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

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

In durum wheat, quality differences between culti- vars are strongly dependent upon their allelic composi- tion for endosperm storage proteins, gliadins and glute- nins (Carrillo et al., 1990, 1991; Kaan et al., 1993; Turchetta et al., 1995; Porceddu et al., 1998). Genetic studies have revealed that these proteins (prolamins) are encoded at several, complex and highly polymorphic loci. Gliadins are controlled by six Gli loci (Gli-1 and Gli-2) mapped on the short arms of the group 1 and 6 chromosomes, respectively (Wrigley and Shepherd, 1973; Payne et al., 1982). Glutenin subunits are classi- fied as high-molecular-weight (HMW) and low-mole- cular-weight (LMW) subunits on the basis of their mobility in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The LMW glutenin subunits are subdivided into B, C and D (Jackson et al., 1983), with the B subunits playing a major role in glu- ten quality (Pogna et al., 1990; Ruiz and Carrillo, 1995; Turchetta et al., 1995). HMW subunits are encoded at the Glu-1 loci on the long arm of the group 1 chromo- somes (Payne et al., 1980). B-LMW glutenin subunits are inherited as groups (designated LMW-) controlled at Glu-A3, Glu-B3 and Glu-B2 (Singh and Shepherd, 1988; Ruiz and Carrillo, 1993). Glu-A3 and Glu-B3 are tightly linked to Gli-A1 and Gli-B1, respectively (Singh and Shepherd, 1988). The natural variation found at all these prolamin loci is very important to improve durum wheat quality. However, the narrow genetic background of modern wheat cultivars may lead to a loss of the exploitable diversity (genetic erosion) and a decrease in the efficiency of breeding. In this context, the diversity of old varieties and forms preserved in gene banks represents an important source of genetic variability and consequently, of valuable traits for wheat improvement. In fact, landrace varieties have proven especially useful to supply new alleles at the protein loci involved in glu- ten strength (Carrillo et al., 1991; Porceddu et al., 1998; Raciti et al., 2003). On the other hand, prolamins are valuable molecular markers for genetic analysis and for the quantification of the genetic diversity present in wheat collections (Kudryavtsev et al., 1996; Aguiriano et al., 2006; Moragues et al., 2006).
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Genetic redundancy among durum wheat accessions as assessed with SSRs and endosperm proteins

Genetic redundancy among durum wheat accessions as assessed with SSRs and endosperm proteins

Reducing duplication in ex-situ collections is complicated and requires good quality genetic markers. This study was conducted to assess the value of endosperm proteins and SSRs for validation of potential duplicates and monitoring intra-accession variability. Fifty durum wheat (Triticum turgidum ssp. durum) accessions grouped in 23 potential duplicates, and previously characterised for 30 agro-morphological traits, were analysed for gliadin and high molecular weight glutenin (HMWG) subunit alleles, total protein, and 24 SSRs, covering a wide genome area. Similarity and dissimilarity matrices were generated based on protein and SSRs alleles. For heterogeneous accessions at gliadins the percent pattern homology (PH) between gliadin patterns and the Nei’s coefficient of genetic identity (I) were computed. Eighteen duplicates identical for proteins showed none or less than 3 unshared SSRs alleles. For heterogeneous accessions PH and I values lower than 80 identified clearly off-types with more than 3 SSRs unshared. Only those biotypes differing in no more than one protein-coding locus were confirmed with SSRs. A good concordance among proteins, morphological traits, and SSR were detected. However, the discrepancy in similarity detected in some cases showed that it is advisable to evaluate redundancy through distinct approaches. The analysis in proteins together with SSRs data are very useful to identify duplicates, biotypes, close related genotypes, and contaminations.
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Grain yield and resource use efficiency of bread wheat, barley and durum wheat under Mediterranean environments

Grain yield and resource use efficiency of bread wheat, barley and durum wheat under Mediterranean environments

canopy structure that allowed intercepting more or less radiation at the critical period for grain number determination (during stem elongation, Fisher, 1985; Slafer and Savin, 2006). Ferrante et al., (2009) using the same cultivars of durum wheat and barley, reported that water and nitrogen availabilities increase the number of grains per unit land area in durum wheat and barley affecting different traits: (i) due to increases in grains per spike in wheat mainly in the distal positions of the spikelets (Miralles and Slafer 1995; Acreche and Slafer 2006) as a consequence of a diminished rate of floret abortion; (ii) associated with changes in tillering capacity in barley, finally producing changes in the number of spikes per m 2 (Prystupa et al. 2003). Photosynthetically active radiation intercepted by the crop canopy during stem elongation and the temperature affecting growth and developmental rates during that phase generate changes in photothermal quotient which ultimately determines the number of grains per m 2 (Fischer 1985; Savin and Slafer 1991; Arisnabarreta and Miralles 2008). Another original contribution of the work conducted for this
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Genetic diversity and association mapping for agromorphological and grain quality traits of a structured collection of Spanish durum wheat

Genetic diversity and association mapping for agromorphological and grain quality traits of a structured collection of Spanish durum wheat

Discovery of new markers associated with key traits in landrace collections has important implications for durum wheat breeding, particularly after validation of significant markers associated with complex traits of economic importance. Genomics approaches enable the identification and selection of chromosome regions harbouring genes/QTLs (Quantitative Trait Loci) controlling agronomic traits in crops [4]. Among such approaches, association mapping is increasingly being adopted as a complementary method to traditional bi-parental linkage mapping to identify genotype–phenotype associations in wheat e.g. [5–8]. The under- lying principle of this approach is that linkage disequilibrium (LD) tends to be maintained over many generations between loci that are genetically linked to one another. High LD is expected to be observed between loci in tight linkage, as recombination events since the muta- tion should have eliminated LD between loci that are not in close distance [9]. The two major advantages of association mapping over standard genetic mapping based on populations of bi- parental crosses are, firstly, that a much larger and more representative gene pool can be sur- veyed, and, secondly, provides broader genomic region/allelic coverage without the need to develop bi-parental mapping populations. Another advantage is the much finer mapping reso- lution, resulting in small confidence intervals of the detected loci compared to classical map- ping, where the identified loci need to become fine-mapped [10]. It is important, however, separate the LD due to physical linkage from the LD due to population structure which can be caused by selection, genetic drift and species-dependent characters such as the mating system [11]. The choice of appropriate germplasm to maximize the number of historical recombina- tion and mutation events (and thus reduce LD) within and around the gene of interest is criti- cal for the success of association analysis. One of the methods to obtain most of the
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Improving durum wheat (Triticum turgidum L  var durum) grain yellow pigment content through plant breeding = Mejora del contenido de pigmentos amarillos del grano de trigo candeal (Triticum turgidum L  var durum) a través de fitomejoramiento

Improving durum wheat (Triticum turgidum L var durum) grain yellow pigment content through plant breeding = Mejora del contenido de pigmentos amarillos del grano de trigo candeal (Triticum turgidum L var durum) a través de fitomejoramiento

trait; for example, work is currently being car- ried out by the PUC and INIA-Quilamapu to improve the grain quality of durum wheat. This project consists of characterizing the semolina yellowness of a durum wheat base population of 124 genotypes mainly from the CIMMYT and the INIA breeding programs. This work has also focused on the genotypic characteriza- tion of the PSY1A and PSY1B loci, which are appropriate candidate genes associated with GYPC based on the existing literature. One objective of the genotypic characterization is to identify the desired haplotype for its potential introduction into the national durum wheat breeding programs. This includes identifying individuals that contain the PSY1Ao and PSY1Bb alleles because these alleles were associated with high GYPC values in previous studies. Subsequently, these individuals will be used as donor parents, and the alleles conferring high GYPC will be introgressed into the Chilean durum wheat cultivars using backcrossing and marker-assisted selection to efficiently acceler- ate the improvement of semolina yellowness of those materials. Finally, other candidate genes or markers related to GYPC could be studied in the future, and their association with endo- sperm yellowness could be sought in the base population to obtain better estimates of the phenotypic values already characterized and to improve the semolina yellowness predictions for plant material not yet evaluated.
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Calidad harino-panadera en trigo blando (T. aestivum L.) : influencia de las prolaminas y microsatélites relacionados

Calidad harino-panadera en trigo blando (T. aestivum L.) : influencia de las prolaminas y microsatélites relacionados

location within the chromosome has not been established. Ruiz and Carrillo, 1993 found recombination within the Glu-B3 locus, designating the new locus as Glu-B4, later Liu and Shepherd (1995) detected a B-type LMW-GS in the durum wheat cultivar Edmore, encoded by a locus located about 20.9 cM from Glu-B3. It was suggested that this locus could be the same as the Glu-B2 locus previously described by Jackson et al. (1985) encoding a D-type subunit. LMW-GS genes are linked to genes (Gli-1loci) coding for γ and ω gliadins. Due to the linkage between Gli- 1 and Glu- 3 loci, Cornish and Lukow (1996), proposed to identify the Glu-3 allele through analysis of Gli-1 encoded omega- gliadins using SDS-PAGE. Chromosomal localization of genes encoding HMW, LMW- GS and gliadins was resumed in Figure 1.6.
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Extracción y caracterización de lignina de paja de trigo (triticum durum) para mejorar las propiedades funcionales de películas de almidón

Extracción y caracterización de lignina de paja de trigo (triticum durum) para mejorar las propiedades funcionales de películas de almidón

x Finally, in part III films from durum wheat starch were prepared by casting method, and the effect of addition of different concentrations of alcohol-soluble lignin was evaluated. The mechanical properties, thermal degradation (TGA), water solubility, color parameters (L, a y b), and antioxidant activity of the resulting films were evaluated, and the starch-lignin films were also characterized by scanning electron microscopy (SEM) and infrared spectroscopy (ATR- IR). The surface of the films obtained was homogeneous in all treatments, agglomerations or undissolved particles of lignin were not observed in the starch matrix at microscopic level. The addition of the alcohol-soluble lignin decreased the lightness of the films. High concentrations of alcohol-soluble lignin gave reddish coloring at the films. The incorporation of lignin delay thermal degradation of the starch-lignin films, especially at high concentrations, these films were degraded totally at temperatures near 900°C. Infrared spectra of the films exhibited signals of each specific component starch and lignin, vibration bands of glycosidic bonds of starch (1200-800 cm -1 ) and vibration of the aromatic rings of lignin (1590 and 1420 cm -1 ). Furthermore
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Insectos asociados a alimentos vegetales deteriorables en tiendas de autoservicio, en Tabasco, México

Insectos asociados a alimentos vegetales deteriorables en tiendas de autoservicio, en Tabasco, México

El objetivo de este estudio fue determinar las especies de insectos que se asocian a productos alimenticios de- teriorables de origen vegetal, para consumo humano, exhibidos en anaquel en tiendas de autoservicio del es- tado de Tabasco, México. Se realizaron muestreos en 12 tiendas de autoservicio con temperatura no controla- da ubicadas en seis localidades de cinco municipios del estado. Se obtuvieron 58 muestras de productos de 14 especies vegetales que presentaron insectos, de las cuales se separaron 3529 ejemplares que correspondieron a 24 especies de los siguientes órdenes: Coleoptera (15), Hymenoptera (4), Lepidoptera (2), Blattodea (1), Psocoptera (1) y Hemiptera (1). Los mayores porcentajes de especímenes fueron de Zabrotes subfasciatus (30.5 %) y Sitophilus zeamais (28.7 %). Las especies que se encontraron en diversos productos fueron Rhizo- pertha dominica, Tribollium castaneum y Cadra cautella. Los productos con mayor número de especies de insectos asociados fueron la pasta para sopa (Triticum durum), el chile seco (Capsicum annuum) y el maíz (Zea mays). Las especies que se encontraron en los cinco municipios considerados fueron S. zeamais, Oryzaephilus surinamensis, T. castaneum y C. cautella. Las especies que se registran por primera vez para Tabasco son Lasioderma serricorne, Araecerus fasciculatus, Conotelus stenoides, Ectopsocus richardsi y Ly- ctocoris campestris.
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Region level yield and area price elasticities for Chilean wheat incorporating climate variables

Region level yield and area price elasticities for Chilean wheat incorporating climate variables

The inclusion of climate variables reduces the level of statistical significance for prices. The values of the price-yield elasticity and their sta- tistical significance decrease when the climate variables are included. This result shows that it is possible to overestimate the price-yield elas- ticity if the climate variables are excluded. It is possible that this result may be applied to the other regions under study. Future research must consider this factor carefully for estima- tions of the sensibility of sowed surface and yield against wheat price in Chile. A possible source of this impact is found in the nature of the prices in the model. As annual averages, prices are imperfect reflections of the real in- centives of the producers, in addition, there is a time overlap between climate variables and prices, therefore, there is a possibility that the average price has already included the effects of the climate variables. Further research is re- quired to determine more precise price mea- sures and to improve the measurement of the factors which are incentives for higher yields for the producers.
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Efecto de la resistencia y altura de planta del trigo en la incidencia de Septoria tritici y su expresión en el rendimiento

Efecto de la resistencia y altura de planta del trigo en la incidencia de Septoria tritici y su expresión en el rendimiento

Mycosphaerella graminicola (anamorph Septoria tritici) is the causal agent of wheat leaf blotch, disease present in the high and rainy areas. In México it has been reported in rainfed areas of the Mexican highlands (States of Mexico, Jalisco and Michoacan). To determine the importance, in the field, of plant height on the disease severity and incidence, and the efect of separation between plants (plots) to foster its development, six tall and six short lines were assessed in plots with and without competence during the spring-summer cycles of 2005 and 2006 in Juchitepec, State of México and Nanacamilpa, Tlaxcala. A completed ramdomized blocks experimental design with three replications was used, with an arrangement of split plot treatments. The leaf blotch afected more the short lines than tall ones. Plots with competence showed greater damage, mainly in short lines, thus the susceptibility is influenced by plant height.
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Male sterility induced by the chemical hybridizing agent clofencet on wheat, Triticum aestivum and T  turgidum var  durum

Male sterility induced by the chemical hybridizing agent clofencet on wheat, Triticum aestivum and T turgidum var durum

Commercial wheat hybrids have been produced using chemical hybridizing agents (CHA), which are growth regulators interfering selec- tively with the development of pollen or natural systems of male fertility(McRae, 1995; Duvick, 1999). In 1997, the Environmental Protection Agency (EPA) of the USA registered clofencet (Genesis) as an androsterility agent for wheat. This and other CHAs (e.g., Sogital SC2053) are used for wheat hybrid production. With the development of CHA technology, a notable decrease in the investigation of CMS as a sys- tem of hybrid production has been observed. Rajaram (1999) says that a system of cytoplas- mic sterility based on sterility derived from T. timopheevii has allowed partial success in the creation of wheat hybrids.
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Wheat bran valorization by supercritical fluid extraction: characterization, formulation and application of wheat bran oil

Wheat bran valorization by supercritical fluid extraction: characterization, formulation and application of wheat bran oil

Wheat bran oil has been reported to have an important content of bioactive compounds such as tocopherols, alkylresorcinols and other phenolic compounds; however, its poor solubility in water systems restricts its applications in the food industry. This chapter is focused on the formulation of oil-in-water (O/W) nanoemulsions of wheat bran oil in order to improve the bioaccessibility of its active compounds. The influence of oil concentration, surfactant type and concentration, and emulsification method, on the droplet size and stability of the nanoemulsions was investigated. Response surface methodology was used to optimize the conditions for preparing stable nanoemulsions with the minimum droplet size. The optimal nanoemulsion was obtained when 1% of wheat bran oil and 7.3% of a surfactant mixture of Span 80 (37.4%) and Tween 80 (62.6%) were emulsified in water by high intensity ultrasonication for 50 s after pre-emulsification with a high speed blender during 5 min. The optimal nanoemulsion showed good stability along time which make it suitable for use in food applications.
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Economics of Wheat in Egypt

Economics of Wheat in Egypt

Coelli and Battese (1996) applied the stochastic frontier production function model [Cobb-Douglas form and the specification of Battese and Coelli (1995)] on the three villages of Aurepalle, Kanzara and Shirapur, which were selected by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) for the in- depth study of the farming operations involved because they were considered broadly representative of the semi-arid tropics of India. The numbers of farmers involved in survey at the three villages are 34, 33 and 35 for Aurepalle, Kanzara and Shirapur, respectively. The predominant crops in the three villages are castor oil plant, sorghum and paddy in Aurepalle; cotton, pigeon pea and sorghum in Kanzara; and sorghum, chickpea, wheat and vegetables in Shirapur. The output was the total value of output from the crops which were grown, while the inputs were land, labor, bullock labor, cost of other inputs, age of farmer, and schooling of farmer. The results indicated that the efficiencies differ substantially within each village. They ranged from quite small values of less than 0.1 to values in excess of 0.9. The mean efficiencies of the farmers in the three villages did not appear to differ substantially. They were 0.747 for Aurepalle, 0.738 for Kanzara and 0.711 for Shirapur.
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