains isolated from durum wheat grains. These results indicate that F. proliferatum and F. verticillioides, among the fumonisin producing species, frequently contaminate durum wheat grains in Argentina, presenting a high risk for human and animal health. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. A large-scale introgression of genomic components of Brassica rapa into B. napus by the bridge of hexaploid derived from hybridization between B. napus and B. oleracea.

    Science.gov (United States)

    Li, Qinfei; Mei, Jiaqin; Zhang, Yongjing; Li, Jiana; Ge, Xianhong; Li, Zaiyun; Qian, Wei

    2013-08-01

    Brassica rapa (AA) has been used to widen the genetic basis of B. napus (AACC), which is a new but important oilseed crop worldwide. In the present study, we have proposed a strategy to develop new type B. napus carrying genomic components of B. rapa by crossing B. rapa with hexaploid (AACCCC) derived from B. napus and B. oleracea (CC). The hexaploid exhibited large flowers and high frequency of normal chromosome segregation, resulting in good seed set (average of 4.48 and 12.53 seeds per pod by self and open pollination, respectively) and high pollen fertility (average of 87.05 %). It was easy to develop new type B. napus by crossing the hexaploid with 142 lines of B. rapa from three ecotype groups, with the average crossability of 9.24 seeds per pod. The genetic variation of new type B. napus was diverse from that of current B. napus, especially in the A subgenome, revealed by genome-specific simple sequence repeat markers. Our data suggest that the strategy proposed here is a large-scale and highly efficient method to introgress genomic components of B. rapa into B. napus.

  13. Dissemination of the highly expressed Bx7 glutenin subunit (Glu-B1al allele) in wheat as revealed by novel PCR markers and RP-HPLC.

    Science.gov (United States)

    Butow, B J; Gale, K R; Ikea, J; Juhász, A; Bedö, Z; Tamás, L; Gianibelli, M C

    2004-11-01

    Increased expression of the high molecular weight glutenin subunit (HMW-GS) Bx7 is associated with improved dough strength of wheat (Triticum aestivum L.) flour. Several cultivars and landraces of widely different genetic backgrounds from around the world have now been found to contain this so-called 'over-expressing' allelic form of the Bx7 subunit encoded by Glu-B1al. Using three methods of identification, SDS-PAGE, RP-HPLC and PCR marker analysis, as well as pedigree information, we have traced the distribution and source of this allele from a Uruguayan landrace, Americano 44D, in the mid-nineteenth century. Results are supported by knowledge of the movement of wheat lines with migrants. All cultivars possessing the Glu-B1al allele can be identified by the following attributes: (1) the elution of the By sub-unit peak before the Dx sub-unit peak by RP-HPLC, (2) high expression levels of Bx7 (>39% Mol% Bx), (3) a 43 bp insertion in the matrix-attachment region (MAR) upstream of the gene promoter relative to Bx7 and an 18 bp nucleotide duplication in the coding region of the gene. Evidence is presented indicating that these 18 and 43 bp sequence insertions are not causal for the high expression levels of Bx7 as they were also found to be present in a small number of hexaploid species, including Chinese Spring, and species expressing Glu-B1ak and Glu-B1a alleles. In addition, these sequence inserts were found in different isolates of the tetraploid wheat, T. turgidum, indicating that these insertion/deletion events occurred prior to hexaploidization.

  14. Infestation of transgenic powdery mildew-resistant wheat by naturally occurring insect herbivores under different environmental conditions.

    Directory of Open Access Journals (Sweden)

    Fernando Álvarez-Alfageme

    Full Text Available A concern associated with the growing of genetically modified (GM crops is that they could adversely affect non-target organisms. We assessed the impact of several transgenic powdery mildew-resistant spring wheat lines on insect herbivores. The GM lines carried either the Pm3b gene from hexaploid wheat, which confers race-specific resistance to powdery mildew, or the less specific anti-fungal barley seed chitinase and β-1,3-glucanase. In addition to the non-transformed control lines, several conventional spring wheat varieties and barley and triticale were included for comparison. During two consecutive growing seasons, powdery mildew infection and the abundance of and damage by naturally occurring herbivores were estimated under semi-field conditions in a convertible glasshouse and in the field. Mildew was reduced on the Pm3b-transgenic lines but not on the chitinase/glucanase-expressing lines. Abundance of aphids was negatively correlated with powdery mildew in the convertible glasshouse, with Pm3b wheat plants hosting significantly more aphids than their mildew-susceptible controls. In contrast, aphid densities did not differ between GM plants and their non-transformed controls in the field, probably because of low mildew and aphid pressure at this location. Likewise, the GM wheat lines did not affect the abundance of or damage by the herbivores Oulema melanopus (L. and Chlorops pumilionis Bjerk. Although a previous study has revealed that some of the GM wheat lines show pleiotropic effects under field conditions, their effect on herbivorous insects appears to be low.

  15. Resistance to Soil-borne cereal mosaic virus in durum wheat is controlled by a major QTL on chromosome arm 2BS and minor loci.

    Science.gov (United States)

    Maccaferri, Marco; Ratti, Claudio; Rubies-Autonell, Concepcion; Vallega, Victor; Demontis, Andrea; Stefanelli, Sandra; Tuberosa, Roberto; Sanguineti, Maria Corinna

    2011-08-01

    Soil-borne cereal mosaic (SBCM) is a viral disease, which seriously affects hexaploid as well as tetraploid wheat crops in Europe. In durum wheat (Triticum durum Desf.), the elite germplasm is characterized by a wide range of responses to SBCMV, from susceptibility to almost complete resistance. In this study, the genetic analysis of SBCMV resistance was carried out using a population of 181 durum wheat recombinant inbred lines (RILs) obtained from Meridiano (resistant) × Claudio (moderately susceptible), which were profiled with SSR and DArT markers. The RILs were characterized for SBCMV response in the field under severe and uniform SBCMV infection during 2007 and 2008. A wide range of disease reactions (as estimated by symptom severity and DAS-ELISA) was observed. A large portion of the variability for SBCMV response was explained by a major QTL (QSbm.ubo-2BS) located in the distal telomeric region of chromosome 2BS near the marker triplet Xbarc35-Xwmc661-Xgwm210, with R(2) values ranging from 51.6 to 91.6%. The favorable allele was contributed by Meridiano. Several QTLs with minor effects on SBCMV response were also detected. Consistently with the observed transgressive segregation, the resistance alleles at minor QTLs were contributed by both parents. The presence and effects of QSbm.ubo-2BS were validated through association mapping in a panel of 111 elite durum wheat accessions.

  16. Production and genetic characterization of near-isogenic lines in the bread-wheat cultivar Alpe.

    Science.gov (United States)

    Pogna, N E; Redaelli, R; Vaccino, P; Biancardi, A M; Peruffo, A D; Curioni, A; Metakovsky, E V; Pagliaricci, S

    1995-04-01

    Two biotypes of the bread-wheat cultivar Alpe were shown to possess contrasting alleles at each of the glutenin (Glu-B1, Glu-D1, Glu-B3 and Glu-D3) and gliadin (Gli-B1 and Gli-D1) loci on chromosomes 1B and 1D. Fourteen near-isogenic lines (NILs) were produced by crossing these biotypes and used to determine the genetic control of both low-molecular-weight (LMW) glutenin subunits and gliadins by means of one-dimensional or two-dimensional electrophoresis. Genes coding for the B, C and D groups of EMW subunits were found to be inherited in clusters tightly linked with those controlling gliadins. Southern-blot analysis of total genomic DNAs hybridized to a γ-gliadin-specific cDNA clone revealed that seven NILs lack both the Gli-D1 and Glu-D3 loci on chromosome 1D. Segregation data indicated that these "null" alleles are normally inherited. Comparison of the "null" NILs with those possessing allele b at the Glu-D3 locus showed one B subunit, seven C subunits and two D subunits, as fractionated by two-dimensional A-PAGExSDS-PAGE, to be encoded by this allele. Alleles b and k at Glu-B3 were found to code for two C subunits plus eight and six B subunits respectively, whereas alleles b and k at Gli-B1 each controlled the synthesis of two β-gliadins, one γ and two ω-gliadins. The novel Gli-B5 locus coding for two ω-gliadins was shown to recombine with the Gli-B1 locus on chromosome 1B. The two-dimensional map of glutenin subunits showed α-gliadins encoded at the Gli-A2 locus on chromosome 6A. The use of Alpe NILs in the study of the individual and combined effects of glutenin subunits on dough properties is discussed.

  17. Genetics of adult plant stripe rust resistance in CSP44, a selection from Australian wheat

    Indian Academy of Sciences (India)

    Renu Khanna; U. K. Bansal; R. G. Saini

    2005-12-01

    Wheat line CSP44, a selection from an Australian bread wheat cultivar Condor, has shown resistance to stripe rust in India since the last twenty years. Seedlings and adult plants of CSP44 showed susceptible infection types against stripe rust race 46S119 but displayed average terminal disease severity of 2.67 on adult plants against this race as compared to 70.33 of susceptible Indian cultivar, WL711. This suggests the presence of nonhypersensitive adult plant stripe rust resistance in the line CSP44. The evaluation of F1, F2 and F3 generations and F6 SSD families from the cross of CSP44 with susceptible wheat cultivar WL711 for stripe rust severity indicated that the resistance in CSP44 is based on two genes showing additive effect. One of these two genes is Yr18 and the second gene is not yet described.

  18. Genetic Diversity under Soil Compaction in Wheat: Root Number as a Promising Trait for Early Plant Vigor

    Science.gov (United States)

    Colombi, Tino; Walter, Achim

    2017-01-01

    Soil compaction of arable land, caused by heavy machinery constitutes a major threat to agricultural soils in industrialized countries. The degradation of soil structure due to compaction leads to decreased (macro-) porosity resulting in increased mechanical impedance, which adversely affects root growth and crop productivity. New crop cultivars, with root systems that are adapted to conditions of increased soil strength, are needed to overcome the limiting effects of soil compaction on plant growth. This study aimed (i) to quantify the genetic diversity of early root system development in wheat and to relate this to shoot development under different soil bulk densities and (ii) to test whether root numbers are suitable traits to assess the genotypic tolerance to soil compaction. Fourteen wheat genotypes were grown for 3 weeks in a growth chamber under low (1.3 g cm-3), moderate (1.45 g cm-3), and high soil bulk density (1.6 g cm-3). Using X-ray computed tomography root system development was quantified in weekly intervals, which was complemented by weekly measurements of plant height. The development of the root system, quantified via the number of axial and lateral roots was strongly correlated (0.78 numbers were significantly correlated (0.57 number was higher than 50% and comparable to values calculated for shoot traits. Our results showed that there is genetic diversity in wheat with respect to root system responses to increased soil strength and that root numbers are suitable indicators to explain the responses and the tolerance to such conditions. Since root numbers are heritable and can be assessed at high throughput rates under laboratory and field conditions, root number is considered a promising trait for screening toward compaction tolerant varieties. PMID:28400783

  19. Allelic variations in Glu-1 and Glu-3 loci of historical and modern Iranian bread wheat (Triticum aestivum L.) cultivars

    Indian Academy of Sciences (India)

    Ali Izadi-Darbandi; Bahman Yazdi-Samadi; Ali-Akbar Su-Boushehri; Mohsen Mohammadi

    2010-08-01

    Proline and glutamine-rich wheat seed endosperm proteins are collectively referred to as prolamins. They are comprised of HMW-GSs, LMW-GSs and gliadins. HMW-GSs are major determinants of gluten elasticity and LMW-GSs considerably affect dough extensibility and maximum dough resistance. The inheritance of glutenin subunits follows Mendelian genetics with multiple alleles in each locus. Identification of the banding patterns of glutenin subunits could be used as an estimate for screening high quality wheat germplasm. Here, by means of a two-step 1D-SDS-PAGE procedure, we identified the allelic variations in high and low-molecular-weight glutenin subunits in 65 hexaploid wheat (Triticum aestivum L.) cultivars representing a historical trend in the cultivars introduced or released in Iran from the years 1940 to 1990. Distinct alleles 17 and 19 were detected for Glu-1 and Glu-3 loci, respectively. The allelic frequencies at the Glu-1 loci demonstrated unimodal distributions. At Glu-A1, Glu-B1 and Glu-D1, we found that the most frequent alleles were the null, 7 + 8, 2 + 12 alleles, respectively, in Iranian wheat cultivars. In contrast, Glu-3 loci showed bimodal or trimodal distributions. At Glu-A3, the most frequent alleles were c and e. At Glu-B3 the most frequent alleles were a, b and c. At Glu-D3 locus, the alleles b and a, were the most and the second most frequent alleles in Iranian wheat cultivars. This led to a significantly higher Nei coefficient of genetic variations in Glu-3 loci (0.756) as compared to Glu-1 loci (0.547). At Glu-3 loci, we observed relatively high quality alleles in Glu-A3 and Glu-D3 loci and low quality alleles at Glu-B3 locus.

  20. Bio-agronomic Evaluation of Old and Modern Wheat, Spelt and Emmer Genotypes for Low-input Farming in Mediterranean Environment

    Directory of Open Access Journals (Sweden)

    Pasquale Codianni

    2007-09-01

    Full Text Available Low-input cropping systems are characterised by the reduction of pesticides and chemical fertilizers and, often, by the use of old cultivars to realize sustainable crop production which can easily integrate in the European Union agricultural subsidies. Market prices and environmental concerns favour low-input wheat production systems, nevertheless protein standards become particularly difficult to achieve in these conditions due to a minimal nitrogen supply. This study assesses the efficiency of a specific breeding program dedicated to improve yield and quality in emmer and spelt wheat in low-input environments. Ten tetraploid (emmer and durum wheat and four hexaploid (spelt and bread wheat wheat genotypes (including parent cultivars and offspring breeding lines selected for adaptation to low-input conditions were investigated for 1 yr (2003-2004 in Italy in three locations in conventional and low-input cropping systems. The main agro-morphological and qualitative traits were recorded (HD, PH, GY, PC GPY, TKW, TW, GC. The results of this study show encouraging agronomic performances of new emmer and spelt genotypes under conventional and low-input cropping systems. The new genotypes are characterized by a yield potential similar to that of the modern wheat cultivar as well as by a protein content higher than old emmer and spelt accessions. The new genetic materials were also characterized by a higher responsiveness to improved environmental conditions. The results described in this study support the suitability of modern emmer and spelt genotypes, improved by introgressing wheat yield and quality traits, for organic farming in Mediterranean environments.

  1. Bio-agronomic Evaluation of Old and Modern Wheat, Spelt and Emmer Genotypes for Low-input Farming in Mediterranean Environment

    Directory of Open Access Journals (Sweden)

    Michele Fornara

    2011-02-01

    Full Text Available Low-input cropping systems are characterised by the reduction of pesticides and chemical fertilizers and, often, by the use of old cultivars to realize sustainable crop production which can easily integrate in the European Union agricultural subsidies. Market prices and environmental concerns favour low-input wheat production systems, nevertheless protein standards become particularly difficult to achieve in these conditions due to a minimal nitrogen supply. This study assesses the efficiency of a specific breeding program dedicated to improve yield and quality in emmer and spelt wheat in low-input environments. Ten tetraploid (emmer and durum wheat and four hexaploid (spelt and bread wheat wheat genotypes (including parent cultivars and offspring breeding lines selected for adaptation to low-input conditions were investigated for 1 yr (2003-2004 in Italy in three locations in conventional and low-input cropping systems. The main agro-morphological and qualitative traits were recorded (HD, PH, GY, PC GPY, TKW, TW, GC. The results of this study show encouraging agronomic performances of new emmer and spelt genotypes under conventional and low-input cropping systems. The new genotypes are characterized by a yield potential similar to that of the modern wheat cultivar as well as by a protein content higher than old emmer and spelt accessions. The new genetic materials were also characterized by a higher responsiveness to improved environmental conditions. The results described in this study support the suitability of modern emmer and spelt genotypes, improved by introgressing wheat yield and quality traits, for organic farming in Mediterranean environments.

  2. Molecular verification of the integration of Tripsacum dactyloides DNA into wheat genome through wide hybridization

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    RAPD and RFLP analyses of double haploid lines which derived from hybridization between hexaploid wheat (Triticum aestivum L.2n=42) and eastern gamagrass (Tripsacum dactyloides L.2n=4x=72) are reported.Two of the 340 Operon primers have been screened,which stably amplified Tripsacum dactyloides (male parent) specific bands in the double haploid lines.These results confirm the fact that Tripsacum dactyloides DNA has been integrated into wheat genome by sexual hybridization at molecular level.This idea has been further testified by RFLP analysis.Application and potentials of transferring Tripsacum dactyloides DNA into wheat genome by sexual hybridization in wheat breeding are discussed.

  3. Comparative genetic mapping revealed powdery mildew resistance gene MlWE4 derived from wild emmer is located in same genomic region of Pm36 and Ml3D232 on chromosome 5BL

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dong; WANG Yong; CHEN Yong-xing; LIU Zhi-yong; OUYANG Shu-hong; WANG Li-li; CUI Yu; WU Qiu-hong; LIANG Yong; WANG Zhen-zhong; XIE Jing-zhong; ZHANG De-yun

    2015-01-01

    Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most devastating wheat diseases. Wild emmer wheat (Triticum turgidum ssp. dicoccoides) is a promising source of disease resistance for wheat. A powdery mildew resistance gene conferring resistance to B. graminis f. sp. tritici isolate E09, originating from wild emmer wheat, has been transferred into the hexaploid wheat line WE4 through crossing and backcrossing. Genetic analyses indicated that the powdery mildew resistance was control ed by a single dominant gene, temporarily designated MlWE4. By mean of comparative genomics and bulked segregant analysis, a genetic linkage map of MlWE4 was constructed, and MlWE4 was mapped on the distal region of chromosome arm 5BL. Comparative genetic linkage maps showed that genes MlWE4, Pm36 and Ml3D232 were co-segregated with markers XBD37670 and XBD37680, indicating they are likely the same gene or al eles in the same locus. The co-segregated markers provide a starting point for chromosome landing and map-based cloning of MlWE4, Pm36 and Ml3D232.

  4. Unraveling the genetics of wheat-necrotrophic pathogen interactions reveals a conundrum

    Science.gov (United States)

    Interactions between wheat and the necrotrophic pathogens Parastagonospora nodorum (Pn) and Pyrenophora tritici-repentis (Ptr), which cause the foliar diseases Septoria nodorum blotch (SNB) and tan spot, respectively, involve host genes that recognize pathogen-produced necrotrophic effectors (NEs) i...

  5. Genetic and epigenetic changes in somatic hybrid introgression lines between wheat and tall wheatgrass

    Science.gov (United States)

    Broad phenotypic variations were induced in derivatives of an asymmetric somatic hybridization of bread wheat (Triticum aestivum) and tall wheatgrass (Thinopyrum ponticum Podp); however, how did these variations happened was unknown. We explored the nature of these variations by cytogenetic assays ...

  6. Quantifying Phenotypic Plasticity Using Genetic Information for Simulating Plant Height in Winter Wheat

    Science.gov (United States)

    A challenge for crop simulation modeling is to incorporate existing and rapidly emerging genomic information into models to develop new and improved algorithms. The objective of this effort was to simulate plant height in winter wheat (Triticum aestivum L.) across a range of environments in Nebraska...

  7. Genetic architecture of resistance to stripe rust in a global winter wheat germplasm collection

    Science.gov (United States)

    Virulence shifts in populations of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, are a major challenge to resistance breeding. The majority of known resistance genes are already ineffective against current races of Pst, necessitating the identification and intr...

  8. Growth stage-based modulation in physiological and biochemical attributes of two genetically diverse wheat (Triticum aestivum L.) cultivars grown in salinized hydroponic culture.

    Science.gov (United States)

    Ashraf, Muhammad Arslan; Ashraf, Muhammad

    2016-04-01

    Hydroponic experiment was conducted to appraise variation in the salt tolerance potential of two wheat cultivars (salt tolerant, S-24, and moderately salt sensitive, MH-97) at different growth stages. These two wheat cultivars are not genetically related as evident from randomized polymorphic DNA analysis (random amplified polymorphic DNA (RAPD)) which revealed 28% genetic diversity. Salinity stress caused a marked reduction in grain yield of both wheat cultivars. However, cv. S-24 was superior to cv. MH-97 in maintaining grain yield under saline stress. Furthermore, salinity caused a significant variation in different physiological attributes measured at different growth stages. Salt stress caused considerable reduction in different water relation attributes of wheat plants. A significant reduction in leaf water, osmotic, and turgor potentials was recorded in both wheat cultivars at different growth stages. Maximal reduction in leaf water potential was recorded at the reproductive stage in both wheat cultivars. In contrast, maximal turgor potential was observed at the boot stage. Salt-induced adverse effects of salinity on different water relation attributes were more prominent in cv. MH-97 as compared to those in cv. S-24. Salt stress caused a substantial decrease in glycine betaine and alpha tocopherols. These biochemical attributes exhibited significant salt-induced variation at different growth stages in both wheat cultivars. For example, maximal accumulation of glycine betaine was evident at the early growth stages (vegetative and boot). However, cv. S-24 showed higher accumulation of this organic osmolyte, and this could be the reason for maintenance of higher turgor than that of cv. MH-97 under stress conditions. Salt stress significantly increased the endogenous levels of toxic ions (Na(+) and Cl(-)) and decreased essential cations (K(+) and Ca(2+)) in both wheat cultivars at different growth stages. Furthermore, K(+)/Na(+) and Ca(2+)/Na(+) ratios

  9. A High-Density Consensus Map of Common Wheat Integrating Four Mapping Populations Scanned by the 90K SNP Array

    Science.gov (United States)

    Wen, Weie; He, Zhonghu; Gao, Fengmei; Liu, Jindong; Jin, Hui; Zhai, Shengnan; Qu, Yanying; Xia, Xianchun

    2017-01-01

    A high-density consensus map is a powerful tool for gene mapping, cloning and molecular marker-assisted selection in wheat breeding. The objective of this study was to construct a high-density, single nucleotide polymorphism (SNP)-based consensus map of common wheat (Triticum aestivum L.) by integrating genetic maps from four recombinant inbred line populations. The populations were each genotyped using the wheat 90K Infinium iSelect SNP assay. A total of 29,692 SNP markers were mapped on 21 linkage groups corresponding to 21 hexaploid wheat chromosomes, covering 2,906.86 cM, with an overall marker density of 10.21 markers/cM. Compared with the previous maps based on the wheat 90K SNP chip detected 22,736 (76.6%) of the SNPs with consistent chromosomal locations, whereas 1,974 (6.7%) showed different chromosomal locations, and 4,982 (16.8%) were newly mapped. Alignment of the present consensus map and the wheat expressed sequence tags (ESTs) Chromosome Bin Map enabled assignment of 1,221 SNP markers to specific chromosome bins and 819 ESTs were integrated into the consensus map. The marker orders of the consensus map were validated based on physical positions on the wheat genome with Spearman rank correlation coefficients ranging from 0.69 (4D) to 0.97 (1A, 4B, 5B, and 6A), and were also confirmed by comparison with genetic position on the previously 40K SNP consensus map with Spearman rank correlation coefficients ranging from 0.84 (6D) to 0.99 (6A). Chromosomal rearrangements reported previously were confirmed in the present consensus map and new putative rearrangements were identified. In addition, an integrated consensus map was developed through the combination of five published maps with ours, containing 52,607 molecular markers. The consensus map described here provided a high-density SNP marker map and a reliable order of SNPs, representing a step forward in mapping and validation of chromosomal locations of SNPs on the wheat 90K array. Moreover, it can be

  10. Genetic dissection of yield and its component traits using high-density composite map of wheat chromosome 3A: bridging gaps between QTLs and underlying genes

    Science.gov (United States)

    Earlier we identified wheat (Triticum aestivum L.) chromosome 3A as a major determinant of grain yield and its component traits. In the present study, a high-density genetic linkage map of 81 chromosome 3A-specific markers was developed to increase the precision of previously identified yield compon...

  11. Genetic Variation in Deep Root Growth of North-European Winter Wheat

    DEFF Research Database (Denmark)

    Ytting, Nanna Karkov

    traits were found to vary between modern North-European winter wheat cultivars including variation in depth penetration rate and root density in the deepest part of the root system. Wheat was shown to be capable of using deep N resources. After three to six weeks of root proliferation in the N rich...... subsoil, 21 to 39 % of the deep N was utilized for shoot growth. Furthermore, the tested cultivars indicated variation in root response to deep N and in N uptake. Increased root density at depth improved N content in the shoot at moderate to high subsoil N levels (3.2 to 12.5 mg N mg-1 soil). However...... the total N content of the shoots. Overall the results show, that variation exists for deeper root traits in existing elite germplasm adapted to North Europe. This opens the way for wider screening to assess the value in breeding for deeper roots in winter wheat. Deeper rooting, but not necessarily higher...

  12. [Sequence polymorphism and mapping of wheat Ca2+-binding protein TaCRT-A gene].

    Science.gov (United States)

    Wang, Ji-Ping; Mao, Xin-Guo; Li, Run-Zhi; Jing, Rui-Lian

    2012-09-01

    Taking thirty-seven hexaploid wheat (AABBDD) accessions with different drought resistance at seedling stage, three wheat species with A genome (AA), and three tetraploid wheat species (AABB) as test materials, and by direct sequencing the single nucleotide polymorphism (SNP) in TaCRT-A, this paper analyzed the relationships of the SNP with the drought resistance of wheat ( Triticum aestivum) at its seedling stage, and mapped the TaCRT-A on the chromosome of wheat. The full-length sequence of the TaCRT-A genomic DNA was 3887 bp. A total of 202 nucleotide variant loci were observed in the full length sequence of 167141 bp, among which, 165 SNP and 37 InDel with the frequencies of 1 SNP/1013 bp and 1 InDel/4517 bp were detected, respectively. The nucleotide diversity (pi) in coding region of TaCRT-A was lower than that in non-coding region, suggesting that the selection pressure in coding region was stronger than that in non-coding region. The 43 accessions could be classified as 14 haplotypes (H1-H14) by haploid analysis, among which, H1, H2, and H13 all contained one accession which was the donor species of A genome in common wheat, H16 and H7 had one high drought-resistant accession, H8 comprised tetraploid wheat, drought-resistant accessions, and drought-sensitive accessions, whereas H11 included the wheat accessions with drought-resistance and medium-drought resistance. Though the expression of TaCRT was induced by water stress, no significant relationship was identified between TaCRT-A polymorphism and drought resistance. Using a population of recombinant inbred lines derived from a cross of Opata 85 x W7984, the TaCRT-A was mapped between SSR markers Xmwg30 and Xmwg570 on chromosome 3A, and the genetic distances were 10.5 cM and 49.6 cM from the flanking markers, respectively.

  13. Dynamics of genetic variation at gliadin-coding loci in bread wheat cultivars developed in small grains research center (Kragujevac during last 35 years

    Directory of Open Access Journals (Sweden)

    Novosljska-Dragovič Aleksandra

    2005-01-01

    Full Text Available Multiple alleles of gliadin-coding loci are well-known genetic markers of common wheat genotypes. Based on analysis of gliadin patterns in common wheat cultivars developed at the Small Grains Research Center in Kragujevac dynamics of genetic variability at gliadin-coding loci has been surveyed for the period of 35 years. It was shown that long-term breeding of the wheat cultivars involved gradual replacement of ancient alleles for those widely spread in some regions in the world, which belong to well-known cultivars-donor of some important traits. Developing cultivars whose pedigree involved much new foreign genetic material has increased genetic diversity as well as has changed frequency of alleles of gliadin-coding loci. So we can conclude that the genetic profile of modern Serbian cultivars has changed considerably. Genetic formula of gliadin was made for each the cultivar studied. The most frequent alleles of gliadin-coding loci among modern cultivars should be of great interest of breeders because these alleles are probably linked with genes that confer advantage to their carriers at present.

  14. Genetic Architecture of Main Effect QTL for Heading Date in European Winter Wheat

    Directory of Open Access Journals (Sweden)

    Christine eZanke

    2014-05-01

    Full Text Available A genome-wide association study (GWAS for heading date (HD was performed with a panel of 358 European winter wheat (Triticum aestivum L. varieties and 14 spring wheat varieties through the phenotypic evaluation of HD in field tests in eight environments. Genotyping data consisted of 770 mapped microsatellite loci and 7934 mapped SNP markers derived from the 90K iSelect wheat chip. Best linear unbiased estimations (BLUEs were calculated across all trials and ranged from 142.5 to 159.6 days after the 1st of January with an average value of 151.4 days. Considering only associations with a –log10 (P-value ≥3.0, a total of 340 SSR and 2983 SNP marker-trait associations (MTAs were detected. After Bonferroni correction for multiple testing, a total of 72 SSR and 438 SNP marker-trait associations remained significant. Highly significant MTAs were detected for the photoperiodism gene Ppd-D1, which was genotyped in all varieties. Consistent associations were found on all chromosomes with the highest number of MTAs on chromosome 5B. Linear regression showed a clear dependence of the HD score BLUEs on the number of favourable alleles (decreasing HD and unfavourable alleles (increasing HD per variety meaning that genotypes with a higher number of favourable or a low number of unfavourable alleles showed lower HD and therefore flowered earlier. For the vernalization gene Vrn-A2 co-locating MTAs on chromosome 5A, as well as for the photoperiodism genes Ppd-A1 and Ppd-B1 on chromosomes 2A and 2B were detected. After the construction of an integrated map of the SSR and SNP markers and by exploiting the synteny to sequenced species, such as rice and Brachypodium distachyon, we were able to demonstrate that a marker locus on wheat chromosome 5BL with homology to the rice photoperiodism gene Hd6 played a significant role in the determination of the heading date in wheat.

  15. Bread wheat milling behavior: effects of genetic and environmental factors, and modeling using grain mechanical resistance traits.

    Science.gov (United States)

    Oury, François-Xavier; Lasme, P; Michelet, C; Dubat, A; Gardet, O; Heumez, E; Rolland, B; Rousset, M; Abecassis, J; Bar L'Helgouac'h, C; Lullien-Pellerin, V

    2017-05-01

    Genetic (Pinb-D1 alleles) and environment (through vitreousness) have important effects on bread wheat milling behavior. SKCS optimal values corresponding to soft vitreous or hard mealy grains were defined to obtain the highest total flour yield. Near-isogenic lines of bread wheat that differ in hardness, due to distinct puroindoline-b alleles (the wild type, Pinb-D1a, or the mutated forms, Pinb-D1b or Pinb-D1d), were grown in different environments and under two nitrogen fertilization levels, to study genetic and environmental effects on milling behavior. Milling tests used a prototype mill, equipped with two break steps, one sizing step, and two reduction steps, and this enabled 21 individual or aggregated milling fractions to be collected. Four current grain characters, thousand grain weight, test weight, grain diameter, and protein content, were measured, and three characters known to influence grain mechanical resistance, NIRS hardness, SKCS hardness index, and grain vitreousness (a character affecting the grain mechanical behavior but generally not studied). As expected, the wild type or mutated forms of Pinb-D1 alleles led to contrasted milling behavior: soft genotypes produced high quantities of break flour and low quantities of reduction flour, whereas reverse quantities were observed for hard genotypes. This different milling behavior had only a moderate influence on total flour production. NIRS hardness and vitreousness were, respectively, the most important and the second most important grain characters to explain milling behavior. However, contrary to NIRS hardness, vitreousness was only involved in endosperm reduction and not in the separation between the starchy endosperm and the outer layers. The highest flour yields were obtained for SKCS values comprised between 30 and 50, which corresponded either to soft vitreous or hard mealy grains. Prediction equations were defined and showed a good accuracy estimating break and reduction flours portions, but

  16. Quantitative trait locus mapping reveals complex genetic architecture of quantitative virulence in the wheat pathogen Zymoseptoria tritici.

    Science.gov (United States)

    Stewart, Ethan L; Croll, Daniel; Lendenmann, Mark H; Sanchez-Vallet, Andrea; Hartmann, Fanny E; Palma-Guerrero, Javier; Ma, Xin; McDonald, Bruce A

    2016-11-21

    We conducted a comprehensive analysis of virulence in the fungal wheat pathogen Zymoseptoria tritici using quantitative trait locus (QTL) mapping. High-throughput phenotyping based on automated image analysis allowed the measurement of pathogen virulence on a scale and with a precision that was not previously possible. Across two mapping populations encompassing more than 520 progeny, 540 710 pycnidia were counted and their sizes and grey values were measured. A significant correlation was found between pycnidia size and both spore size and number. Precise measurements of percentage leaf area covered by lesions provided a quantitative measure of host damage. Combining these large and accurate phenotypic datasets with a dense panel of restriction site-associated DNA sequencing (RADseq) genetic markers enabled us to genetically dissect pathogen virulence into components related to host damage and those related to pathogen reproduction. We showed that different components of virulence can be under separate genetic control. Large- and small-effect QTLs were identified for all traits, with some QTLs specific to mapping populations, cultivars and traits and other QTLs shared among traits within the same mapping population. We associated the presence of four accessory chromosomes with small, but significant, increases in several virulence traits, providing the first evidence for a meaningful function associated with accessory chromosomes in this organism. A large-effect QTL involved in host specialization was identified on chromosome 7, leading to the identification of candidate genes having a large effect on virulence.

  17. Seed Biochemical Analysis Based Profiling of Diverse Wheat Genetic Resource from Pakistan

    Directory of Open Access Journals (Sweden)

    Anam Khalid

    2017-07-01

    Full Text Available Wheat is the major nutrient source worldwide. In Pakistan, it has a crucial place in agriculture as well as in national economy. For seed biochemical compositional analysis, wheat germplasm (77 genotypes was collected from different agro-climatic zones of Pakistan. Significant variation (p < 0.05 was observed for tested parameters among tested genotypes. Highest activity of ascorbate peroxidase (APX was detected in Pavon (1,426.67 Units/g s. wt., catalase (CAT in Pasban-90 (633.33 Units/g s. wt., peroxidase (POD in IQBAL-2000 (42,579.6 Units/g s. wt., and superoxide dismutase (SOD in Manthar-2003 (278.93 Units/g s. wt.. Whereas, maximum activity of alpha amylase was found in SH-2002 (292.70 mg/g s. wt., esterase in Dharabi 2011 (987.80 μM/min/g s. wt., and protease in NR-234 (11,183.33 Units/g s. wt. and highest total oxidant status (TOS was detected in Faisalabad-2008 (390.0 μM/g s. wt., malondialdehyde (MDA content in Margalla-99 (679.23 μM/g s. wt., total phenolic content (TPC in Bhakkar-2000 (25,383.33 μM/g s. wt., and ascorbic acid (AsA content in SH-2002 (713.0 μg/g s. wt.. Maximum total soluble sugar was found in Saleem-2000 (29.86 mg/g s. wt., reducing sugars in Punjab-96 (12.68 mg/g s. wt., non-reducing sugars in Saleem-2000 (27.33 mg/g s. wt.. However, highest albumins was identified in TC-4928 (352.89 mg/g s. wt. and globulins in MEXI PAK (252.67 mg/g s. wt., salt soluble proteins in Faisalabad-2008 (162.44 mg/g s. wt., and total soluble proteins in Punjab-96 (487.33 mg/g s. wt. indicating good quality of wheat genotypes as well as good nutritional status. Genotypes which have been ranked high in respective parameter can be employed in breeding to enhance the nutritional quality of wheat.

  18. Physiological processes associated with genetic progress in yield potential of wheat (Triticum aestivum L.)

    OpenAIRE

    Aisawi, Khaled A. Boulgasem

    2012-01-01

    Wheat (Triticum aestivum L.) is the most widely grown of any crop and provides one-fifth of the total calories of the world's population. Since the 1960s, increases in productivity have been achieved as a result of wide-scale adoption of Green Revolution technologies. However, in spite of growing demand, the challenges of increasing production to feed an estimated world population of 9 billion in 2050 are still considerable. Due to the increased demand, it is estimated that food production mu...

  19. Classification of the waxy condition of durum wheat by near infrared reflectance spectroscopy using wavelets and a genetic algorithm

    Science.gov (United States)

    Near infrared (NIR) reflectance spectroscopy has been applied to the problem of differentiating four genotypes of durum wheat: ‘waxy’, wx-A1 null, wx-B1 null and wild type. The test data consisted of 95 NIR reflectance spectra of wheat samples obtained from a USDA-ARS wheat breeding program. A two...

  20. Analysis of Triticum boeoticum and Triticum urartu seed defensins: To the problem of the origin of polyploid wheat genomes.

    Science.gov (United States)

    Odintsova, Tatyana I; Korostyleva, Tatyana V; Odintsova, Margarita S; Pukhalsky, Vitaliy A; Grishin, Eugene V; Egorov, Tsezi A

    2008-06-01

    The origin of polyploid wheat genomes has been the subject of numerous studies and is the key problem in wheat phylogeny. Different diploid species have been supposed to donate genomes to tetraploid and hexaploid wheat species. To shed light on phylogenetic relationships between the presumable A genome donors and hexaploid wheat species we have applied a new approach: the comparison of defensins from diploid Triticum species, Triticum boeoticum Boiss. and Triticum urartu Thum. ex Gandil., with previously characterized Triticum kiharae defensins [T.I. Odintsova et al., Biochimie 89 (2007) 605-612]. Defensins were isolated by acidic extraction of seeds followed by three-step chromatographic separation. Isolated defensins were identified by molecular masses using MALDI-TOF mass spectrometry and N-terminal sequencing. For the first time, we have shown that T. urartu defensins are more similar to those of the hexaploid wheat than T. boeoticum defensins, although variation among samples collected in different regions of the world was revealed. Our results clearly demonstrate that T. urartu of the Asian origin contributed the A genome to polyploid wheat species.

  1. Genetic controls on starch amylose content in wheat and rice grains

    Indian Academy of Sciences (India)

    Parviz Fasahat; Sadequr Rahman; Wickneswari Ratnam

    2014-04-01

    Starch accumulates in plants as granules in chloroplasts of source organs such as leaves (transitory starch) or in amyloplasts of sink organs such as seeds, tubers and roots (storage starch). Starch is composed of two types of glucose polymers: the essentially linear polymer amylose and highly branched amylopectin. The amylose content of wheat and rice seeds is an important quality trait, affecting the nutritional and sensory quality of two of the world’s most important crops. In this review, we focus on the relationship between amylose biosynthesis and the structure, physical behaviour and functionality of wheat and rice grains. We briefly describe the structure and composition of starch and then in more detail describe what is known about the mechanism of amylose synthesis and how the amount of amylose in starch might be controlled. This more specifically includes analysis of GBSS alleles, the relationship between waxy allelic forms and amylose, and related quantitative trait loci. Finally, different methods for increasing or lowering amylose content are evaluated.

  2. The genetic diversity of culturable nitrogen-fixing bacteria in the rhizosphere of wheat.

    Science.gov (United States)

    Venieraki, Anastasia; Dimou, Maria; Pergalis, Panagiotis; Kefalogianni, Io; Chatzipavlidis, Iordanis; Katinakis, Panagiotis

    2011-02-01

    A total of 17 culturable nitrogen-fixing bacterial strains associated with the roots of wheat growing in different regions of Greece were isolated and characterized for plant-growth-promoting traits such as auxin production and phosphate solubilization. The phylogenetic position of the isolates was first assessed by the analysis of the PCR-amplified 16S rRNA gene. The comparative sequence analysis and phylogenetic analysis based on 16S rRNA gene sequences show that the isolates recovered in this study are grouped with Azospirillum brasilense, Azospirillum zeae, and Pseudomonas stutzeri. The diazotrophic nature of all isolates was confirmed by amplification of partial nifH gene sequences. The phylogenetic tree based on nifH gene sequences is consistent with 16S rRNA gene phylogeny. The isolates belonging to Azospirillum species were further characterized by examining the partial dnaK gene phylogenetic tree. Furthermore, it was demonstrated that the ipdC gene was present in all Azospirillum isolates, suggesting that auxin is mainly synthesized via the indole-3-pyruvate pathway. Although members of P. stutzeri and A. zeae are known diazotrophic bacteria, to the best of our knowledge, this is the first report of isolation and characterization of strains belonging to these bacterial genera associated with wheat.

  3. Genetic Analysis for Some of Morphological Traits in Bread Wheat under Drought Stress Condition Using Generations Mean Analysis

    Directory of Open Access Journals (Sweden)

    Jamileh Abedi

    2015-06-01

    Full Text Available Perception of genes action controlling of quantitative traits is very important in genetic breeding methods the plant populations. to study and estimate the parameters of genetic and appointment the best genetically model for justification the genetic changing some of traits the bread wheat under drought stress condition, parents (P1 & P2 and F3, F4, F5 generations together the four control cultivars (Kharchia, Gaspard, Moghan and Mahuti were evaluated by generation mean analysis using a agoment design including six blocks. Generation mean analysis was performed for all traits with Mather and Jinks model using joint scaling test. Three parameter model [m d h] provided the best fit for all traits expect harvest index, main spike grain weight, number of grain per plant, Total spike weight of plant with significant at 5% and 1% levels . Though additive and dominance effect both had interfered in controlling often the traits but with attention to difference effects and variety component was determined that dominance is more impressive than additive effect for traits of number of tiller, main spike weight, grain yield and grain number of main spike. Therefore will benefit using of these traits in the collection and to improve these traits hybridization would be much efficient than the selection strategies. In this study additive Ч additive epistasis effect only observed for traits of Total spike weight of plant, number of grain per plant, main spike grain weight and harvest index and other traits hadn’t any epistasis effect that it was demonstration lack of existence the genes reciprocal effect in the inheritance studied traits. Therefore we can suggest that the selection strategies perform in terminal generations and additive Ч additive epistasis effect would be confirmed in selection under self-pollination condition.

  4. Mapping of stripe rust resistance gene in an Aegilops caudata introgression line in wheat and its genetic association with leaf rust resistance

    Indian Academy of Sciences (India)

    PUNEET INDER TOOR; SATINDER KAUR; MITALY BANSAL; BHARAT YADAV; PARVEEN CHHUNEJA

    2016-12-01

    A pair of stripe rust and leaf rust resistance genes was introgressed from Aegilops caudata, a nonprogenitor diploid species with the CC genome, to cultivated wheat. Inheritance and genetic mapping of stripe rust resistance gene in backcrossrecombinant inbred line (BC-RIL) population derived from the cross of a wheat–Ae. caudata introgression line (IL) T291-2(pau16060) with wheat cv. PBW343 is reported here. Segregation of BC-RILs for stripe rust resistance depicted a single major gene conditioning adult plant resistance (APR) with stripe rust reaction varying from TR-20MS in resistant RILs signifying the presence of some minor genes as well. Genetic association with leaf rust resistance revealed that two genes are located at a recombination distance of 13%. IL T291-2 had earlier been reported to carry introgressions on wheat chromosomes 2D, 3D, 4D, 5D, 6D and 7D. Genetic mapping indicated the introgression of stripe rust resistance gene on wheat chromosome 5DS in the region carrying leaf rust resistance gene LrAc, but as an independent introgression. Simple sequence repeat (SSR) and sequence-tagged site (STS) markers designed from the survey sequence data of 5DS enriched the target region harbouring stripe and leaf rust resistance genes. Stripe rust resistance locus, temporarily designated as YrAc, mapped at the distal most end of 5DS linked with a group of four colocated SSRs and two resistance gene analogue (RGA)-STS markers at a distanceof 5.3 cM. LrAc mapped at a distance of 9.0 cM from the YrAc and at 2.8 cM from RGA-STS marker Ta5DS_2737450, YrAc and LrAc appear to be the candidate genes for marker-assisted enrichment of the wheat gene pool for rust resistance.

  5. Genetic Diversity under Soil Compaction in Wheat: Root Number as a Promising Trait for Early Plant Vigor.

    Science.gov (United States)

    Colombi, Tino; Walter, Achim

    2017-01-01

    Soil compaction of arable land, caused by heavy machinery constitutes a major threat to agricultural soils in industrialized countries. The degradation of soil structure due to compaction leads to decreased (macro-) porosity resulting in increased mechanical impedance, which adversely affects root growth and crop productivity. New crop cultivars, with root systems that are adapted to conditions of increased soil strength, are needed to overcome the limiting effects of soil compaction on plant growth. This study aimed (i) to quantify the genetic diversity of early root system development in wheat and to relate this to shoot development under different soil bulk densities and (ii) to test whether root numbers are suitable traits to assess the genotypic tolerance to soil compaction. Fourteen wheat genotypes were grown for 3 weeks in a growth chamber under low (1.3 g cm(-3)), moderate (1.45 g cm(-3)), and high soil bulk density (1.6 g cm(-3)). Using X-ray computed tomography root system development was quantified in weekly intervals, which was complemented by weekly measurements of plant height. The development of the root system, quantified via the number of axial and lateral roots was strongly correlated (0.78 soil strength final axial and lateral root numbers were significantly correlated (0.57 soil strength and that root numbers are suitable indicators to explain the responses and the tolerance to such conditions. Since root numbers are heritable and can be assessed at high throughput rates under laboratory and field conditions, root number is considered a promising trait for screening toward compaction tolerant varieties.

  6. Molecular genetic analysis of grain protein content and flour whiteness degree using RILs in common wheat

    Indian Academy of Sciences (India)

    XIANYIN SUN; KE WU; YAN ZHAO; ZHAOGUO QIAN; FANMEI KONG; YING GUO; YINGYING WANG; SISHEN LI

    2016-06-01

    Grain protein content (GPC) and flour whiteness degree (FWD) are important qualitative traits in common wheat. Quantitativetrait locus (QTL) mapping for GPC and FWD was conducted using a set of 131 recombinant-inbred lines derived fromthe cross ‘Chuan 35050 ×Shannong 483’ in six environmental conditions. A total of 22 putative QTLs (nine GPC and13 FWD) were identified on 12 chromosomes with individual QTL explaining 4.5–34.0% phenotypic variation. Nine QTLs(40.9%) were detected in two or more environments. The colocated QTLs were on chromosomes 1B and 4B. Among theQTLs identified for GPC,QGpc.sdau-4Afrom the parent Shannong 483 represented some important favourable QTL alleles.QGpc.sdau-2A.1andQFwd.sdau-2A.1had a significant association with both GPC and FWD. The markers detected on topof QTL regions could be potential targets for marker-assisted selection.

  7. Cytotype distribution at a diploid–hexaploid contact zone in Aster amellus (Asteraceae)

    Science.gov (United States)

    Castro, S.; Loureiro, J.; Procházka, T.; Münzbergová, Z.

    2012-01-01

    Background and Aims The present study aims to assess the diversity and distribution of cytotypes of Aster amellus in central and eastern Europe, contributing with data to improve understanding of the evolutionary dynamics of the contact zone between diploids and hexaploids of this polyploid complex. Methods Large-scale cytotype screening of 4720 individuals collected in 229 populations was performed using 4′,6-diamidino-2-phenylindole (DAPI) flow cytometry. Fine-scale cytotype screening was performed in the mixed-ploidy population. Reproductive variables, such as number of florets per flower head, seed set and seedling emergence, as well as ploidy level of seeds and seedlings were recorded in this population. Key Results The diploid–hexaploid contact zone is large and complex, reaching the Czech Republic in the west, Austria in the south, Poland in the north-east and Romania in the extreme east of the surveyed areas. Most populations presented only one cytotype, either diploid or hexaploid. In several areas of the contact zone both cytotypes were found to grow in parapatry. One mixed-ploidy population of diploids and hexaploids was detected for the first time, but no signs of hybridization were detected. In this population, diploids had a significantly lower reproductive success, and significantly higher production of intercytotype offspring, being in reproductive disadvantage in comparison with hexaploids. Conclusions The contact zone of diploid and hexaploid A. amellus in central and eastern Europe seems to be highly dynamic and diffuse, with both primary and secondary contacts being possible. The obtained results suggest the origin of hexaploids through diploids, overall supporting previous hypotheses that this species is autopolyploid. Data from the only mixed-ploidy population detected so far suggest that the minority cytotype exclusion is an important evolutionary mechanisms driving the prevalence of single-cytotype populations, and thus contributing to

  8. AB-QTL analysis in winter wheat: II. Genetic analysis of seedling and field resistance against leaf rust in a wheat advanced backcross population.

    Science.gov (United States)

    Naz, Ali Ahmad; Kunert, Antje; Lind, Volker; Pillen, Klaus; Léon, Jens

    2008-05-01

    The present study aimed to localize exotic quantitative trait locus (QTL) alleles for the improvement of leaf rust (P. triticina) resistance in an advanced backcross (AB) population, B22, which is derived from a cross between the winter wheat cultivar Batis (Triticum aestivum) and the synthetic wheat accession Syn022L. The latter was developed from hybridization of T. turgidum ssp. dicoccoides and T. tauschii. Altogether, 250 BC2F3 lines of B22 were assessed for seedling resistance against the leaf rust isolate 77WxR under controlled conditions. In addition, field resistance against leaf rust was evaluated by assessing symptom severity under natural infestation across multiple environments. Simultaneously, population B22 was genotyped with a total of 97 SSR markers, distributed over the wheat A, B and D genomes. The phenotype and genotype data were subjected to QTL analysis by applying a 3-factorial mixed model analysis of variance including the marker genotype as a fixed effect and the environments, the lines and the marker by environment interactions as random effects. The QTL analysis revealed six putative QTLs for seedling resistance and seven for field resistance. For seedling resistance, the effects of exotic QTL alleles improved resistance at all detected loci. The maximum decrease of disease symptoms (-46.3%) was associated with marker locus Xbarc149 on chromosome 1D. For field resistance, two loci had stable main effects across environments and five loci exhibited marker by environment interaction effects. The strongest effects were detected at marker locus Xbarc149 on chromosome 1D, at which the exotic allele decreased seedling symptoms by 46.3% and field symptoms by 43.6%, respectively. Some of the detected QTLs co-localized with known resistance genes, while others appear to be as novel resistance loci. Our findings indicate, that the exotic wheat accession Syn022L may be useful for the improvement of leaf rust resistance in cultivated wheat.

  9. Genetic mapping of common bunt resistance and plant height QTL in wheat.

    Science.gov (United States)

    Singh, Arti; Knox, Ron E; DePauw, R M; Singh, A K; Cuthbert, R D; Kumar, S; Campbell, H L

    2016-02-01

    Breeding for field resistance to common bunt in wheat will need to account for multiple genes and epistatic and QTL by environment interactions. Loci associated with quantitative resistance to common bunt are co-localized with other beneficial traits including plant height and rust resistance. Common bunt, also known as stinking smut, is caused by seed borne fungi Tilletia tritici (Bjerk.) Wint. [syn. Tilletia caries (DC.) Tul.] and Tilletia laevis Kühn [syn. Tilletia foetida (Wallr.) Liro.]. Common bunt is known to cause grain yield and quality losses in wheat due to bunt ball formation and infestation of the grain. The objectives of this research were to identify and map quantitative trait loci (QTL) for common bunt resistance, to study the epistatic interactions between the identified QTL, and investigate the co-localization of bunt resistance with plant height. A population of 261 doubled haploid lines from the cross Carberry/AC Cadillac and checks were genotyped with polymorphic genome wide microsatellite and DArT(®) markers. The lines were grown in 2011, 2012, and 2013 in separate nurseries for common bunt incidence and height evaluation. AC Cadillac contributed a QTL (QCbt.spa-6D) for common bunt resistance on chromosome 6D at markers XwPt-1695, XwPt-672044, and XwPt-5114. Carberry contributed QTL for bunt resistance on chromosomes 1B (QCbt.spa-1B at XwPt743523) 4B (QCbt.spa-4B at XwPt-744434-Xwmc617), 4D (QCbt.spa-4D at XwPt-9747), 5B (QCbt.spa-5B at XtPt-3719) and 7D (QCbt.spa-7D at Xwmc273). Significant epistatic interactions were identified for percent bunt incidence between QCbt.spa-1B × QCbt.spa-4B and QCbt.spa-1B × QCbt.spa-6D, and QTL by environment interaction between QCbt.spa-1B × QCbt.spa-6D. Plant height QTL were found on chromosomes 4B (QPh.spa-4B) and 6D (QPh.spa-6D) that co-located with bunt resistance QTL. The identification of previously unreported common bunt resistance QTL (on chromosomes 4B, 4D and 7D), and new understanding of QTL

  10. GENETIC DETERMINATION OF THE NITROGEN SUPPLY OF SPRING WHEAT (TRITICUM AESTIVUM L.

    Directory of Open Access Journals (Sweden)

    Sitnikov M.N.

    2012-08-01

    Full Text Available The maximum grain productivity can be achieved only taking into account plant biological needs. The need in mineral nutrients depends on the plant hereditary nature and environmental conditions. The greatest demand for nitrogen is characteristic in cereals for spring and winter wheat, the lowest one for barley and rye. The use of mineral nutrients in amounts exceeding plant needs does not result in yield increasing and can worsen the production quality. We were studying reaction of spring bread wheat (Triticum aestivum L. genotypes to changes in nutrition soil conditions. In the experiment, ITMI mapping population consisting of 110 recombinant inbred lines was evaluated for a number of morphological, biological and economically important traits under different levels of the nitrogen supply. To create different soil nutrition level and to prevent leaching of fertilizers during the plant vegetation season we prepared trenches with depth 0.4 m, width 1 m and length 20 m; the bottoms of which were covered with plastic films. The trenches were filled with soil from the lower soil horizons. In first variant of the experiment, nutrient mixture on the basis of the physiological rate for cereals (N – 0.15 g, P - 0.1 g, K - 0.1 g of active substances per 1 kg of dry soil was applied. In the second variant, nitrogen dose was reduced half with the same phosphorus and potassium doses. Variant without fertilizers applying was used as a control. Thirty nine characters were analyzed during the all growing season. The combination of field and vegetation experiment conditions allowed approximating maximally to real conditions of the experiment and at the same time to control strictly plant vegetation. QTLs identified in our study can be differentiated as dependent and independent on environmental conditions. For example, some QTLs controlling such traits as a wax bloom, phenological phases, etc. are stable under different conditions of soil nutrition. QTLs of

  11. A Novel Retrotransposon Inserted in the Dominant Vrn-B1 Allele Confers Spring Growth Habit in Tetraploid Wheat (Triticum turgidum L.).

    Science.gov (United States)

    Chu, C-G; Tan, C T; Yu, G-T; Zhong, S; Xu, S S; Yan, L

    2011-12-01

    Vernalization genes determine winter/spring growth habit in temperate cereals and play important roles in plant development and environmental adaptation. In wheat (Triticum L. sp.), it was previously shown that allelic variation in the vernalization gene VRN1 was due to deletions or insertions either in the promoter or in the first intron. Here, we report a novel Vrn-B1 allele that has a retrotransposon in its promoter conferring spring growth habit. The VRN-B1 gene was mapped in a doubled haploid population that segregated for winter-spring growth habit but was derived from two spring tetraploid wheat genotypes, the durum wheat (T. turgidum subsp. durum) variety 'Lebsock' and T. turgidum subsp. carthlicum accession PI 94749. Genetic analysis revealed that Lebsock carried the dominant Vrn-A1 and recessive vrn-B1 alleles, whereas PI 94749 had the recessive vrn-A1 and dominant Vrn-B1 alleles. The Vrn-A1 allele in Lebsock was the same as the Vrn-A1c allele previously reported in hexaploid wheat. No differences existed between the vrn-B1 and Vrn-B1 alleles, except that a 5463-bp insertion was detected in the 5'-UTR region of the Vrn-B1 allele. This insertion was a novel retrotransposon (designated as retrotrans_VRN), which was flanked by a 5-bp target site duplication and contained primer binding site and polypurine tract motifs, a 325-bp long terminal repeat, and an open reading frame encoding 1231 amino acids. The insertion of retrotrans_VRN resulted in expression of Vrn-B1 without vernalization. Retrotrans_VRN is prevalent among T. turgidum subsp. carthlicum accessions, less prevalent among T. turgidum subsp. dicoccum accessions, and rarely found in other tetraploid wheat subspecies.

  12. Genetic dissection of grain size and grain number trade-offs in CIMMYT wheat germplasm.

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    Simon Griffiths

    Full Text Available Grain weight (GW and number per unit area of land (GN are the primary components of grain yield in wheat. In segregating populations both yield components often show a negative correlation among themselves. Here we use a recombinant doubled haploid population of 105 individuals developed from the CIMMYT varieties Weebill and Bacanora to understand the relative contribution of these components to grain yield and their interaction with each other. Weebill was chosen for its high GW and Bacanora for high GN. The population was phenotyped in Mexico, Argentina, Chile and the UK. Two loci influencing grain yield were indicated on 1B and 7B after QTL analysis. Weebill contributed the increasing alleles. The 1B effect, which is probably caused by to the 1BL.1RS rye introgression in Bacanora, was a result of increased GN, whereas, the 7B QTL controls GW. We concluded that increased in GW from Weebill 7B allele is not accompanied by a significant reduction in grain number. The extent of the GW and GN trade-off is reduced. This makes this locus an attractive target for marker assisted selection to develop high yielding bold grain varieties like Weebill. AMMI analysis was used to show that the 7B Weebill allele appears to contribute to yield stability.

  13. Genetic dissection of grain size and grain number trade-offs in CIMMYT wheat germplasm.

    Science.gov (United States)

    Griffiths, Simon; Wingen, Luzie; Pietragalla, Julian; Garcia, Guillermo; Hasan, Ahmed; Miralles, Daniel; Calderini, Daniel F; Ankleshwaria, Jignaben Bipinchandra; Waite, Michelle Leverington; Simmonds, James; Snape, John; Reynolds, Matthew

    2015-01-01

    Grain weight (GW) and number per unit area of land (GN) are the primary components of grain yield in wheat. In segregating populations both yield components often show a negative correlation among themselves. Here we use a recombinant doubled haploid population of 105 individuals developed from the CIMMYT varieties Weebill and Bacanora to understand the relative contribution of these components to grain yield and their interaction with each other. Weebill was chosen for its high GW and Bacanora for high GN. The population was phenotyped in Mexico, Argentina, Chile and the UK. Two loci influencing grain yield were indicated on 1B and 7B after QTL analysis. Weebill contributed the increasing alleles. The 1B effect, which is probably caused by to the 1BL.1RS rye introgression in Bacanora, was a result of increased GN, whereas, the 7B QTL controls GW. We concluded that increased in GW from Weebill 7B allele is not accompanied by a significant reduction in grain number. The extent of the GW and GN trade-off is reduced. This makes this locus an attractive target for marker assisted selection to develop high yielding bold grain varieties like Weebill. AMMI analysis was used to show that the 7B Weebill allele appears to contribute to yield stability.

  14. Genetic diversity of plant growth promoting rhizobacteria isolated from rhizospheric soil of wheat under saline condition.

    Science.gov (United States)

    Upadhyay, Sudhir K; Singh, Devendra P; Saikia, Ratul

    2009-11-01

    In this study, a total of 130 rhizobacteria was isolated from a saline infested zone of wheat rhizosphere, and screened for plant growth promoting (PGP) traits at higher salt (NaCl) concentrations (2, 4, 6, and 8%). The results revealed that 24 rhizobacterial isolates were tolerant at 8% NaCl. Although all the 24 salt tolerable isolates produced indole-3-acetic acid (IAA), while 10 isolates solubilized phosphorus, eight produced siderophore, and six produced gibberellin. However, only three isolates showed the production of 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Diversity was analyzed through 16S rDNA-RFLP, and of these isolates with three tetra cutter restriction enzymes (HaeIII, AluI, and MspI), the representative cluster groups were identified by 16S rDNA sequencing. Bacillus and Bacillus-derived genera were dominant which showed PGP attributes at 8% NaCl concentration. Out of 24 isolates, nitrogen fixing ability (nif H gene) was detected in the two isolates, SU18 (Arthrobacter sp.) and SU48.

  15. Genome-Wide Analysis of Microsatellite Markers Based on Sequenced Database in Chinese Spring Wheat (Triticum aestivum L..

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    Bin Han

    Full Text Available Microsatellites or simple sequence repeats (SSRs are distributed across both prokaryotic and eukaryotic genomes and have been widely used for genetic studies and molecular marker-assisted breeding in crops. Though an ordered draft sequence of hexaploid bread wheat have been announced, the researches about systemic analysis of SSRs for wheat still have not been reported so far. In the present study, we identified 364,347 SSRs from among 10,603,760 sequences of the Chinese spring wheat (CSW genome, which were present at a density of 36.68 SSR/Mb. In total, we detected 488 types of motifs ranging from di- to hexanucleotides, among which dinucleotide repeats dominated, accounting for approximately 42.52% of the genome. The density of tri- to hexanucleotide repeats was 24.97%, 4.62%, 3.25% and 24.65%, respectively. AG/CT, AAG/CTT, AGAT/ATCT, AAAAG/CTTTT and AAAATT/AATTTT were the most frequent repeats among di- to hexanucleotide repeats. Among the 21 chromosomes of CSW, the density of repeats was highest on chromosome 2D and lowest on chromosome 3A. The proportions of di-, tri-, tetra-, penta- and hexanucleotide repeats on each chromosome, and even on the whole genome, were almost identical. In addition, 295,267 SSR markers were successfully developed from the 21 chromosomes of CSW, which cover the entire genome at a density of 29.73 per Mb. All of the SSR markers were validated by reverse electronic-Polymerase Chain Reaction (re-PCR; 70,564 (23.9% were found to be monomorphic and 224,703 (76.1% were found to be polymorphic. A total of 45 monomorphic markers were selected randomly for validation purposes; 24 (53.3% amplified one locus, 8 (17.8% amplified multiple identical loci, and 13 (28.9% did not amplify any fragments from the genomic DNA of CSW. Then a dendrogram was generated based on the 24 monomorphic SSR markers among 20 wheat cultivars and three species of its diploid ancestors showing that monomorphic SSR markers represented a promising

  16. The grain Hardness locus characterized in a diverse wheat panel (Triticum aestivum L.) adapted to the central part of the Fertile Crescent: genetic diversity, haplotype structure, and phylogeny.

    Science.gov (United States)

    Shaaf, Salar; Sharma, Rajiv; Baloch, Faheem Shehzad; Badaeva, Ekaterina D; Knüpffer, Helmut; Kilian, Benjamin; Özkan, Hakan

    2016-06-01

    Wheat belongs to the most important crops domesticated in the Fertile Crescent. In this region, fortunately, locally adapted wheat landraces are still present in farmers' fields. This material might be of immense value for future breeding programs. However, especially wheat germplasm adapted to the central part of the Fertile Crescent has been poorly characterized for allelic variation at key loci of agricultural importance. Grain hardness is an important trait influencing milling and baking quality of wheat. This trait is mainly determined by three tightly linked genes, namely, Puroindoline a (Pina), Puroindoline b (Pinb), and Grain softness protein-1 (Gsp-1), at the Hardness (Ha-D) locus on chromosome 5DS. To investigate genetic diversity and haplotype structure, we resequenced 96 diverse wheat lines at Pina-D1, Pinb-D1, Gsp-A1, Gsp-B1, and Gsp-D1. Three types of null alleles were identified using diagnostic primers: the first type was a multiple deletion of Pina-D1, Pinb-D1, and Gsp-D1 (Pina-D1k), the second was a Pina-D1 deletion (Pina-D1b); and the third type was a deletion of Gsp-D1, representing a novel null allele designated here as Gsp-D1k. Sequence analysis resulted in four allelic variants at Pinb-D1 and five at Gsp-A1, among them Gsp-A1-V was novel. Pina-D1, Gsp-B1 and Gsp-D1 sequences were monomorphic. Haplotype and phylogenetic analysis suggested that (1) bread wheat inherited its 5DS telomeric region probably from wild diploid Ae. tauschii subsp. tauschii found within an area from Transcaucasia to Caspian Iran; and that (2) the Ha-A and Ha-B homoeoloci were most closely related to sequences of wild tetraploid T. dicocco ides. This study provides a good overview of available genetic diversity at Pina-D1, Pinb-D1, and Gsp-1, which can be exploited to extend the range of grain texture traits in wheat.

  17. Discrimination Capacity of RAPD, ISSR and SSR Markers and of their Effectiveness in Establishing Genetic Relationship and Diversity among Egyptian and Saudi Wheat Cultivars

    Directory of Open Access Journals (Sweden)

    Salah E.D. El-Assal

    2012-01-01

    Full Text Available Problem statement: Yield crop cultivars and landraces are valuable sources of genetic variations that the knowledge and implication of these variations are critical in the plant breeding programs. our major objective of this study is investigating the discriminating capacity of RAPD, ISSR and SSR markers and of their effectiveness in establishing genetic relationship and diversity among Egyptian and Saudi wheat cultivars. Approach: Eleven wheat cultivars and landraces collected from Egypt and Saudi Arabia, five Egyptian wheat (Sakha 93, Sods 1, Sods 4, Gmiza 9 and Sohag 3 and six Saudi wheat landrace cultivars (Hmees, Al-Kaseem, Hegazi, Abo-Sakr, Dubai 1 and Nagran were characterized using RAPD, ISSR and SSR molecular markers as efficient tools. Ten and nine oligonucleotide primers of RAPD and ISSR respectively and four primer pairs of SSR were used in wheat samples analysis. Only clear and repeatable band profile of 6 RAPD, 8 ISSR and 2 SSR primers were obtained. In RAPD analyses, 74 out of 141 bands (52% were polymorphic. Results: The number of alleles ranged from 8-21 per primer, with an average of 14.1 per primer. In ISSR analyses, a total of 78 alleles were detected, along with 36 alleles (46% were polymorphic. The number of alleles per primer ranged from 5-10 with an average of 8.6 alleles per ISSR primer. SSR reactions recorded 6 alleles, of which 5 alleles (83% were polymorphic. Cluster analysis was conducted using Unweighted Pair Group Method that depends on Arithmetic Average (UPGMA. The dendrogram cluster diagram classified the evaluated genotypes in three major clusters corresponding to the cultivation regions. The first group contains Sakha 93, Sods 1 and Sods 4 with more than 80% Genetic Similarity (GS. The GS between Sakha 93 and Sods 1, Sakha 93 and Sods 4 or Sods 1 and Sods 4 were 83.6%, 83.9 and 85.4 respectively. The second group contains Gmiza 9 and Sohag 3 with GS 83.1%. The third group contains most of the Saudi landrace

  18. Genetic Analysis of Carbon Isotope Discrimination and its Relation to Yield in a Wheat Doubled Haploid Population

    Institute of Scientific and Technical Information of China (English)

    Xianshan Wu; Xiaoping Chang; Ruilian Jing

    2011-01-01

    Carbon isotope discrimination (△13C) is considered a useful indicator for indirect selection of grain yield (GY) in cereals.Therefore,it is important to evaluate the genetic variation in △13C and its relationship with GY.A doubled haploid (DH) population derived from a cross of two common wheat varieties,Hanxuan 10 (H10) and Lumai 14 (L14),was phenotyped for △13C in the flag leaf,GY and yield associated traits in two trials contrasted by water availability,specifically,rain-fed and irrigated.Quantitative trait loci (QTLs) were identified by single locus and two locus QTL analyses.QTLs for △13C were located on chromosomes 1A,2B,3B,5A,7A and 7B,and QTLs for other traits on all chromosomes except 1A,4D,5A,5B and 6D.The population selected for high △13C had an increased frequency of QTL for high △13C,GY and number of spikes per plant (NSP) when grown under rain-fed conditions and only for high △13C and NSP when grown under irrigated conditions,which was consistent with agronomic performance of the corresponding trait values in the high △13C progeny; that is,significantly greater than that in the low △13C.Therefore,selection for △13C was beneficial in increasing grain yield in rain-fed environments.

  19. SNP Discovery and Chromosome Anchoring Provide the First Physically-Anchored Hexaploid Oat Map and Reveal Synteny with Model Species

    Science.gov (United States)

    Chao, Shiaoman; Jellen, Eric N.; Carson, Martin L.; Rines, Howard W.; Obert, Donald E.; Lutz, Joseph D.; Shackelford, Irene; Korol, Abraham B.; Wight, Charlene P.; Gardner, Kyle M.; Hattori, Jiro; Beattie, Aaron D.; Bjørnstad, Åsmund; Bonman, J. Michael; Jannink, Jean-Luc; Sorrells, Mark E.; Brown-Guedira, Gina L.; Mitchell Fetch, Jennifer W.; Harrison, Stephen A.; Howarth, Catherine J.; Ibrahim, Amir; Kolb, Frederic L.; McMullen, Michael S.; Murphy, J. Paul; Ohm, Herbert W.; Rossnagel, Brian G.; Yan, Weikai; Miclaus, Kelci J.; Hiller, Jordan; Maughan, Peter J.; Redman Hulse, Rachel R.; Anderson, Joseph M.; Islamovic, Emir

    2013-01-01

    A physically anchored consensus map is foundational to modern genomics research; however, construction of such a map in oat (Avena sativa L., 2n = 6x = 42) has been hindered by the size and complexity of the genome, the scarcity of robust molecular markers, and the lack of aneuploid stocks. Resources developed in this study include a modified SNP discovery method for complex genomes, a diverse set of oat SNP markers, and a novel chromosome-deficient SNP anchoring strategy. These resources were applied to build the first complete, physically-anchored consensus map of hexaploid oat. Approximately 11,000 high-confidence in silico SNPs were discovered based on nine million inter-varietal sequence reads of genomic and cDNA origin. GoldenGate genotyping of 3,072 SNP assays yielded 1,311 robust markers, of which 985 were mapped in 390 recombinant-inbred lines from six bi-parental mapping populations ranging in size from 49 to 97 progeny. The consensus map included 985 SNPs and 68 previously-published markers, resolving 21 linkage groups with a total map distance of 1,838.8 cM. Consensus linkage groups were assigned to 21 chromosomes using SNP deletion analysis of chromosome-deficient monosomic hybrid stocks. Alignments with sequenced genomes of rice and Brachypodium provide evidence for extensive conservation of genomic regions, and renewed encouragement for orthology-based genomic discovery in this important hexaploid species. These results also provide a framework for high-resolution genetic analysis in oat, and a model for marker development and map construction in other species with complex genomes and limited resources. PMID:23533580

  20. SNP discovery and chromosome anchoring provide the first physically-anchored hexaploid oat map and reveal synteny with model species.

    Directory of Open Access Journals (Sweden)

    Rebekah E Oliver

    Full Text Available A physically anchored consensus map is foundational to modern genomics research; however, construction of such a map in oat (Avena sativa L., 2n = 6x = 42 has been hindered by the size and complexity of the genome, the scarcity of robust molecular markers, and the lack of aneuploid stocks. Resources developed in this study include a modified SNP discovery method for complex genomes, a diverse set of oat SNP markers, and a novel chromosome-deficient SNP anchoring strategy. These resources were applied to build the first complete, physically-anchored consensus map of hexaploid oat. Approximately 11,000 high-confidence in silico SNPs were discovered based on nine million inter-varietal sequence reads of genomic and cDNA origin. GoldenGate genotyping of 3,072 SNP assays yielded 1,311 robust markers, of which 985 were mapped in 390 recombinant-inbred lines from six bi-parental mapping populations ranging in size from 49 to 97 progeny. The consensus map included 985 SNPs and 68 previously-published markers, resolving 21 linkage groups with a total map distance of 1,838.8 cM. Consensus linkage groups were assigned to 21 chromosomes using SNP deletion analysis of chromosome-deficient monosomic hybrid stocks. Alignments with sequenced genomes of rice and Brachypodium provide evidence for extensive conservation of genomic regions, and renewed encouragement for orthology-based genomic discovery in this important hexaploid species. These results also provide a framework for high-resolution genetic analysis in oat, and a model for marker development and map construction in other species with complex genomes and limited resources.

  1. Genetic, environmental and cultural factors influencing the resistance to septoria tritici blotch (Mycosphaerella graminicola) in wheat

    NARCIS (Netherlands)

    Simón, M.R.

    2003-01-01

    KeyWord:Genetic, environmental and cultural factors influencing the resistance to septoria tritici blotch (Mycosphaerella

  2. Genetic, environmental and cultural factors influencing the resistance to septoria tritici blotch (Mycosphaerella graminicola) in wheat

    NARCIS (Netherlands)

    Simón, M.R.

    2003-01-01

    KeyWord:Genetic, environmental and cultural factors influencing the resistance to septoria tritici blotch (Mycosphaerella

  3. Genome-wide genetic dissection of supernumerary spikelet and related traits in common wheat (Triticum aestivum L.)

    Science.gov (United States)

    In wheat (Triticum aestivum L), exotic genotypes express a broad range of spike-related traits and could be used as a source of new genes to enrich the germplasm for wheat breeding programs. In the present study, a population of 163 recombinant inbred lines derived from a cross between an elite line...

  4. Evolution of New Disease Specificity at a Simple Resistance Locus in a Crop–Weed Complex: Reconstitution of the Lr21 Gene in Wheat

    OpenAIRE

    Huang, Li; Brooks, Steven; Li, Wanlong; Fellers, John; Nelson, James C.; Gill, Bikram

    2009-01-01

    The wheat leaf-rust resistance gene Lr21 was first identified in an Iranian accession of goatgrass, Aegilops tauschii Coss., the D-genome donor of hexaploid bread wheat, and was introgressed into modern wheat cultivars by breeding. To elucidate the origin of the gene, we analyzed sequences of Lr21 and lr21 alleles from 24 wheat cultivars and 25 accessions of Ae. tauschii collected along the Caspian Sea in Iran and Azerbaijan. Three basic nonfunctional lr21 haplotypes, H1, H2, and H3, were ide...

  5. Chromosome arm-specific BAC end sequences permit comparative analysis of homoeologous chromosomes and genomes of polyploid wheat

    Directory of Open Access Journals (Sweden)

    Sehgal Sunish K

    2012-05-01

    Full Text Available Abstract Background Bread wheat, one of the world’s staple food crops, has the largest, highly repetitive and polyploid genome among the cereal crops. The wheat genome holds the key to crop genetic improvement against challenges such as climate change, environmental degradation, and water scarcity. To unravel the complex wheat genome, the International Wheat Genome Sequencing Consortium (IWGSC is pursuing a chromosome- and chromosome arm-based approach to physical mapping and sequencing. Here we report on the use of a BAC library made from flow-sorted telosomic chromosome 3A short arm (t3AS for marker development and analysis of sequence composition and comparative evolution of homoeologous genomes of hexaploid wheat. Results The end-sequencing of 9,984 random BACs from a chromosome arm 3AS-specific library (TaaCsp3AShA generated 11,014,359 bp of high quality sequence from 17,591 BAC-ends with an average length of 626 bp. The sequence represents 3.2% of t3AS with an average DNA sequence read every 19 kb. Overall, 79% of the sequence consisted of repetitive elements, 1.38% as coding regions (estimated 2,850 genes and another 19% of unknown origin. Comparative sequence analysis suggested that 70-77% of the genes present in both 3A and 3B were syntenic with model species. Among the transposable elements, gypsy/sabrina (12.4% was the most abundant repeat and was significantly more frequent in 3A compared to homoeologous chromosome 3B. Twenty novel repetitive sequences were also identified using de novo repeat identification. BESs were screened to identify simple sequence repeats (SSR and transposable element junctions. A total of 1,057 SSRs were identified with a density of one per 10.4 kb, and 7,928 junctions between transposable elements (TE and other sequences were identified with a density of one per 1.39 kb. With the objective of enhancing the marker density of chromosome 3AS, oligonucleotide primers were successfully designed from

  6. A wheat intervarietal genetic linkage map based on microsatellite and target region amplified polymorphism markers and its utility for detecting quantitative trait loci.

    Science.gov (United States)

    Liu, Z H; Anderson, J A; Hu, J; Friesen, T L; Rasmussen, J B; Faris, J D

    2005-08-01

    Efficient user-friendly methods for mapping plant genomes are highly desirable for the identification of quantitative trait loci (QTLs), genotypic profiling, genomic studies, and marker-assisted selection. SSR (microsatellite) markers are user-friendly and efficient in detecting polymorphism, but they detect few loci. Target region amplification polymorphism (TRAP) is a relatively new PCR-based technique that detects a large number of loci from a single reaction without extensive pre-PCR processing of samples. In the investigation reported here, we used both SSRs and TRAPs to generate over 700 markers for the construction of a genetic linkage map in a hard red spring wheat intervarietal recombinant inbred population. A framework map consisting of 352 markers accounted for 3,045 cM with an average density of one marker per 8.7 cM. On average, SSRs detected 1.9 polymorphic loci per reaction, while TRAPs detected 24. Both marker systems were suitable for assigning linkage groups to chromosomes using wheat aneuploid stocks. We demonstrated the utility of the maps by identifying major QTLs for days to heading and reduced plant height on chromosomes 5A and 4B, respectively. Our results indicate that TRAPs are highly efficient for genetic mapping in wheat. The maps developed will be useful for the identification of quality and disease resistance QTLs that segregate in this population.

  7. Multicollinearity in spatial genetics: separating the wheat from the chaff using commonality analyses.

    Science.gov (United States)

    Prunier, J G; Colyn, M; Legendre, X; Nimon, K F; Flamand, M C

    2015-01-01

    Direct gradient analyses in spatial genetics provide unique opportunities to describe the inherent complexity of genetic variation in wildlife species and are the object of many methodological developments. However, multicollinearity among explanatory variables is a systemic issue in multivariate regression analyses and is likely to cause serious difficulties in properly interpreting results of direct gradient analyses, with the risk of erroneous conclusions, misdirected research and inefficient or counterproductive conservation measures. Using simulated data sets along with linear and logistic regressions on distance matrices, we illustrate how commonality analysis (CA), a detailed variance-partitioning procedure that was recently introduced in the field of ecology, can be used to deal with nonindependence among spatial predictors. By decomposing model fit indices into unique and common (or shared) variance components, CA allows identifying the location and magnitude of multicollinearity, revealing spurious correlations and thus thoroughly improving the interpretation of multivariate regressions. Despite a few inherent limitations, especially in the case of resistance model optimization, this review highlights the great potential of CA to account for complex multicollinearity patterns in spatial genetics and identifies future applications and lines of research. We strongly urge spatial geneticists to systematically investigate commonalities when performing direct gradient analyses.

  8. Genetics and Molecular Mapping of a High-Temperature Resistance Gene to Stripe Rust in Seeding-Stage in Winter Wheat Cultivar Lantian 1

    Institute of Scientific and Technical Information of China (English)

    MA Dong-fang; JING Jin-xue; HOU Dong-yuan; LI Qiang; ZHOU Xin-li; DU Jiu-yuan; and LU Qing-lin

    2013-01-01

    Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is a severe foliar disease of common wheat (Triticum aestivum L.) in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene(s) for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 (M169). Seedlings of the parents, and F1, F2 and F2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat (SSR) techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively;and the two markers in combination could distinguish the alleles at the resistance locus in 97.9%of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.

  9. Progress Towards Genetics and Breeding for Minor Genes Based Resistance to Ug99 and Other Rusts in CIMMYT High-Yielding Spring Wheat

    Institute of Scientific and Technical Information of China (English)

    Ravi Prakash Singh; Sybil Herrera-Foessel; Julio Huerta-Espino; Sukhwinder Singh; Sridhar Bhavani; Caixia Lan; and Bhoja Raj Basnet

    2014-01-01

    Wheat rusts continue to cause signiifcant losses worldwide despite major efforts given to their genetic control. This is due to frequent evolution and selection of virulence in pathogen overcoming the deployed race-speciifc resistance genes. Although the life of effective race-speciifc resistance genes can be prolonged by using gene combinations, an alternative approach being implemented at CIMMYT is to deploy varieties that posses adult plant resistance (APR) based on combinations of minor, slow rusting genes. When present alone, the APR genes do not confer adequate resistance especially under high disease pressure; however, combinations of 4 or 5 minor genes usually result in “near-immunity” or a high level of resistance. Although only a few APR genes are catalogued, various APR QTLs are now known and could lead to further characterization of additional genes. Four characterized genes have pleiotropic effects in conferring partial APR to all 3 rusts and powdery mildew, thus simplifying the task of breeding wheat varieties that are resistant to multiple diseases. Signiifcant progress was made recently in developing high-yielding wheat germplasm that possesses high levels of APR to all three rusts by implementing a Mexico-Kenya shuttle breeding scheme. Parents with APR to Ug99 were hybridized with high-yielding parents that had adequate to high levels of APR to leaf rust and yellow rust. Segregating populations and advanced lines from these crosses were selected under high rust pressures in Mexico (leaf rust and yellow rust) and Kenya (Ug99 stem rust and yellow rust) to identify high-yielding progenies that possess high to adequate APR to all three rusts. International distribution of these high-yielding wheats is underway through CIMMYT international yield trials and screening nurseries. It is expected that several wheat varieties with APR to three rusts will be released and grown in various countries in the near-future that will allow determining the

  10. Wheat production and wheat rust management in Canada%加拿大小麦生产和锈病防治

    Institute of Scientific and Technical Information of China (English)

    Allen G. Xue; Dawn T. Chi; 张淑珍; 李卓夫; 徐鹏飞; 姜良宇; 范素杰; 王欣

    2012-01-01

    Wheat is Canada's largest crop with most of the production in the western Canadian Prairie Provinces of Manitoba, Saskatchewan and Alberta. There were approximately ten million hm2 seeded to wheat in Canada, including seven million hm2 of hexaploid spring wheat (Triticum aestivum L), two million hm2 of durum wheat (T. Turgkjum L ssp. Durum (Desf.) Husn.), and one million hm2 of winter wheat (T. Aestivum). Within hexaploid wheat there has been diversification into a number of market classes based on differentend-use quality criteria. The predominant spring bread wheat class has been the Canada Western Red Spring (CWRS) class. Historically, the disease of major concern in wheat was stem rust, caused by Pucdnia graminis f. Sp. Tritid. The first significant stem rust resistant cuttivar in Canada was Thatcher, grown extensively from 1939 until the early 1970s. Thatcher, however, was very susceptible to leaf rust, caused by Pucdnia triticina. Over the years, improved resistance to both stem and leaf rust was achieved with the release of cultivars with additional genes for resistance, primarily Sr2, Sr6, Sr7a, Sr9b, Lr13, Lr14a, Lr16, and Lr34. The genetic resistance has adequately controlled stem rust but leaf rust continues to cause significant losses, partially due to changes in the P. Triticina population which reduced the effectiveness of resistance genes such as Lr13 and Lr16. Stripe rust on wheat, caused by Pucdnia striiformis f. Sp. Tritid, was historically a problem under irrigation in southern Alberta, but since 2000 it has been found annually in the central Canadian prairies and southern Ontario. The genetic basis of resistance to stripe rust in most Canadian wheat cultivars has not been determined, although VTI8 provides partial resistance in many cultivars. In the future, other rust diseases such as wheat stripe rust, or highly virulent new pathotypes of current rust pathogens, such as P. Graminis f. Sp. Tritid race Ug-99, may pose new threats to cereal

  11. Development of high-density genetic maps for barley and wheat using a novel two-enzyme genotyping-by-sequencing approach.

    Directory of Open Access Journals (Sweden)

    Jesse A Poland

    Full Text Available Advancements in next-generation sequencing technology have enabled whole genome re-sequencing in many species providing unprecedented discovery and characterization of molecular polymorphisms. There are limitations, however, to next-generation sequencing approaches for species with large complex genomes such as barley and wheat. Genotyping-by-sequencing (GBS has been developed as a tool for association studies and genomics-assisted breeding in a range of species including those with complex genomes. GBS uses restriction enzymes for targeted complexity reduction followed by multiplex sequencing to produce high-quality polymorphism data at a relatively low per sample cost. Here we present a GBS approach for species that currently lack a reference genome sequence. We developed a novel two-enzyme GBS protocol and genotyped bi-parental barley and wheat populations to develop a genetically anchored reference map of identified SNPs and tags. We were able to map over 34,000 SNPs and 240,000 tags onto the Oregon Wolfe Barley reference map, and 20,000 SNPs and 367,000 tags on the Synthetic W9784 × Opata85 (SynOpDH wheat reference map. To further evaluate GBS in wheat, we also constructed a de novo genetic map using only SNP markers from the GBS data. The GBS approach presented here provides a powerful method of developing high-density markers in species without a sequenced genome while providing valuable tools for anchoring and ordering physical maps and whole-genome shotgun sequence. Development of the sequenced reference genome(s will in turn increase the utility of GBS data enabling physical mapping of genes and haplotype imputation of missing data. Finally, as a result of low per-sample costs, GBS will have broad application in genomics-assisted plant breeding programs.

  12. Alien Introgression in Wheat

    OpenAIRE

    Molnár-Láng, M.; Ceoloni, C; Doležel, J

    2015-01-01

    This book provides an overview of the latest advancements in the field of alien introgression in wheat. The discovery and wide application of molecular genetic techniques including molecular markers, in situ hybridization, and genomics has led to a surge in interspecific and intergeneric hybridization in recent decades. The work begins with the taxonomy of cereals, especially of those species which are potential gene sources for wheat improvement. The text then goes on to cover.

  13. Genetic variation in degradability of wheat straw and potential for improvement through plant breeding

    DEFF Research Database (Denmark)

    Jensen, Jacob Wagner; Magid, Jakob; Hansen-Møller, Jens

    2011-01-01

    contemporary gene pool. The cultivars were grown at two different locations to assess the potential for breeding for improved degradability. The straws exhibited much variation in degradability ranging from 258 g kg1 to 407 g kg1 of dry matter. The heritability for degradability was estimated to 29% indicating...... a reasonable potential for response to selection. Inclusion of height as a regression-term, indicated that only a minor part of genetic differences are directly related to plant height and that improvements in degradability may be achieved without unacceptable changes in straw length. Finally, a lack...... of correlation between degradability and grain yield indicated that straw degradability may be improved through breeding without serious negative effect on grain yield....

  14. SOME CONSTRAINTS ON INTERSPECIFIC CROSSING OF DURUM WHEAT WITH AEGILOPS TAUSCHII ACCESSIONS SCREENED UNDER WATER-DEFICIT STRESS

    Directory of Open Access Journals (Sweden)

    Masanori Inagaki

    2014-04-01

    Full Text Available A total of 400 accessions of Aegilops tauschii Coss. (goat grass collected from western Asia and the Caucasus were screened for the productive tillering capacity under rain-fed field conditions with the aim of developing new, synthetic hexaploid wheats having enhanced drought adaptation. Of these, 23 Ae. tauschii accessions were selected for interspecific crossing with two durum wheat varieties ‘Belikh-2’ and ‘Jennah Khetifa’. Fifteen of the selected accessions were of Pakistani origin and exhibited early ear-emergence and low cross-compatibility, and five accessions were from Iran and Turkmenistan and exhibited high cross-compatibility. A wide variation among accessions in cross-compatibility might be related to their region of origin. Successful hybridization resulted in the formation of immature embryos, which are capable of regenerating to plants on culture medium. The Ae. tauschii accession ig 47219, of Turkmenistan origin, gave the highest frequency of embryos in crosses with both wheat varieties, but regeneration from the crosses with ‘Belikh-2’ failed due to the occurrence of hybrid necrosis. Thus, a high frequency of embryo production did not always result in the satisfactory development of hybrid plants. Treatment of the hybrid plants with colchicine was essential for the successful set of hexaploid seeds on the newly-synthesized plants. These constraints were discussed for the efficient development of new, synthetic hexaploid wheats.

  15. Genetic diversity of Fusarium graminearum sensu lato isolates from wheat associated with Fusarium Head Blight in diverse geographic locations of Argentina.

    Science.gov (United States)

    Consolo, Verónica F; Ortega, Leonel M; Salerno, Graciela; Astoreca, Andrea L; Alconada, Teresa M

    2015-01-01

    Fusarium Head Blight is an important wheat disease in the Argentine Pampas region, being Fusarium graminearum the predominant pathogen. DNA polymorphism of the isolates was analyzed by IGS-RFLP and ISSR. IGS-RFLP and ISSR profiling were carried out using six endonucleases and eight primers, respectively. IGS-RFLP yielded 41 bands, 30 of which were polymorphic while ISSR produced 87 bands with 47 polymorphic bands. Both markers showed genetic variability among the analyzed isolates; however, IGS-RFLP was more efficient than ISSR, showing a higher polymorphic average (59.91%) than the latter (44.11%). The averages of polymorphic information content (PIC) were 0.211 and 0.129, respectively. Twenty haplotypes were identified by IGS-RFLP and 15 haplotypes by ISSR. Genotype clustering within dendrograms was different for both types of markers. The genetic groups obtained by IGS-RFLP showed a partial association to geographic origin. This is the first report on genetic variability of F. graminearum isolates from wheat in Argentina using IGS-RFLP and ISSR markers.

  16. A large-scale mutant panel in wheat developed using heavy-ion beam mutagenesis and its application to genetic research

    Energy Technology Data Exchange (ETDEWEB)

    Murai, Koji, E-mail: murai@fpu.ac.jp [Department of Bioscience, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji-cho, Yoshida-gun, Fukui 910-1195 (Japan); Nishiura, Aiko [Department of Bioscience, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji-cho, Yoshida-gun, Fukui 910-1195 (Japan); Kazama, Yusuke [RIKEN, Innovation Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Abe, Tomoko [RIKEN, Innovation Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); RIKEN, Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2013-11-01

    Mutation analysis is a powerful tool for studying gene function. Heavy-ion beam mutagenesis is a comparatively new approach to inducing mutations in plants and is particularly efficient because of its high linear energy transfer (LET). High LET radiation induces a higher rate of DNA double-strand breaks than other mutagenic methods. Over the last 12 years, we have constructed a large-scale mutant panel in diploid einkorn wheat (Triticum monococcum) using heavy-ion beam mutagenesis. Einkorn wheat seeds were exposed to a heavy-ion beam and then sown in the field. Selfed seeds from each spike of M{sub 1} plants were used to generate M{sub 2} lines. Every year, we obtained approximately 1000 M{sub 2} lines and eventually developed a mutant panel with 10,000 M{sub 2} lines in total. This mutant panel is being systematically screened for mutations affecting reproductive growth, and especially for flowering-time mutants. To date, we have identified several flowering-time mutants of great interest: non-flowering mutants (mvp: maintained vegetative phase), late-flowering mutants, and early-flowering mutants. These novel mutations will be of value for investigations of the genetic mechanism of flowering in wheat.

  17. Genetic Analysis and Molecular Mapping of a Stripe Rust Resistance Gene YrH9014 in Wheat Line H9014-14-4-6-1

    Institute of Scientific and Technical Information of China (English)

    MA Dong-fang; HOU Lu; TANG Ming-shuang; WANG Hai-ge; LI Qiang; JING Jin-xue

    2013-01-01

    Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most widespread and destructive wheat diseases in many wheat-growing regions of the world. The winter wheat translocation line H9014-14-4-6-1 has all stage resistance. To identify stripe rust resistance genes, the segregating populations were developed from the cross between H9014-14-4-6-1 and Mingxian 169 (a wheat cultivar susceptible to all Pst races identified in China). The seedlings of the parents and F1 plants, F2, F3 and BC1 generations were tested with Pst races under controlled greenhouse conditions. Two genes for resistance to stripe rust were identified, one dominant gene conferred resistance to SUN11-4, temporarily designated YrH9014 and the other recessive gene conferred resistance to CYR33. The bulked segregant analysis and simple sequence repeat (SSR) markers were used to identify polymorphic markers associated with YrH9014. Seven polymorphic SSR markers were used to genotype the F2 population inoculated with SUN11-4. A linkage map was constructed according to the genotypes of seven SSR markers and resistance gene. The molecular map spanned 24.3 cM, and the genetic distance of the two closest markers Xbarc13 and Xbarc55 to gene locus was 1.4 and 3.6 cM, respectively. Based on the position of SSR marker, the resistance gene YrH9014 was located on chromosome arm 2BS. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xbarc13 indicated that YrH9014 was located on chromosome 2B. Based on chromosomal location, the reaction patterns and pedigree analysis, YrH9014 should be a novel resistance gene to stripe rust. This new gene and flanking markers got from this study should be useful for marker-assisted selection (MAS) in breeding programs for stripe rust.

  18. Soft durum wheat - a paradigm shift

    Science.gov (United States)

    Two traits define most aspects of wheat quality and utilization: kernel texture (hardness) and gluten. The former is far simpler genetically and is controlled by two genes, Puroindoline a and Puroindoline b. Durum wheat lacks puroindolines and has very hard kernels. As such, durum wheat when milled ...

  19. Genetic control of wheat quality: interactions between chromosomal regions determining protein content and composition, dough rheology, and sponge and dough baking properties.

    Science.gov (United States)

    Mann, Gulay; Diffey, Simon; Cullis, Brian; Azanza, Fermin; Martin, David; Kelly, Alison; McIntyre, Lynne; Schmidt, Adele; Ma, Wujun; Nath, Zena; Kutty, Ibrahim; Leyne, P Emmett; Rampling, Lynette; Quail, Ken J; Morell, Matthew K

    2009-05-01

    While the genetic control of wheat processing characteristics such as dough rheology is well understood, limited information is available concerning the genetic control of baking parameters, particularly sponge and dough (S&D) baking. In this study, a quantitative trait loci (QTL) analysis was performed using a population of doubled haploid lines derived from a cross between Australian cultivars Kukri x Janz grown at sites across different Australian wheat production zones (Queensland in 2001 and 2002 and Southern and Northern New South Wales in 2003) in order to examine the genetic control of protein content, protein expression, dough rheology and sponge and dough baking performance. The study highlighted the inconsistent genetic control of protein content across the test sites, with only two loci (3A and 7A) showing QTL at three of the five sites. Dough rheology QTL were highly consistent across the 5 sites, with major effects associated with the Glu-B1 and Glu-D1 loci. The Glu-D1 5 + 10 allele had consistent effects on S&D properties across sites; however, there was no evidence for a positive effect of the high dough strength Glu-B1-al allele at Glu-B1. A second locus on 5D had positive effects on S&D baking at three of five sites. This study demonstrated that dough rheology measurements were poor predictors of S&D quality. In the absence of robust predictive tests, high heritability values for S&D demonstrate that direct selection is the current best option for achieving genetic gain in this product category.

  20. Genetic Relationships, Carbendazim Sensitivity and Mycotoxin Production of the Fusarium Graminearum Populations from Maize, Wheat and Rice in Eastern China

    Directory of Open Access Journals (Sweden)

    Jianbo Qiu

    2014-08-01

    Full Text Available Members of the Fusarium graminearum species complex (FGSC are important pathogens on wheat, maize, barley, and rice in China. Harvested grains are often contaminated by mycotoxins, such as the trichothecene nivalenol (NIV and deoxynivalenol (DON and the estrogenic mycotoxin zearalenone (ZEN, which is a big threat to humans and animals. In this study, 97 isolates were collected from maize, wheat, and rice in Jiangsu and Anhui provinces in 2013 and characterized by species- and chemotype-specific PCR. F. graminearum sensu stricto (s. str. was predominant on maize, while most of the isolates collected from rice and wheat were identified as F. asiaticum. Fusarium isolates from three hosts varied in trichothecene chemotypes. The 3-acetyldeoxynivalenol (3ADON chemotype predominated on wheat and rice population, while 15ADON was prevailing in the remaining isolates. Sequence analysis of the translation elongation factor 1α and trichodiene synthase indicated the accuracy of the above conclusion. Additionally, phylogenetic analysis suggested four groups with strong correlation with species, chemotype, and host. These isolates were also evaluated for their sensitivity to carbendazim and mycotoxins production. The maize population was less sensitive than the other two. The DON levels were similar in three populations, while those isolates on maize produced more ZEN. More DON was produced in carbendazim resistant strains than sensitive ones, but it seemed that carbendazim resistance had no effect on ZEN production in wheat culture.

  1. Genetic Relationships, Carbendazim Sensitivity and Mycotoxin Production of the Fusarium Graminearum Populations from Maize, Wheat and Rice in Eastern China

    Science.gov (United States)

    Qiu, Jianbo; Shi, Jianrong

    2014-01-01

    Members of the Fusarium graminearum species complex (FGSC) are important pathogens on wheat, maize, barley, and rice in China. Harvested grains are often contaminated by mycotoxins, such as the trichothecene nivalenol (NIV) and deoxynivalenol (DON) and the estrogenic mycotoxin zearalenone (ZEN), which is a big threat to humans and animals. In this study, 97 isolates were collected from maize, wheat, and rice in Jiangsu and Anhui provinces in 2013 and characterized by species- and chemotype-specific PCR. F. graminearum sensu stricto (s. str.) was predominant on maize, while most of the isolates collected from rice and wheat were identified as F. asiaticum. Fusarium isolates from three hosts varied in trichothecene chemotypes. The 3-acetyldeoxynivalenol (3ADON) chemotype predominated on wheat and rice population, while 15ADON was prevailing in the remaining isolates. Sequence analysis of the translation elongation factor 1α and trichodiene synthase indicated the accuracy of the above conclusion. Additionally, phylogenetic analysis suggested four groups with strong correlation with species, chemotype, and host. These isolates were also evaluated for their sensitivity to carbendazim and mycotoxins production. The maize population was less sensitive than the other two. The DON levels were similar in three populations, while those isolates on maize produced more ZEN. More DON was produced in carbendazim resistant strains than sensitive ones, but it seemed that carbendazim resistance had no effect on ZEN production in wheat culture. PMID:25093387

  2. Wheat in the Mediterranean revisited - tetraploid wheat landraces assessed with elite bread wheat Single Nucleotide Polymorphism markers

    OpenAIRE

    Oliveira, Hugo R; Hagenblad, Jenny; Leino, Matti W.; Leigh, Fiona J; Lister, Diane L.; Peña-Chocarro, Leonor; Jones, Martin K.

    2014-01-01

    Abstract Background Single Nucleotide Polymorphism (SNP) panels recently developed for the assessment of genetic diversity in wheat are primarily based on elite varieties, mostly those of bread wheat. The usefulness of such SNP panels for studying wheat evolution and domestication has not yet been fully explored and ascertainment bias issues can potentially affect their applicability when studying landraces and tetraploid ancestors of bread wheat. We here evaluate whether population structure...

  3. Wheat allergy: diagnosis and management

    Directory of Open Access Journals (Sweden)

    Cianferoni A

    2016-01-01

    Full Text Available Antonella Cianferoni Department of Pediatrics, Division of Allergy and Immunology, The Children’s Hospital of Philadelphia, PA, USA Abstract: Triticum aestivum (bread wheat is the most widely grown crop worldwide. In genetically predisposed individuals, wheat can cause specific immune responses. A food allergy to wheat is characterized by T helper type 2 activation which can result in immunoglobulin E (IgE and non-IgE mediated reactions. IgE mediated reactions are immediate, are characterized by the presence of wheat-specific IgE antibodies, and can be life-threatening. Non-IgE mediated reactions are characterized by chronic eosinophilic and lymphocytic infiltration of the gastrointestinal tract. IgE mediated responses to wheat can be related to wheat ingestion (food allergy or wheat inhalation (respiratory allergy. A food allergy to wheat is more common in children and can be associated with a severe reaction such as anaphylaxis and wheat-dependent, exercise-induced anaphylaxis. An inhalation induced IgE mediated wheat allergy can cause baker’s asthma or rhinitis, which are common occupational diseases in workers who have significant repetitive exposure to wheat flour, such as bakers. Non-IgE mediated food allergy reactions to wheat are mainly eosinophilic esophagitis (EoE or eosinophilic gastritis (EG, which are both characterized by chronic eosinophilic inflammation. EG is a systemic disease, and is associated with severe inflammation that requires oral steroids to resolve. EoE is a less severe disease, which can lead to complications in feeding intolerance and fibrosis. In both EoE and EG, wheat allergy diagnosis is based on both an elimination diet preceded by a tissue biopsy obtained by esophagogastroduodenoscopy in order to show the effectiveness of the diet. Diagnosis of IgE mediated wheat allergy is based on the medical history, the detection of specific IgE to wheat, and oral food challenges. Currently, the main treatment of a

  4. Physical mapping resources for large plant genomes: radiation hybrids for wheat D-genome progenitor Aegilops tauschii

    Directory of Open Access Journals (Sweden)

    Kumar Ajay

    2012-11-01

    Full Text Available Abstract Background Development of a high quality reference sequence is a daunting task in crops like wheat with large (~17Gb, highly repetitive (>80% and polyploid genome. To achieve complete sequence assembly of such genomes, development of a high quality physical map is a necessary first step. However, due to the lack of recombination in certain regions of the chromosomes, genetic mapping, which uses recombination frequency to map marker loci, alone is not sufficient to develop high quality marker scaffolds for a sequence ready physical map. Radiation hybrid (RH mapping, which uses radiation induced chromosomal breaks, has proven to be a successful approach for developing marker scaffolds for sequence assembly in animal systems. Here, the development and characterization of a RH panel for the mapping of D-genome of wheat progenitor Aegilops tauschii is reported. Results Radiation dosages of 350 and 450 Gy were optimized for seed irradiation of a synthetic hexaploid (AABBDD wheat with the D-genome of Ae. tauschii accession AL8/78. The surviving plants after irradiation were crossed to durum wheat (AABB, to produce pentaploid RH1s (AABBD, which allows the simultaneous mapping of the whole D-genome. A panel of 1,510 RH1 plants was obtained, of which 592 plants were generated from the mature RH1 seeds, and 918 plants were rescued through embryo culture due to poor germination (1 seeds. This panel showed a homogenous marker loss (2.1% after screening with SSR markers uniformly covering all the D-genome chromosomes. Different marker systems mostly detected different lines with deletions. Using markers covering known distances, the mapping resolution of this RH panel was estimated to be cM/cR ratio of 1:5.2 and 15 distinct bins. Additionally, with this small set of lines, almost all the tested ESTs could be mapped. A set of 399 most informative RH lines with an average deletion frequency of ~10% were identified for developing high density marker

  5. Haplotype variation of Glu-D1 locus and the origin of Glu-D1d allele conferring superior end-use qualities in common wheat.

    Directory of Open Access Journals (Sweden)

    Zhenying Dong

    Full Text Available In higher plants, seed storage proteins (SSPs are frequently expressed from complex gene families, and allelic variation of SSP genes often affects the quality traits of crops. In common wheat, the Glu-D1 locus, encoding 1Dx and 1Dy SSPs, has multiple alleles. The Glu-D1d allele frequently confers superior end-use qualities to commercial wheat varieties. Here, we studied the haplotype structure of Glu-D1 genomic region and the origin of Glu-D1d. Using seven diagnostic DNA markers, 12 Glu-D1 haplotypes were detected among common wheat, European spelt wheat (T. spelta, a primitive hexaploid relative of common wheat, and Aegilops tauschii (the D genome donor of hexaploid wheat. By comparatively analyzing Glu-D1 haplotypes and their associated 1Dx and 1Dy genes, we deduce that the haplotype carrying Glu-D1d was likely differentiated in the ancestral hexaploid wheat around 10,000 years ago, and was subsequently transmitted to domesticated common wheat and T. spelta. A group of relatively ancient Glu-D1 haplotypes was discovered in Ae. tauschii, which may serve for the evolution of other haplotypes. Moreover, a number of new Glu-D1d variants were found in T. spelta. The main steps in Glu-D1d differentiation are proposed. The implications of our work for enhancing the utility of Glu-D1d in wheat quality improvement and studying the SSP alleles in other crop species are discussed.

  6. Detection of QTL for metabolic and agronomic traits in wheat with adjustments for variation at genetic loci that affect plant phenology.

    Science.gov (United States)

    Hill, Camilla B; Taylor, Julian D; Edwards, James; Mather, Diane; Langridge, Peter; Bacic, Antony; Roessner, Ute

    2015-04-01

    Mapping of quantitative trait loci associated with levels of individual metabolites (mQTL) was combined with the mapping of agronomic traits to investigate the genetic basis of variation and co-variation in metabolites, agronomic traits, and plant phenology in a field-grown bread wheat population. Metabolome analysis was performed using liquid chromatography-mass spectrometry resulting in identification of mainly polar compounds, including secondary metabolites. A total of 558 metabolic features were obtained from the flag leaves of 179 doubled haploid lines, of which 197 features were putatively identified, mostly as alkaloids, flavonoids and phenylpropanoids. Coordinated genetic control was observed for several groups of metabolites, such as organic acids influenced by two loci on chromosome 7A. Five major phenology-related loci, which were introduced as cofactors in the analyses, differed in their impact upon metabolic and agronomic traits with QZad-aww-7A having more impact on the expression of both metabolite and agronomic QTL than Ppd-B1, Vrn-A1, Eps, and QZad-aww-7D. This QTL study validates the utility of combining agronomic and metabolomic traits as an approach to identify potential trait enhancement targets for breeding selection and reinforces previous results that demonstrate the importance of including plant phenology in the assessment of useful traits in this wheat mapping population.

  7. Wheat Allergy

    Science.gov (United States)

    ... but also, in some cases, by inhaling wheat flour. Wheat can be found in many foods, including ... protein Soy sauce Some condiments, such as ketchup Meat products, such as hot dogs or cold cuts ...

  8. Wheat Allergy

    Science.gov (United States)

    ... Events Blog Media Shop Alerts Donate About Food Allergies Home About Food Allergy Food Allergy Basics Facts ... Registration Create Your Own Events Educational Events Wheat Allergy Wheat allergy is most common in children, and ...

  9. Population genetic structure and mycotoxin potential of the wheat crown rot and head blight pathogen Fusarium culmorum in Algeria

    Science.gov (United States)

    Surveys for crown rot (FCR) and head blight (FHB) of Algerian wheat conducted during 2014 and 2015 revealed that Fusarium culmorum strains producing 3-acetyl-deoxynivalenol (3ADON) or nivalenol (NIV) were the primary causal agents of these important diseases. Morphological identification of the isol...

  10. Genetic mapping of MlUM15: an Aegilops neglecta-derived powdery mildew resistance gene in common wheat

    Science.gov (United States)

    Powdery mildew, caused by Blumeria graminis DC f. sp. tritici, is a major fungal disease of wheat (Triticum aestivum L.) in cool and humid climates. Race-specific host plant resistance is a reliable, economical, and environmentally benign form of disease prevention. The identification of molecular m...

  11. Detection of the Molecular Marker and Chromosomal Segment linked to Un-reduced Gamete Gene in Common Wheat%小麦未减数配子基因的连锁标记及染色体区段检测

    Institute of Scientific and Technical Information of China (English)

    寇春兰; 赵来宾; 刘梦; 郝明; 甯顺腙; 袁中伟; 刘登才; 张连全

    2016-01-01

    六倍体普通小麦(Triticumaestivum L., AABBDD,2n =42)由四倍体小麦(T. turgidum, AABB,2n =28)与节节麦(Aegilops tauschiiCosson, DD,2n=14)天然杂交,然后通过染色体自动加倍形成。加倍过程主要受四倍体小麦未减数配子基因控制,且不同四倍体小麦存在不同的遗传效应。本研究利用位于3B 染色体上未减数配子基因QTug.sau-3B的连锁SSR标记Xgpw1146和高通量DArTseq分子标记,筛选出可能转入四倍体小麦未减数配子基因的人工合成小麦改良后代。在105份改良材料中检测出17份具有四倍体小麦的Xgpw1146等位位点,表明四倍体小麦的未减数配子基因可能转入了这17份材料。利用DArTseq高通量标记技术分析人工合成小麦SHW-L1的88份改良后代,发现含四倍体小麦Xgpw1146等位位点的材料均具有来自SHW-L1、且可能包含Xgpw1146的一个染色体区段,表明未减数配子基因临近区域以一个区段传递到改良后代。这些人工合成小麦改良材料在加倍单倍体育种中有重要的应用潜力。%Hexaploid common wheat (Triticum aestivumL., AABBDD, 2n= 42) arose from spontaneous chromosome doubling of the hybrid betweenT. turgidumandAegilops tauschiiCosson. The process of chromosomes doubling is mainly determined by unreduced gametes (UG) genes inT. turgidum. The genetic effects on the UG production may vary amongT. turgidum lines. In this study, a SSR marker close to the UG geneQTug.sau-3B(Xgpw1146) and high throughput DArTseq genotyping technique were used to screen the UG gene in common wheat lines transferred fromT. turgidum via synthetic hexaploid wheat (SHW) as a bridge. Out of the analyzed 105 SHW-derived elite lines, 17 had theXgpw1146 allele fromT. turgidum, indicating that the UG gene was probably transferred into these wheat lines. According to the DArTseq genotyping data on 88 lines derived from the synthetic hexaploid wheat SHW-L1, all these lines with theT. turgidumXgpw1146 allele

  12. Wheat Woes

    Institute of Scientific and Technical Information of China (English)

    DING SHENGJUN

    2010-01-01

    @@ Chicago wheat futures began to skyrocket in early June,jumping 62 percent and reaching their highest level since September 2008. In Russia, wheat prices increased 70 percent recently. And Europe's wheat prices also rose 8 percent within a short time.

  13. Wheat Woes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Soaringwheat prices are unlikely to endanger globalgrain security chicago wheat futures began to skyrocket in early June, jumping 62 percent and reaching their highest level since September 2008. In Russia,wheat prices increased 70 percent recently.And Europe’s wheat prices also rose 8 percent within a short time.

  14. Transmission of the Aegilops ovata chromosomes carrying gametocidal factors in hexaploid triticale (×Triticosecale Wittm.) hybrids.

    Science.gov (United States)

    Kwiatek, M; Majka, M; Ślusarkiewicz-Jarzina, A; Ponitka, A; Pudelska, H; Belter, J; Wiśniewska, H

    2016-08-01

    The main aim of this work was to induce the chromosome rearrangements between Aegilops ovata (UUMM) and hexaploid triticale (AABBRR) by expression of the gametocidal factor located on the chromosome 4M. The Aegilops ovata × Secale cereale (UUMMRR) amphiploids and triticale 'Moreno' were used to produce hybrids by reciprocal crosses. Chromosome dynamics was observed in subsequent generations of hybrids during mitotic metaphase of root meristems and first metaphase of meiosis of pollen mother cells. Chromosomes were identified by genomic in situ hybridisation (GISH) and fluorescence in situ hybridisation (FISH) using pTa71, pTa791, pSc119.2 and pAs1 DNA probes. It has been shown that the origin of the genetic background had an influence on Aegilops chromosome transmission. Moreover, it has been reported that the preferential transmission of chromosome 4M appeared during both androgenesis and gynogenesis. It is also hypothesised that the expression of the triticale Gc gene suppressor had an influence on the semi-fertility of hybrids but did not inhibit the chromosome rearrangements. This paper also describes the double haploid production, which enabled to obtain plants with two identical copies of triticale chromosomes with translocations of Aegilops chromatin segments.

  15. Embryo and endosperm development in caryopses of hybrids from crosses between tetraploid wheats and their alloplasmic lines with rye

    Directory of Open Access Journals (Sweden)

    Wijciech Sodkiewicz

    2014-01-01

    Full Text Available Data concerning the embryo and endosperm development in twenty-day-old caryopses of hybrids obtained as the result of pollination with rye pollen of tetraploid wheats (Triticum dicoccoides, T. dicoccum, T. durum and T. polonicum, their alloplasmic lines with T. timopheevi plasma and aIlaplasmic T. timopheevi lines with cytoplasma of the above mentioned tetraploid wheats and hexaploid wheat (T. macha were analysed. A high variability was noted between the tetraploid wheats as regards the degree of development of the embryo and of the endosperm in the hybrid caryopses and a decisive influence of the wheat genotype on these characters. The data for alloplasmic lines showed that the cytoplasm may have a modifying effect on the expression of these genotype characters.

  16. Genetic Basis for Spontaneous Hybrid Genome Doubling during Allopolyploid Speciation of Common Wheat Shown by Natural Variation Analyses of the Paternal Species

    Science.gov (United States)

    Matsuoka, Yoshihiro; Nasuda, Shuhei; Ashida, Yasuyo; Nitta, Miyuki; Tsujimoto, Hisashi; Takumi, Shigeo; Kawahara, Taihachi

    2013-01-01

    The complex process of allopolyploid speciation includes various mechanisms ranging from species crosses and hybrid genome doubling to genome alterations and the establishment of new allopolyploids as persisting natural entities. Currently, little is known about the genetic mechanisms that underlie hybrid genome doubling, despite the fact that natural allopolyploid formation is highly dependent on this phenomenon. We examined the genetic basis for the spontaneous genome doubling of triploid F1 hybrids between the direct ancestors of allohexaploid common wheat (Triticum aestivum L., AABBDD genome), namely Triticumturgidum L. (AABB genome) and Aegilopstauschii Coss. (DD genome). An Ae. tauschii intraspecific lineage that is closely related to the D genome of common wheat was identified by population-based analysis. Two representative accessions, one that produces a high-genome-doubling-frequency hybrid when crossed with a T. turgidum cultivar and the other that produces a low-genome-doubling-frequency hybrid with the same cultivar, were chosen from that lineage for further analyses. A series of investigations including fertility analysis, immunostaining, and quantitative trait locus (QTL) analysis showed that (1) production of functional unreduced gametes through nonreductional meiosis is an early step key to successful hybrid genome doubling, (2) first division restitution is one of the cytological mechanisms that cause meiotic nonreduction during the production of functional male unreduced gametes, and (3) six QTLs in the Ae. tauschii genome, most of which likely regulate nonreductional meiosis and its subsequent gamete production processes, are involved in hybrid genome doubling. Interlineage comparisons of Ae. tauschii’s ability to cause hybrid genome doubling suggested an evolutionary model for the natural variation pattern of the trait in which non-deleterious mutations in six QTLs may have important roles. The findings of this study demonstrated that the

  17. Genetic basis for spontaneous hybrid genome doubling during allopolyploid speciation of common wheat shown by natural variation analyses of the paternal species.

    Directory of Open Access Journals (Sweden)

    Yoshihiro Matsuoka

    Full Text Available The complex process of allopolyploid speciation includes various mechanisms ranging from species crosses and hybrid genome doubling to genome alterations and the establishment of new allopolyploids as persisting natural entities. Currently, little is known about the genetic mechanisms that underlie hybrid genome doubling, despite the fact that natural allopolyploid formation is highly dependent on this phenomenon. We examined the genetic basis for the spontaneous genome doubling of triploid F1 hybrids between the direct ancestors of allohexaploid common wheat (Triticum aestivum L., AABBDD genome, namely Triticumturgidum L. (AABB genome and Aegilopstauschii Coss. (DD genome. An Ae. tauschii intraspecific lineage that is closely related to the D genome of common wheat was identified by population-based analysis. Two representative accessions, one that produces a high-genome-doubling-frequency hybrid when crossed with a T. turgidum cultivar and the other that produces a low-genome-doubling-frequency hybrid with the same cultivar, were chosen from that lineage for further analyses. A series of investigations including fertility analysis, immunostaining, and quantitative trait locus (QTL analysis showed that (1 production of functional unreduced gametes through nonreductional meiosis is an early step key to successful hybrid genome doubling, (2 first division restitution is one of the cytological mechanisms that cause meiotic nonreduction during the production of functional male unreduced gametes, and (3 six QTLs in the Ae. tauschii genome, most of which likely regulate nonreductional meiosis and its subsequent gamete production processes, are involved in hybrid genome doubling. Interlineage comparisons of Ae. tauschii's ability to cause hybrid genome doubling suggested an evolutionary model for the natural variation pattern of the trait in which non-deleterious mutations in six QTLs may have important roles. The findings of this study demonstrated

  18. Wheat allergy: diagnosis and management.

    Science.gov (United States)

    Cianferoni, Antonella

    2016-01-01

    Triticum aestivum (bread wheat) is the most widely grown crop worldwide. In genetically predisposed individuals, wheat can cause specific immune responses. A food allergy to wheat is characterized by T helper type 2 activation which can result in immunoglobulin E (IgE) and non-IgE mediated reactions. IgE mediated reactions are immediate, are characterized by the presence of wheat-specific IgE antibodies, and can be life-threatening. Non-IgE mediated reactions are characterized by chronic eosinophilic and lymphocytic infiltration of the gastrointestinal tract. IgE mediated responses to wheat can be related to wheat ingestion (food allergy) or wheat inhalation (respiratory allergy). A food allergy to wheat is more common in children and can be associated with a severe reaction such as anaphylaxis and wheat-dependent, exercise-induced anaphylaxis. An inhalation induced IgE mediated wheat allergy can cause baker's asthma or rhinitis, which are common occupational diseases in workers who have significant repetitive exposure to wheat flour, such as bakers. Non-IgE mediated food allergy reactions to wheat are mainly eosinophilic esophagitis (EoE) or eosinophilic gastritis (EG), which are both characterized by chronic eosinophilic inflammation. EG is a systemic disease, and is associated with severe inflammation that requires oral steroids to resolve. EoE is a less severe disease, which can lead to complications in feeding intolerance and fibrosis. In both EoE and EG, wheat allergy diagnosis is based on both an elimination diet preceded by a tissue biopsy obtained by esophagogastroduodenoscopy in order to show the effectiveness of the diet. Diagnosis of IgE mediated wheat allergy is based on the medical history, the detection of specific IgE to wheat, and oral food challenges. Currently, the main treatment of a wheat allergy is based on avoidance of wheat altogether. However, in the near future immunotherapy may represent a valid way to treat IgE mediated reactions to

  19. Fine physical and genetic mapping of powdery mildew resistance gene MlIW172 originating from wild emmer (Triticum dicoccoides.

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    Shuhong Ouyang

    Full Text Available Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most important wheat diseases in the world. In this study, a single dominant powdery mildew resistance gene MlIW172 was identified in the IW172 wild emmer accession and mapped to the distal region of chromosome arm 7AL (bin7AL-16-0.86-0.90 via molecular marker analysis. MlIW172 was closely linked with the RFLP probe Xpsr680-derived STS marker Xmag2185 and the EST markers BE405531 and BE637476. This suggested that MlIW172 might be allelic to the Pm1 locus or a new locus closely linked to Pm1. By screening genomic BAC library of durum wheat cv. Langdon and 7AL-specific BAC library of hexaploid wheat cv. Chinese Spring, and after analyzing genome scaffolds of Triticum urartu containing the marker sequences, additional markers were developed to construct a fine genetic linkage map on the MlIW172 locus region and to delineate the resistance gene within a 0.48 cM interval. Comparative genetics analyses using ESTs and RFLP probe sequences flanking the MlIW172 region against other grass species revealed a general co-linearity in this region with the orthologous genomic regions of rice chromosome 6, Brachypodium chromosome 1, and sorghum chromosome 10. However, orthologous resistance gene-like RGA sequences were only present in wheat and Brachypodium. The BAC contigs and sequence scaffolds that we have developed provide a framework for the physical mapping and map-based cloning of MlIW172.

  20. Genetic diversity of wheat grain quality and determination the best clustering technique and data type for diversity assessment

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    Khodadadi Mostafa

    2014-01-01

    Full Text Available Wheat is an important staple in human nutrition and improvement of its grain quality characters will have high impact on population's health. The objectives of this study were assessing variation of some grain quality characteristics in the Iranian wheat genotypes and identify the best type of data and clustering method for grouping genotypes. In this study 30 spring wheat genotypes were cultivated through randomized complete block design with three replications in 2009 and 2010 years. High significant difference among genotypes for all traits except for Sulfate, K, Br and Cl content, also deference among two years mean for all traits were no significant. Meanwhile there were significant interaction between year and genotype for all traits except Sulfate and F content. Mean values for crude protein, Zn, Fe and Ca in Mahdavi, Falat, Star, Sistan genotypes were the highest. The Ca and Br content showed the highest and the lowest broadcast heritability respectively. In this study indicated that the Root Mean Square Standard Deviation is efficient than R Squared and R Squared efficient than Semi Partial R Squared criteria for determining the best clustering technique. Also Ward method and canonical scores identified as the best clustering method and data type for grouping genotypes, respectively. Genotypes were grouped into six completely separate clusters and Roshan, Niknejad and Star genotypes from the fourth, fifth and sixth clusters had high grain quality characters in overall.

  1. Effect of environmental and genetic factors on the correlation and stability of grain yield components in wheat

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    Hristov Nikola

    2011-01-01

    Full Text Available More effective breeding and development of new wheat genotypes depend on an intricate analysis of the complex relationships among many different traits. The objective of this paper was to determine the interrelationship, direct and indirect effects, and stability of different yield components in wheat. Forty divergent genotypes were analyzed in a three- year study (2005-2007. Highly significant correlations were found between grain yield per plant and all the other traits analyzed except spike length, with the only negative correlation being that with plant height. Path analysis revealed highly significant direct effects of grain number per spike, grain mass per spike and 1000 grain weight on grain yield per plant. Analysis of stability parameters showed that the stability of grain yield per plant depended for the most part on the stability of grain number per spike, grain mass per spike and harvest index. Cluster analysis identified genotypes with a high performance for grain yield per plant and good stability parameters, indicating the possibility of developing wheat varieties with a high potential and high stability for a particular trait.

  2. Genetic Diversity and Association Analysis for Solvent Retention Capacity in the Accessions Derived from Soft Wheat Ningmai 9

    Science.gov (United States)

    Jiang, Peng; Zhang, Ping-Ping

    2017-01-01

    Solvent retention capacity (SRC) test is an effective method for quality evaluation of soft wheat. Ningmai 9 is a founder in soft wheat breeding. The SRC and genotype of Ningmai 9 and its 117 derivatives were tested. Association mapping was employed to identify the quantitative trait loci (QTL) associated with SRCs. Ningmai 9 had the allele frequency of 75.60% and 67.81% to its first- and second-generation derivatives, respectively, indicating higher contribution than theoretical expectation. Neighbor-joining cluster based on the genotyping data showed that Ningmai 9 and most of its first-generation derivatives were clustered together, whereas its second-generation derivatives were found in another group. The variation coefficients of SRCs in the derivatives ranged from 5.35% to 8.63%. A total of 29 markers on 13 chromosomes of the genome were associated with the SRCs. There were 6 markers associated with more than one SRC or detected in two years. The results suggested that QTL controlling SRCs in Ningmai 9 might be different from other varieties. Markers Xgwm44, Xbarc126, Xwmc790, and Xgwm232 associated with SRCs in Ningmai 9 might be used for quality improvement in soft wheat breeding.

  3. Characterization and Genetic Analysis of a Novel Light-Dependent Lesion Mimic Mutant, lm3, Showing Adult-Plant Resistance to Powdery Mildew in Common Wheat.

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    Fang Wang

    Full Text Available Lesion mimics (LMs that exhibit spontaneous disease-like lesions in the absence of pathogen attack might confer enhanced plant disease resistance to a wide range of pathogens. The LM mutant, lm3 was derived from a single naturally mutated individual in the F1 population of a 3-1/Jing411 cross, backcrossed six times with 3-1 as the recurrent parent and subsequently self-pollinated twice. The leaves of young seedlings of the lm3 mutant exhibited small, discrete white lesions under natural field conditions. The lesions first appeared at the leaf tips and subsequently expanded throughout the entire leaf blade to the leaf sheath. The lesions were initiated through light intensity and day length. Histochemical staining revealed that lesion formation might reflect programmed cell death (PCD and abnormal accumulation of reactive oxygen species (ROS. The chlorophyll content in the mutant was significantly lower than that in wildtype, and the ratio of chlorophyll a/b was increased significantly in the mutant compared with wildtype, indicating that lm3 showed impairment of the biosynthesis or degradation of chlorophyll, and that Chlorophyll b was prone to damage during lesion formation. The lm3 mutant exhibited enhanced resistance to wheat powdery mildew fungus (Blumeria graminis f. sp. tritici; Bgt infection, which was consistent with the increased expression of seven pathogenesis-related (PR and two wheat chemically induced (WCI genes involved in the defense-related reaction. Genetic analysis showed that the mutation was controlled through a single partially dominant gene, which was closely linked to Xbarc203 on chromosome 3BL; this gene was delimited to a 40 Mb region between SSR3B450.37 and SSR3B492.6 using a large derived segregating population and the available Chinese Spring chromosome 3B genome sequence. Taken together, our results provide information regarding the identification of a novel wheat LM gene, which will facilitate the additional fine

  4. Removing celiac disease-related gluten proteins from bread wheat while retaining technological properties: a study with Chinese Spring deletion lines

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    Bosch Dirk

    2009-04-01

    Full Text Available Abstract Background Gluten proteins can induce celiac disease (CD in genetically susceptible individuals. In CD patients gluten-derived peptides are presented to the immune system, which leads to a CD4+ T-cell mediated immune response and inflammation of the small intestine. However, not all gluten proteins contain T-cell stimulatory epitopes. Gluten proteins are encoded by multigene loci present on chromosomes 1 and 6 of the three different genomes of hexaploid bread wheat (Triticum aestivum (AABBDD. Results The effects of deleting individual gluten loci on both the level of T-cell stimulatory epitopes in the gluten proteome and the technological properties of the flour were analyzed using a set of deletion lines of Triticum aestivum cv. Chinese Spring. The reduction of T-cell stimulatory epitopes was analyzed using monoclonal antibodies that recognize T-cell epitopes present in gluten proteins. The deletion lines were technologically tested with respect to dough mixing properties and dough rheology. The results show that removing the α-gliadin locus from the short arm of chromosome 6 of the D-genome (6DS resulted in a significant decrease in the presence of T-cell stimulatory epitopes but also in a significant loss of technological properties. However, removing the ω-gliadin, γ-gliadin, and LMW-GS loci from the short arm of chromosome 1 of the D-genome (1DS removed T-cell stimulatory epitopes from the proteome while maintaining technological properties. Conclusion The consequences of these data are discussed with regard to reducing the load of T-cell stimulatory epitopes in wheat, and to contributing to the design of CD-safe wheat varieties.

  5. The development of hexaploid tobacco by hybridization of heteroploid tobaccos%不同倍性烟草杂交获得六倍体烟草植株

    Institute of Scientific and Technical Information of China (English)

    魏烨昕; 党江波; 刘超; 吴天姣; 汪卫星; 郭启高; 梁国鲁

    2013-01-01

    以本实验室自行创制的云烟87八倍体(2n=8x=96)为母本,L-8四倍体为父本进行杂交,成功获得烟草六倍体(2n=6x=72)植株。经观察统计其花器官特征,花粉特征,并通过体外萌发及杂交试验对其育性进行初步研究。结果显示:烟草六倍体花蕾和花药明显大于云烟87四倍体×L-8四倍体杂交组合四倍体(简称四倍体杂种)后代的花蕾和花药,但花粉量较少;其花粉体外萌发率仅9.78%,明显低于四倍体杂种;六倍体花粉在六倍体及云烟87四倍体柱头上只极少量萌发并穿过花柱;以六倍体为父本,与云烟87四倍体烟草品种杂交以及六倍体自交,不能坐果;而以六倍体为母本、云烟87四倍体为父本可得到一定量种子,其单果种子数与杂种四倍体作母本、云烟87四倍体为父本时差异不大,但发芽率只有21.2%。这表明本研究中的六倍体植株作父本不育,而作母本具有一定的育性,后续研究利用中可将其用作母本。%Tobacco hexaploid plants were obtained successfully by crossingYunyan87 octoploids (2n=8x=96) with L-8 tetraploids, with octoploids as maternal parent. Fertility was studied with traits of flower and pollen, pollen germination in vitro and cross experiment. Results showed that:flower buds and anthers of hexaploid tobaccos were bigger than those of tetraploid tobaccos, with less amount of pollen. Under in vitro conditions, pollen germination rate of hexaploids was only 9.78%, significantly lower than that of tetraploid. Only a very small amount of hexaploid pollen could germinate on Yunyan87 stigma. There was no fruit when hexaploid as male parent while only some mature seeds were harvested when hexaploid as maternal parent. Germination rate of these seeds was only 21.2%. Our data suggested that hexaploid tobacco plants was male sterile and could be used as female parent in future breeding and genetic study.

  6. Artificial neural network - Genetic algorithm to optimize wheat germ fermentation condition: Application to the production of two anti-tumor benzoquinones.

    Science.gov (United States)

    Zheng, Zi-Yi; Guo, Xiao-Na; Zhu, Ke-Xue; Peng, Wei; Zhou, Hui-Ming

    2017-07-15

    Methoxy-ρ-benzoquinone (MBQ) and 2, 6-dimethoxy-ρ-benzoquinone (DMBQ) are two potential anticancer compounds in fermented wheat germ. In present study, modeling and optimization of added macronutrients, microelements, vitamins for producing MBQ and DMBQ was investigated using artificial neural network (ANN) combined with genetic algorithm (GA). A configuration of 16-11-1 ANN model with Levenberg-Marquardt training algorithm was applied for modeling the complicated nonlinear interactions among 16 nutrients in fermentation process. Under the guidance of optimized scheme, the total contents of MBQ and DMBQ was improved by 117% compared with that in the control group. Further, by evaluating the relative importance of each nutrient in terms of the two benzoquinones' yield, macronutrients and microelements were found to have a greater influence than most of vitamins. It was also observed that a number of interactions between nutrients affected the yield of MBQ and DMBQ remarkably. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Genetic dissection of yield and its component traits using high-density composite map of wheat chromosome 3A: bridging gaps between QTLs and underlying genes.

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    Sachin Rustgi

    Full Text Available Earlier we identified wheat (Triticum aestivum L. chromosome 3A as a major determinant of grain yield and its component traits. In the present study, a high-density genetic linkage map of 81 chromosome 3A-specific markers was developed to increase the precision of previously identified yield component QTLs, and to map QTLs for biomass-related traits. Many of the previously identified QTLs for yield and its component traits were confirmed and were localized to narrower intervals. Four novel QTLs one each for shoot biomass (Xcfa2262-Xbcd366, total biomass (wPt2740-Xcfa2076, kernels/spike (KPS (Xwmc664-Xbarc67, and Pseudocercosporella induced lodging (PsIL were also detected. The major QTLs identified for grain yield (GY, KPS, grain volume weight (GVWT and spikes per square meter (SPSM respectively explained 23.2%, 24.2%, 20.5% and 20.2% of the phenotypic variation. Comparison of the genetic map with the integrated physical map allowed estimation of recombination frequency in the regions of interest and suggested that QTLs for grain yield detected in the marker intervals Xcdo549-Xbarc310 and Xpsp3047-Xbarc356 reside in the high-recombination regions, thus should be amenable to map-based cloning. On the other hand, QTLs for KPS and SPSM flanked by markers Xwmc664 and Xwmc489 mapped in the low-recombination region thus are not suitable for map-based cloning. Comparisons with the rice (Oryza sativa L. genomic DNA sequence identified 11 candidate genes (CGs for yield and yield related QTLs of which chromosomal location of two (CKX2 and GID2-like was confirmed using wheat aneuploids. This study provides necessary information to perform high-resolution mapping for map-based cloning and for CG-based cloning of yield QTLs.

  8. Genetic control and combining ability of flag leaf area and relative water content traits of bread wheat cultivars under drought stress condition

    Directory of Open Access Journals (Sweden)

    Golparvar Ahmad Reza

    2013-01-01

    Full Text Available In order to compare mode of inheritance, combining ability, heterosis and gene action in genetic control of traits flag leaf area, relative water content and grain filling rate of bread wheat under drought stress, a study was conducted on 8 cultivars using of Griffing’s method2 in fixed model. Mean square of general combining ability was significant also for all traits and mean square of specific combining ability was significant also for all traits except relative water content of leaf which show importance of both additive and dominant effects of genes in heredity of these traits under stress. GCA to SCA mean square ratio was significant for none of traits. Results of this study showed that non additive effects of genes were more important than additive effect for all traits. According to results we can understand that genetic improvement of mentioned traits will have low genetic efficiency by selection from the best crosses of early generations. Then it is better to delay selection until advanced generations and increase in heritability of these traits.

  9. Selección recurrente en triticale hexaploide (X Triticosecale Wittmack bajo condiciones de secano Recurrent selection in hexaploid triticale (X Triticosecale Wittmack under rainfed conditions

    Directory of Open Access Journals (Sweden)

    R. Maich

    2007-06-01

    Full Text Available El objetivo de este trabajo fue detectar cambios en una población de triticale hexaploide sometida a un proceso de selección y recombinación en condiciones de secano. Fueron evaluadas diez familias de triticale hexaploide S1:2 (2004 y S1:3 (2005 por cada uno de los ciclos de selección recurrente analizados: C0, C1, C2 y C3,, para lo cual se usaron diseños completamente aleatorizados con dos repeticiones. Diez caracteres fueron medidos o estimados. Se consideró a los ciclos de selección, años de evaluación e interacción entre ambas variables como fuentes de variación. El índice de cosecha por espiga incrementó significativamente en C2 y C3 con respecto a C0; en cambio no existieron diferencias significativas entre C2 y C3. ; en tanto para el peso de 1000 semillas ocurrieron diferencias significativas en C3 con respecto a C2. Se continuará con el proceso de selección y recombinación en curso, mediante el uso de un índice de selección que incluya al rendimiento y sus principales componentes, introduciendo nuevas combinaciones genotípicas fijadas, de probada aptitud agronómica, derivadas de los distintos ciclos de selección recurrente alcanzados.The objective of this study was to detect changes within an hexaploid triticale population submitted to a selection and recombination process under rainfed conditions. Ten S1:2 (2004 and S1:3 (2005 families per each one of analyzed recurrent selection cycles: C0, C1, C2 y C3, were evaluated. Completely randomized designs with two replications were used. At harvest, ten characters were measured or estimated. The recurrent selection cycles, years of evaluation and the interaction between them were considered as variation sources. Spike harvest index increased significantly at C2 and C3 with respect to C0; not statistical differences between C2 and C3 were observed. The 1000 grain weight of C3 was statistically superior than C2. The selection and recombination process will be continued

  10. Anthocyanins in Wheat Seed – A Mini Review

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    Havrlentová Michaela

    2014-06-01

    Full Text Available Improving the micronutrients in food has become an important field of the Second Green Revolution. In recent years, minor bioactive compounds such as polyphenols, pigments and carotenoids, have attracted more and more interest from both researchers and food manufactures as health-promoting and disease-preventing effects in both in vitro and in vivo studies. One of plant pigments, wheat anthocyanins as plant phenolics are increasingly attractive as natural compounds positively affecting consumer´s health and condition moreover wheat is staple food source consumed usually daily. For a purple, blue, or red colour of wheat seed are responsible glycosylated cyanidins, delphinidins, malvinidins, pelargonidins, petunidins, and peonidins located in aleurone layer or pericarp, respectively. Other than white seed colour is not natural for common hexaploid wheat but this trait can be introduced from donors by aimed breeding programs. The way of wheat anthocyanins to provide positive effects for consumer´s physiology is limited due to their specific occurrence in seed parts usually removed during grain milling practice and lower stability during processing to foods

  11. 粗山羊草细胞质对普通小麦细胞核的遗传效应%Genetic Effects of the Cytoplasm from Aegilops squarrosa L. on the Wheat Cell Nucleus

    Institute of Scientific and Technical Information of China (English)

    张玲丽; 卢碧霞; 马守才; 张永杰

    2001-01-01

    将粗山羊草细胞质导入普通小麦,研究其对普通小麦细胞核的遗传效应。结果表明,粗山羊草细胞质对普通小麦开花习性具有优良的作用;能增加小麦的株高,提高小穗数、穗粒数、结实率和发芽势,但延迟小麦的生育期;对其他性状影响不显著;粗山羊草细胞质对普通小麦细胞核之间有一定的核质杂种优势。%The genetic effects of Aegilops squarrosa L. cytoplasm were studied by transferring Aegilops squarrosa L. cytoplasm into wheat. The results showed that Aegilops squarrosa L. cytoplasm had fine effects on wheat flowering habits and characteristics.Meanwhile, plant height, number of spikelets, grains per spike,setting rate and germinating potential of wheat were improved significantly, but wheat growth phase was lengthened. There were no significant effects on other agronomic characters. There was sure nucleo-cytoplasmic heterosis between Ae. squarrosa L. cytoplasm and wheat cell nucleus.

  12. Genetics of gliadins coded by the group 1 chromosomes in the high-quality bread wheat cultivar Neepawa.

    Science.gov (United States)

    Dachkevitch, T; Redaelli, R; Biancardi, A M; Metakovsky, E V; Pogna, N E

    1993-04-01

    The inheritance and biochemical properties of gliadins controlled by the group 1 chromosomes of the high-quality bread wheat cultivar Neepawa were studied in the progeny of the cross Neepawa x Costantino by six different electrophoretic procedures. Chromosome 1B of Neepawa contains two gliadin loci, one (Gli-B1) coding for at least six ω- or γ-gliadins, the other (Gli-B3) controlling the synthesis of gliadin N6 only. The map distance between these loci was calculated as 22.1 cM. Amongst the chromosome 1A gliadins, three proteins are encoded at the Gli-A1 locus whereas polypeptides N14-N15-N16 are controlled by a remote locus which recombines with Gli-A1. Six other gliadins are controlled by a gene cluster at Gli-D1 on chromosome 1D. Canadian wheat cultivars sharing the Gli-B1 allele of Neepawa were found to differ in the presence or absence of gliadin N6. The electrophoretic mobilities of proteins N6 and N14-N15-N16 were unaffected by the addition of a reducing agent during two-dimensional sodium dodecyl sulphate polyacrylamid-gel electrophoresis, suggesting the absence of intra-chain disulphide bonds in their structure.

  13. Eat Wheat!

    Science.gov (United States)

    Idaho Wheat Commission, Boise.

    This pamphlet contains puzzles, games, and a recipe designed to teach elementary school pupils about wheat. It includes word games based on the U.S. Department of Agriculture Food Guide Pyramid and on foods made from wheat. The Food Guide Pyramid can be cut out of the pamphlet and assembled as a three-dimensional information source and food guide.…

  14. Effects of Azospirillum brasilense with genetically modified auxin biosynthesis gene ipdC upon the diversity of the indigenous microbiota of the wheat rhizosphere.

    Science.gov (United States)

    Baudoin, Ezékiel; Lerner, Anat; Mirza, M Sajjad; El Zemrany, Hamdy; Prigent-Combaret, Claire; Jurkevich, Edouard; Spaepen, Stijn; Vanderleyden, Jos; Nazaret, Sylvie; Okon, Yaacov; Moënne-Loccoz, Yvan

    2010-04-01

    The phytostimulatory properties of Azospirillum inoculants, which entail production of the phytohormone indole-3-acetic acid (IAA), can be enhanced by genetic means. However, it is not known whether this could affect their interactions with indigenous soil microbes. Here, wheat seeds were inoculated with the wild-type strain Azospirillum brasilense Sp245 or one of three genetically modified (GM) derivatives and grown for one month. The GM derivatives contained a plasmid vector harboring the indole-3-pyruvate/phenylpyruvate decarboxylase gene ipdC (IAA production) controlled either by the constitutive promoter PnptII or the root exudate-responsive promoter PsbpA, or by an empty vector (GM control). All inoculants displayed equal rhizosphere population densities. Only inoculation with either ipdC construct increased shoot biomass compared with the non-inoculated control. At one month after inoculation, automated ribosomal intergenic spacer analysis (ARISA) revealed that the effect of the PsbpA construct on bacterial community structure differed from that of the GM control, which was confirmed by 16S rDNA-based denaturing gradient gel electrophoresis (DGGE). The fungal community was sensitive to inoculation with the PsbpA construct and especially the GM control, based on ARISA data. Overall, fungal and bacterial communities displayed distinct responses to inoculation of GM A. brasilense phytostimulators, whose effects could differ from those of the wild-type.

  15. Additive-dominance genetic model analyses for late-maturity alpha-amylase activity in a bread wheat factorial crossing population.

    Science.gov (United States)

    Rasul, Golam; Glover, Karl D; Krishnan, Padmanaban G; Wu, Jixiang; Berzonsky, William A; Ibrahim, Amir M H

    2015-12-01

    Elevated level of late maturity α-amylase activity (LMAA) can result in low falling number scores, reduced grain quality, and downgrade of wheat (Triticum aestivum L.) class. A mating population was developed by crossing parents with different levels of LMAA. The F2 and F3 hybrids and their parents were evaluated for LMAA, and data were analyzed using the R software package 'qgtools' integrated with an additive-dominance genetic model and a mixed linear model approach. Simulated results showed high testing powers for additive and additive × environment variances, and comparatively low powers for dominance and dominance × environment variances. All variance components and their proportions to the phenotypic variance for the parents and hybrids were significant except for the dominance × environment variance. The estimated narrow-sense heritability and broad-sense heritability for LMAA were 14 and 54%, respectively. High significant negative additive effects for parents suggest that spring wheat cultivars 'Lancer' and 'Chester' can serve as good general combiners, and that 'Kinsman' and 'Seri-82' had negative specific combining ability in some hybrids despite of their own significant positive additive effects, suggesting they can be used as parents to reduce LMAA levels. Seri-82 showed very good general combining ability effect when used as a male parent, indicating the importance of reciprocal effects. High significant negative dominance effects and high-parent heterosis for hybrids demonstrated that the specific hybrid combinations; Chester × Kinsman, 'Lerma52' × Lancer, Lerma52 × 'LoSprout' and 'Janz' × Seri-82 could be generated to produce cultivars with significantly reduced LMAA level.

  16. Genetic mapping of stem rust resistance gene Sr13 in tetraploid wheat (Triticum turgidum ssp. durum L.).

    Science.gov (United States)

    Simons, Kristin; Abate, Zewdie; Chao, Shiaoman; Zhang, Wenjun; Rouse, Matt; Jin, Yue; Elias, Elias; Dubcovsky, Jorge

    2011-02-01

    Wheat stem rust caused by Puccinia graminis f. sp. tritici, can cause significant yield losses. To combat the disease, breeders have deployed resistance genes both individually and in combinations to increase resistance durability. A new race, TTKSK (Ug99), identified in Uganda in 1999 is virulent on most of the resistance genes currently deployed, and is rapidly spreading to other regions of the world. It is therefore important to identify, map, and deploy resistance genes that are still effective against TTKSK. One of these resistance genes, Sr13, was previously assigned to the long arm of chromosome 6A, but its precise map location was not known. In this study, the genome location of Sr13 was determined in four tetraploid wheat (T. turgidum ssp. durum) mapping populations involving the TTKSK resistant varieties Kronos, Kofa, Medora and Sceptre. Our results showed that resistance was linked to common molecular markers in all four populations, suggesting that these durum lines carry the same resistance gene. Based on its chromosome location and infection types against different races of stem rust, this gene is postulated to be Sr13. Sr13 was mapped within a 1.2-2.8 cM interval (depending on the mapping population) between EST markers CD926040 and BE471213, which corresponds to a 285-kb region in rice chromosome 2, and a 3.1-Mb region in Brachypodium chromosome 3. These maps will be the foundation for developing high-density maps, identifying diagnostic markers, and positional cloning of Sr13.

  17. Identification and Characterization of Reverse Transcriptase Domain of Transcriptionally Active Retrotransposons in Wheat Genomes

    Institute of Scientific and Technical Information of China (English)

    Yi-Miao TANG; You-Zhi MA; Lian-Cheng LI; Xing-Guo YE

    2005-01-01

    To clarify activation characterization of wheat (Triticum aestivum L.) retrotransposons, transcriptionally active Ty1-copia retrotransposons were found in wheat by using RT-PCR to amplify the RT domain. Sequence analysis of random RT-PCR clones reveals that Ty1-copia retrotransposons are highly heterogeneous and can be divided into at least four groups, which are tentatively named TaRT-1 to TaRT-4.Dot blot hybridization indicates that TaRT- 1 exists in the wheat genome as multiple copies (at 30 000 copies/a hexaploid genome (ABD)). Northern blot hybridization showed that TaRT-1 is only expressed at a low level under normal conditions in seedlings, but at a high level when induced by powdery mildew fungus, jasmonic acid (JA) and salicylic acid (SA). These results suggest that the TaRT-1 expression is highly sensitive to biotic and abiotic stresses.

  18. 人工合成小麦 HMW-GS Dtx1.5亚基的 AS-PCR 鉴定程序优化及遗传分析%Optimization of AS-PCR Identification System for HMW-GS Dtx1.5 of Wheat Syndeme Developed with Durum Wheat and Aegilops tauschii and Its Genetic Analysis

    Institute of Scientific and Technical Information of China (English)

    万洪深; 温雯; 李俊; 杨武云

    2014-01-01

    Synthetic hexaploids have gradually been used as a bridge-tool for common wheat improvement to introduce elite gene sources from its wild relatives with strong resistance to biotic/abiotic stresses, increased yield potential and good making quality. The high molecular weight glutenin subunits (HMW-GS) Dtx1.5 from Aegilops tauschii is thought to be associated with fine making quality. In this study, the reaction condition of the Dtx1.5 AS-PCR system has been optimized step by step, and the distribution of the HMW-GS Dtx1.5 in the F2 and F9 RIL populations derived from Chuanyu 12 crossed with synthetic wheat Syn780 was also investigated using this AS-PCR system. The sharp and stable fragments amplified by this optimum AS-PCR system indicated its availability and convenience in the identification of HMW-GS Dtx1.5. And the observed distribution of Dtx1.5 obeyed Mendelian law of segregation in both low (F2) and advanced (F9) generation populations, suggesting the stable inheritance of Dtx1.5. Therefore, the Dtx1.5 from Aegilops tauschii could be used in common wheat breeding for quality and the optimum AS-PCR system could enhance the efficiency of selection by molecular markers.%人工合成小麦综合了自然界中现有四倍体小麦(Triticum turgidun)和粗山羊草(节节麦, Aegilops tauschii)的丰富遗传变异,是将野生祖先种中优异的抗病、抗逆基因成功利用到普通小麦育种中的重要桥梁。源于粗山羊草的高分子量谷蛋白(HMW-GS) Dtx1.5亚基,是一种新的优质亚基。本研究对 HMW-GS Dtx1.5亚基 AS-PCR 反应体系及扩增程序进行了逐步的优化,并利用普通小麦川育12与人工合成小麦 Syn780(含有Dtx1.5亚基)杂交 F2代(低代)和 F9重组自交系(高代)群体对 Dtx1.5亚基的遗传规律进行了分析。结果表明:优化后目的扩增条带清晰、稳定、可靠,可以用于 Dtx1.5亚基的分子鉴定;Dtx1.5亚基在普通小麦与人工合成小麦杂交的低代

  19. Self-sterility in the hexaploid Handroanthus serratifolius (Bignoniaceae, the national flower of Brazil

    Directory of Open Access Journals (Sweden)

    Mariana Ferreira Alves

    2013-12-01

    Full Text Available Polyploidization is common among angiosperms and might induce typically allogamous plants to become autogamous (self-compatible, relying on sexual self-fertilization or apomictic (achieving asexual reproduction through seeds. This work aimed to determine whether neopolyploidy leads to the breakdown of the self-incompatibility system in the hexaploid non-apomictic species Handroanthus serratifolius (Vahl S. Grose, through analyses of its floral biology, pollination biology and breeding system. Although anthesis lasted for three days, increasing the overall floral display, receptivity decreased as of the second day. Centridini and Euglossini bees were the main pollinators, and low nectar availability (1.95 ± 1.91 µl/flower might have obliged them to visit multiple flowers. We observed low reproductive efficacy. That might be explained by self-sterility and by the great number of flowers per individual, which could increase the frequency of geitonogamy. Ovule penetration by the pollen tubes in self-pollinated pistils with posterior abscission indicated late-acting self-incompatibility in H. serratifolius, as observed in other diploid Bignoniaceae species, although inbreeding depression cannot be excluded. The self-sterility found in the monoembryonic, hexaploid individuals studied here contrasts with the results for other neopolyploid Handroanthus and Anemopaegma species, which are often autogamous and apomictic. Our results suggest that neopolyploidy is not the main factor leading to self-fertility in Handroanthus.

  20. The vanishing wheat landraces of the Fertile Crescent

    Science.gov (United States)

    Genetic diversity of wheat landraces constituted a sizable portion of the mega diversity in the Fertile Crescent as a center of origin and of diversity of major crop plants. Following wheat domestication in the Fertile Crescent, early farmers developed diverse wheat landraces, and contributed to the...

  1. Soluble carbohydrates in cereal (wheat, rye, triticale) seed after storage under accelerated ageing conditions

    OpenAIRE

    Agnieszka I. Piotrowicz-Cieślak; Maciej Niedzielski; Dariusz J. Michalczyk; Wiesław Łuczak; Barbara Adomas

    2011-01-01

    Germinability and the content of soluble carbohydrates were analysed in cereal seed (winter rye, cv. Warko; spring wheat, cv. Santa; hexaploid winter triticale, cv. Fidelio and cv. Woltario). Seed moisture content (mc) was equilibrated over silica gel to 0.08 g H2O/g dry mass and stored in a desiccator at 20oC for up to 205 weeks or were equilibrated to mc 0.06, 0.08 or 0.10 g H2O/g dm and subjected to artificial aging at 35oC in air-tight laminated aluminium foil packages for 205 weeks. It w...

  2. Comparative Proteomic Analysis of Flag Leaves Reveals New Insight into Wheat Heat Adaptation

    Directory of Open Access Journals (Sweden)

    Yunze Lu

    2017-06-01

    Full Text Available Hexaploid wheat (Triticum aestivum L. is an important food crop but it is vulnerable to heat. The heat-responsive proteome of wheat remains to be fully elucidated because of previous technical and genomic limitations, and this has hindered our understanding of the mechanisms of wheat heat adaptation and advances in improving thermotolerance. Here, flag leaves of wheat during grain filling stage were subjected to high daytime temperature stress, and 258 heat-responsive proteins (HRPs were identified with iTRAQ analysis. Enrichment analysis revealed that chlorophyll synthesis, carbon fixation, protein turnover, and redox regulation were the most remarkable heat-responsive processes. The HRPs involved in chlorophyll synthesis and carbon fixation were significantly decreased, together with severe membrane damage, demonstrating the specific effects of heat on photosynthesis of wheat leaves. In addition, the decrease in chlorophyll content may result from the decrease in HRPs involved in chlorophyll precursor synthesis. Further analysis showed that the accumulated effect of heat stress played a critical role in photosynthesis reduction, suggested that improvement in heat tolerance of photosynthesis, and extending heat tolerant period would be major research targets. The significantly accumulation of GSTs and Trxs in response to heat suggested their important roles in redox regulation, and they could be the promising candidates for improving wheat thermotolerance. In summary, our results provide new insight into wheat heat adaption and provide new perspectives on thermotolerance improvement.

  3. Homoeologous gene silencing in tissue cultured wheat callus

    Directory of Open Access Journals (Sweden)

    Chapman Natalie H

    2008-10-01

    Full Text Available Abstract Background In contrast to diploids, most polyploid plant species, which include the hexaploid bread wheat, possess an additional layer of epigenetic complexity. Several studies have demonstrated that polyploids are affected by homoeologous gene silencing, a process in which sub-genomic genomic copies are selectively transcriptionally inactivated. This form of silencing can be tissue specific and may be linked to developmental or stress responses. Results Evidence was sought as to whether the frequency of homoeologous silencing in in vitro cultured wheat callus differ from that in differentiated organs, given that disorganized cells are associated with a globally lower level of DNA methylation. Using a reverse transcription PCR (RT-PCR single strand conformation polymorphism (SSCP platform to detect the pattern of expression of 20 homoeologous sets of single-copy genes known to be affected by this form of silencing in the root and/or leaf, we observed no silencing in any of the wheat callus tissue tested. Conclusion Our results suggest that much of the homoeologous silencing observed in differentiated tissues is probably under epigenetic control, rather than being linked to genomic instability arising from allopolyploidization. This study reinforces the notion of plasticity in the wheat epi-genome.

  4. Wheat: The Whole Story.

    Science.gov (United States)

    Oklahoma State Dept. of Education, Oklahoma City.

    This publication presents information on wheat. Wheat was originally a wild grass and not native to the United States. Wheat was not planted there until 1777 (and then only as a hobby crop). Wheat is grown on more acres than any other grain in this country. Soft wheats are grown east of the Mississippi River, and hard wheats are grown west of the…

  5. A new class of wheat gliadin genes and proteins.

    Directory of Open Access Journals (Sweden)

    Olin D Anderson

    Full Text Available The utility of mining DNA sequence data to understand the structure and expression of cereal prolamin genes is demonstrated by the identification of a new class of wheat prolamins. This previously unrecognized wheat prolamin class, given the name δ-gliadins, is the most direct ortholog of barley γ3-hordeins. Phylogenetic analysis shows that the orthologous δ-gliadins and γ3-hordeins form a distinct prolamin branch that existed separate from the γ-gliadins and γ-hordeins in an ancestral Triticeae prior to the branching of wheat and barley. The expressed δ-gliadins are encoded by a single gene in each of the hexaploid wheat genomes. This single δ-gliadin/γ3-hordein ortholog may be a general feature of the Triticeae tribe since examination of ESTs from three barley cultivars also confirms a single γ3-hordein gene. Analysis of ESTs and cDNAs shows that the genes are expressed in at least five hexaploid wheat cultivars in addition to diploids Triticum monococcum and Aegilops tauschii. The latter two sequences also allow assignment of the δ-gliadin genes to the A and D genomes, respectively, with the third sequence type assumed to be from the B genome. Two wheat cultivars for which there are sufficient ESTs show different patterns of expression, i.e., with cv Chinese Spring expressing the genes from the A and B genomes, while cv Recital has ESTs from the A and D genomes. Genomic sequences of Chinese Spring show that the D genome gene is inactivated by tandem premature stop codons. A fourth δ-gliadin sequence occurs in the D genome of both Chinese Spring and Ae. tauschii, but no ESTs match this sequence and limited genomic sequences indicates a pseudogene containing frame shifts and premature stop codons. Sequencing of BACs covering a 3 Mb region from Ae. tauschii locates the δ-gliadin gene to the complex Gli-1 plus Glu-3 region on chromosome 1.

  6. Acetosyringone, pH and temperature effects on transient genetic transformation of immature embryos of Brazilian wheat genotypes by Agrobacterium tumefaciens

    Directory of Open Access Journals (Sweden)

    Ernandes Manfroi

    2015-01-01

    Full Text Available AbstractLow transformation efficiency is one of the main limiting factors in the establishment of genetic transformation of wheat via Agrobacterium tumefaciens. To determine more favorable conditions for T-DNA delivery and explant regeneration after infection, this study investigated combinations of acetosyringone concentration and pH variation in the inoculation and co-cultivation media and co-culture temperatures using immature embryos from two Brazilian genotypes (BR 18 Terena and PF 020037. Based on transient expression of uidA, the most favorable conditions for T-DNA delivery were culture media with pH 5.0 and 5.4 combined with co-culture temperatures of 22 °C and 25 °C, and a 400 μM acetosyringone supplement. These conditions resulted in blue foci in 81% of the embryos. Media with more acidic pH also presented reduced A. tumefaciensovergrowth during co-culture, and improved regeneration frequency of the inoculated explants. BR 18 Terena was more susceptible to infection by A. tumefaciens than PF 020037. We found that it is possible to improve T-DNA delivery and explant regeneration by adjusting factors involved in the early stages of A. tumefaciens infection. This can contribute to establishing a stable transformation procedure in the future.

  7. Fine mapping of Hch1, the causal D-genome gene for hybrid chlorosis in interspecific crosses between tetraploid wheat and Aegilops tauschii.

    Science.gov (United States)

    Hirao, Kana; Nishijima, Ryo; Sakaguchi, Kohei; Takumi, Shigeo

    2015-01-01

    Hybrid chlorosis, one of the reproductive barriers between tetraploid wheat and its D-genome progenitor, Aegilops tauschii, inhibits normal growth of synthetic wheat hexaploids. Hybrid chlorosis appears to be due to an epistatic interaction of two loci from the AB and D wheat genomes. Our previous study assigned the causal D-genome gene for hybrid chlorosis, Hch1, to the short arm of chromosome 7D. Here, we constructed a fine map of 7DS near Hch1 using 280 F2 individuals from a cross of two wheat synthetic lines, one showing normal growth and the other showing hybrid chlorosis. The hybrid chlorosis phenotype was controlled by a single dominant allele of the Hch1 locus in the synthetic hexaploids. Hch1 was closely linked to four new markers within 0.2 cM, and may be localized near or within the two Ae. tauschii scaffolds containing the linked markers on 7DS. Comparative analysis of the Hch1 chromosomal region for Ae. tauschii, barley and Brachypodium showed that a local inversion occurred in the region proximal to Hch1 during the divergence between barley and Ae. tauschii, and that the Hch1 region on wheat 7DS is syntenic to Brachypodium chromosome 1. These observations provide useful information for further studies toward map-based cloning of Hch1.

  8. Characterization of genetic coefficients of durum wheat (Triticum turgidumL. ssp. durum'Llareta-INIA' and 'Corcolén-INIA'

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    Marco Garrido

    2013-06-01

    Full Text Available The genetic coefficients, representative of a crop, are necessary to use growth models; in many cases the range of the species is known, but there are no specific values for varieties. Durum wheat (Triticum turgidumL. ssp. durum'Llareta-INIA' and 'Corcolén-INIA' were sown under irrigation in the experiment station Antumapu of the Universidad de Chile on 29 June 2007, 19 May 2009, and 15 June 2010 in order to determinate four genetic coefficients: developmental thermal time, phyllochron (PHLN, extinction coefficient (k, and radiation use efficiency (RUE, and to evaluate the performance of these coefficients. Thermal times to anthesis and from anthesis to physiological maturity were 652 and 541 °C d, respectively. Two PHLN values were found, 46.6 °C d leaf-1 from emergence to fifth leaf and 102.9 °C d leaf-1 from fifth to eighth leaf. In both cases neither variety nor sowing date was significant. The value of kdid not vary among sowing dates for 'Llareta-INIA' and was not significantly different from that of 'Corcolén-INIA' for normal planting date, due to which a single fit for the two varieties was adjusted, obtaining a value of 0.46. However, 'Corcolén-INIA' had a lower value of kfor later sowing dates. RUE did not vary between varieties or sowing dates; its estimated value was 2.83 g MJ-1. The evaluation of the coefficients obtained showed coherent results, thus they can be used in model simulations.

  9. Identification and genetic mapping of the putative Thinopyrum intermedium-derived dominant powdery mildew resistance gene PmL962 on wheat chromosome arm 2BS

    Science.gov (United States)

    Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease affecting the production of wheat (Triticum aestivum). Powdery mildew resistance was putatively transferred from Thinopyrum intermedium to the common wheat line L962, which conferred resistance to multiple Ch...

  10. Genetic variability in anthocyanin composition and nutritional properties of blue, purple, and red bread (Triticum aestivum L.) and durum (Triticum turgidum L. ssp. turgidum convar. durum) wheats.

    Science.gov (United States)

    Ficco, Donatella B M; De Simone, Vanessa; Colecchia, Salvatore A; Pecorella, Ivano; Platani, Cristiano; Nigro, Franca; Finocchiaro, Franca; Papa, Roberto; De Vita, Pasquale

    2014-08-27

    Renewed interest in breeding for high anthocyanins in wheat (Triticum ssp.) is due to their antioxidant potential. A collection of different pigmented wheats was used to investigate the stability of anthocyanins over three crop years. The data show higher anthocyanins in blue-aleurone bread wheat (Triticum aestivum L.), followed by purple- and red-pericarp durum wheat (Triticum turgidum L. ssp. turgidum convar. durum), using cyanidin 3-O-glucoside as standard. HPLC of the anthocyanin components shows five to eight major anthocyanins for blue wheat extracts, compared to three anthocyanins for purple and red wheats. Delphinidin 3-O-rutinoside, delphinidin 3-O-glucoside, and malvidin 3-O-glucoside are predominant in blue wheat, with cyanidin 3-O-glucoside, peonidin 3-O-galactoside, and malvidin 3-O-glucoside in purple wheat. Of the total anthocyanins, 40-70% remain to be structurally identified. The findings confirm the high heritability for anthocyanins, with small genotype × year effects, which will be useful for breeding purposes, to improve the antioxidant potential of cereal-based foods.

  11. Dissection of genetic factors underlying wheat kernel shape and size in an elite x nonadapted cross using a high density SNP linkage map

    Science.gov (United States)

    Wheat kernel shape and size has been under selection since early domestication. Kernel morphology is a major consideration in wheat breeding, as it impacts grain yield and quality. A population of 160 recombinant inbred lines (RIL), developed using an elite (ND 705) and a nonadapted genotype (PI 414...

  12. 抗条锈、抗穗发芽六倍体人工合成小麦Cereta/Aegilops tauschii783的SSR标记分析%Genetic Evaluation of a Synthetic Hexaploid Wheat Cereta/Aegilops tauschii783 with Resistances to Stripe Rust and Pre-harvest Sprouting by SSR Marker

    Institute of Scientific and Technical Information of China (English)

    李俊; 魏会廷; 杨武云; 彭正松

    2005-01-01

    Cereta/Aegilops tauschii783是由CIMMYT引进的硬粒小麦/节节麦人工合成种,具有高抗条锈和高抗穗发芽等优良特性.本文选用小麦A、B、D染色体组的91对SSR引物将人工合成小麦Cereta/Aegilops tauschii783与绵阳26在分子水平上进行了比较分析,结果表明:91对引物中有88对引物能扩增出清晰条带;88对引物中除3对引物外,86对引物(96.59%)均能揭示出Cereta/Aegilops tauschii783与绵阳26之间的差异.人工合成小麦Cereta/Aegilops tauschii783与育成小麦品种遗传差异很大,是丰富现代小麦遗传多样性的优异基因源;利用人工合成小麦Cereta/Aegilops tauschii783与绵阳26构建SSR标记群体,可有效标记双亲优良基因.

  13. Accelerated senescence and enhanced disease resistance in hybrid chlorosis lines derived from interspecific crosses between tetraploid wheat and Aegilops tauschii.

    Science.gov (United States)

    Nakano, Hiroki; Mizuno, Nobuyuki; Tosa, Yukio; Yoshida, Kentaro; Park, Pyoyun; Takumi, Shigeo

    2015-01-01

    Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions.

  14. Accelerated senescence and enhanced disease resistance in hybrid chlorosis lines derived from interspecific crosses between tetraploid wheat and Aegilops tauschii.

    Directory of Open Access Journals (Sweden)

    Hiroki Nakano

    Full Text Available Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions.

  15. Genotyping by Sequencing Using Specific Allelic Capture to Build a High-Density Genetic Map of Durum Wheat.

    Directory of Open Access Journals (Sweden)

    Yan Holtz

    Full Text Available Targeted sequence capture is a promising technology which helps reduce costs for sequencing and genotyping numerous genomic regions in large sets of individuals. Bait sequences are designed to capture specific alleles previously discovered in parents or reference populations. We studied a set of 135 RILs originating from a cross between an emmer cultivar (Dic2 and a recent durum elite cultivar (Silur. Six thousand sequence baits were designed to target Dic2 vs. Silur polymorphisms discovered in a previous RNAseq study. These baits were exposed to genomic DNA of the RIL population. Eighty percent of the targeted SNPs were recovered, 65% of which were of high quality and coverage. The final high density genetic map consisted of more than 3,000 markers, whose genetic and physical mapping were consistent with those obtained with large arrays.

  16. Genotyping by Sequencing Using Specific Allelic Capture to Build a High-Density Genetic Map of Durum Wheat.

    Science.gov (United States)

    Holtz, Yan; Ardisson, Morgane; Ranwez, Vincent; Besnard, Alban; Leroy, Philippe; Poux, Gérard; Roumet, Pierre; Viader, Véronique; Santoni, Sylvain; David, Jacques

    2016-01-01

    Targeted sequence capture is a promising technology which helps reduce costs for sequencing and genotyping numerous genomic regions in large sets of individuals. Bait sequences are designed to capture specific alleles previously discovered in parents or reference populations. We studied a set of 135 RILs originating from a cross between an emmer cultivar (Dic2) and a recent durum elite cultivar (Silur). Six thousand sequence baits were designed to target Dic2 vs. Silur polymorphisms discovered in a previous RNAseq study. These baits were exposed to genomic DNA of the RIL population. Eighty percent of the targeted SNPs were recovered, 65% of which were of high quality and coverage. The final high density genetic map consisted of more than 3,000 markers, whose genetic and physical mapping were consistent with those obtained with large arrays.

  17. Assessment of Lipid Transfer Protein (LTP1) Gene in Wheat Powdery Mildew Resistance

    Institute of Scientific and Technical Information of China (English)

    LI Ai-li; MENG Cheng-sheng; ZHOU Rong-hua; MA Zhi-ying; JIA Ji-zeng

    2006-01-01

    This study is to investigate the role of lipid transfer protein (LTP1) gene of wheat (Triticum aestivum L.) in powdery mildew (Blumeria graminis f. sp. tritici, Bgt) resistance. A pair of primers based on the full length cDNA of wheat LTP1was used for amplifying the coding regions of LTP in hexaploid (AABBDD) wheat and its diploid donors T. urartu (AA),Ae. speltoides ssp speltoide (SS) and Ae. tauchii ssp strangulate (DD). LTP1 and LTP2 of wheat were isolated from the tested two hexaploid (ABD) materials: powdery mildew resistance near isogenic line (NIL) Mardler/7 x B ainong 3217 and its susceptible parent Bainong 3217 at the same time, while only one kind of LTP gene was found in the tested three diploid materials respectively by using the above PCR primer pairs. Two peaks of the expression of LTP1 and LTP2 induced by powdery mildew were observed [one occurred at 3 h after inoculation (hai); the other occurred at 10 hai] in resistant NIL Mardler/7 x Bainong3217 in comparison with a steady transcript level of LTP1 and LTP2 in susceptible Bainong3217.Transient over-expression result showed that LTP1 reduced the penetration efficiency (PE) of powdery mildew in susceptible cultivar by about 28.3%. This result indicated an obvious effectiveness of LTP1 in powdery mildew resistance. Expression analysis also showed that LTP1 and LTP2 of wheat are generally involved in salt/drought, but not in low temperature stress early responses.

  18. Karyotype characterization and comparison of three hexaploid species of Bromus Linnaeus, 1753 (Poaceae)

    Science.gov (United States)

    Artico, Leonardo Luís; Mazzocato, Ana Cristina; Ferreira, Juliano Lino; Carvalho, Carlos Roberto; Clarindo, Wellington Ronildo

    2017-01-01

    Abstract Chromosome morphometry and nuclear DNA content are useful data for cytotaxonomy and to understand the evolutionary history of different taxa. For the genus Bromus Linnaeus, 1753, distinct ploidy levels have been reported, occurring from diploid to duodecaploid species. The geographic distribution of Bromus species has been correlated with chromosome number and ploidy level. In this study, the aims were to determine the nuclear genome size and characterize the karyotype of the South American Bromus species: Bromus auleticus Trinius ex Nees, 1829, Bromus brachyanthera Döll, 1878 and Bromus catharticus Vahl, 1791. The mean nuclear 2C value ranged from 2C = 12.64 pg for B. catharticus to 2C = 17.92 pg for B. auleticus, meaning a maximum variation of 2C = 5.28 pg, equivalent to 41.70%. Despite this significant difference in 2C value, the three species exhibit the same chromosome number, 2n = 6x = 42, which confirms their hexaploid origin. Corroborating the genome size, the chromosome morphometry (total, short- and long-arm length) and, consequently, the class differed among the karyotypes of the species. Based on the first karyograms for these Bromus species, some morphologically similar and several distinct chromosome pairs were found. Therefore, the karyotype characterization confirmed the hexaploid origin of the studied Bromus species, which differ in relation to the karyogram and the nuclear 2C value. Considering this, cytogenetics and flow cytometry can be used to discriminate Bromus species, contributing to taxonomy and systematic studies and providing information on the evolutionary history of this taxa. PMID:28919960

  19. Genome-Wide Association Mapping for Resistance to Leaf and Stripe Rust in Winter-Habit Hexaploid Wheat Landraces

    National Research Council Canada - National Science Library

    Kertho, Albert; Mamidi, Sujan; Bonman, J Michael; McClean, Phillip E; Acevedo, Maricelis

    2015-01-01

    .... Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst requires a constant search for new sources of resistance...

  20. Efficient and transgene-free genome editing in wheat through transient expression of CRISPR/Cas9 DNA or RNA.

    Science.gov (United States)

    Zhang, Yi; Liang, Zhen; Zong, Yuan; Wang, Yanpeng; Liu, Jinxing; Chen, Kunling; Qiu, Jin-Long; Gao, Caixia

    2016-08-25

    Editing plant genomes is technically challenging in hard-to-transform plants and usually involves transgenic intermediates, which causes regulatory concerns. Here we report two simple and efficient genome-editing methods in which plants are regenerated from callus cells transiently expressing CRISPR/Cas9 introduced as DNA or RNA. This transient expression-based genome-editing system is highly efficient and specific for producing transgene-free and homozygous wheat mutants in the T0 generation. We demonstrate our protocol to edit genes in hexaploid bread wheat and tetraploid durum wheat, and show that we are able to generate mutants with no detectable transgenes. Our methods may be applicable to other plant species, thus offering the potential to accelerate basic and applied plant genome-engineering research.

  1. Pushing Wheat

    DEFF Research Database (Denmark)

    Sharp, Paul Richard

    This paper documents the evolution of variables central to understanding the creation of an Atlantic Economy in wheat between the US and the UK in the nineteenth century. The cointegrated VAR model is then applied to the period 1838-1913 in order to find long-run relationships between these varia......This paper documents the evolution of variables central to understanding the creation of an Atlantic Economy in wheat between the US and the UK in the nineteenth century. The cointegrated VAR model is then applied to the period 1838-1913 in order to find long-run relationships between...

  2. Natural Selection Causes Adaptive Genetic Resistance in Wild Emmer Wheat against Powdery Mildew at "Evolution Canyon" Microsite, Mt. Carmel, Israel: e0122344

    National Research Council Canada - National Science Library

    Huayan Yin; Yuval Ben-Abu; Hongwei Wang; Anfei Li; Eviatar Nevo; Lingrang Kong

    2015-01-01

    .... A major model organism in ECI is wild emmer, Triticum dicoccoides, the progenitor of cultivated wheat, which displays dramatic interslope adaptive and speciational divergence on the tropical-xeric "African" slope...

  3. Duplication and partitioning in evolution and function of homoeologous Q loci governing domestication characters in polyploid wheat

    Science.gov (United States)

    Zhang, Zengcui; Belcram, Harry; Gornicki, Piotr; Charles, Mathieu; Just, Jérémy; Huneau, Cécile; Magdelenat, Ghislaine; Couloux, Arnaud; Samain, Sylvie; Gill, Bikram S.; Rasmussen, Jack B.; Barbe, Valérie; Faris, Justin D.; Chalhoub, Boulos

    2011-01-01

    The Q gene encodes an AP2-like transcription factor that played an important role in domestication of polyploid wheat. The chromosome 5A Q alleles (5AQ and 5Aq) have been well studied, but much less is known about the q alleles on wheat homoeologous chromosomes 5B (5Bq) and 5D (5Dq). We investigated the organization, evolution, and function of the Q/q homoeoalleles in hexaploid wheat (Triticum aestivum L.). Q/q gene sequences are highly conserved within and among the A, B, and D genomes of hexaploid wheat, the A and B genomes of tetraploid wheat, and the A, S, and D genomes of the diploid progenitors, but the intergenic regions of the Q/q locus are highly divergent among homoeologous genomes. Duplication of the q gene 5.8 Mya was likely followed by selective loss of one of the copies from the A genome progenitor and the other copy from the B, D, and S genomes. A recent V329-to-I mutation in the A lineage is correlated with the Q phenotype. The 5Bq homoeoalleles became a pseudogene after allotetraploidization. Expression analysis indicated that the homoeoalleles are coregulated in a complex manner. Combined phenotypic and expression analysis indicated that, whereas 5AQ plays a major role in conferring domestication-related traits, 5Dq contributes directly and 5Bq indirectly to suppression of the speltoid phenotype. The evolution of the Q/q loci in polyploid wheat resulted in the hyperfunctionalization of 5AQ, pseudogenization of 5Bq, and subfunctionalization of 5Dq, all contributing to the domestication traits. PMID:22042872

  4. 不同诱导培养基对小麦花药培养胚状体诱导率的影响%Effect of Different Media on the Induction Rate of Embryoid in Wheat Anther Culture

    Institute of Scientific and Technical Information of China (English)

    周迪; 孙连发; 陈立君

    2012-01-01

    为明确W14-F诱导培养基对黑龙江省春小麦品种及人工合成小麦材料的花药培养胚状体诱导率,以6份人工合成小麦材料和4个普通小麦品种为材料,采用4种诱导培养基W14-F、MS、N6和c17进行花药培养比较试验。结果表明:不同的诱导培养基对于小麦材料的胚状体诱导率不同,4种诱导培养基的胚状体诱导能力依次为W14-F〉C17〉N6〉MS,W14-F培养基胚状体诱导率明显高于其它3个培养基。人工合成小麦和普通小麦在4种培养基上都得到了相近的胚状体诱导率,说明w14-F培养基同样适合人工合成小麦。利用该技术体系培养人工合成小麦与普通小麦的杂种F1材料,得到了较高的诱导率,这为该技术体系直接应用于利用人工合成小麦改良小麦品种抗病抗逆性研究中提供了可靠的依据。%In order to clarify the effect of W14-F induction media on induction rate of embryoid of synthetic hex-aploid wheat and common wheat, 6 synthetic hexaploid wheat accessions and 4 common wheat varieties were cultivated on four induction media:Wl4-F, MS,N6 and C17. The results showed that different induction media got different induction rate of embryoid,W14-F〉Cl7〉N6〉MS,the induction rate of W14-F was higher than that of the other media evidently; The research on the comparison of synthetic hexaploid wheat and common wheat showed that there was no difference between synthetic hexaploid wheat and common wheat cultivars a- dapted in Heilongjiang on the rate of embryoid in anther culture. The F1 derived from crosses of synthetic hexa-ploid wheat and common wheat got a higher induction rate of embryoid by this technology system, indicating that W14-F medium could be important for enhancing efficiency of breeding for resistance to bio- and abio-stress using synthetic hexaploid wheat.

  5. Structural analysis of the wheat genes encoding NADH-dependent glutamine-2-oxoglutarate amidotransferases and correlation with grain protein content.

    Directory of Open Access Journals (Sweden)

    Domenica Nigro

    Full Text Available BACKGROUND: Nitrogen uptake and the efficient absorption and metabolism of nitrogen are essential elements in attempts to breed improved cereal cultivars for grain or silage production. One of the enzymes related to nitrogen metabolism is glutamine-2-oxoglutarate amidotransferase (GOGAT. Together with glutamine synthetase (GS, GOGAT maintains the flow of nitrogen from NH4 (+ into glutamine and glutamate, which are then used for several aminotransferase reactions during amino acid synthesis. RESULTS: The aim of the present work was to identify and analyse the structure of wheat NADH-GOGAT genomic sequences, and study the expression in two durum wheat cultivars characterized by low and high kernel protein content. The genomic sequences of the three homoeologous A, B and D NADH-GOGAT genes were obtained for hexaploid Triticum aestivum and the tetraploid A and B genes of Triticum turgidum ssp. durum. Analysis of the gene sequences indicates that all wheat NADH-GOGAT genes are composed of 22 exons and 21 introns. The three hexaploid wheat homoeologous genes have high conservation of sequence except intron 13 which shows differences in both length and sequence. A comparative analysis of sequences among di- and mono-cotyledonous plants shows both regions of high conservation and of divergence. qRT-PCR performed with the two durum wheat cvs Svevo and Ciccio (characterized by high and low protein content, respectively indicates different expression levels of the two NADH-GOGAT-3A and NADH-GOGAT-3B genes. CONCLUSION: The three hexaploid wheat homoeologous NADH-GOGAT gene sequences are highly conserved - consistent with the key metabolic role of this gene. However, the dicot and monocot amino acid sequences show distinctive patterns, particularly in the transit peptide, the exon 16-17 junction, and the C-terminus. The lack of conservation in the transit peptide may indicate subcellular differences between the two plant divisions - while the sequence

  6. Melhoramento do trigo: II. Estudo genético de fontes de nanismo para a cultura do trigo Wheat breeding II: genetic studies of different sources of dwarfism in wheat

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Oliveira Camargo

    1981-01-01

    Itararé Experimental Station. All data were determined on an individual plant basis. It was observed partial dominance for tall plants when Siete Cerros, Vicam-71 and Olesen were crossed with IAC-5 and partial dominance for short plants when Tordo was crossed with IAC-5. Broad sense herltability for plant height and grain yield showed high and low values, respectively. Narrow sense heritability and coefficient of determination for plant height were high. Narrow sense heritability for grain yield was low. Results suggest it would be possible to select plant types with semi-dwarf and dwarf height levels in the F2 or Fa populations and for yield in later generations where progeny tests would be possible. Height and yield correlations were also computed for all crosses. In general the magnitude of the environmental, phenotypic and genetic correlations were high and consistent for all crosses. Segregating populations from crosses between the tall cultivar IAC-5 and different sources of dwarfism indicated that the short stature sources could be used efficiently in a breeding program toward the development of semi-dwarf or dwarf wheat cultivars with high yield potential. However, large F2 populations would be required to ensure the frequency of desired recombinants. Tordo would be the best source due to the heigher frequency of short statured individuals.

  7. Genetic Variations of Gliadin and HMW Glutenins Subunits in Durum Wheat%硬粒小麦(Triticum durum)贮藏蛋白的遗传变异分析

    Institute of Scientific and Technical Information of China (English)

    王含彦; 魏育明; 颜泽洪; 郑有良

    2006-01-01

    对来源于美、中、俄及埃塞阿比亚等22个国家的142份硬粒小麦材料的种子贮藏蛋白位点及遗传变异进行了研究.供试的硬粒小麦(Triticum durum Desf)材料共检测出37条醇溶蛋白条带,无1条带纹为所有材料共有,多态性达到100%,说明硬粒小麦具有丰富的醇溶蛋白等位变异.聚类分析将142份供试材料分为3个大类,材料间遗传差异大小在不同的国家有所不同,表明醇溶蛋白带型与地理来源有一定关系.高分子量谷蛋白电泳共分离出14种亚基和15种亚基组合,但是优质亚基所占比例不高,这可能是因为硬粒小麦加工用途的特殊性,使得多年的育种并未太多改变硬粒小麦高分子量谷蛋白亚基等位变异的频率,促成优质亚基的累计.%The wheat baking quality is controlled by the content and composition of wheat endosperm proteins. To exploit new genetic resources and provide fundamental materials for the improvement of bread wheat quality, the genetic variations of the storage proteins in 142 durum wheat (Triticum durum Desf.) accessions from 22 countries were characterized by A-PAGE and SDS-PAGE. A total of 37 gliadin bands were detected, among which all bands(100%) were polymorphic. Furthermore, 142 accessions could be divided into three major groups using the clustering analysis, indicating that the gliadin variations among durum wheat were associated with their geographic origin. Fourteen high-molecular-weight (HMW) glutenin subunits alleles and fifteen subunits combinations were identified. Glu-A1-c(null) was observed at the highest frequency among the 4 Glu-A1 alleles, and Glu-B1-b and Glu-B1-e were the major subunits encoded by Glu-B1.

  8. Wheat induced urticaria

    Directory of Open Access Journals (Sweden)

    Uppal Monica

    2004-09-01

    Full Text Available Wheat is widely consumed all over India in various forms - flour, daliya, maida, suji and wheat bran. Very few cases of wheat induced urticaria have been reported. This may be due to unusual features of wheat related hypersensitivity. A 35 year old female presented to us with history of chronic urticaria and angioedema. History revealed correlation between wheat intake and urticaria episodes. Prick testing was done with wheat antigen in the standard series and derivatives of raw wheat. Normal saline and histamine were used as controls. Prick testing was positive. Oral challenge induced urticaria within half an hour. This report discusses clinical features of wheat related hypersensitivity.

  9. Sequencing of chloroplast genomes from wheat, barley, rye and their relatives provides a detailed insight into the evolution of the Triticeae tribe.

    Directory of Open Access Journals (Sweden)

    Christopher P Middleton

    Full Text Available Using Roche/454 technology, we sequenced the chloroplast genomes of 12 Triticeae species, including bread wheat, barley and rye, as well as the diploid progenitors and relatives of bread wheat Triticum urartu, Aegilops speltoides and Ae. tauschii. Two wild tetraploid taxa, Ae. cylindrica and Ae. geniculata, were also included. Additionally, we incorporated wild Einkorn wheat Triticum boeoticum and its domesticated form T. monococcum and two Hordeum spontaneum (wild barley genotypes. Chloroplast genomes were used for overall sequence comparison, phylogenetic analysis and dating of divergence times. We estimate that barley diverged from rye and wheat approximately 8-9 million years ago (MYA. The genome donors of hexaploid wheat diverged between 2.1-2.9 MYA, while rye diverged from Triticum aestivum approximately 3-4 MYA, more recently than previously estimated. Interestingly, the A genome taxa T. boeoticum and T. urartu were estimated to have diverged approximately 570,000 years ago. As these two have a reproductive barrier, the divergence time estimate also provides an upper limit for the time required for the formation of a species boundary between the two. Furthermore, we conclusively show that the chloroplast genome of hexaploid wheat was contributed by the B genome donor and that this unknown species diverged from Ae. speltoides about 980,000 years ago. Additionally, sequence alignments identified a translocation of a chloroplast segment to the nuclear genome which is specific to the rye/wheat lineage. We propose the presented phylogeny and divergence time estimates as a reference framework for future studies on Triticeae.

  10. Functional characterisation of wheat Pgip genes reveals their involvement in the local response to wounding.

    Science.gov (United States)

    Janni, M; Bozzini, T; Moscetti, I; Volpi, C; D'Ovidio, R

    2013-11-01

    Polygalacturonase-inhibiting proteins (PGIPs) are cell wall leucine-rich repeat (LRR) proteins involved in plant defence. The hexaploid wheat (Triticum aestivum, genome AABBDD) genome contains one Pgip gene per genome. Tapgip1 (B genome) and Tapgip2 (D genome) are expressed in all tissues, whereas Tapgip3 (A genome) is inactive because of a long terminal repeat, Copia retrotransposon insertion within the coding region. To verify whether Tapgip1 and Tapgip2 encode active PGIPs and are involved in the wheat defence response, we expressed them transiently and analysed their expression under stress conditions. Neither TaPGIP1 nor TaPGIP2 showed inhibition activity in vitro against fungal polygalacturonases. Moreover, a wheat genotype (T. turgidum ssp. dicoccoides) lacking active homologues of Tapgip1 or Tapgip2 possesses PGIP activity. At transcript level, Tapgip1 and Tapgip2 were both up-regulated after fungal infection and strongly induced following wounding. This latter result has been confirmed in transgenic wheat plants expressing the β-glucuronidase (GUS) gene under control of the 5'-flanking region of Tdpgip1, a homologue of Tapgip1 with an identical sequence. Strong and transient GUS staining was mainly restricted to the damaged tissues and was not observed in adjacent tissues. Taken together, these results suggest that Tapgips and their homologues are involved in the wheat defence response by acting at the site of the lesion caused by pathogen infection.

  11. Genetic analyses using GGE model and a mixed linear model approach, and stability analyses using AMMI bi-plot for late-maturity alpha-amylase activity in bread wheat genotypes.

    Science.gov (United States)

    Rasul, Golam; Glover, Karl D; Krishnan, Padmanaban G; Wu, Jixiang; Berzonsky, William A; Fofana, Bourlaye

    2017-06-01

    Low falling number and discounting grain when it is downgraded in class are the consequences of excessive late-maturity α-amylase activity (LMAA) in bread wheat (Triticum aestivum L.). Grain expressing high LMAA produces poorer quality bread products. To effectively breed for low LMAA, it is necessary to understand what genes control it and how they are expressed, particularly when genotypes are grown in different environments. In this study, an International Collection (IC) of 18 spring wheat genotypes and another set of 15 spring wheat cultivars adapted to South Dakota (SD), USA were assessed to characterize the genetic component of LMAA over 5 and 13 environments, respectively. The data were analysed using a GGE model with a mixed linear model approach and stability analysis was presented using an AMMI bi-plot on R software. All estimated variance components and their proportions to the total phenotypic variance were highly significant for both sets of genotypes, which were validated by the AMMI model analysis. Broad-sense heritability for LMAA was higher in SD adapted cultivars (53%) compared to that in IC (49%). Significant genetic effects and stability analyses showed some genotypes, e.g. 'Lancer', 'Chester' and 'LoSprout' from IC, and 'Alsen', 'Traverse' and 'Forefront' from SD cultivars could be used as parents to develop new cultivars expressing low levels of LMAA. Stability analysis using an AMMI bi-plot revealed that 'Chester', 'Lancer' and 'Advance' were the most stable across environments, while in contrast, 'Kinsman', 'Lerma52' and 'Traverse' exhibited the lowest stability for LMAA across environments.

  12. The chloroplast genome of the hexaploid Spartina maritima (Poaceae, Chloridoideae): Comparative analyses and molecular dating.

    Science.gov (United States)

    Rousseau-Gueutin, M; Bellot, S; Martin, G E; Boutte, J; Chelaifa, H; Lima, O; Michon-Coudouel, S; Naquin, D; Salmon, A; Ainouche, K; Ainouche, M

    2015-12-01

    The history of many plant lineages is complicated by reticulate evolution with cases of hybridization often followed by genome duplication (allopolyploidy). In such a context, the inference of phylogenetic relationships and biogeographic scenarios based on molecular data is easier using haploid markers like chloroplast genome sequences. Hybridization and polyploidization occurred recurrently in the genus Spartina (Poaceae, Chloridoideae), as illustrated by the recent formation of the invasive allododecaploid S. anglica during the 19th century in Europe. Until now, only a few plastid markers were available to explore the history of this genus and their low variability limited the resolution of species relationships. We sequenced the complete chloroplast genome (plastome) of S. maritima, the native European parent of S. anglica, and compared it to the plastomes of other Poaceae. Our analysis revealed the presence of fast-evolving regions of potential taxonomic, phylogeographic and phylogenetic utility at various levels within the Poaceae family. Using secondary calibrations, we show that the tetraploid and hexaploid lineages of Spartina diverged 6-10 my ago, and that the two parents of the invasive allopolyploid S. anglica separated 2-4 my ago via long distance dispersal of the ancestor of S. maritima over the Atlantic Ocean. Finally, we discuss the meaning of divergence times between chloroplast genomes in the context of reticulate evolution. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. A wheat cinnamyl alcohol dehydrogenase TaCAD12 contributes to host resistance to the sharp eyespot disease

    Directory of Open Access Journals (Sweden)

    Wei Rong

    2016-11-01

    Full Text Available Sharp eyespot, caused mainly by the necrotrophic fungus Rhizoctonia cerealis, is a destructive disease in hexaploid wheat (Triticum aestivum L.. In Arabidopsis, certain cinnamyl alcohol dehydrogenases (CADs have been implicated in monolignol biosynthesis and in defense response to bacterial pathogen infection. However, little is known about CADs in wheat defense responses to necrotrophic or soil-borne pathogens. In this study, we isolate a wheat CAD gene TaCAD12 in response to R. cerealis infection through microarray-based comparative transcriptomics, and study the enzyme activity and defense role of TaCAD12 in wheat. The transcriptional levels of TaCAD12 in sharp eyespot-resistant wheat lines were significantly higher compared with those in susceptible wheat lines. The sequence and phylogenetic analyses revealed that TaCAD12 belongs to IV group in CAD family. The biochemical assay proved that TaCAD12 protein is an authentic CAD enzyme and possesses catalytic efficiencies towards both coniferyl aldehyde and sinapyl aldehyde. Knock-down of TaCAD12 transcript significantly repressed resistance of the gene-silenced wheat plants to sharp eyespot caused by R. cerealis, whereas TaCAD12 overexpression markedly enhanced resistance of the transgenic wheat lines to sharp eyespot. Furthermore, certain defense genes (Defensin, PR10, PR17c, and Chitinase1 and monolignol biosynthesis-related genes (TaCAD1, TaCCR, and TaCOMT1 were up-regulated in the TaCAD12-overexpressing wheat plants but down-regulated in TaCAD12-silencing plants. These results suggest that TaCAD12 positively contributes to resistance against sharp eyespot through regulation of the expression of certain defense genes and monolignol biosynthesis-related genes in wheat.

  14. Genetic control of wheat seedling root growth Controle genético do crescimento radicular de plântulas de trigo

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Oliveira Camargo

    2005-08-01

    Full Text Available Wheat cultivars should have long primary roots to allow good crop establishment, considering the short crop establishment season (April in the State of São Paulo, Brazil, where the occurrence of water stress is frequent. This paper demonstrates the control and type of inheritance of the primary root growth trait. Crosses were made between genotypes, BH-1146 and KAUZ "S"/IAC-24 M4 with strong and reduced primary root growth, respectively. F2 and F3 generation seeds from these crosses and F2 generation seeds from the backcrosses of both parents were also obtained. Seedlings from these genotypes plus the parentals were evaluated in relation to primary root growth in complete nutrient solutions containing 3.875 mg L-1 phosphorus, at pH 4.0 and a temperature of 25 ± 1°C for 10 days. Control of the primary root growth trait was demonstrated to have quantitative inheritance. The degrees of dominance showed that the genes for strong root growth had a partially recessive behavior. Heterosis and heterobeltiosis values were negative. The estimated broad-sense heritability for root growth indicated that a great part of the observed variation was of genetic origin. The narrow-sense heritability indicated that a great part of the total genetic variability in relation to the trait under consideration is due to a small number of genes. Considering the estimated coefficient of determination, selection for strong root growth would be effective even when made in the early segregant generations after the cross.Os cultivares de trigo devem apresentar raízes primárias longas para permitir um bom estabelecimento da cultura, considerando o curto período de estabelecimento da cultura (abril no Estado de São Paulo, onde é freqüente a ocorrência de estresse hídrico. Este trabalho visa demonstrar o controle e o tipo de herança envolvida na expressão do caracter crescimento da raiz primária. Foram feitos cruzamentos entre os cultivares BH-1146 e KAUZ "S

  15. Genetic mapping of major-effect seed dormancy quantitative trait loci on chromosome 2B using recombinant substitution lines in tetraploid wheat

    Science.gov (United States)

    Durum wheat cultivars can benefit from having some level of seed dormancy to help reduce seed damage and lower grain quality caused by pre-harvest sprouting (PHS) occurring during wet harvesting conditions. Previously a single chromosome substitution line carrying chromosome 2B of wild emmer in the...

  16. Genetic mapping of resistance to the Ug99 race group of Puccinia graminis f. sp tritici in a spring wheat landrace CItr 4311

    Science.gov (United States)

    Wheat landrace CItr 4311 has seedling resistance to stem rust caused by Puccinia graminis f. sp tritici Eriks. & E. Henn (Pgt) race TTKSK and field resistance to the Ug99 race group. Parents, F1 seedlings, 121 doubled haploid (DH) lines, and 124 recombinant inbred lines (RILs) developed from a cross...

  17. Genetics

    Science.gov (United States)

    ... Inheritance; Heterozygous; Inheritance patterns; Heredity and disease; Heritable; Genetic markers ... The chromosomes are made up of strands of genetic information called DNA. Each chromosome contains sections of ...

  18. Changes in the Russian Wheat Aphid (Hemiptera: Aphididae) Biotype Complex in South Africa.

    Science.gov (United States)

    Jankielsohn, Astrid

    2016-04-01

    Russian wheat aphid Diuraphis noxia (Kurdjumov) has spread from its native area in central Asia to all the major wheat-producing countries in the world to become an international wheat pest. Because the Russian wheat aphid is a serious threat to the wheat industry in South Africa, it is important to investigate the key factors involved in the distribution of Russian wheat aphid biotypes and in the changes of the Russian wheat aphid biotype complex in South Africa. There are currently four known Russian wheat aphid biotypes occurring in South Africa. Russian wheat aphid samples were collected from 2011 to 2014 during the wheat-growing season in spring and summer and these samples were screened to determine the biotype status. RWASA1 occurred predominantly in the Western Cape, while RWASA2 and RWASA3 occurred predominantly in the Eastern Free State. Following the first record of RWASA4 in 2011, this biotype was restricted to the Eastern Free State. The surveys suggest that the Russian wheat aphid bioype complex was more diverse in the Eastern Free State than in the other wheat production areas. There was also a shift in Russian wheat aphid biotype composition over time. The Russian wheat aphid biotype complex is dynamic, influenced by environmental factors such as host plants, altitude, and climate, and it can change and diversify over time causing fluctuation in populations over sites and years. This dynamic nature of the Russian wheat aphid will continue to challenge the development of Russian wheat aphid-resistant wheat cultivars in South Africa, and the continued monitoring of the biotypic and genetic structure, to determine genetic relatedness and variation in different biotypes, of Russian wheat aphid populations is important for protecting wheat.

  19. The role of Aegilops species in the origin and improvement of common wheat

    Directory of Open Access Journals (Sweden)

    Roman Prażak

    2014-01-01

    Full Text Available Some Aegilops species participated in wheat evolution playing a major role in wheat domestication and therefore the genus Aegilops represents a big part of the additional gene pool determining important traits of wheat. Breeders have been using these genes for many years to produce improved cultivars. Wide crosses between its wild relatives are sources of desirable characteristics for genetic improvement of common wheat. Triticum aestivum evolution and methods for transfer of alien material into wheat, briefly reviewed in this article, include incorporation of the whole genomes, single chromosomes, small chromosomal segments, single genes and cytoplasm substitution in wheat.

  20. Variation in Susceptibility to Wheat dwarf virus among Wild and Domesticated Wheat

    Science.gov (United States)

    Nygren, Jim; Shad, Nadeem; Kvarnheden, Anders; Westerbergh, Anna

    2015-01-01

    We investigated the variation in plant response in host-pathogen interactions between wild (Aegilops spp., Triticum spp.) and domesticated wheat (Triticum spp.) and Wheat dwarf virus (WDV). The distribution of WDV and its wild host species overlaps in Western Asia in the Fertile Crescent, suggesting a coevolutionary relationship. Bread wheat originates from a natural hybridization between wild emmer wheat (carrying the A and B genomes) and the wild D genome donor Aegilops tauschii, followed by polyploidization and domestication. We studied whether the strong selection during these evolutionary processes, leading to genetic bottlenecks, may have resulted in a loss of resistance in domesticated wheat. In addition, we investigated whether putative fluctuations in intensity of selection imposed on the host-pathogen interactions have resulted in a variation in susceptibility to WDV. To test our hypotheses we evaluated eighteen wild and domesticated wheat taxa, directly or indirectly involved in wheat evolution, for traits associated with WDV disease such as leaf chlorosis, different growth traits and WDV content. The plants were exposed to viruliferous leafhoppers (Psammotettix alienus) in a greenhouse trial and evaluated at two time points. We found three different plant response patterns: i) continuous reduction in growth over time, ii) weak response at an early stage of plant development but a much stronger response at a later stage, and iii) remission of symptoms over time. Variation in susceptibility may be explained by differences in the intensity of natural selection, shaping the coevolutionary interaction between WDV and the wild relatives. However, genetic bottlenecks during wheat evolution have not had a strong impact on WDV resistance. Further, this study indicates that the variation in susceptibility may be associated with the genome type and that the ancestor Ae. tauschii may be useful as genetic resource for the improvement of WDV resistance in wheat. PMID

  1. Variation in susceptibility to Wheat dwarf virus among wild and domesticated wheat.

    Directory of Open Access Journals (Sweden)

    Jim Nygren

    Full Text Available We investigated the variation in plant response in host-pathogen interactions between wild (Aegilops spp., Triticum spp. and domesticated wheat (Triticum spp. and Wheat dwarf virus (WDV. The distribution of WDV and its wild host species overlaps in Western Asia in the Fertile Crescent, suggesting a coevolutionary relationship. Bread wheat originates from a natural hybridization between wild emmer wheat (carrying the A and B genomes and the wild D genome donor Aegilops tauschii, followed by polyploidization and domestication. We studied whether the strong selection during these evolutionary processes, leading to genetic bottlenecks, may have resulted in a loss of resistance in domesticated wheat. In addition, we investigated whether putative fluctuations in intensity of selection imposed on the host-pathogen interactions have resulted in a variation in susceptibility to WDV. To test our hypotheses we evaluated eighteen wild and domesticated wheat taxa, directly or indirectly involved in wheat evolution, for traits associated with WDV disease such as leaf chlorosis, different growth traits and WDV content. The plants were exposed to viruliferous leafhoppers (Psammotettix alienus in a greenhouse trial and evaluated at two time points. We found three different plant response patterns: i continuous reduction in growth over time, ii weak response at an early stage of plant development but a much stronger response at a later stage, and iii remission of symptoms over time. Variation in susceptibility may be explained by differences in the intensity of natural selection, shaping the coevolutionary interaction between WDV and the wild relatives. However, genetic bottlenecks during wheat evolution have not had a strong impact on WDV resistance. Further, this study indicates that the variation in susceptibility may be associated with the genome type and that the ancestor Ae. tauschii may be useful as genetic resource for the improvement of WDV resistance in

  2. Study on Bar-coding of Wheat Variety Based on Genetic Diversity of Seed Storage Protein%基于籽粒贮藏蛋白遗传多样性的小麦条形码研究

    Institute of Scientific and Technical Information of China (English)

    康志钰; 王建军

    2012-01-01

    为便于小麦品种管理及保护,针对植物DNA条形码研制存在的问题,以36份品种为材料,分析其HMW-GS和醇溶蛋白组分,并根据谱带的有无,对谱带进行数量化处理,存在的谱带标为1,不存在的谱带标为0,建立谱带二进制代码,再转化为十进制代码,最后通过数据整合,建立了小麦品种身份识别码,并将其转换为条形码,研制出基于籽粒贮藏蛋白遗传多样性的小麦身份识别码制作方法,使原来需要用119位数字表明的品种间差距现在只需37位数字即可表示出来。%To be convenient for the management and protection of wheat varieties, and aimed at the problems on DNA bar-coding of plant, the high molecular weight gluten subunit (HMW-GS) and gli- adin of 36 wheat varieties were investigated and used to establish their codes. By number processing, according to the presence and absence of the bands as presence of band was signed with "1" and ab- sence of band was signed with "0", the binary code system was established and then the binary code system was translated into decimal code system, finally, the identification code system of wheat varie- ty was established through the conformity of data, and translated the identification code for bar-cod- ing. An method for the identification code system of wheat was built based on the genetic diversity of seed storage protein. In this way, the difference between the varieties could be distinguished by 37 digits, instead of 119 digits used in the past.

  3. QUALITY PARAMETRES OF EMMER WHEAT LANDRACES

    Directory of Open Access Journals (Sweden)

    Petr KONVALINA

    2009-03-01

    Full Text Available Emmer wheat, Triticum dicoccum SCHUEBL, is an old variety of cereals which has been traditionally grown in aride areas. Nowdays, it is mainly grown in Italy, Spain, Turkey, Austria and in the Czech republic. This article deals with a study of quality parametres and selected economic parametres of 6 varieties coming from the genetic resources of emmer wheat. High crude protein content in grain was proved during the trials. Nevertheless, such a characteristic is not suitable for the classical bakery processing (production of leavened products. Low figure of the harvest index is supposed to be the most problematic economic character. However, emmer wheat is a suitable variety for organic farming system. Growing of emmer wheat contributes to an extension of the agrobiodiversity in the countryside and to the suistainable development of a region.

  4. Specific patterns of gene space organisation revealed in wheat by using the combination of barley and wheat genomic resources

    Directory of Open Access Journals (Sweden)

    Waugh Robbie

    2010-12-01

    Full Text Available Abstract Background Because of its size, allohexaploid nature and high repeat content, the wheat genome has always been perceived as too complex for efficient molecular studies. We recently constructed the first physical map of a wheat chromosome (3B. However gene mapping is still laborious in wheat because of high redundancy between the three homoeologous genomes. In contrast, in the closely related diploid species, barley, numerous gene-based markers have been developed. This study aims at combining the unique genomic resources developed in wheat and barley to decipher the organisation of gene space on wheat chromosome 3B. Results Three dimensional pools of the minimal tiling path of wheat chromosome 3B physical map were hybridised to a barley Agilent 15K expression microarray. This led to the fine mapping of 738 barley orthologous genes on wheat chromosome 3B. In addition, comparative analyses revealed that 68% of the genes identified were syntenic between the wheat chromosome 3B and barley chromosome 3 H and 59% between wheat chromosome 3B and rice chromosome 1, together with some wheat-specific rearrangements. Finally, it indicated an increasing gradient of gene density from the centromere to the telomeres positively correlated with the number of genes clustered in islands on wheat chromosome 3B. Conclusion Our study shows that novel structural genomics resources now available in wheat and barley can be combined efficiently to overcome specific problems of genetic anchoring of physical contigs in wheat and to perform high-resolution comparative analyses with rice for deciphering the organisation of the wheat gene space.

  5. Quantitation of the immunodominant 33-mer peptide from α-gliadin in wheat flours by liquid chromatography tandem mass spectrometry

    Science.gov (United States)

    Schalk, Kathrin; Lang, Christina; Wieser, Herbert; Koehler, Peter; Scherf, Katharina Anne

    2017-01-01

    Coeliac disease (CD) is triggered by the ingestion of gluten proteins from wheat, rye, and barley. The 33-mer peptide from α2-gliadin has frequently been described as the most important CD-immunogenic sequence within gluten. However, from more than 890 published amino acid sequences of α-gliadins, only 19 sequences contain the 33-mer. In order to make a precise assessment of the importance of the 33-mer, it is necessary to elucidate which wheat species and cultivars contain the peptide and at which concentrations. This paper presents the development of a stable isotope dilution assay followed by liquid chromatography tandem mass spectrometry to quantitate the 33-mer in flours of 23 hexaploid modern and 15 old common (bread) wheat as well as two spelt cultivars. All flours contained the 33-mer peptide at levels ranging from 91–603 μg/g flour. In contrast, the 33-mer was absent (wheat, emmer, einkorn), most likely because of the absence of the D-genome, which encodes α2-gliadins. Due to the presence of the 33-mer in all common wheat and spelt flours analysed here, the special focus in the literature on this most immunodominant peptide seems to be justified. PMID:28327674

  6. Influence of iron complexes on formation of photosynthetic apparatus and outcome of genetic changes at the gamma irradiated seeds of wheat

    Directory of Open Access Journals (Sweden)

    E. N. Shamilov

    2010-07-01

    Full Text Available Influence of various doses of γ-irradiation on biosynthesis of chlorophyll and carotinoids, and also on a progress of mitotic divisions of meristematic cells of root hairs at sprouting wheat seeds at the presence of pyrocatechol, iron pyrocatecholat, thiocarbamide, iron thiocarbamide, rutine, iron rutinate, juglon and iron juglonate was studied. There was revealed that iron pyrocatecholate, iron rutinate, juglon and iron juglonate possess appreciable radioprotective properties which stimulate adaptive biosynthesis of chlorophyll and carotinoids, and also considerably reduce a number of chromosomal aberrations under irradiation.

  7. [Molecular-genetic polymorphism of cellular lines of wheat resistant to cultural filtrate Gaeumannomyces graminis var. tritici and plant-regenerants from them].

    Science.gov (United States)

    Bavol, A V; Dubrovna, O V

    2009-01-01

    DNA polymorphism of wheat cellular lines resistant to culture filtrate of G. graminis var. tritici and regenerated plants has been investigated using ISSR-analysis. Specific changes in DNA sequence were revealed in resistant calluses. It was established, that all resistant cellular lines differed by the presence of specific amplicons of 2347 bp (primer 5'-TCTCTCTCTCTCTCTCG-3') and 1745 bp (primer 5'-AGAGAGAGAGAGAGAGTC-3'), as well as the absence of the amplicon of 1108 bp (primer 5'-ACACACACACACACACC-3') from the initial callus and the callus not exposed to the action of selective factor. These changes have been also revealed in R0 and R1 plants.

  8. Wheat and gluten intolerance

    NARCIS (Netherlands)

    Busink-van den Broeck, Hetty; Gilissen, L.J.W.J.; Brouns, F.

    2016-01-01

    With this White Paper, the current state of scientific knowledge on human disorders related to gluten and wheat is presented, with reference to other grains such as spelt, barley, rye, and oats. Backgrounds are described of coeliac disease (gluten intolerance), wheat allergies and any kind of wheat

  9. Molecular Characteristics of New Wheat Starch and Its Digestion Behaviours

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhong-kai; HUA Ze-tian; YANG Yan; ZHENG Pai-yun; ZHANG Yan; CHEN Xiao-shan

    2014-01-01

    In order to understand the effect of starch molecular characteristics on the gel structure, which subsequently inlfuence the gel digestion behaviours, three wheat starches, control (conventional wheat starch), two new wheat cultivars with different genetic backgrounds (by knocking out SBE IIb and SBE IIa, respectively) were used in this study. In comparison with control, slight differences in the morphology of the starch granules of new wheat 1 were observed, whereas the starch granules of new wheat 2 had irregular shapes both for A-type granules and B-type granules. Starch molecular weight size was determined by SE-HPLC, and the results indicate that there was a subtle increase in the amylose content in the starch of new wheat 1 compared to that of control. The starch of new wheat 2 had the highest amylose content, and the molecular weight (MW) of its amylopectin was the lowest among the three starches. Fourier transform infrared spectroscopy (FTIR) was employed to investigate starch gel structure and the results suggest that the molecules of starch gel from new wheat 2 are more likely to re-associate to form an organized conformation. The digestion behaviours of the three starch gels were measured using a mixture of pancreatinα-amylase and amyloglucosidase. The results indicated that the starch gels of control and new wheat 1 had very high digestibility of 91.7 and 91.9%, respectively, whereas the digestibility of wheat 2 starch gel was only 36.2%. In comparison with the digestion curve patterns of control and new wheat 1 starch gels, the new wheat 2 exhibited a much lower initial velocity. These results indicated that the molecules in the starch of new wheat 2 are more readily to re-associate to form an organized structure during gel formation because of its unique molecular characteristics.

  10. HULLED WHEAT FARMING IN DEVELI

    Directory of Open Access Journals (Sweden)

    Sancar Bulut

    2016-07-01

    Full Text Available Emmer (Triticum dicoccum and einkorn (T. monococcum cultivation has a long history in Anatolia. The crops, cultivated in Anatolia over thousands years, can still be found in some parts of the country, especially Develi in the Kayseri province. The total cultivation area of these crops was around 36 000 ha in 2015. The species is mainly cultivated in sloping and marginal lands by poor farmers, where no other crops can be economically grown. Cultivation area is rapidly declining, and if such trend continues, hulled wheats will be shortly completely wiped out from Turkey. Present-day distribution of emmer and spelt within Turkey is concentrated in countryside areas of Develi where traditional farming systems still survive. This group of wheats is called in Turkish the general name of ‘kaplìca’ which means ‘covered’ or ‘hulled’. More specifically, the tetraploid species (emmer is called ‘gacer’ in the Develi. Being a low-yielding type of wheat, emmer was replaced by other improved varieties of Triticum. This decrease was mainly due to the widespread use of improved cultivars of wheat and the adoption of new agricultural techniques, but also to social and economic factors. In fact, wheat yielded 2840 t/ha, whereas hulled wheats yielded 1200 t/ha. The cultivation of these two crops shows disadvantages that relate to the harvesting techniques used and the need to dehisce the spikelets to obtain the grain for human consumption. The increasing interest in low-input systems due to the actual ecological and economical situation has led to a growing interest in specific genetic variability. Organic agriculture and health food products have been gaining increasing popularity that has led to a renewed interest in hulled wheat species such as emmer and spelt. The objective of this study was to estimate agronomical and grain quality characteristics of some Turkey (Develi emmer landraces. This effort was motivated by the fact that autochthonous

  11. Genome Wide Association Mapping for Arabinoxylan Content in a Collection of Tetraploid Wheats

    OpenAIRE

    2015-01-01

    Background Arabinoxylans (AXs) are major components of plant cell walls in bread wheat and are important in bread-making and starch extraction. Furthermore, arabinoxylans are components of soluble dietary fibre that has potential health-promoting effects in human nutrition. Despite their high value for human health, few studies have been carried out on the genetics of AX content in durum wheat. Results The genetic variability of AX content was investigated in a set of 104 tetraploid wheat gen...

  12. Drought tolerance in modern and wild wheat.

    Science.gov (United States)

    Budak, Hikmet; Kantar, Melda; Kurtoglu, Kuaybe Yucebilgili

    2013-01-01

    The genus Triticum includes bread (Triticum aestivum) and durum wheat (Triticum durum) and constitutes a major source for human food consumption. Drought is currently the leading threat on world's food supply, limiting crop yield, and is complicated since drought tolerance is a quantitative trait with a complex phenotype affected by the plant's developmental stage. Drought tolerance is crucial to stabilize and increase food production since domestication has limited the genetic diversity of crops including wild wheat, leading to cultivated species, adapted to artificial environments, and lost tolerance to drought stress. Improvement for drought tolerance can be achieved by the introduction of drought-grelated genes and QTLs to modern wheat cultivars. Therefore, identification of candidate molecules or loci involved in drought tolerance is necessary, which is undertaken by "omics" studies and QTL mapping. In this sense, wild counterparts of modern varieties, specifically wild emmer wheat (T. dicoccoides), which are highly tolerant to drought, hold a great potential. Prior to their introgression to modern wheat cultivars, drought related candidate genes are first characterized at the molecular level, and their function is confirmed via transgenic studies. After integration of the tolerance loci, specific environment targeted field trials are performed coupled with extensive analysis of morphological and physiological characteristics of developed cultivars, to assess their performance under drought conditions and their possible contributions to yield in certain regions. This paper focuses on recent advances on drought related gene/QTL identification, studies on drought related molecular pathways, and current efforts on improvement of wheat cultivars for drought tolerance.

  13. Somaclonal variation for disease resistance in wheat and production of dihaploids through wheat x maize hybrids

    Directory of Open Access Journals (Sweden)

    Yeshwant R. Mehta

    2000-09-01

    Full Text Available Seven wheat cultivars having some degree of resistance to Bipolaris sorokiniana, Magnaporthe grisea or Xanthomonas campestris pv. undulosa (Xcu provided somaclonal variation for disease resistance. Callus induction varied from 69.4 to 100% across the cultivars, whereas regeneration frequency of R1 plants (regenerated plants of first generation varied between 2.7 and 23.1%. Resistance variation in the R2-regenerated second generation plants was observed for B. sorokiniana and M. grisea but not for Xcu. Attempts were made to fix the resistance characteristics of R3-regenerated third generation somaclones through wheat x maize hybrids. Wheat and maize hybridization of seven wheat somaclones yielded 81 embryos. A total of 11,624 somaclone florets were pollinated, of which 8.4% produced haploid embryos across the seven wheat genotypes. Hybrid embryo production varied between 0 and 25%. The somaclones had a constant chromosome number as observed in their original hexaploid wheat genotypes (2n = 6x = 42 whereas the haploid plants had n = 21. Hybrid embryo production and haploid and dihaploid plant production were affected by 2,4-D concentration, but not by the wheat genotype.Sete cultivares de trigo possuindo certo nível de resistência a Bipolaris sorokiniana, Magnaporthe grisea, Xanthomonas campestris pv. undulosa (Xcu, foram usadas para variação somaclonal, a fim de induzir um nível maior de resistência. A freqüência de indução de calos variou entre 69,4 e 100 entre as cultivares, enquanto que, a freqüência de regeneração de plantas R1 variou entre 2,7 e 23,1, dependendo da cultivar. A variação para resistência entre as plantas de R2 foi observada para B. sorokiniana e M. grisea, mas não para Xcu. Procurou-se fixar as características de resistência dos somaclones (R3 através de hibridação com milho. A hibridação entre trigo e milho produziu 81 embriões zigotos. Um total de 11.624 flores de somaclones foram polinizadas, das

  14. Genomic dissection of drought resistance in durum wheat x wild emmer wheat recombinant inbreed line population.

    Science.gov (United States)

    Peleg, Zvi; Fahima, Tzion; Krugman, Tamar; Abbo, Shahal; Yakir, Dan; Korol, Abraham B; Saranga, Yehoshua

    2009-07-01

    Drought is the major factor limiting wheat productivity worldwide. The gene pool of wild emmer wheat, Triticum turgidum ssp. dicoccoides, harbours a rich allelic repertoire for morpho-physiological traits conferring drought resistance. The genetic and physiological bases of drought responses were studied here in a tetraploid wheat population of 152 recombinant inbreed lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (acc# G18-16), under contrasting water availabilities. Wide genetic variation was found among RILs for all studied traits. A total of 110 quantitative trait loci (QTLs) were mapped for 11 traits, with LOD score range of 3.0-35.4. Several QTLs showed environmental specificity, accounting for productivity and related traits under water-limited (20 QTLs) or well-watered conditions (15 QTLs), and in terms of drought susceptibility index (22 QTLs). Major genomic regions controlling productivity and related traits were identified on chromosomes 2B, 4A, 5A and 7B. QTLs for productivity were associated with QTLs for drought-adaptive traits, suggesting the involvement of several strategies in wheat adaptation to drought stress. Fifteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. The identified QTLs may facilitate the use of wild alleles for improvement of drought resistance in elite wheat cultivars.

  15. Adapting wheat in Europe for climate change.

    Science.gov (United States)

    Semenov, M A; Stratonovitch, P; Alghabari, F; Gooding, M J

    2014-05-01

    Increasing cereal yield is needed to meet the projected increased demand for world food supply of about 70% by 2050. Sirius, a process-based model for wheat, was used to estimate yield potential for wheat ideotypes optimized for future climatic projections for ten wheat growing areas of Europe. It was predicted that the detrimental effect of drought stress on yield would be decreased due to enhanced tailoring of phenology to future weather patterns, and due to genetic improvements in the response of photosynthesis and green leaf duration to water shortage. Yield advances could be made through extending maturation and thereby improve resource capture and partitioning. However the model predicted an increase in frequency of heat stress at meiosis and anthesis. Controlled environment experiments quantify the effects of heat and drought at booting and flowering on grain numbers and potential grain size. A current adaptation of wheat to areas of Europe with hotter and drier summers is a quicker maturation which helps to escape from excessive stress, but results in lower yields. To increase yield potential and to respond to climate change, increased tolerance to heat and drought stress should remain priorities for the genetic improvement of wheat.

  16. Efficient induction of Wheat-agropyron cristatum 6P translocation lines and GISH detection.

    Directory of Open Access Journals (Sweden)

    Liqiang Song

    Full Text Available The narrow genetic background restricts wheat yield and quality improvement. The wild relatives of wheat are the huge gene pools for wheat improvement and can broaden its genetic basis. Production of wheat-alien translocation lines can transfer alien genes to wheat. So it is important to develop an efficient method to induce wheat-alien chromosome translocation. Agropyroncristatum (P genome carries many potential genes beneficial to disease resistance, stress tolerance and high yield. Chromosome 6P possesses the desirable genes exhibiting good agronomic traits, such as high grain number per spike, powdery mildew resistance and stress tolerance. In this study, the wheat-A. cristatum disomic addition was used as bridge material to produce wheat-A. cristatum translocation lines induced by (60Co-γirradiation. The results of genomic in situ hybridization showed that 216 plants contained alien chromosome translocation among 571 self-pollinated progenies. The frequency of translocation was 37.83%, much higher than previous reports. Moreover, various alien translocation types were identified. The analysis of M2 showed that 62.5% of intergeneric translocation lines grew normally without losing the translocated chromosomes. The paper reported a high efficient technical method for inducing alien translocation between wheat and Agropyroncristatum. Additionally, these translocation lines will be valuable for not only basic research on genetic balance, interaction and expression of different chromosome segments of wheat and alien species, but also wheat breeding programs to utilize superior agronomic traits and good compensation effect from alien chromosomes.

  17. Meiotic homoeologous recombination-based alien gene introgression in the genomics era of wheat

    Science.gov (United States)

    Wheat (Triticum spp.) has a narrow genetic basis due to its allopolyploid origin. However, wheat has numerous wild relatives usable for expanding genetic variability of its genome through meiotic homoeologous recombination. Traditionally, laborious cytological analyses have been employed to detect h...

  18. Field release of genetically modified Pseudomonas putida WCS358r : molecular analysis of effects on microbial communities in the rhizosphere of wheat

    NARCIS (Netherlands)

    Viebahn, Mareike

    2005-01-01

    Genetically modified microorganisms (GMMs) with enhanced biocontrol activity are attractive to apply in agriculture. To investigate potential ecological risks of field introduction of GMMs, effects of P. putida strain WCS358r and two genetically modified derivatives of this strain on the indigenous

  19. Characterization of a gene from chromosome 1B encoding the large subunit of ADPglucose pyrophosphorylase from wheat: evolutionary divergence and differential expression of Agp2 genes between leaves and developing endosperm.

    Science.gov (United States)

    Thorneycroft, David; Hosein, Felicia; Thangavelu, Madan; Clark, Joanna; Vizir, Igor; Burrell, Michael M; Ainsworth, Charles

    2003-07-01

    A full-length genomic clone containing the gene encoding the large subunit of the ADPglucose pyrophosphorylase (Agp2), was isolated from a genomic library prepared from etiolated shoots of hexaploid wheat (Triticum aestivum L., cv, Chinese Spring). The coding region of this gene is identical to one of the cDNA clones previously isolated from a developing wheat grain cDNA library and is therefore an actively transcribed gene. The sequence represented by the cDNA spans 4.8 kb of the genomic clone and contains 15 introns. 2852 bp of DNA flanking the transcription start site of the gene was cloned upstream of the GUS (beta-glucuronidase) reporter gene. This Agp2::GUS construct and promoter deletions were used to study the pattern of reporter gene expression in both transgenic tobacco and wheat plants. Histochemical analysis of GUS expression in transgenic tobacco demonstrated that the reporter gene was expressed in guard cells of leaves and throughout the seed. In transgenic wheat, reporter gene expression was confined to the endosperm and aleurone with no expression in leaves. The cloned Agp2 gene was located to chromosome 1B by gene-specific PCR with nullisomic-tetrasomic lines. Northern analysis demonstrated that the Agp2 genes are differentially expressed in leaves and developing endosperm; while all three classes of Agp2 genes are transcribed in developing wheat grain endosperm, only one is transcribed in leaves. The differences between the Agp2 genes are discussed in relation to the evolution of hexaploid wheat.

  20. Starch facilitates enzymatic wheat gluten hydrolysis

    NARCIS (Netherlands)

    Hardt, N.A.; Boom, R.M.; Goot, van der A.J.

    2015-01-01

    Wheat gluten can be hydrolyzed by either using (vital) wheat gluten or directly from wheat flour. This study investigates the influence of the presence of starch, the main component of wheat, on enzymatic wheat gluten hydrolysis. Wheat gluten present in wheat flour (WFG) and vital wheat gluten (VWG)

  1. Starch facilitates enzymatic wheat gluten hydrolysis

    NARCIS (Netherlands)

    Hardt, N.A.; Boom, R.M.; Goot, van der A.J.

    2015-01-01

    Wheat gluten can be hydrolyzed by either using (vital) wheat gluten or directly from wheat flour. This study investigates the influence of the presence of starch, the main component of wheat, on enzymatic wheat gluten hydrolysis. Wheat gluten present in wheat flour (WFG) and vital wheat gluten (VWG)

  2. Association analysis of SP-SNPs and Avr genes in Puccinia striiformis f. sp. tritici, the wheat stripe rust pathogen

    Science.gov (United States)

    Puccinia striiformis f. sp. tritici (Pst) is one of the pathogenic fungi on wheat, caused stripe rust disease which is a great threat for wheat production all over the world. Intensive efforts have been made to study genetics of wheat resistance to this disease, but few on avirulence of the pathogen...

  3. Genome-wide analysis of complex wheat gliadins, the dominant carriers of celiac disease epitopes.

    Science.gov (United States)

    Wang, Da-Wei; Li, Da; Wang, Junjun; Zhao, Yue; Wang, Zhaojun; Yue, Guidong; Liu, Xin; Qin, Huanju; Zhang, Kunpu; Dong, Lingli; Wang, Daowen

    2017-03-16

    Gliadins, specified by six compound chromosomal loci (Gli-A1/B1/D1 and Gli-A2/B2/D2) in hexaploid bread wheat, are the dominant carriers of celiac disease (CD) epitopes. Because of their complexity, genome-wide characterization of gliadins is a strong challenge. Here, we approached this challenge by combining transcriptomic, proteomic and bioinformatic investigations. Through third-generation RNA sequencing, full-length transcripts were identified for 52 gliadin genes in the bread wheat cultivar Xiaoyan 81. Of them, 42 were active and predicted to encode 25 α-, 11 γ-, one δ- and five ω-gliadins. Comparative proteomic analysis between Xiaoyan 81 and six newly-developed mutants each lacking one Gli locus indicated the accumulation of 38 gliadins in the mature grains. A novel group of α-gliadins (the CSTT group) was recognized to contain very few or no CD epitopes. The δ-gliadins identified here or previously did not carry CD epitopes. Finally, the mutant lacking Gli-D2 showed significant reductions in the most celiac-toxic α-gliadins and derivative CD epitopes. The insights and resources generated here should aid further studies on gliadin functions in CD and the breeding of healthier wheat.

  4. Genome-wide analysis of complex wheat gliadins, the dominant carriers of celiac disease epitopes

    Science.gov (United States)

    Wang, Da-Wei; Li, Da; Wang, Junjun; Zhao, Yue; Wang, Zhaojun; Yue, Guidong; Liu, Xin; Qin, Huanju; Zhang, Kunpu; Dong, Lingli; Wang, Daowen

    2017-01-01

    Gliadins, specified by six compound chromosomal loci (Gli-A1/B1/D1 and Gli-A2/B2/D2) in hexaploid bread wheat, are the dominant carriers of celiac disease (CD) epitopes. Because of their complexity, genome-wide characterization of gliadins is a strong challenge. Here, we approached this challenge by combining transcriptomic, proteomic and bioinformatic investigations. Through third-generation RNA sequencing, full-length transcripts were identified for 52 gliadin genes in the bread wheat cultivar Xiaoyan 81. Of them, 42 were active and predicted to encode 25 α-, 11 γ-, one δ- and five ω-gliadins. Comparative proteomic analysis between Xiaoyan 81 and six newly-developed mutants each lacking one Gli locus indicated the accumulation of 38 gliadins in the mature grains. A novel group of α-gliadins (the CSTT group) was recognized to contain very few or no CD epitopes. The δ-gliadins identified here or previously did not carry CD epitopes. Finally, the mutant lacking Gli-D2 showed significant reductions in the most celiac-toxic α-gliadins and derivative CD epitopes. The insights and resources generated here should aid further studies on gliadin functions in CD and the breeding of healthier wheat. PMID:28300172

  5. Induced mutations in the starch branching enzyme II (SBEII) genes increase amylose and resistant starch content in durum wheat.

    Science.gov (United States)

    Hazard, Brittany; Zhang, Xiaoqin; Colasuonno, Pasqualina; Uauy, Cristobal; Beckles, Diane M; Dubcovsky, Jorge

    2012-01-01

    Starch is the largest component of the wheat (Triticum aestivum L.) grain and consists of approximately 70-80% amylopectin and 20-30% amylose. Amylopectin is a highly-branched, readily digested polysaccharide, whereas amylose has few branches and forms complexes that resist digestion and mimic dietary fiber (resistant starch). Down-regulation of the starch branching enzyme II (SBEII) gene by RNA interference (RNAi) was previously shown to increase amylose content in both hexaploid and tetraploid wheat. We generated ethyl methane sulphonate (EMS) mutants for the SBEIIa-A and SBEIIa-B homoeologs in the tetraploid durum wheat variety Kronos (T. turgidum ssp. durum L.). Single-gene mutants showed non-significant increases in amylose and resistant starch content, but a double mutant combining a SBEIIa-A knock-out mutation with a SBEIIa-B splice-site mutation showed a 22% increase in amylose content (P<0.0001) and a 115% increase in resistant starch content (P<0.0001). In addition, we obtained mutants for the A and B genome copies of the paralogous SBEIIb gene, mapped them 1-2 cM from SBEIIa, and generated double SBEIIa-SBEIIb mutants to study the effect of the SBEIIb gene in the absence of SBEIIa. These mutants are available to those interested in increasing amylose content and resistant starch in durum wheat.

  6. Genetic Basis and Characterization of Salt Tolerance in Alloplasmic Wheat D2-'Jian 26'%异源细胞质小麦D2-鉴26的耐盐特征及其遗传基础

    Institute of Scientific and Technical Information of China (English)

    刘春光; 侯宁; 刘立科; 刘根齐; 吴郁文; 张翠兰; 张炎

    2005-01-01

    以核亲本品种鉴26和耐盐品种科遗26为对照,设计3种NaCl浓度(85.56 mmol/L, 171.04 mmol/L, 256.67 mmol/L)处理及无盐对照,研究了异源细胞质小麦D2-鉴26苗期的生长发育和生理生化特征.结果表明,D2型细胞质对核基因型鉴26存在明显的耐盐性遗传效应,效应值的大小因性状而异,核基因型鉴26与科遗26之间也存在差异;盐胁迫下,D2型细胞质能有效降低核基因型鉴26的生长受抑程度,提高其叶片相对含水量RWC,减轻其细胞质膜损伤度和增强对K+的选择性吸收能力,改变叶片功能蛋白的表达.这些研究结果表明,D2型细胞质是小麦耐盐育种的有用资源;异质系D2-鉴26是一个新的耐盐种质材料,其生长发育和渗透调节等相关耐盐特征可以作为D2型细胞质小麦遗传育种耐盐选择的有用指标;D2型细胞质小麦耐盐相关机制的阐明与利用也必将丰富小麦耐盐育种途径.%Alloplasmic wheat D2-'Jian 26', euplasmic wheat'Jian 26' and salt-tolerant control cultivar `Keyi 26' were evaluated in developmental and physiological traits at seedling stage under four levels of NaCl (0 mmol/L, 85.56 mmol/L, 171.04 mmol/L, 256.67 mmol/L). Significant genetic effects of D2-type cytoplasm on salt tolerance and genotypic differences in salt tolerance were observed. A clear improvement in terms of the developmental and physiological behaviours of D2-'Jian 26' and 'Jian 26' was demonstrated for alloplasmic line D2-'Jian 26'. In view of its better salt-tolerance compared with 'Keyi 26' and 'Jian 26', D2-'Jian 26' could be used as a new salt-tolerant germplasm. Under the low or medium salt-concentration, more root branching, large SK, Na(uptake) and SK, Na(transport), and good properties of leaf (relatively higher RWC and relatively lower cell-membrane damage and relatively higher chlorophyll content) were the potential usefulness as a salinity stress avoidance mechanism, suggesting that these parameters in stress

  7. Isolation and sequence analysis of the wheat B genome subtelomeric DNA

    Directory of Open Access Journals (Sweden)

    Huneau Cecile

    2009-09-01

    Full Text Available Abstract Background Telomeric and subtelomeric regions are essential for genome stability and regular chromosome replication. In this work, we have characterized the wheat BAC (bacterial artificial chromosome clones containing Spelt1 and Spelt52 sequences, which belong to the subtelomeric repeats of the B/G genomes of wheats and Aegilops species from the section Sitopsis. Results The BAC library from Triticum aestivum cv. Renan was screened using Spelt1 and Spelt52 as probes. Nine positive clones were isolated; of them, clone 2050O8 was localized mainly to the distal parts of wheat chromosomes by in situ hybridization. The distribution of the other clones indicated the presence of different types of repetitive sequences in BACs. Use of different approaches allowed us to prove that seven of the nine isolated clones belonged to the subtelomeric chromosomal regions. Clone 2050O8 was sequenced and its sequence of 119 737 bp was annotated. It is composed of 33% transposable elements (TEs, 8.2% Spelt52 (namely, the subfamily Spelt52.2 and five non-TE-related genes. DNA transposons are predominant, making up 24.6% of the entire BAC clone, whereas retroelements account for 8.4% of the clone length. The full-length CACTA transposon Caspar covers 11 666 bp, encoding a transposase and CTG-2 proteins, and this transposon accounts for 40% of the DNA transposons. The in situ hybridization data for 2050O8 derived subclones in combination with the BLAST search against wheat mapped ESTs (expressed sequence tags suggest that clone 2050O8 is located in the terminal bin 4BL-10 (0.95-1.0. Additionally, four of the predicted 2050O8 genes showed significant homology to four putative orthologous rice genes in the distal part of rice chromosome 3S and confirm the synteny to wheat 4BL. Conclusion Satellite DNA sequences from the subtelomeric regions of diploid wheat progenitor can be used for selecting the BAC clones from the corresponding regions of hexaploid wheat

  8. Adenosine diphosphate glucose pyrophosphorylase genes in wheat: differential expression and gene mapping.

    Science.gov (United States)

    Ainsworth, C; Hosein, F; Tarvis, M; Weir, F; Burrell, M; Devos, K M; Gale, M D

    1995-01-01

    A full-length cDNA clone representing the large (shrunken-2) subunit of ADP-glucose pyrophosphorylase (AGP; EC 2.7.7.27) has been isolated from a cDNA library prepared from developing grain of hexaploid wheat (Triticum aestivum L., cv. Chinese Spring). The 2084-bp cDNA insert contains an open reading frame of 1566 nucleotides and primer-extension analysis indicated that the 5' end is 10 nucleotides shorter than the mRNA. The deduced protein contains 522 amino acids (57.8 kDa) and includes a putative transit peptide of 62 amino acids (6.5 kDa). The similarity of the deduced protein to the small subunit of AGP and to other AGP genes from plants and microorganisms is discussed. Northern hybridisation shows that the Agp1 genes (encoding the small subunit in the wheat endosperm) and the Agp2 genes (encoding the large subunit in the wheat endosperm) are differentially expressed in the wheat grain. Transcripts from both gene sets accumulate to high levels in the endosperm during grain development with the majority of the expression in the endopsperm rather than the embryo and pericarp layers. Although enzyme activity is detected in developing grains prior to 10 d post anthesis, only the Agp1 genes are active at this time (the Agp2 genes are not expressed until 10 d post anthesis). The possibility that the enzyme expressed during early grain development is a homotetramer of small subunits is discussed. The Agp1 and Agp2 genes are arranged as triplicate sets of single-copy homoeoloci in wheat. The Agp2 genes are located on the long arms of chromosomes 1A, 1B and 1D, about 80 cM from the centromere. The Agp1 genes have been mapped to a position just distal to the centromere on the long arms of chromosomes 7A, 7B and 7D.

  9. Hypersensitive Response-Like Reaction Is Associated with Hybrid Necrosis in Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii Coss

    OpenAIRE

    Nobuyuki Mizuno; Naoki Hosogi; Pyoyun Park; Shigeo Takumi

    2010-01-01

    BACKGROUND: Hybrid speciation is classified into homoploid and polyploid based on ploidy level. Common wheat is an allohexaploid species that originated from a naturally occurring interploidy cross between tetraploid wheat and diploid wild wheat Aegilops tauschii Coss. Aegilops tauschii provides wide naturally occurring genetic variation. Sometimes its triploid hybrids with tetraploid wheat show the following four types of hybrid growth abnormalities: types II and III hybrid necrosis, hybrid ...

  10. Development of genome-specific primers for homoeologous genes in allopolyploid species: the waxy and starch synthase II genes in allohexaploid wheat (Triticum aestivum L. as examples

    Directory of Open Access Journals (Sweden)

    Brûlé-Babel Anita

    2010-05-01

    Full Text Available Abstract Background In allopolypoid crops, homoeologous genes in different genomes exhibit a very high sequence similarity, especially in the coding regions of genes. This makes it difficult to design genome-specific primers to amplify individual genes from different genomes. Development of genome-specific primers for agronomically important genes in allopolypoid crops is very important and useful not only for the study of sequence diversity and association mapping of genes in natural populations, but also for the development of gene-based functional markers for marker-assisted breeding. Here we report on a useful approach for the development of genome-specific primers in allohexaploid wheat. Findings In the present study, three genome-specific primer sets for the waxy (Wx genes and four genome-specific primer sets for the starch synthase II (SSII genes were developed mainly from single nucleotide polymorphisms (SNPs and/or insertions or deletions (Indels in introns and intron-exon junctions. The size of a single PCR product ranged from 750 bp to 1657 bp. The total length of amplified PCR products by these genome-specific primer sets accounted for 72.6%-87.0% of the Wx genes and 59.5%-61.6% of the SSII genes. Five genome-specific primer sets for the Wx genes (one for Wx-7A, three for Wx-4A and one for Wx-7D could distinguish the wild type wheat and partial waxy wheat lines. These genome-specific primer sets for the Wx and SSII genes produced amplifications in hexaploid wheat, cultivated durum wheat, and Aegilops tauschii accessions, but failed to generate amplification in the majority of wild diploid and tetraploid accessions. Conclusions For the first time, we report on the development of genome-specific primers from three homoeologous Wx and SSII genes covering the majority of the genes in allohexaploid wheat. These genome-specific primers are being used for the study of sequence diversity and association mapping of the three homoeologous Wx

  11. [Use of the common winter wheat homozygous population for genetic analysis of beta-amylase and evaluation of its aggregation ability].

    Science.gov (United States)

    Netsvetaev, V P; Akinshina, O V; Bondarenko, L S

    2014-11-01

    We investigated a self-pollinated homozygous population of common winter wheat, F(-> ∞) 24/04 x Odesskaya krasnokolosaya, for variants of beta-amylase and the aggregation ability of the protein complex of weevil via disulfide bonds. It was found that variation in the electrophoretic types of this enzyme was due to four isoenzymes. Two of them (a and b) are doubled and controlled by separate loci with independent inheritance. Isoenzyme c was due to three dominant factors, and four loci were responsible for d. Analysis of the number of -S-S-bonds of five genotypes, which were harvested in 2013 and differed in the types of beta-amylase, showed that some of them were significantly different from others in this indicator. In general, the samples were grouped by the type of this enzyme, forming the following continuous series with respect to aggregation ability: I ≥ B ≥ F ≥ D ≥ G or 59.13 ± 3.18 ≥ 56.65 ± 2.46 ≥ 52.54 ± 2.24 ≥ 50.16 ± 1.67 ≥ 48.63 ± 6.25 of cond. units. Significant differences were observed for this property between groups B > D and I > D. Therefore, genotypes having types I and B have a positive influence on the rheological properties of dough.

  12. Genetics

    DEFF Research Database (Denmark)

    Christensen, Kaare; McGue, Matt

    2016-01-01

    The sequenced genomes of individuals aged ≥80 years, who were highly educated, self-referred volunteers and with no self-reported chronic diseases were compared to young controls. In these data, healthy ageing is a distinct phenotype from exceptional longevity and genetic factors that protect...

  13. Evolution of new disease specificity at a simple resistance locus in a crop-weed complex: reconstitution of the Lr21 gene in wheat.

    Science.gov (United States)

    Huang, Li; Brooks, Steven; Li, Wanlong; Fellers, John; Nelson, James C; Gill, Bikram

    2009-06-01

    The wheat leaf-rust resistance gene Lr21 was first identified in an Iranian accession of goatgrass, Aegilops tauschii Coss., the D-genome donor of hexaploid bread wheat, and was introgressed into modern wheat cultivars by breeding. To elucidate the origin of the gene, we analyzed sequences of Lr21 and lr21 alleles from 24 wheat cultivars and 25 accessions of Ae. tauschii collected along the Caspian Sea in Iran and Azerbaijan. Three basic nonfunctional lr21 haplotypes, H1, H2, and H3, were identified. Lr21 was found to be a chimera of H1 and H2, which were found only in wheat. We attempted to reconstitute a functional Lr21 allele by crossing the cultivars Fielder (H1) and Wichita (H2). Rust inoculation of 5876 F(2) progeny revealed a single resistant plant that proved to carry the H1H2 haplotype, a result attributed to intragenic recombination. These findings reflect how plants balance the penalty and the necessity of a resistance gene and suggest that plants can reuse "dead" alleles to generate new disease-resistance specificity, leading to a "death-recycle" model of plant-resistance gene evolution at simple loci. We suggest that selection pressure in crop-weed complexes contributes to this process.

  14. Oxygen and radiation effects on C02 exchange in fight and in darkness of decaploid and hexaploid tall fescue (Festuca arundinacea Schreb.

    Directory of Open Access Journals (Sweden)

    Jerzy W. Poskuta

    2014-01-01

    Full Text Available Rates of apparent photosynthesis (APS. photorespiration (PR, CO2 compensation (I and dark respiration (DR were determined on attached shoots of decaploid (70 chromosomes and a hexaploid (42 chromosomes genotype of tall fescue (Festuca arundinacea Schreb. using an infra red CO2 analyzer arranged in a closed circuit system. Plants were grown at a photon flux density 500 µmol m-2s-1 (400-700 nm and at 25°C. Measurements were made at 25°C in O2 concentrations of l, 21 and 100% and at irradiance of 500 or 1800 µmol m-2s-1. The decaploid exhibited rates of APS that was from 26 to 46% higher in 1 and 21% O2 but not in 100% O2, than those of hexaploid. Rates of PR were positively related to rates of APS. Values of r were very similar for both genotypes, they were little affected by irradiance, and were a linear function of O2 Concentration. The percentages of PR in true photosynthesis (TPS = APS+ PR were also similar for the two genotypes, and were a linear function of O2 concentration. Alternatively, rates of DR were by 16-26% higher in the hexaploid than decaploid genotype, and were little affected by O2 concentration or by previous rates of APS.

  15. Construction of Genetic Linkage Map of Bread Wheat (Triticum aestivum L.) Using an Intervarietal Cross and QTL Map for Spike Related Traits

    Institute of Scientific and Technical Information of China (English)

    E. Nalini; S.G. Bhagwat; N. Jawali

    2007-01-01

    @@ Most often a genetic linkage map is prepared using populations obtained from two highly diverse genotypes.However, the markers from such a map may not be useful in a breeding program as these markers may not be polymorphie among the varieties used in breeding.

  16. 应用SSR分子标记分析小麦品种(系)的遗传重组%Genetic Recombination in Wheat Using SSR Markers

    Institute of Scientific and Technical Information of China (English)

    李小军; 冯素伟; 李淦; 董娜; 陈向东; 宋杰; 茹振钢

    2013-01-01

    To understand the characteristics of inheritance and recombination of parental chromosome fragments in wheat proge-nies, we screened the genomes of 23 genotypes derived from Zhoumai 18 and Bainong AK58 with 340 SSR markers covering the whole wheat genome, together with the parents. The average recombination frequency in cultivars from single-cross was 12.3, which was smaller than that in cultivars from single backcross (13.9). Recombination mostly occurred on chromosomes 4A, 5A, 7A, 1B, 3B, 4B, 7B, 1D, 2D, 3D, 5D, 6D, and 7D. The distal and central chromosomal regions had similar frequencies of recom-bination which were 6.1, and 6.0, respectively. Some chromosomal regions were hot in recombination, such as marker intervals gwm358–wmc357 on chromosome 5D, cfd49–barc196 on chromosome 6D, wmc158–barc23 on chromosome 7A, and gwm274–gwm146 on chromosome 7B, with 35, 19, 15, and 14 recombination events, respectively. The analysis for inheritance of large linkage blocks indicated that large chromosome fragments inherited from one parent varied from 14 to 29 in each derivative, with 2–8 consecutive and informative SSR loci in a fragment. These large fragments were mainly distributed on chromosomes 4A, 5A, 5B, 5D, and 7D, which might harbor genes controlling important agronomic traits.%  为了解小麦品种形成中亲本基因组的遗传重组和遗传保留区段的分布特点,对周麦18和百农AK58及其衍生品系共23个材料进行了全基因组SSR扫描分析.遗传重组分析表明,单交组合的平均重组数(12.3)低于回交组合(13.9);染色体4A、5A、7A、1B、3B、4B、7B、1D、2D、3D、5D、6D和7D重组发生较多,其余染色体重组相对较少,染色体的中间区段与远端区段重组数相当,分别为6.1和6.0.子代间基因组比较发现,一些染色体区段成为重组的多发区,如5D的gwm358–wmc357、6D的cfd49–barc196、7A的wmc158–barc23和7B的gwm274–gwm146区段,分别有35、19

  17. Genetic analysis and molecular mapping of a new fertility restorer gene Rf8 for Triticum timopheevi cytoplasm in wheat (Triticum aestivum L.) using SSR markers.

    Science.gov (United States)

    Sinha, Pallavi; Tomar, S M S; Vinod; Singh, Vikas K; Balyan, H S

    2013-12-01

    A study on mode of inheritance and mapping of fertility restorer (Rf) gene(s) using simple sequence repeat (SSR) markers was conducted in a cross of male sterile line 2041A having Triticum timopheevi cytoplasm and a restorer line PWR4099 of common wheat (Triticum aestivum L.). The F1 hybrid was completely fertile indicating that fertility restoration is a dominant trait. Based on the pollen fertility and seed set of bagged spikes in F2 generation, the individual plants were classified into fertile and sterile groups. Out of 120 F2 plants, 97 were fertile and 23 sterile (based on pollen fertility) while 98 plants set ≥ 5 seeds/spike and 22 produced ≤ 4 or no seed. The observed frequency fits well into Mendelian ratio of 3 fertile: 1 sterile with χ(2) value of 2.84 for pollen fertility and 2.17 for seed setting indicating that the fertility restoration is governed by a single dominant gene in PWR4099. The three linked SSR markers, Xwmc503, Xgwm296 and Xwmc112 located on the chromosome 2DS were placed at a distance of 3.3, 5.8 and 6.7 cM, respectively, from the Rf gene. Since, no known Rf gene is located on the chromosome arm 2DS, the Rf gene in PWR4099 is a new gene and proposed as Rf8. The closest SSR marker, Xwmc503, linked to the Rf8 was validated in a set of Rf, maintainer and cytoplasmic male sterile lines. The closely linked SSR marker Xwmc503 may be used in marker-assisted backcross breeding facilitating the transfer of fertility restoration gene Rf8 into elite backgrounds with ease.

  18. Wheat-related disorders: A broad spectrum of 'evolving' diseases.

    Science.gov (United States)

    Gasbarrini, Gb; Mangiola, F

    2014-08-01

    Throughout the world, cereals have always been recognized as a fundamental food. Human evolution, through the development of cooking, led to the production of food rich in gluten, in order to take full advantage of the nutritional properties of this food. The result has been that gluten intolerance has arisen only in those populations that developed the art of cooking wheat. It is also recognized that wheat, one of the central elements of the Mediterranean diet, cannot be tolerated in some individuals. Among the wheat-related pathologies, coeliac disease is the best known: it is a chronic inflammatory condition affecting the gastrointestinal tract, which develops in genetically predisposed individuals. The most common manifestation is the malabsorption of nutrients. Recently, another wheat-related disease has appeared: non-coeliac gluten sensitivity, defined as the onset of a variety of manifestations related to wheat, rye and barley ingestion, in patients in whom coeliac disease and wheat allergy have been excluded. In this paper we will explore the damaging power of wheat, analysing the harmful process by which it realizes the onset of clinical manifestations associated with wheat-related disorders.

  19. Wheat Allergy and Intolerence; Recent Updates and Perspectives.

    Science.gov (United States)

    Pasha, Imran; Saeed, Farhan; Sultan, Muhammad Tauseef; Batool, Rizwana; Aziz, Mahwash; Ahmed, Waqas

    2016-01-01

    The current review paper highlights the complicacies associated with communities relying on wheat as their dietary staple. Although, wheat is an important source of nutrients but is also linked with allergenic responses in genetically susceptible subjects. The wheat proteins especially α-amylase inhibitors, ω-5 gliadins, prolamins, nonprolamin, glucoprotein, and profilins are of significance importance. The allergenic responses are further categorized into IgE-mediated and non-IgE-mediated reactions. Conjugation and degranulation of the IgEs with the allergens results in release of several mediators. In contrary, non-IgE-mediated wheat allergy depends on immune complexes formed by food and food antibodies and cell-mediated immunity. As results, different diseases tend to occur on the completion of these reactions, i.e., celiac disease, baker's asthma, diarrhea, atopic dermatitis, and urticaria. This instant paper highlighted the concept of food allergy with special reference to wheat. The models are developed that are included in this paper showing the wheat allergen, their possible routes, impact on human health, and indeed possible remedies. The paper would provide the basic information for the researchers, common man, and allied stakeholders to cater the issue in details. However, the issue needs the attention of the researchers as there is a need to clarify the issues of wheat allergy and wheat intolerance.

  20. 21 CFR 137.195 - Crushed wheat.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Crushed wheat. 137.195 Section 137.195 Food and... Related Products § 137.195 Crushed wheat. Crushed wheat, coarse ground wheat, is the food prepared by so crushing cleaned wheat other than durum wheat and red durum wheat that, when tested by the method...

  1. Investigating the role of respiration in plant salinity tolerance by analyzing mitochondrial proteomes from wheat and a salinity-tolerant Amphiploid (wheat × Lophopyrum elongatum).

    Science.gov (United States)

    Jacoby, Richard P; Millar, A Harvey; Taylor, Nicolas L

    2013-11-01

    The effect of salinity on mitochondrial properties was investigated by comparing the reference wheat variety Chinese Spring (CS) to a salt-tolerant amphiploid (AMP). The octoploid AMP genotype was previously generated by combining hexaploid bread wheat (CS) with the diploid wild wheatgrass adapted to salt marshes, Lophopyrum elongatum. Here we used a combination of physiological, biochemical, and proteomic analyses to explore the mitochondrial and respiratory response to salinity in these two genotypes. The AMP showed greater growth tolerance to salinity treatments and altered respiration rate in both roots and shoots. A proteomic workflow of 2D-DIGE and MALDI TOF/TOF mass spectrometry was used to compare the protein composition of isolated mitochondrial samples from roots and shoots of both genotypes, following control or salt treatment. A large set of mitochondrial proteins were identified as responsive to salinity in both genotypes, notably enzymes involved in detoxification of reactive oxygen species. Genotypic differences in mitochondrial composition were also identified, with AMP exhibiting a higher abundance of manganese superoxide dismutase, serine hydroxymethyltransferase, aconitase, malate dehydrogenase, and β-cyanoalanine synthase compared to CS. We present peptide fragmentation spectra derived from some of these AMP-specific protein spots, which could serve as biomarkers to track superior protein variants.

  2. MEASUREMENT OF WHEAT DENSITY

    Institute of Scientific and Technical Information of China (English)

    冯跟胜; 党金春; 等

    1995-01-01

    A method used for on line determining the change of wheat density with a automatic watering machine in a lqarge flour mill has been studied.The results show that the higher distinguishing ability is obtained when using 241Am as a γ-ray source for measuring the wheat density than using 137Cs.

  3. Primary studies on tissue culture from mature embryos in diploid and tetraploid wheat

    Institute of Scientific and Technical Information of China (English)

    Ruiming BI; Honggang WANG

    2008-01-01

    Using mature embryos (MEs) as the explants,the callus induction,embryogenic callus differentiation,plantlet regeneration and culture efficiency in diploid and tetraploid wheat of four genotypes were studied.The tested four genotypes wheat included cultivable emmer wheat ( Triticum dicoccum Schuble),durum wheat ( Triticum durum Desf.) and the common wheat progenitors Triticum dicoccoides and Triticum aegilopides.Results indicated that there were significant differences in the efficiency of callus induction,callus differentiation and plant regeneration among the tested genotypes.The efficiency of differentiation and regeneration shows strong genotype dependence.The rates of callus induction,embryogenic callus differentiation,plantlet regeneration and culture efficiency respectively were 95.00%,90.00%,32.40%,and 27.70% in cultivable emmer wheat,which were significantly higher than other tested genotypes.Therefore,this study has provided a basis for genetic transformation,gene cloning and molecular plant breeding in wheat and other related species.

  4. Sensory Profiles and Volatile Compounds of Wheat Species, Landraces and Modern Varieties

    DEFF Research Database (Denmark)

    Starr, Gerrard

    ). Seventy two volatile compounds were identified in the grain of 81 wheat varieties (Paper II). Out of these, 7 selected wheat volatile compounds were significantly varied among 14 wheat varieties, indicating huge variation in volatile compound profiles among wheat varieties. Multivariate analysis showed...... that several wheat samples retained their configuration of distribution throughout the sensory tests. The same varieties also retained the same distribution configuration when analysed for volatile compounds which could link volatile profiles to sensory evaluation results (Papers II and III). Landraces were...... distinguishable from modern varieties and varieties from Austria could be distinguished from Danish, French and British varieties based on volatile profiles. This suggests that wheat volatile composition has genetic causes. The results in this study provide a strong case that there is wide variation among wheat...

  5. Microsatellite-based molecular diversity of bread wheat germplasm and association mapping of wheat resistance to the Russian wheat aphid.

    Science.gov (United States)

    Peng, J H; Bai, Y; Haley, S D; Lapitan, N L V

    2009-01-01

    Genetic diversity of a set of 71 wheat accessions, including 53 biotype 2 Russian wheat aphid (RWA2)-resistant landraces and 18 RWA2 susceptible accessions, was assessed by examining molecular variation at multiple microsatellite (SSR) loci. Fifty-one wheat SSR primer pairs were used, 81 SSR loci were determined, and 545 SSR alleles were detected. These SSR loci covered all the three genomes, 21 chromosomes, and at least 41 of the 42 chromosome arms. Diversity values averaged over SSR loci were high with mean number of SSR alleles/locus = 6.7, mean Shannon's index (H) = 1.291, and mean Nei's gene diversity (He) = 0.609. The three wheat genomes ranked as A > D > B and the homoeologous groups ranked as 7 > 3 > 1 > 2 > 6 > 5 > 4 based on the number of alleles per locus. Xgwm136 on chromosome arm 1AS is the most polymorphic SSR locus with the largest number of observed and effective alleles and the highest H and He. Among all 2485 pairs of wheat accessions, genetic distance (GD) ranged from 0.054 to 1.933 and averaged 0.9832. A dendrogram based on GD matrix showed that all the wheat accessions could be grouped into distinct clusters. Most of the susceptible cultivars (13/18) were clustered into groups that contains all or mostly susceptible accessions. Most of the U.S. cultivars belong to a group that is distinguishable from all the different RWA2 resistant groups. Diversity analysis was also conducted separately for subgroups containing 53 RWA2-resistant accessions and 18 RWA2-susceptible accessions. Association mapping revealed 28 SSR loci significantly associated with leaf chlorosis, and 8 with leaf rolling. New chromosome regions associated with RWA2 resistance were detected, and indicated existence of new RWA resistance genes located on chromosomes of all other homoeologous groups in addition to the groups 1 and 7 in bread wheat. This information is helpful for development of mapping populations for RWA2 resistance genes from different phylogenetic groups, and for

  6. The impact of Ty3-gypsy group LTR retrotransposons Fatima on B-genome specificity of polyploid wheats

    Directory of Open Access Journals (Sweden)

    Huneau Cecile

    2011-06-01

    Full Text Available Abstract Background Transposable elements (TEs are a rapidly evolving fraction of the eukaryotic genomes and the main contributors to genome plasticity and divergence. Recently, occupation of the A- and D-genomes of allopolyploid wheat by specific TE families was demonstrated. Here, we investigated the impact of the well-represented family of gypsy LTR-retrotransposons, Fatima, on B-genome divergence of allopolyploid wheat using the fluorescent in situ hybridisation (FISH method and phylogenetic analysis. Results FISH analysis of a BAC clone (BAC_2383A24 initially screened with Spelt1 repeats demonstrated its predominant localisation to chromosomes of the B-genome and its putative diploid progenitor Aegilops speltoides in hexaploid (genomic formula, BBAADD and tetraploid (genomic formula, BBAA wheats as well as their diploid progenitors. Analysis of the complete BAC_2383A24 nucleotide sequence (113 605 bp demonstrated that it contains 55.6% TEs, 0.9% subtelomeric tandem repeats (Spelt1, and five genes. LTR retrotransposons are predominant, representing 50.7% of the total nucleotide sequence. Three elements of the gypsy LTR retrotransposon family Fatima make up 47.2% of all the LTR retrotransposons in this BAC. In situ hybridisation of the Fatima_2383A24-3 subclone suggests that individual representatives of the Fatima family contribute to the majority of the B-genome specific FISH pattern for BAC_2383A24. Phylogenetic analysis of various Fatima elements available from databases in combination with the data on their insertion dates demonstrated that the Fatima elements fall into several groups. One of these groups, containing Fatima_2383A24-3, is more specific to the B-genome and proliferated around 0.5-2.5 MYA, prior to allopolyploid wheat formation. Conclusion The B-genome specificity of the gypsy-like Fatima, as determined by FISH, is explained to a great degree by the appearance of a genome-specific element within this family for Ae

  7. Wheat-Aegilops biuncialis amphiploids have efficient photosynthesis and biomass production during osmotic stress.

    Science.gov (United States)

    Dulai, Sándor; Molnár, István; Szopkó, Dóra; Darkó, Éva; Vojtkó, András; Sass-Gyarmati, Andrea; Molnár-Láng, Márta

    2014-04-15

    Osmotic stress responses of water content, photosynthetic parameters and biomass production were investigated in wheat-Aegilops biuncialis amphiploids and in wheat genotypes to clarify whether they can use to improve the drought tolerance of bread wheat. A decrease in the osmotic pressure of the medium resulted in considerable water loss, stomatal closure and a decreased CO2 assimilation rate for the wheat genotypes, while the changes in these parameters were moderate for the amphiploids. Maximal assimilation rate was maintained at high level even under severe osmotic stress in the amphiploids, while it decreased substantially in the wheat genotypes. Nevertheless, the effective quantum yield of PS II was higher and the quantum yield of non-photochemical quenching of PS II and PS I was lower for the amphiploids than for the wheat cultivars. Parallel with this, higher cyclic electron flow was detected in wheat than in the amphiploids. The elevated photosynthetic activity of amphiploids under osmotic stress conditions was manifested in higher biomass production by roots and shoots as compared to wheat genotypes. These results indicate that the drought-tolerant traits of Ae. biuncialis can be manifested in the wheat genetic background and these amphiploids are suitable genetic materials for improving drought tolerance of wheat.

  8. MARKER ASSISTED SELECTION (MAS FOR DEVELOPMENT OF BARLEY AND WHEAT LINES WITH REQUESTED TRAITS

    Directory of Open Access Journals (Sweden)

    M. Hudcovicová

    2008-09-01

    Full Text Available Molecular markers closely linked to interesting genes enable early, proper and fast detection of plant individuals with desired allele during backcross breeding, what can make plant breeding faster and cheaper. We are focused on molecular breeding of barley and wheat lines for disease resistance and some important quality traits. As acceptors of interesting genes we use especially elite Slovak and Czech cultivars and lines. After five backcross generations with the help of MAS new created lines carrying markers linked to desired genes undergo resistance, agronomic and technological tests. In breeding of winter barley for resistance to BaYMV/BaMMV viruses we use codominant STS and SSR markers linked to rym4 and rym11 resistance genes. Cultivar Romanze has been used as a donor of rym4 gene and landrace Russia57 as gene rym11 donor. In spring barley we are focused on transfer of Yd2 gene from landraces Shannon and Sutter resistant to BYDV by use of dominant ASPCR marker. We are also working on transfer of effective leaf rust resistance genes Lr19, Lr24 derived from Thinopyrum ponticum and gene Lr35 from Aegilops speltoides into hexaploid wheat by use of dominant STS and SCAR markers. Near isogenic lines with these genes are used in gene pyramiding to develop a single line with all three genes. By use of protein markers we develop near isogenic wheat lines for higher sedimentation values, higher dough strength and better breadmaking quality. These are lines with new combination of HMW glutenin subunits (21*, 7+8, 5+10 as well as wheat lines with new unknown HMW-GS and with new HMW-GS pair.

  9. Drought Tolerance in Modern and Wild Wheat

    Science.gov (United States)

    Budak, Hikmet; Kantar, Melda; Yucebilgili Kurtoglu, Kuaybe

    2013-01-01

    The genus Triticum includes bread (Triticum aestivum) and durum wheat (Triticum durum) and constitutes a major source for human food consumption. Drought is currently the leading threat on world's food supply, limiting crop yield, and is complicated since drought tolerance is a quantitative trait with a complex phenotype affected by the plant's developmental stage. Drought tolerance is crucial to stabilize and increase food production since domestication has limited the genetic diversity of crops including wild wheat, leading to cultivated species, adapted to artificial environments, and lost tolerance to drought stress. Improvement for drought tolerance can be achieved by the introduction of drought-grelated genes and QTLs to modern wheat cultivars. Therefore, identification of candidate molecules or loci involved in drought tolerance is necessary, which is undertaken by “omics” studies and QTL mapping. In this sense, wild counterparts of modern varieties, specifically wild emmer wheat (T. dicoccoides), which are highly tolerant to drought, hold a great potential. Prior to their introgression to modern wheat cultivars, drought related candidate genes are first characterized at the molecular level, and their function is confirmed via transgenic studies. After integration of the tolerance loci, specific environment targeted field trials are performed coupled with extensive analysis of morphological and physiological characteristics of developed cultivars, to assess their performance under drought conditions and their possible contributions to yield in certain regions. This paper focuses on recent advances on drought related gene/QTL identification, studies on drought related molecular pathways, and current efforts on improvement of wheat cultivars for drought tolerance. PMID:23766697

  10. Drought Tolerance in Modern and Wild Wheat

    Directory of Open Access Journals (Sweden)

    Hikmet Budak

    2013-01-01

    Full Text Available The genus Triticum includes bread (Triticum aestivum and durum wheat (Triticum durum and constitutes a major source for human food consumption. Drought is currently the leading threat on world's food supply, limiting crop yield, and is complicated since drought tolerance is a quantitative trait with a complex phenotype affected by the plant's developmental stage. Drought tolerance is crucial to stabilize and increase food production since domestication has limited the genetic diversity of crops including wild wheat, leading to cultivated species, adapted to artificial environments, and lost tolerance to drought stress. Improvement for drought tolerance can be achieved by the introduction of drought-grelated genes and QTLs to modern wheat cultivars. Therefore, identification of candidate molecules or loci involved in drought tolerance is necessary, which is undertaken by “omics” studies and QTL mapping. In this sense, wild counterparts of modern varieties, specifically wild emmer wheat (T. dicoccoides, which are highly tolerant to drought, hold a great potential. Prior to their introgression to modern wheat cultivars, drought related candidate genes are first characterized at the molecular level, and their function is confirmed via transgenic studies. After integration of the tolerance loci, specific environment targeted field trials are performed coupled with extensive analysis of morphological and physiological characteristics of developed cultivars, to assess their performance under drought conditions and their possible contributions to yield in certain regions. This paper focuses on recent advances on drought related gene/QTL identification, studies on drought related molecular pathways, and current efforts on improvement of wheat cultivars for drought tolerance.

  11. Drought Tolerance in Modern and Wild Wheat

    OpenAIRE

    Hikmet Budak; Melda Kantar; Kuaybe Yucebilgili Kurtoglu

    2013-01-01

    The genus Triticum includes bread (Triticum aestivum) and durum wheat (Triticum durum) and constitutes a major source for human food consumption. Drought is currently the leading threat on world's food supply, limiting crop yield, and is complicated since drought tolerance is a quantitative trait with a complex phenotype affected by the plant's developmental stage. Drought tolerance is crucial to stabilize and increase food production since domestication has limited the genetic diversity of c...

  12. Variabilidade genética em trigos brasileiros a partir de caracteres componentes da qualidade industrial e produção de grãos Genetic variability for bread making quality and grain yield among Brazilian wheat genotypes

    Directory of Open Access Journals (Sweden)

    Douglas André Mallmann Schmidt

    2009-01-01

    Full Text Available O melhoramento genético para a qualidade industrial do trigo pode representar uma oportunidade de agregar valor de mercado aos produtos agrícolas, sendo o trigo um dos cereais com maior associação entre a qualidade intrínseca e a remuneração ao agricultor. O objetivo do trabalho foi o de determinar a variabilidade genética a partir de caracteres indicativos da qualidade industrial e o rendimento de grãos, e estimar o grau de associação entre estes caracteres em 22 genótipos de trigo. O experimento foi desenvolvido em área experimental pertencente à Universidade Federal de Pelotas, Capão do Leão (RS. Os resultados indicaram a provável existência de variabilidade genética para os caracteres em estudo, a qual pode auxiliar pesquisadores na escolha de genitores. Cruzamentos artificiais envolvendo os genótipos BRS 208, Rubi e Safira podem ser os mais promissores no intuito de incrementar o ganho genético, tanto para a qualidade industrial quanto para a produtividade de grãos. O rendimento de grãos manifestou correlação negativa com o conteúdo de proteína da farinha revelando que a superioridade genotípica para o rendimento de grãos pode afetar negativamente a proporção protéica. Entretanto, o conteúdo de proteína não evidenciou associação significativa com a força de glúten (indicador da qualidade industrial, revelando que a concentração de proteína da farinha não foi eficiente para predizer a qualidade industrial. Este resultado sugere a possibilidade de obtenção de genótipos superiores para o rendimento de grãos sem comprometer a qualidade industrial.The breeding for wheat bread making quality represents a great opportunity to incorporate commercial value to agricultural products. Wheat has one of the best relationship between end product quality and farmer earnings. Genetic variability among 22 different genotypes based on bread making quality traits and grain yield and the degree of their association

  13. Similarities of omega gliadins from Triticum urartu to those encoded on chromosome 1A of hexaploid wheat and evidence for their post-translational processing.

    Science.gov (United States)

    DuPont, F M; Vensel, W; Encarnacao, T; Chan, R; Kasarda, D D

    2004-05-01

    The omega-gliadins encoded on chromosome 1 of the A genome were purified from Triticum aestivum L. (2n=6 x=42, AABBDD) cv. Butte86, nullisomic 1D-tetrasomic 1A of cv. Chinese Spring (CS N1DT1A), and the diploid T. urartu (2n=2 x=14, AA ). Reverse-phase high-performance liquid chromatography combined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis of gliadin extracts from CS nullisomic-tetrasomic (NT) lines confirmed the assignment to chromosome 1A. The purified omega-gliadins were characterized by mass spectrometry and N-terminal sequencing. The 1A-encoded omega-gliadins were smaller than 1B- or 1D-encoded omega-gliadins. The N-terminal amino acid sequences for 1A omega-gliadin mature peptides were nearly identical to those for the T. urartu omega-gliadins and were more similar to 1D omega-gliadin sequences than to sequences for T. monococum omega-gliadins, barley C-hordeins, or rye omega-secalins. They diverged greatly from the N-terminal sequences for the 1B omega-gliadins. The data suggest that T. urartu is the A-genome donor, and that post-translational cleavage by an asparaginyl endoprotease produces those omega-gliadins with N-terminal sequences beginning with KEL.

  14. Genome-Wide Association Mapping for Resistance to Leaf and Stripe Rust in Winter-Habit Hexaploid Wheat Landraces: e0129580

    National Research Council Canada - National Science Library

    Albert Kertho; Sujan Mamidi; J Michael Bonman; Phillip E McClean; Maricelis Acevedo

    2015-01-01

    .... Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst requires a constant search for new sources of resistance...

  15. Isolation and characterization of a gene encoding a polyethylene glycol-induced cysteine protease in common wheat

    Indian Academy of Sciences (India)

    Qing-Wei Zang; Cai-Xiang Wang; Xu-Yan Li; Zhi-Ai Guo; Rui-Lian Jing; Jun Zhao; Xiao-Ping Chang

    2010-09-01

    Plant cysteine protease (CP) genes are induced by abiotic stresses such as drought, yet their functions remain largely unknown. We isolated the full-length cDNA encoding a Triticum aestivum CP gene, designated TaCP, from wheat by the rapid amplification of cDNA ends (RACE) method. Sequence analysis revealed that TaCP contains an open reading frame encoding a protein of 362 amino acids, which is 96% identical to barley cysteine protease HvSF42. The TaCP transcript level in wheat seedlings was upregulated during polyethylene glycol (PEG) stress, with a peak appearing around 12 h after treatment. TaCP expression level increased rapidly with NaCl treatment at 48 h. TaCP responded strongly to low temperature (4°C) treatment from 1 h post-treatment and reached a peak of about 40-fold at 72 h. However, it showed only a very slight response to abscisic acid (ABA). More than one copy of TaCP was present in each of the three genomes of hexaploid wheat and its diploid donors. TaCP fused with green fluorescent protein (GFP) was located in the plasma membrane of onion epidermis cells. Transgenic Arabidopsis plants overexpressing TaCP showed stronger drought tolerance and higher CP activity under water-stressed conditions than wild-type Arabidopsis plants. The results suggest that TaCP plays a role in tolerance to water deficit.

  16. Effects of heavy-ion beams on chromosomes of common wheat, Triticum aestivum

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Shinji; Saito, Yoshinaka [Laboratory of Plant Genetics and Breeding Science, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori 680-8553 (Japan); Ryuto, Hiromichi; Fukunishi, Nobuhisa; Abe, Tomoko [RIKEN Nishina Center, RIKEN, Hirosawa, Wako 351-0198 (Japan); Tanaka, Hiroyuki [Laboratory of Plant Genetics and Breeding Science, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori 680-8553 (Japan); Tsujimoto, Hisashi, E-mail: tsujim@muses.tottori-u.ac.jp [Laboratory of Plant Genetics and Breeding Science, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori 680-8553 (Japan)

    2009-10-02

    To investigate the nature of plant chromosomes irradiated by heavy-ion beams, the effects of nitrogen (N) and neon (Ne) ion beams on hexaploid wheat chromosomes were compared with those of X-ray. Chromosome aberrations, such as short, ring and dicentric chromosomes appeared in high frequency. The average numbers of chromosome breaks at LD-50 by irradiation with X-ray, N and Ne ion beams were 32, 20 and 20, respectively. These values may be underestimated because chromosome rearrangement without change in chromosome morphology was not counted. Thus, we subsequently used a wheat line with a pair of extra chromosomes from an alien species (Leymus racemosus) and observed the fate of the irradiated marker chromosomes by genomic in situ hybridization. This analysis revealed that 50 Gy of neon beam induced about eight times more breaks than those induced by X-ray. This result suggests that heavy-ion beams induce chromosome rearrangement in high frequency rather than loss of gene function. This suggests further that most of the novel mutations produced by ion beam irradiation, which have been used in plant breeding, may not be caused by ordinary gene disruption but by chromosome rearrangements.

  17. Molecular cloning and expression analysis of multiple polyphenol oxidase genes in developing wheat (Triticum aestivum) kernels

    Science.gov (United States)

    Polyphenol oxidase (PPO, EC 1.10.31) is a major cause of discoloring in raw dough containing wheat flour. Minimization of PPO activity has proven difficult because bread wheat is genetically complex, composed of the genomes of three grass species. The PPO-A1 and PPO-D1 genes, on chromosomes 2A and...

  18. Mechanisms of waterlogging tolerance in wheat - a review of root and shoot physiology

    DEFF Research Database (Denmark)

    Herzog, Max; Striker, Gustavo G; Colmer, Timothy D;

    2016-01-01

    We review the detrimental effects of waterlogging on physiology, growth and yield of wheat. We highlight traits contributing to waterlogging tolerance and genetic diversity in wheat. Death of seminal roots and restriction of adventitious root length due to O2 deficiency result in low root...

  19. Prediction of wheat tortilla quality using multivariate modeling of kernel, flour and dough properties

    Science.gov (United States)

    Wheat grain attributes that influence tortilla quality are not fully understood. This impedes genetic improvement efforts to develop wheat varieties for the growing market. This study used a multivariate discriminant analysis to predict tortilla quality using a set of 16 variables derived from kerne...

  20. Wild emmer genome architecture and diversity elucidate wheat evolution and domestication

    Science.gov (United States)

    Wheat (Triticum spp.) is one of the founder crops that likely drove the Neolithic transition to sedentary agrarian societies in the Fertile Crescent over 10,000 years ago. Identifying genetic modifications underlying wheat's domestication requires knowledge of the genome of its allo-tetraploid proge...

  1. Changes in Root Hydraulic Conductivity During Wheat Evolution

    Institute of Scientific and Technical Information of China (English)

    Chang-Xing ZHAO; Xi-Ping DENG; Lun SHAN; Ernst STEUDLE; Sui-Qi ZHANG; Qing YE

    2005-01-01

    A better understanding of the mechanisms of water uptake by plant roots should be vital for improving drought resistance and water use efficiency (WUE). In the present study, we have demonstrated correlations between root system hydraulic conductivity and root characteristics during evolution using six wheat evolution genotypes (solution culture) with different ploidy chromosome sets (Triticum boeoticum Bioss., T. monococcum L.: 2n = 2x = 14; T. dicoccides Koern., T. dicoccon (Schrank) Schuebl.: 2n = 4x = 28;T. vulgare Vill., T. aestivum L. cv. Xiaoyan No. 6: 2n = 6x = 42). The experimental results showed that significant correlations were found between root system hydraulic conductivity and root characteristics of the materials with the increase in ploidy chromosomes (2x→6x) during wheat evolution. Hydraulic conductivity of the wheat root system at the whole-plant level was increased with chromosome ploidy during evolution, which was positively correlated with hydraulic conductivity of single roots, whole plant biomass,root average diameter, and root growth (length, area), whereas the root/shoot ratio had an inverse correlation with the hydraulic conductivity of root system with increasing chromosome ploidy during wheat evolution. Therefore, it is concluded that that the water uptake ability of wheat roots was strengthened from wild to modern cultivated species during evolution, which will provide scientific evidence for genetic breeding to improve the WUE of wheat by genetic engineering.

  2. Studies of the genetics of inheritance of stem rust resistance in ...

    African Journals Online (AJOL)

    User

    2013-05-22

    May 22, 2013 ... fungus could affect the entire wheat crop, especially during the early growth ... either through a single mutation event or deletion of the effector molecule of the host ..... Wheat Genotypes. Crop breeding, genetics and cytology.

  3. 21 CFR 137.190 - Cracked wheat.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Cracked wheat. 137.190 Section 137.190 Food and... Related Products § 137.190 Cracked wheat. Cracked wheat is the food prepared by so cracking or cutting into angular fragments cleaned wheat other than durum wheat and red durum wheat that, when tested by...

  4. Wheat for Kids! [and] Teacher's Guide.

    Science.gov (United States)

    Idaho Wheat Commission, Boise.

    "Wheat for Kids" contains information at the elementary school level about: the structure of the wheat kernel; varieties of wheat and their uses; growing wheat; making wheat dough; the U.S. Department of Agriculture Food Guide Pyramid and nutrition; Idaho's part of the international wheat market; recipes; and word games based on the…

  5. Wheat for Kids! [and] Teacher's Guide.

    Science.gov (United States)

    Idaho Wheat Commission, Boise.

    "Wheat for Kids" contains information at the elementary school level about: the structure of the wheat kernel; varieties of wheat and their uses; growing wheat; making wheat dough; the U.S. Department of Agriculture Food Guide Pyramid and nutrition; Idaho's part of the international wheat market; recipes; and word games based on the…

  6. Occurrence of toxigenic Aspergillus flavus in commercial Bulgur wheat

    Directory of Open Access Journals (Sweden)

    Carla Bertechini FARIA

    Full Text Available Abstract Aflatoxins are mutagenic, carcinogenic, and teratogenic mycotoxins. The objective of this work was to study the presence of aflatoxigenic Aspergillus in commercial Bulgur wheat in the city of Maringá, Paraná, Brazil. Thirty samples of commercial Bulgur wheat, acquired in the period of August 2011 to January 2012, were evaluated. The enumeration analysis showed that samples had up to 273.3 CFU of molds and 133.3 CFU of aflatoxigenic Aspergillus per gram of wheat. Forty-two monosporic isolates were obtained and identified as Aspergillus flavus. The isolates were analyzed regarding their aflatoxigenic potential by culture in coconut milk agar; hydroxide vapor exposure; chromatography; and polymerase chain reaction (PCR targeting genes that code enzymes of the aflatoxins synthesis pathway. Some of the isolates were confirmed to be aflatoxin producers and several of them presented a genetic profile of aflatoxin synthesis. The obtained results demonstrated that Bulgur wheat A. flavus contamination is concerning.

  7. Split-gene system for hybrid wheat seed production.

    Science.gov (United States)

    Kempe, Katja; Rubtsova, Myroslava; Gils, Mario

    2014-06-24

    Hybrid wheat plants are superior in yield and growth characteristics compared with their homozygous parents. The commercial production of wheat hybrids is difficult because of the inbreeding nature of wheat and the lack of a practical fertility control that enforces outcrossing. We describe a hybrid wheat system that relies on the expression of a phytotoxic barnase and provides for male sterility. The barnase coding information is divided and distributed at two loci that are located on allelic positions of the host chromosome and are therefore "linked in repulsion." Functional complementation of the loci is achieved through coexpression of the barnase fragments and intein-mediated ligation of the barnase protein fragments. This system allows for growth and maintenance of male-sterile female crossing partners, whereas the hybrids are fertile. The technology does not require fertility restorers and is based solely on the genetic modification of the female crossing partner.

  8. Effects of feeding deoxynivalenol (DON)-contaminated wheat to laying hens and roosters of different genetic background on the reproductive performance and health of the newly hatched chicks.

    Science.gov (United States)

    Ebrahem, Mohammad; Kersten, Susanne; Valenta, Hana; Breves, Gerhard; Beineke, Andreas; Hermeyer, Kathrin; Dänicke, Sven

    2014-08-01

    A total of 216 23-week-old laying hens from two different genetic backgrounds (half of the birds were Lohmann brown [LB] and [LSL] hens, respectively) and 24 adult roosters were assigned to a feeding trial to study the effect of increasing concentrations of deoxynivalenol (DON) in the diet (0, 5, 10 mg/kg) on the reproductive performance of hens and roosters, and the health of the newly hatched chicks. Hatchability was adversely affected by the presence of DON in LB hens' diet, while the hatchability of the LSL chicks was significantly higher than LB chicks. An interaction effect between DON in the hens' diet and the breed was noticed on fertility, as the fertility was decreased in the eggs of LB hens receiving 10 mg/kg DON in their diet and increased in the eggs of LSL hens fed 10 mg/kg DON. Moreover, spleen relative weight was significantly decreased in the chicks hatched from eggs of hens fed contaminated diets, while gizzard relative weight was significantly decreased in LB chicks with 10 mg/kg DON in their diet compared with the control group. On the other hand, the chicks' haematology and organ histopathology were not affected by the dietary treatment. Additionally, the presence of DON in the roosters' diet had no effect on fertility (the percentage of fertile eggs of all laid eggs). Consequently, the current results indicate a negative impact of DON in LB hens' diet on fertility and hatchability, indicating that the breed of the hens seems to be an additional factor influencing the effect of DON on reproductive performance of the laying hens.

  9. Wheat Production and Economics

    Directory of Open Access Journals (Sweden)

    Elgilany Ahmed

    2011-01-01

    Full Text Available Problem statement: The crop in the irrigated scheme has faced by manifold problems contributed to low level of productivity and high cost of production of wheat. The crop is commonly produced under pump irrigation from the River Nile. In River Nile State (RNS, wheat is grown under the irrigated sector, the State is considered as a suitable environment for producing this crop. The study was conducted at Elzeidab irrigated scheme of RNS which is regarded as the oldest and biggest scheme belonging to the Ministry of Agriculture of RNS. Approach: Primary data was collected by using structured questionnaire for (70 randomly selected respondents. More than one technique used to assess economic aspects of the crop. Cobb-Douglas production function, descriptive statistics and partial budgeting have been employed to analyze the primary data. The study detected that the major socioeconomic characteristics of Elzeidab farmers were educated, the scheme tenants have had a cumulative experience in agriculture and average farm size is found to be small and the majority 50% of surveyed tenants in Elzeidab scheme were rented. The farming system of Elzeidab scheme is dominated by wheat production which counts to 25% of the farm land. The yield gab with the potential yield obtained by Agricultural Research Corporation (ARC in the State amounts 66%. The microfinance market in Elzeidab scheme is not well developed. Water charges in the scheme were high. About 53% of the annual running expenses were allocated for fuel that made irrigation costs to be the highest single component of production costs of the crop, while irrigation water cost was considered as the most agricultural constraint, this item was found to be as 19% of the total cost of production as the highest percentage overall the variable cost items. Results: The regression analysis revealed that the most factors affecting wheat productivity under the study were: the average of tenants age, family labor

  10. Transgenic expression of lactoferrin imparts enhanced resistance to head blight of wheat caused by Fusarium graminearum

    Directory of Open Access Journals (Sweden)

    Han Jigang

    2012-03-01

    Full Text Available Abstract Background The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Using the tools of plant genetic engineering, a broad-spectrum antimicrobial gene was tested for resistance against head blight caused by Fusarium graminearum Schwabe, a devastating disease of wheat (Triticum aestivum L. and barley (Hordeum vulgare L. that reduces both grain yield and quality. Results A construct containing a bovine lactoferrin cDNA was used to transform wheat using an Agrobacterium-mediated DNA transfer system to express this antimicrobial protein in transgenic wheat. Transformants were analyzed by Northern and Western blots to determine lactoferrin gene expression levels and were inoculated with the head blight disease fungus F. graminearum. Transgenic wheat showed a significant reduction of disease incidence caused by F. graminearum compared to control wheat plants. The level of resistance in the highly susceptible wheat cultivar Bobwhite was significantly higher in transgenic plants compared to control Bobwhite and two untransformed commercial wheat cultivars, susceptible Wheaton and tolerant ND 2710. Quantification of the expressed lactoferrin protein by ELISA in transgenic wheat indicated a positive correlation between the lactoferrin gene expression levels and the levels of disease resistance. Conclusions Introgression of the lactoferrin gene into elite commercial wheat, barley and other susceptible cereals may enhance resistance to F. graminearum.

  11. Grinding up Wheat: a Massive Loss of Nucleotide Diversity Since Domestication

    DEFF Research Database (Denmark)

    Haudry, Anabelle; Cenci, Alberto; Ravel, Catherine;

    2007-01-01

    Several demographic and selective events occurred during the domestication of wheat from the allotetraploid wild emmer (Triticum turgidum ssp. dicoccoides). Cultivated wheat has since been affected by other historical events. We analyzed nucleotide diversity at 21 loci in a sample of 101 individu......Several demographic and selective events occurred during the domestication of wheat from the allotetraploid wild emmer (Triticum turgidum ssp. dicoccoides). Cultivated wheat has since been affected by other historical events. We analyzed nucleotide diversity at 21 loci in a sample of 101...... individuals representing 4 taxa corresponding to representative steps in the recent evolution of wheat (wild, domesticated, cultivated durum, and bread wheats) to unravel the evolutionary history of cultivated wheats and to quantify its impact on genetic diversity. Sequence relationships are consistent...... with a single domestication event and identify 2 genetically different groups of bread wheat. The wild group is not highly polymorphic, with only 212 polymorphic sites among the 21,720 bp sequenced, and, during domestication, diversity was further reduced in cultivated forms-by 69% in bread wheat and 84...

  12. Wheat Rust Information Resources - Integrated tools and data for improved decision making

    DEFF Research Database (Denmark)

    Hodson, David; Hansen, Jens Grønbech; Lassen, Poul

    Wheat rusts present an ever-changing global threat to the worlds wheat crop. Emergence of virulent new races in one region has implications for other regions, due to wind-borne or human-borne movements. Therefore informed decision making regarding control and mitigation of wheat rusts requires...... an integrated set of datasets on both pathogen and host at the global scale. The Global Cereal Rust Monitoring System (GCRMS), created under the Durable Rust resistance in Wheat (DRRW) project, represents a unique and increasingly comprehensive resource of rust information. A suite of tools are now available....... Integration of the CIMMYT Wheat Atlas and the Genetic Resources Information System (GRIS) databases provides a rich resource on wheat cultivars and their resistance to important rust races. Data access is facilitated via dedicated web portals such as Rust Tracker (www.rusttracker.org) and the Global Rust...

  13. Wheat Quality Council, Hard Spring Wheat Technical Committee, 2015 Crop

    Science.gov (United States)

    Nine experimental lines of hard spring wheat were grown at up to five locations in 2015 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Wheat samples were submitted through the Wheat Quality Council and processed and milled at the USDA-ARS Hard Red Sprin...

  14. New Uses for Wheat and Modified Wheat Products

    Science.gov (United States)

    Hard wheat from the Great Plains historically has been used as a source of flour for the production of leavened bakery products. However, potentially applications of wheat in both new markets and new products has necessitated the need to develop wheats with novel processing attributes. The most lo...

  15. Chromosomal Passports Provide New Insights into Diffusion of Emmer Wheat: e0128556

    National Research Council Canada - National Science Library

    Ekaterina D Badaeva; Jens Keilwagen; Helmut Knüpffer; Louise Waßermann; Olga S Dedkova; Olga P Mitrofanova; Olga N Kovaleva; Olga A Liapunova; Vitaly A Pukhalskiy; Hakan Özkan; Andreas Graner; George Willcox; Benjamin Kilian

    2015-01-01

      Emmer wheat, Triticum dicoccon schrank (syn. T. dicoccum (schrank) schÜbl.), is one of the earliest domesticated crops, harboring a wide range of genetic diversity and agronomically valuable traits...

  16. Wild emmer genome architecture and diversity elucidate wheat evolution and domestication.

    Science.gov (United States)

    Avni, Raz; Nave, Moran; Barad, Omer; Baruch, Kobi; Twardziok, Sven O; Gundlach, Heidrun; Hale, Iago; Mascher, Martin; Spannagl, Manuel; Wiebe, Krystalee; Jordan, Katherine W; Golan, Guy; Deek, Jasline; Ben-Zvi, Batsheva; Ben-Zvi, Gil; Himmelbach, Axel; MacLachlan, Ron P; Sharpe, Andrew G; Fritz, Allan; Ben-David, Roi; Budak, Hikmet; Fahima, Tzion; Korol, Abraham; Faris, Justin D; Hernandez, Alvaro; Mikel, Mark A; Levy, Avraham A; Steffenson, Brian; Maccaferri, Marco; Tuberosa, Roberto; Cattivelli, Luigi; Faccioli, Primetta; Ceriotti, Aldo; Kashkush, Khalil; Pourkheirandish, Mohammad; Komatsuda, Takao; Eilam, Tamar; Sela, Hanan; Sharon, Amir; Ohad, Nir; Chamovitz, Daniel A; Mayer, Klaus F X; Stein, Nils; Ronen, Gil; Peleg, Zvi; Pozniak, Curtis J; Akhunov, Eduard D; Distelfeld, Assaf

    2017-07-07

    Wheat (Triticum spp.) is one of the founder crops that likely drove the Neolithic transition to sedentary agrarian societies in the Fertile Crescent more than 10,000 years ago. Identifying genetic modifications underlying wheat's domestication requires knowledge about the genome of its allo-tetraploid progenitor, wild emmer (T. turgidum ssp. dicoccoides). We report a 10.1-gigabase assembly of the 14 chromosomes of wild tetraploid wheat, as well as analyses of gene content, genome architecture, and genetic diversity. With this fully assembled polyploid wheat genome, we identified the causal mutations in Brittle Rachis 1 (TtBtr1) genes controlling shattering, a key domestication trait. A study of genomic diversity among wild and domesticated accessions revealed genomic regions bearing the signature of selection under domestication. This reference assembly will serve as a resource for accelerating the genome-assisted improvement of modern wheat varieties. Copyright © 2017, American Association for the Advancement of Science.

  17. Dissimilaridade genética entre genótipos de trigo avaliados em cultivo hidropônico sob estresse por alumínio Genetic dissimilarity among wheat genotypes evaluated in hydroponic culture under aluminum stress

    Directory of Open Access Journals (Sweden)

    Ivandro Bertan

    2006-01-01

    Full Text Available O conhecimento da distância genética entre genótipos é importante ferramenta utilizada na escolha de genitores que vão dar origem às populações segregantes. Essa informação serve como parâmetro para indicação de cruzamentos que possibilitem recuperar recombinantes superiores para o caráter desejado. O principal objetivo do estudo foi promover informações de dissimilaridade genética para o caráter tolerância ao alumínio tóxico em genótipos de trigo da Região Sul do Brasil, avaliados em cultivo hidropônico sob estresse por alumínio em nível tóxico, utilizando diferentes técnicas de agrupamento e visualização gráfica. Entre os 23 genótipos testados, foi constatada a presença de variabilidade genética para tolerância ao alumínio, verificada pela formação de diferentes classes na média das variáveis consideradas bem como agrupamentos distintos. As técnicas de agrupamento e dispersão gráfica utilizadas juntamente com a comparação de médias permitiram identificar de modo eficiente os genótipos promissores na formação de populações segregantes superiores para o caráter estudado. Os genótipos ICAT 01338, ICAT 011, ICA 2, ICA 5, CD 106, CEP 24, CD 103, CD 105, IPR 85, IPR 110 e ICAT 012 são indicados para cruzamentos na expectativa de incremento de tolerância ao alumínio nas progênies formadas.The quantification of genetic distance among genotypes is an important tool for the choice of parents originating the segregating populations. This information serves as a parameter for directing crosses that increase the probability of recover superior recombinants for the desired character. The main object of this study was to provide information recording the genetic dissimilarity for the character tolerance to toxic aluminum in wheat genotypes from the Southern Region of Brazil, evaluated in hydroponic culture under aluminum stress, using different clustering and graphic techniques. It was observed the

  18. PESTICIDES EFFICIENCY IN WHEAT PRODUCTION

    OpenAIRE

    2009-01-01

    It is suggested that the Karate Zeon insecticide is highly effective in wheat protection against pests. The profitability of soft spring wheat production with the above preparation used is about 176%. The economic effect of Karate Zeon is the same as that of Krezatsin, Mival and TMTD Plus preparations that are used for wheat seeds treatment against plant diseases

  19. Pollen flow of wheat under natural conditions in the Huanghuai River Wheat Region, China

    OpenAIRE

    Sun, Ai-Qing; Zhang, Chun-Qing; Wu, Cheng-Lai; Gao, Qing-Rong

    2015-01-01

    The transgenic pollen spread is the main pathway of transgenic plant gene flow. The maximum distance of pollen dispersal (horizontal), the spatial dynamics of pollen movement (vertical), and the patterns of pollen dispersal are important considerations in biosafety assessments of genetically modified crops. To evaluate wheat (Triticum aestivum) pollen dispersal, we measured the pollen suspension velocity and analyzed pollen dispersal patterns under natural conditions in the Huanghuai River wh...

  20. Thermoformed wheat gluten biopolymers.

    Science.gov (United States)

    Pallos, Ferenc M; Robertson, George H; Pavlath, Attila E; Orts, William J

    2006-01-25

    The quantity of available wheat gluten exceeds the current food use markets. Thermoforming is an alternative technical means for transforming wheat gluten. Thermoforming was applied here to wheat gluten under chemically reductive conditions to form pliable, translucent sheets. A wide variety of conditions, i.e., temperature, reducing agents, plasticizers and additives were tested to obtain a range of elastic properties in the thermoformed sheets. These properties were compared to those of commercially available polymers, such as polypropylene. Elasticity of the gluten formulations were indexed by Young's modulus and were in the range measured for commercial products when tested in the 30-70% relative humidity range. Removal of the gliadin subfraction of gluten yielded polymers with higher Young's modulus since this component acts as a polymer-chain terminator. At relative humidity less than 30% all whole gluten-based sheets were brittle, while above 70% they were highly elastic.

  1. Durum wheat modeling

    DEFF Research Database (Denmark)

    Toscano, P.; Ranieri, R.; Matese, A.

    2012-01-01

    durum wheat during phenological development, at regional scale. We present an innovative system capable of predicting spatial yield variation and temporal yield fluctuation in long-term analysis, that are the main purposes of regional crop simulation study. The Delphi system was applied to simulate...... growth and yield of durum wheat in the major Italian supply basins (Basilicata, Capitanata, Marche, Tuscany). The model was validated and evaluated for three years (1995–1997) at 11 experimental fields and then used in operational mode for eleven years (1999–2009), showing an excellent/good accuracy...

  2. EFFECT OF PLANTITNG PATTERN OF WINTER WHEAT ON AGRODIVERSITY

    Directory of Open Access Journals (Sweden)

    Моskalets Т. Z.

    2015-08-01

    Full Text Available We studied the introductions of cultivars and lines of wheat soft winter wheat that are adaptive to specific physical and climatic conditions ecotopes regards forest-steppe and Polissia ecotypes by ecological and biological characteristics. We also determined their influence on formation of the diversity and productivity of agricultural ecosystems. It was established that mosaic planting pattern of winter wheat allows to get a high yield (up to 9 t/ha and of strong and superstrong wheat (Ariivka, L 4696/96, KC-5, KC-7, KC-14, KC-22, Yuvivata 60, etc. in comparison to monocultivar technology. Some genotypes, namely Yuvivata 60, Ariiivka KC-22, KC-7 have moderate and high resistance towards complex diseases. The mosaic planting pattern of cultivars is the important factor of increasing the diversity and strengthening the links in agricultural ecosystems. Based on the long-term ecological research of genetic forms of winter soft wheat in different ecotopes and comparing them by major agronomic features with cultivar-standards we selected some promising cultivars and lines. We suggested the semi dwarf, medium-grown productive, and high adaptive genotypes of wheat soft winter, like Prydesnianska, Ariiivka, Nosshpa 100, КС-5, КС-7, КС-14, КС-21, КС-22, Yuvivata 60, Zoriana Nosivska, КС-16, КС-17, Л9646/96.

  3. Identification of novel powdery mildew resistance sources in wheat

    Science.gov (United States)

    Powdery mildew is a globally dominating disease of wheat with a high occurrence frequency, and genetic resistance plays an important role in managing this devastating disease. The objectives of this study were to evaluate leaf rust resistance and the underlying genes of breeding lines in the USA, a...

  4. 小麦-簇毛麦端体附加系中6VS的细胞遗传学行为及其抗性遗传研究%Study on the Resistance Genetics and Cytogenetic Behaviour of 6VS in Wheat-D.Villosum Telosomic Addition Line

    Institute of Scientific and Technical Information of China (English)

    陈静; 邓光兵; 余懋群; 任正隆

    2001-01-01

    Wheat-D.Villosum 6VS telosomic addition line“AD134” possesses powdery mildew resistance that is controlled by a gene on 6VS and expressed under different wheat background. The added 6VS univalent suppresses wheat homologous chromosome pairing, leading to the increase of wheat univalent, which is also relative to the interaction between wheat genetic backgrounds. Although various abnormal chromosomal meiotic behaviour is observed, chromosome break happens with lower frequency, showing that hybridization progenies should be enlarged for the selection and development of translocation induced by telosomic addition line. AD134 (2n=42+2t) is unstable on cytology. In heterozygous plants, the transmission frequency of gametes with 6VS decreases clearly, but is higher through female gametes than through male gametes (the mean of 23.8% and 7.4%, respectively), also than that of 6V through female gametes. Possible reasons for these results are discussed in the paper.%小麦-簇毛麦6VS端体附加系AD134抗白粉病特性受6VS上基因的控制,在不同小麦背景下都能充分表达。单体附加的6VS抑制小麦染色体正常配对,造成单价体数量增加,但其影响程度还与小麦遗传背景的互作有关。观察到多种减数分裂异常现象,但染色体断裂的频率较低,表明使用端体附加系选育易位系应增大杂交后代的群体。AD134细胞学稳定性较差。在杂合状态下,6VS通过雌、雄配子的传递率均显著下降,但其通过雌配子的传递率(平均23.8%)仍显著高于通过雄配子的传递率(平均7.4%),也高于6V通过雌配子的传递率,文中对这一结果可能的原因进行了讨论。

  5. Vernalization and Photoperiod Genes in Iranian Wheat Cultivars

    Directory of Open Access Journals (Sweden)

    Seyyed Hamid Reza Ramazani

    2016-04-01

    Full Text Available Wheat (Triticum aestivum L. can avoid the deleterious effects of low temperatures by using environmental adaptation strategies such as vernalization requirement and photoperiod reaction. Awareness of the genetic factors influencing growth and flowering patterns is necessary for introducing new varieties to specific environments. We performed morphological and genetic studies of 104 lines and cultivars of Iranian wheat genotypes, including four durum genotypes, obtained from national wheat breeding programmes. We used sequence-tagged site (STS-PCR with specific primers to identify alleles affecting the sensitivity to vernalization and photoperiod response at the Vrn-A1, Vrn-B1, Vrn-D1, Ppd-A1, Ppd-B1, and Ppd-D1 loci. Some morphological traits such as percentage germination, growth habit, final leaf number (FLN, ear length, and days to ear emergence were also measured. Results showed that FLN and days to ear emergence are the best morphological traits to study wheat flowering time. Allelic variation showed that Vrn-D1 is more frequent than other genes in Iranian wheat genotypes, and so most Iranian genotypes are vernalization-insensitive. In addition, most genotypes were photoperiod-insensitive because of the semi-dominant mutation allele, Ppd-D1a. Based on allelic variation and morphological traits, we identified five classes of Iranian genotypes. The allelic variation study and morphology evaluation of this germplasm showed that the majority of Iranian cultivars and breeding lines are spring varieties and insensitive to day length.

  6. Genetic analysis of seedling resistance to crown rust in five diploid oat (Avena strigosa) accessions.

    Science.gov (United States)

    Cabral, A L; Park, R F

    2016-02-01

    Crown rust, caused by Puccinia coronata Corda f. sp. avenae Eriks., is a serious menace in oats, for which resistance is an effective means of control. Wild diploid oat accessions are a source of novel resistances that first need to be characterised prior to introgression into locally adapted oat cultivars. A genetic analysis of resistance to crown rust was carried out in three diverse diploid oat accessions (CIav6956, CIav9020, PI292226) and two cultivars (Saia and Glabrota) of A. strigosa. A single major gene conditioning resistance to Australian crown rust pathotype (Pt) 0000-2 was identified in each of the three accessions. Allelism tests suggested that these genes are either the same, allelic, or tightly linked with less than 1 % recombination. Similarly, a single gene was identified in Glabrota, and possibly two genes in Saia; both cultivars previously reported to carry two and three crown rust resistance genes, respectively. The identified seedling resistance genes could be deployed in combination with other resistance gene(s) to enhance durability of resistance to crown rust in hexaploid oat. Current diploid and hexaploid linkage maps and molecular anchor markers (simple sequence repeat [SSR] and diversity array technology [DArT] markers) should facilitate their mapping and introgression into hexaploid oat.

  7. Genetics and Mapping of Seedling Resistance to Ug99 Stem Rust in the Winter Wheat Cultivar Triumph 64 and Differentiation of SrTmp, SrCad, and Sr42

    Science.gov (United States)

    Stem rust, caused by the fungus Puccinia graminis f. sp. tritici Eriks. & E. Henn. (Pgt), is an important disease of wheat that can be controlled by deploying effective stem rust resistance (Sr) genes. The emergence of virulent Pgt races in Africa, namely Ug99 and its variants, has stimulated the se...

  8. Genetic loci conditioning adult plant resistance to the Ug99 race group and seedling resistance to races TRTTF and TTTTF of the stem rust pathogen in wheat landrace CItr 15026

    Science.gov (United States)

    Wheat landrace CItr 15026 previously showed adult plant resistance (APR) to the Ug99 stem rust race group in Kenya and seedling resistance to Puccinia graminis f. sp tritici (Pgt) races QFCSC, TTTTF, and TRTTF. CItr 15026 was crossed to susceptible accessions LMPG-6 and Red Bobs, and 180 DH lines an...

  9. Multidisciplinary approach in estimating genetic diversity of Ethiopian tetraploid wheat (Triticum turgidum L.) landraces = Multidisciplinaire benadering in het schatten van de genetische diversiteit van Ethiopische tetraploïde landrassen van tarwe (Triticum turgidum L.)

    NARCIS (Netherlands)

    Tesfaye Messele,

    2001-01-01

    This thesis presents a diversity analysis for 26 tetraploid wheat landraces from the central region of Ethiopia and four cultivars using five markers: morphological traits, chromosome portraits, microsatellites, AFLP and storage proteins.The aim of the study is: