Search

Crop rotation in agriculture can lead to increased crop productivity in the rotation and improved soil fertility as a result of residue incorporation. Unfortunately, residue incorporation is not a common practice in crop production systems under the Mediterranean regime, largely due to the lack of information on the effect of the follow-up crops. Therefore, this study was conducted with six biannual rotations (bread wheat–canola, bread wheat–bean, durum wheat–canola, durum wheat–bean, corn–canola and corn–bean) using four residue incorporation levels (0, 50, 100 and 200%) in an Andisol in south central Chile. Grain yield and residue production were evaluated in the canola and bean crops 5 years after initiating crop rotation. The previous crop affected canola grain yield and residue production, which were both higher after corn. Meanwhile, the residue incorporation level had a slight effect on residue production after bread wheat. Only bean grain yield was affected by the previous crop, which was higher after the durum wheat and corn crops. The residue incorporation has marginally affected residue production after bread wheat. Finally, residue incorporation at different levels under the conditions of the present experiment had a minimal effect on bean and canola residue production following the bread wheat crop. The best crop rotation for canola grain yield was corn–canola, which produced 0.54 Mg/ha (18.3%) higher yield than the average of the other two rotations. The best crop rotation for achieving higher bean grain yield was corn–bean, which yielded 0.52 Mg/ha (12.3%) higher than the average of the other two rotations.

Under intense breeding, modern wheats, such as durum (Triticum turgidum L. ssp. durum), are believed to have lost nutritional quality and protein content while increasing productivity. Emmer (Triticum turgidum ssp. dicoccum Thell) and wild emmer (Triticum turgidum ssp. dicoccoides) are alternative resources for breeding programs by offering favorable alleles to be introgressed into modern materials and thus broadening their genetic diversity. Studies conducted so far have shown that durum wheat has better performance in agronomical qualities and protein quality than T. dicoccum and T. dicoccoides. However, its grain protein content (GPC) and Fe/Zn concentrations are lower. Several QTL for yield, GPC, and nutrient content in T. dicoccoides have been described, demonstrating its potential for transfer of important genes such as Gpc-B1 into modern cultivars. The Gpc-B1 gene increased the grain protein and Fe and Zn contents, but the agronomic performance of some of the modern recipients was reduced. Understanding the correlations and relationships between agronomic, chemical, and nutritional qualities would simplify selection through breeding for a single trait. Combining this knowledge with conventional breeding, MAS, and new breeding techniques would facilitate the QTL studies in these ancestral wheats and the development of new durum cultivars while retaining the agronomic qualities. In this review, we compare some grain parameters of T. durum, T. dicoccum, and T. dicoccoides wheats, including Fe and Zn content and their genetic aspects, and the existing information is analyzed and integrated for the future prospects of durum wheat improvement.

Background and Aims. The study aims to explore the impact of advancements in wheat genetics on root structure and rhizosphere biology, which are still not fully understood. Specifically, we investigated various factors including the exudation of carboxylates, colonization by arbuscular mycorrhizal fungi, microbial activity, and root architecture in winter wheat varieties that have been released between 1965 and 2020. Methods. To conduct our study, we sowed fourteen different winter wheat varieties with four replicates on acidic Andisol at field conditions. Complete root systems and soil samples were extracted using a tractor-mounted hydraulic sampler tube of 3.5 cm diameter, which reached a depth of 60 cm. Results. In this sense, succinate showed a significant increase by 21%. Mycorrhizal colonization was inversely proportional to P concentrations and all varieties showed higher microbial activity at anthesis. The longest roots were found in varieties released after the year 2000, but no significant differences were found in other root architecture parameters. There was no clear pattern observed in root architecture or biological activity as a function of the year of release. Plant genetics moderated root architecture, carboxylate exudation, microbial activity, and mycorrhizal colonization, all of which are affected by high P concentrations. Conclusions. This study investigated plant-microorganism interactions, often overlooked due to root system analysis challenges. Older wheat varieties showed higher carboxylate exudation. We identified wheat varieties with potential for improved root systems and crop efficiency.

This study aims to evaluate the medium-term effect of two biannual rotations and four residue rate incorporation on durum wheat production and its nutritional composition and nutrient extraction. The effects of two biannual rotations of canola (Brassica napus L.) durum wheat (Triticum turgidum L.) and bean (Phaseolus vulgaris L.)-durum wheat and four incorporation rates (0%, 50%, 100%, and 200%) of residues of each preceding crop were evaluated after four seasons on durum wheat production and on its nutritional composition and nutrient extraction, in a volcanic soil in south-central Chile. Results indicated that the highest grain yield and residue production of durum wheat was obtained after bean (7.40 and 7.92 Mg ha−1, respectively). In the grain were obtained lower N and P concentrations after bean, and higher K, Ca, and Mg concentrations in the residue. The extraction of most durum wheat grain and residue nutrients was higher after bean. Nutrient distribution in the durum wheat plant concentrated in the grain was 79.9 to 80.7% N, 91.3 to 92.1% P, 27.1 to 27.4% K, 16.8 to 18.8% Ca, 68.3 to 70.4% Mg, and 56.3 to 57.4% S. In the residue, nutrient distribution was 19.3 to 20.4% N, 7.9 to 8.7% P, 72.6 to 72.9% K, 81.2 to 83.2%, Ca, 29.6 to 31.7% Mg, and 42.6 to 43.7% S. The highest grain and residue production of durum wheat was obtained after bean crop and also the extraction of most nutrients.

RESUMEN 'Chevignon' es una variedad de trigo de invierno, creada por la empresa ASUR Plant Breeding de Francia e introducida a Chile por el Programa de Mejoramiento de Trigo de INIA Carillanca. Es un trigo de altura mediana, ciclo intermedio, resistente a polvillo estriado (Puccinia striiformis West. f. sp. tritici Erikss) y oidio (Blumeria graminis D.C. f. sp. tritici Marchal), moderadamente resistente a polvillo de la hoja (Puccinia triticina f. sp. tritici Erikss y Henn) y muy buena tolerancia a septoria (Mycosphaerella graminicola (Fuckel) Sand). Es una variedad de alto rendimiento, con buenas características de calidad para panificación directa. Es de hábito de desarrollo invernal, de crecimiento rastrero al estado de plántula y de buena macolla terminal. Sus hojas son de color verde pálido, con hoja bandera semi curvada. La espiga es de color blanco, semi erecta, forma paralela, densidad alta y sin barbas. El grano es de forma redondeada, tamaño mediano, color rojo, pudiendo presentar ocasionalmente ciertos cambios de pigmentación en el endosperma. La altura de planta adulta varía entre 105 y 110 cm, con un promedio de 105 cm, y con una moderada resistencia a la tendedura. Su período vegetativo desde siembra a espigadura es más tardío que 'Maxwell' en alrededor de cinco días y más precoz que 'Bicentenario INIA' y 'Kiron INIA' en aproximadamente 8 a 10 días, respectivamente.

Crop rotations and residue management contribute to the sustainability of the soil and environment and reduction of fertiliser use. However, appropriate crop and residue level combinations have yet...

Water deficit is the most limiting factor for wheat production, so wheat-breeding programmes are currently focused on developing high-performance genotypes under such conditions. Carbon isotope dis...

Conservation agriculture using crop rotations and residue management is increasingly accepted in conventional agricultural systems. However, the effects on crop productivity and soil properties of different rotations, levels of use, and residue management have yet to be fully understood. Our study considered the effect of three previous crops (bread wheat, durum wheat, and corn) and four levels of residue incorporation (0%, 50%, 100%, and 200%) in a split plot design with four replicates on canola production parameters and soil chemical properties at the end of this crop. Production parameters and soil chemical properties were mostly affected by the previous crop and less by the residue incorporation rates under the conditions of this experiment; however, neither of these factors affected grain yield (ranging from 4.0 to 4.8 Mg ha−1). Canola residue production was higher (9.7%) after the corn crop, regardless of the residue incorporation rate, but the harvest index was lower after this crop. Most of the soil chemical properties were also affected, revealing increased organic matter and exchangeable K when the previous crop was corn and decreased concentrations of the cations with basic reaction when the previous crop was durum wheat.

Residue incorporation in agriculture associated with crop rotation, benefits the environment, soil fertility, and crop production. However, the benefits of conservation agriculture practices in soi...

Grain protein composition is important in wheat quality and may influence the amino acidic sequence of bioactive peptides obtained from this feedstock. However, the genetic basis modulating the amino acid profile in durum wheat is not well-understood. Therefore, strong and weak gluten strength durum wheat genotypes were evaluated for their amino acid composition along grain filling. Strong gluten strength lines showed higher expression levels of low-molecular-weight glutenin-related genes between 21 and 35 days post-anthesis (DPA) and exhibited up to 43.5% more alanine than the weak lines at 42 DPA, which was supported by the higher expression levels of putative alanine amino transferase genes in strong genotypes. Therefore, with the involvement of chemistry and molecular biology, the results present here may influence the science of wheat.

The incorporation of previous crop residues in agricultural management benefits soil fertility, crop production, and environment. However, there is no enough information about maximum residue appli...

Conservation agriculture using crop rotation benefits the environment, soil fertility, and crop production. A biannual rotation experiment during a period of 2 years was conducted in volcanic soil in south-central Chile in a production system under conservation agriculture. The experiment considered two previous crops, canola (Brassica napus L.) and bean (Phaseolus vulgaris L.), and four levels of residue incorporation (0%, 50%, 100%, and 200% of generated residue). Grain yield (0.41 Mg ha−1), grain sedimentation value (5.5%), grain K (0.031%) and Ca (0.006%) concentrations, and residue K concentration (0.159%) were higher when the previous crop was bean. The Ca concentration (0.037%) in wheat residue increased after the canola crop. The different applied residue levels of the previous crop had no effect on any of the evaluated parameters in wheat. There was a very consistent negative correlation between the grain S concentration and the residue P (− 0.55), K (− 0.55), Mg (− 0.61), and S (− 0.63) concentrations in wheat when it was cultivated after bean. A larger number of study cycles are required to obtain more consistent results about the effect of the different residue levels on these two biannual rotations.

Cadmium (Cd) is a metalloid present in agricultural soils and harmful for human health. A large part of the Cd entering into the soil can be fixed, while another portion can contribute to increasing availability indices of this element (residual effect). The present study evaluated Cd residual effect and Cd fixation derived from anthropic applications at four locations in Chile during two seasons. Three crop rotations were used, which included white lupine (Lupinus albus L.), narrow-leafed lupine (Lupinus angustifolius L.), and durum wheat (Triticum turgidum L. var. durum) as the first crop and durum wheat as the second crop. Results indicated that the anthropic application of Cd to the soil, in the three crop rotations and at the four locations under study, exhibited a low residual effect in the next season and null effect two seasons after its application. Among the three preceding crops of each rotation, the highest effect on Cd residuality in both seasons was achieved using both lupines, especially narrow-leafed lupine. The Cd fixation coefficient in the upper 0.2 m of soil in the three crop rotations and at the four locations was very high, and it was greater than 99.9% in all cases.

Water deficit represents an important challenge for wheat production in many regions of the world. Accumulation and remobilization of water-soluble carbohydrates (WSCs) in stems are part of the physiological responses regulated by plants to cope with water stress and, in turn, determine grain yield (GY). The genetic mechanisms underlying the variation in WSC are only partially understood. In this study, we aimed to identify Single Nucleotide Polymorphism (SNP) markers that account for variation in a suite of WSC and GY, evaluated in 225 cultivars and advanced lines of spring wheat. These genotypes were established in two sites in the Mediterranean region of Central Chile, under water-limited and full irrigation conditions, and assessed in two growing seasons, namely anthesis and maturity growth periods. A genome-wide association study (GWAS) was performed by using 3243 SNP markers. Genetic variance accounted for 5 to 52% of phenotypic variation of the assessed traits. A rapid linkage disequilibrium decay was observed across chromosomes (r2 ≤ 0.2 at 2.52 kbp). Marker-trait association tests identified 96 SNPs related to stem weight (SW), WSCs, and GY, among other traits, at the different sites, growing seasons, and growth periods. The percentage of SNPs that were part of the gene-coding regions was 34%. Most of these genes are involved in the defensive response to drought and biotic stress. A complimentary analysis detected significant effects of different haplotypes on WSC and SW, in anthesis and maturity. Our results evidence both genetic and environmental influence on WSC dynamics in spring wheat. At the same time, they provide a series of markers suitable for supporting assisted selection approaches and functional characterization of genes.

Refereed/Peer-reviewed It is well known that phosphorus (P) addition helps mitigate the adverse effects of water deficit stress on plants. However, the efficiency of spring wheat genotypes in the use of both components has not been addressed. The objective of this study was to evaluate the combined effect of P and water limiting conditions over phosphorus use efficiency (PUE) and water use efficiency (WUE) to categorize different spring wheat genotypes. Eight spring wheat genotypes were selected based on their yield tolerance index score (YTI) obtained from a previous screening of 384 wheat genotypes. They were evaluated for their ability to use P and water. Plants were grown under semi-controlled conditions on an Andisol with soil P-concentration of 3.4 mg P kg−1 (-P), which was enriched to 30 mg P kg−1 (+P). Irrigation was applied at two levels: well-watered (+W) and 30% +W (water-stressed, -W). Wheat was grown until the end of its phenological cycle. The P and water scarcity produced a delay in wheat development, especially in the first vegetative stages. Genotypic differences in growth, development, P accumulation, and yield were observed in response to P and water limiting conditions. The lowest performance in plant growth and grain yield was regarded when the P and water restrictions were applied. However, differences were observed in terms of PUE and WUE. In this sense, spring wheat genotypes were grouped into three and four classes for PUE and WUE, respectively. The most efficient genotype for all the conditions was “QUP2418”, which obtained the highest score in the consolidated PUE and WUE ranking. On the contrary, “FONTAGRO 92″ and “F6CL091337″ were the most inefficient genotypes. Strong correlations were observed between PUE components and WUE, enabling the future selection of co-adapted wheat genotypes efficient in the use of P and water.

RESUMEN Maxwell es un cultivar de trigo (Triticum aestivum L.) de invierno, introducido a Chile en el año 2004 por el Instituto de Investigaciones Agropecuarias (INIA) en colaboración con la Empresa Saaten Union Research de Francia, y liberado comercialmente el año 2012. Maxwell fue evaluado por el Programa de Mejoramiento de Trigo del INIA de Chile. Esta investigación se realizó con el fin de evaluar su comportamiento agronómico en el área nacional más importante de producción de trigo, bajo diferentes condiciones de suelo y clima. En base a los resultados obtenidos se pudo establecer que para el hábito de crecimiento, altura de la planta, precocidad, sanidad, rendimiento y calidad industrial, el cultivar Maxwell se destacó por sobre los testigos comerciales y mostró gran adaptabilidad para siembras tempranas, en zonas de inviernos largos y primaveras húmedas. La planta alcanza una altura promedio de 90 cm, siendo clasificado como un trigo enano a semienano. Su rendimiento promedio, en diferentes localidades y varios años de evaluación, fue 1,06 t ha-1, superior al testigo, siendo clasificado desde el punto de vista industrial como un trigo de calidad intermedia.

Phytoene synthase 1 ( Psy-1 ) is an essential synthesis gene influencing semolina yellowness while catalase ( Cat3-A ) is a catabolic enzyme that causes color loss. The main objective of this study was to evaluate the expression of Psy-A1 , Psy-B1 and Cat3-A as candidate genes for semolina yellowness, using a panel of 94 durum wheat genotypes differing in yellowness. Real Time-qPCR experiments of a subset of 12 genotypes showed greater expression of Psy-A1 , which specifically peaked at 35 days post-anthesis (DPA). At this time, Psy-A1 was 21-fold higher expressed in the high-yellowness relative to the low-yellowness genotypes. Psy-B1 and Cat3-A peaked at 21 DPA, suggesting different timing of expression of these genes during grain filling. The contribution of Psy-B1 was relatively higher in the genotypes showing low semolina yellowness than those with high semolina yellowness. Cat3-A did not exhibit clear differences in transcript accumulation throughout grain filling. We conclude that Psy-A1 has a major role in determining semolina yellowness, particularly in genotypes with high levels for this trait.

Phytoene synthase (Psy) is a key gene influencing semolina yellowness. Specific molecular markers have been developed to identify some of the known allelic variants of Psy1-A1 (Psy1-A1a, Psy1-A1l, Psy1-A1o) and Psy1-B1 (Psy1-B1a, Psy1-B1b) associated to semolina yellow color. This study was undertaken to assess the genetic variability existing for Psy1, and to evaluate the relationship between genotype and phenotype, in two contrasting durum wheat panels formed mostly by American breeding lines (BL panel), and a collection that included 155 Mediterranean landraces and 20 modern cultivars (M panel). The BL panel showed h 2 values over 0.93 for two indicators of yellowness [i.e. semolina yellow pigments absorbance, and b* values that were strongly correlated (r = 0.95, P

The absorption and partitioning of N is determined by its availability and demand during the various phenological stages of the crop. In two experiments conducted in rainfed areas of the Mediterranean climate region of central Chile, legume-wheat (Triticum aestivum L.) rotations were compared to oat (Avena sativa L.)-wheat systems (with and without applications of N fertilizer). The objective was to assess the contribution of legumes to the availability of soil N and N uptake by the wheat crop following grain legumes. N mineralization and uptake, N use efficiency (NUE), and N uptake efficiency (NUpE) by wheat were evaluated at different phenological stages in 2010. Synchronization existed between accumulated soil N mineralization and N uptake by the wheat. N uptake by wheat was higher in Experiment II (Andean foothill) than in Experiment I (interior dryland). Grain yields after legumes ranged 60-110% and 72-103% of yields in the fertilized cereal rotation (oat-wheat) in Experiments I and II, respectively. There was high correlation between soil N availability vs. grain yield (R² = 0.84 and 0.64) and N uptake vs. grain yield (R² = 0.55 and 0.64) for Experiments I and II, respectively. Rotations with lupine (Lupinus spp.) and field peas (Pisum sativum L.) showed high NUE and NUpE in Experiment I, and Experiment II in pea. The lowest NUE was after oats with N fertilizers. It is concluded that wheat cultivated in both agro-ecological areas after grain legumes or green manure was more efficient in N uptake and use than cereal, especially when the latter was fertilized.

Plant breeding based on grain yield (GY) is an expensive and time-consuming method, so new indirect estimation techniques to evaluate the performance of crops represent an alternative method to improve grain yield. The present study evaluated the ability of canopy reflectance spectroscopy at the range from 350 to 2500 nm to predict GY in a large panel (368 genotypes) of wheat (Triticum aestivum L.) through multivariate ridge regression models. Plants were treated under three water regimes in the Mediterranean conditions of central Chile: severe water stress (SWS, rain fed), mild water stress (MWS; one irrigation event around booting) and full irrigation (FI) with mean GYs of 1655, 4739, and 7967 kg∙ha−1, respectively. Models developed from reflectance data during anthesis and grain filling under all water regimes explained between 77% and 91% of the GY variability, with the highest values in SWS condition. When individual models were used to predict yield in the rest of the trials assessed, models fitted during anthesis under MWS performed best. Combined models using data from different water regimes and each phenological stage were used to predict grain yield, and the coefficients of determination (R2) increased to 89.9% and 92.0% for anthesis and grain filling, respectively. The model generated during anthesis in MWS was the best at predicting yields when it was applied to other conditions. Comparisons against conventional reflectance indices were made, showing lower predictive abilities. It was concluded that a Ridge Regression Model using a data set based on spectral reflectance at anthesis or grain filling represents an effective method to predict grain yield in genotypes under different water regimes.

Wheat yields in Chile have increased significantly during the last four decades as a consequence of plant improvement and better crop husbandry. Central Chile is characterised by high-yield Mediterranean conditions, where precipitation received by the crop in most years does not represent a major limitation to productivity. This study assesses the changes in agronomic and physiological traits of spring cultivars released in the country between 1920 and 2000. A total of 95 spring bread wheat accessions, representing 20 old and 75 modern cultivars (released before and after 1960, respectively) were tested in a humid Mediterranean-type climate, with irrigation. Modern genotypes exhibited higher grain yield, harvest index, number of grains per ear and sedimentation values and lower height, test weight, wet gluten content and hardness index. No differences were found for days to heading, and ear length, whereas kernel weight decreased with the Green Revolution. Principal component (PC) analysis using ten agronomic traits clearly separated modern from old cultivars. Grain yield, a trait not included in PC analysis, was highly correlated with the first PC ( r = 0.80, P

In crop breeding, the interest of predicting the performance of candidate cultivars in the field has increased due to recent advances in molecular breeding technologies. However, the complexity of the wheat genome presents some challenges for applying new technologies in molecular marker identification with next-generation sequencing. We applied genotyping-by-sequencing, a recently developed method to identify single-nucleotide polymorphisms, in the genomes of 384 wheat (Triticum aestivum) genotypes that were field tested under three different water regimes in Mediterranean climatic conditions: rain-fed only, mild water stress, and fully irrigated. We identified 102,324 single-nucleotide polymorphisms in these genotypes, and the phenotypic data were used to train and test genomic selection models intended to predict yield, thousand-kernel weight, number of kernels per spike, and heading date. Phenotypic data showed marked spatial variation. Therefore, different models were tested to correct the trends observed in the field. A mixed-model using moving-means as a covariate was found to best fit the data. When we applied the genomic selection models, the accuracy of predicted traits increased with spatial adjustment. Multiple genomic selection models were tested, and a Gaussian kernel model was determined to give the highest accuracy. The best predictions between environments were obtained when data from different years were used to train the model. Our results confirm that genotyping-by-sequencing is an effective tool to obtain genome-wide information for crops with complex genomes, that these data are efficient for predicting traits, and that correction of spatial variation is a crucial ingredient to increase prediction accuracy in genomic selection models.

Pasta color is considered an important quality trait, which is determined by intrinsic color characteristics of the semolina obtained from durum wheat (Triticum turgidum L. var. durum) grains. Eighteen genotypes of durum wheat were tested in thirteen environments under the Chilean Mediterranean conditions. In addition to grain yield (GY), three semolina color-associated traits were studied: the semolina yellow pigment absorbance (SYPA), the b* value and the brown index (BI). The main objective of this study is to decompose the phenotypic values of these traits using Chilean germplasm grown under local environmental conditions. Additionally, the thousand kernel weight (TKW) and the test weight (TW), were measured to study their relationships with these traits. The ANOVA combined over environments showed highly significant effects of genotypes (G), environments (E) and their interaction (G×E) on SYPA, b* value, BI and GY. Narrow sense heritabilities (h2) were 0.82, 0.82, 0.48 and 0.07 for SYPA, b* value, BI and GY, respectively. Comparisons between two water managements, irrigated and rainfed conditions, and between southern and northern production zones showed significant effects on GY and at least on two of the color-associated traits. Possible causes of these environmental effects are inferred and discussed. Most of the G×E component was of cross-over type, but the changes on the genotype rankings expected for SYPA and the b* values were not abrupt, which would facilitate the development of cultivars with stable yellow color potential. Much more abrupt changes on the genotype rankings would occur for BI and GY. The specific local adaptation pattern identified showing high GY, TW and semolina yellowness, plus the lack of correlation between semolina yellowness and GY or TW, and the high h2 of semolina yellowness, will enable to improve the potential color of pasta without causing detrimental effects on the production and the industrial quality in the future.

Agronomic practices, climatic variables, and soil conditions are key factors in crop productivity. Although the effects of soil chemical properties and water and agronomic crop management are known, there is little information about effective soil depth and its influence on crop productivity. Since most crop fertilization systems are based on the productive potential associated with climatic conditions and chemical properties of the first 20 cm of soil depth, the objective of this study was to determine the importance of effective depth in terms of increasing fertilization rates on durum wheat (Triticum turgidum L. var. durum) productivity. Two experiments were conducted in the 2006-2007 season in the Santa Rosa Experimental Station (71°54’ S, 36°31’ W, 220 m a.s.l.) of the Instituto de Investigaciones Agropecuarias (INIA) located in south central Chile. We used the hard wheat cvs. Llareta-INIA and Corcolén-INIA because both respond differently to soil physicochemical properties. Each cultivar was sown in sectors with different depths: 1) 0.45 m depth, silt loam on river material and 2) 1.0 m depth, loam on deep sediments. Fertilization was: 1) control without fertilization, 2) basal fertilization (BF) based on P, K, Ca, Mg, S, B, and Zn plus 90 kg N ha-1, and 3) BF plus 210 kg N ha-1. Grain yield, plant height, and number of stems m-2 were positively affected by increasing depth of soil profile. The increasing fertilization rate affected grain yield and plant height. Grain yield for cv. Corcolén-INIA had a greater response than cv. Llareta-INIA when soil depth was increased.

RESUMEN Pionero INIA es la primera variedad de trigo doble propósito liberado por el Programa Nacional de Trigo del INIA Carillanca. Es una variedad de invierno (Triticum aestivum L.) producto de la selección de germoplasma recibido de la Empresa Saaten Union Research de Francia. Mostró excelente adaptabilidad para siembras tempranas, en zonas de inviernos largos y primaveras húmedas. La altura promedio de planta adulta alcanza los 90 cm, siendo clasificado como una variedad de trigo enano a semi enano. El rendimiento promedio, en diferentes localidades y varios años de evaluación, fue significativamente superior al testigo Kumpa INIA, destacándose por su resistencia a enfermedades y tipo agronómico. Sus características de calidad molinera y de almidón permiten utilizarlo en la industria galletera, ganadera y acuícola.

Different physiological traits have been proposed as key traits associated with yield potential as well as performance under water stress. The aim of this paper is to examine the genotypic variability of leaf chlorophyll, stem water-soluble carbohydrate content and carbon isotope discrimination (Δ(13)C), and their relationship with grain yield (GY) and other agronomical traits, under contrasting water conditions in a Mediterranean environment. The study was performed on a large collection of 384 wheat genotypes grown under water stress (WS, rainfed), mild water stress (MWS, deficit irrigation), and full irrigation (FI). The average GY of two growing seasons was 2.4, 4.8, and 8.9 Mg ha(-1) under WS, MWS, and FI, respectively. Chlorophyll content at anthesis was positively correlated with GY (except under FI in 2011) and the agronomical components kernels per spike (KS) and thousand kernel weight (TKW). The WSC content at anthesis (WSCCa) was negatively correlated with spikes per square meter (SM2), but positively correlated with KS and TKW under WS and FI conditions. As a consequence, the relationships between WSCCa with GY were low or not significant. Therefore, selecting for high stem WSC would not necessary lead to genotypes of GY potential. The relationship between Δ(13)C and GY was positive under FI and MWS but negative under severe WS (in 2011), indicating higher water use under yield potential and MWS conditions.

El trigo (Triticum aestivum L.) es el cultivo mas importante en Chile en terminos de superficie sembrada y areas geograficas en las cuales se siembra, cubriendo una gran diversidad de condiciones climaticas. Este estudio evaluo los cambios de varias caracteristicas agronomicas de variedades de trigo de invierno liberadas en el pais entre 1920 y 2000. Un total de 117 genotipos de trigos de invierno, que representa 45 cultivares antiguos y 72 cultivares modernos, se evaluaron en un clima humedo de tipo mediterraneo, en condiciones de riego, en el ano 2003. Los cultivares antiguos corresponden a aquellos liberados antes del ano 1960 y los modernos a los liberados despues del ano 1960. Mediante un analisis de componentes principales (CP) usando 10 caracteristicas agronomicas, permitio separar claramente los cultivares modernos de los antiguos. Al comparar los cultivares modernos con los antiguos se determino que la altura de la planta se ha reducido un 25,6%, pero en otras caracteristicas se produjo un aumento, como el indice de cosecha (21,1%), numero de granos por espiga (42,6%), valor de sedimentacion (103%) y la dureza del grano (32,0%). La variacion en la altura de la planta se correlaciono negativamente con el indice de cosecha (r = -0,30, p < 0,001). El rendimiento de grano, una caracteristica no incluida en el analisis de PC, estuvo altamente correlacionado con el segundo PC (r = 0,81, p < 0,0001). Correlaciones significativas (p < 0,01) se encontraron entre el ano de la liberacion de los cultivares y las caracteristicas agronomicas: altura de planta (r = -0,82), indice de cosecha (r = 0,40), numero de granos por espiga (0,69), valor de sedimentacion (r = 0,64), y peso del grano (r = -0,46). Estas correlaciones fueron en su mayoria una consecuencia de ausencia o presencia de genes de enanismo en el germoplasma. Finalmente el avance en rendimiento, calculado a partir de datos de rendimiento de ensayos en los que se probaron entre 15 y 25 cultivares y lineas avanzadas de trigo de invierno evaluados casi todos los anos entre 1965 y hasta 2001, no mostro ningun aumento en el rendimiento entre 1965 y 1975, pero si un aumento de 246 kg ha-1 por ano entre 1976 y 1998, lo que representa un incremento anual de 2,6%.

The potential benefits of using a legumes have not been evaluated in the rainfed, cropping systems of central Chile where wheat (Triticum aestivum) is typically grown in rotation with oats (Avena sativa) using high rates of nitrogen (N) fertilizer. Two experiments were initiated to compare unfertilized legume-wheat cropping sequences to the current oat–wheat system without and with applications of N fertilizer (160 or 207 kg N ha−1). One experiment was located in the interior dryland of central Chile (average annual rainfall 650 mm), and the other in the Andean foothills (average annual rainfall 1200 mm). Treatments were established in different areas of the same two experimental sites in consecutive years (2008 and 2009) resulting in four separate trials evaluating legume effects on wheat yield (2009 or 2010). Estimates of N2 fixation determined using the 15N natural abundance technique indicated that around 21 kg shoot N was fixed for every tonne (t) of shoot dry matter accumulated by either narrow-leaf lupin (Lupinus angustifolius), field peas (Pisum sativum), yellow lupin (Lupinus luteus), or white lupin (Lupinus albus) grown for grain, and by vetch (Vicia atroporpurea) grown in association with oats for green manure. When the amounts of N2 fixed were adjusted to account for N in the nodulated roots, narrow-leaf lupin was calculated to have returned the lowest average net inputs of fixed N to the system following grain harvest (26 kg N ha−1) and field pea the highest (192 kg N ha−1). By comparison vetch in the green manure treatments where all above-ground biomass were incorporated into the soil returned 67 kg fixed N ha−1. Depending upon location and year, growing grain legumes increased the subsequent N uptake by wheat by up to 60 kg N ha−1 (average 35 kg N ha−1) and vetch + oats green manure up to 103 kg N ha−1 (average 50 kg N ha−1). Wheat yields after grain legumes ranged from 2.4 to 3.0 t ha−1 in the interior dryland and 5.4–6.4 t ha−1 in the Andean foothills which were respectively 72–110% (90% average) and 69–83% (75% average) of the yields achieved by N fertilized wheat. Wheat yields after the vetch + oats green manure were 1.8 and 7.9 t ha−1 representing 60% and 102% of the yield of N fertilized wheat. In the absence of N fertilizer or legumes wheat yields after oats were around half that of the N fertilized wheat. It was concluded that grain legumes or legume-based green manures provide opportunities to greatly reduce the reliance of wheat production upon N fertilizer.

11 paginas, 6 tablas, 2 figuras. The definitive version is available at www.blackwell-synergy.com

Millán-INIA is a variety of spring bread wheat (Triticum aestivum L.) originating from a cross carried out in the Wheat Plant Breeding Project of the Instituto de Investigaciones Agropecuarias (INIA), in the Centro Regional de Investigación Quilamapu in 1995. This is a spring wheat variety with an early to medium-early head emergence and upright growth habit in the seedling stage. The adult plant is low to medium height and varies between 75 and 90 cm, with a mean of 85 cm. The spike is white with long awns along its full length. The grain is large-sized, white, and vitreous. The weight of 1000 grains varies between 50 and 59 g. It was sown in mid-August at the Santa Rosa Experimental Station (36°31’ S; 71°54’ W), Chillán. Head emergence occurred 88 to 89 d after sowing, which is 2 to 3 d after Ciko-INIA. On average, Millán-INIA reached a yield similar to that of the var. Ciko-INIA. This line stands out for its good resistance to disease, high protein content (11.5% mean), high sedimentation value, and high W value.

La variedad de trigo candeal (Triticum turgidum var. durum L.) de primavera Lleuque-INIA proviene de un cruzamiento efectuado el ano 1993 por el Programa Nacional de Trigo del Instituto de Investigaciones Agropecuarias INIA en el Centro Regional de Investigacion La Platina, Santiago, Chile. Es un trigo con habito de crecimiento erecto al estado de plantula, la planta adulta es de altura mediana y varia entre 80 y 90 cm. La espiga es de tamano medio, compacta, de color blanco, presenta barbas largas de color blanquizco en toda su extension. El grano es de tamano grande, de forma alargada, color amarillo dorado y vitreo. Sembrado a mediados de agosto en el Campo Experimental Santa Rosa (36°31’ S; 71°54’ O), Chillan, la emision de espigas ocurre entre los 89 y 91 dias despues de la siembra, siendo entre 6 a 8 dias mas tardio que ‘Llareta-INIA’ y ‘Corcolen-INIA’. En La Platina ‘Lleuque-INIA’ tuvo un rendimiento medio 16,7% y 20,8% superior a la vars. Llareta-INIA y Corcolen-INIA, respectivamente; en la localidad de Chillan este rendimiento fue superior en 10,3% y 10,1%, respectivamente; por otro lado en Yungay, precordillera de Nuble, el rendimiento de ‘Lleuque-INIA’ supero a ‘Llareta-INIA’ en 13,07% y a la var. Corcolen-INIA en 16,97%. En la localidad de Human el rendimiento de la var. Lleuque-INIA tambien supero en 15,23% y 24,03% a las variedades testigo Llareta-INIA y Corcolen-INIA, respectivamente. La var. Lleuque-INIA es un trigo de buen peso del hectolitro, buen contenido de gluten humedo (%) y con valores medios de proteina que fluctuan entre 10,47% y 12,3%.

Durum wheat (Triticum turgidum L. var. durum) is an important crop for the world population and occupies a large cultivated area worldwide. New cultivars need constant improvement of their agronomic management, within which N fertilization is highlighted. Durum wheat is also important in Chile where genetic breeding and agronomic management have been developed to increase yield, industrial, and nutritional grain quality. The objective of this experiment was to determine the appropriate number of N applications during a crop cycle in a volcanic ash soil in South Central Chile. Nitrogen split applications were carried out on three durum wheat cultivars in a Melanoxerands soil during the 2003-2004 and 2004-2005 seasons. A rate of 200 kg ha -1 N was applied at different growing stages including planting, tillering, flag leaf, and heading (200-0-0-0, 100-100-0-0, 66-67-67-0, and 50-50-50-50 kg N ha -1 , respectively). The evaluated traits were grain yield, hectoliter weight, and wet gluten content. Results indicated that the use of two and three split N applications increased grain yield and wet gluten content with differences among genotypes. The best N split strategy corresponded to two and three N splits: at planting and tillering; at planting, tillering, and flag leaf, respectively.

Faraon-INIA is a new winter triticale (×Triticosecale Wittmack) cultivar released by the National Wheat Program of the Instituto de Investigaciones Agropecuarias INIA in Chile. It is derived from an F9 material received from Nordsaat, Germany, under a germplasm exchange agreement signed in 2006 by both institutions. The crossing was Piano/Focus with Nord 93.7548 pedigree. Faraon-INIA has a winter growth habit, a short stem (semi-dwarf), with a mean height of 106 cm. The spike is long, compact, decumbent, white, and awned. The grain is soft, yellow, with 1000-grain weight of 36 g, and a mean of hectoliter weight of 76 kg hL -1 . It is resistant to stripe rust (Puccinia striiformis West. f. sp. tritici) and leaf rust (Puccinia triticina Erikss.) as well as moderately resistant to septoria leaf blotch. Its mean yield for four seasons in three different locations: Temuco (38o50´ S, 72o25´ W), Traiguen (38o45´ S, 72o38´ W), and Purranque (36°31’ S, 71°54’ W) varied between 8.2 and 15.0 t ha -1 with a general mean of 11.0 t ha -1 . Bromatological analysis of the grain showed good protein content (10.6%) and a generally better quality than

Grain yield and plant height of 80 recombinant chromosome substitution lines (RCSLs) of barley were measured in six environments with contrasting available moisture profiles. Two environments were in OR, USA (Moro and Pendleton) during one growing season (2004), and four in Chile (Cauquenes and Santa Rosa) during two growing seasons (2004/2005 and 2007/2008). From the yield data obtained in the different environments, yield adaptability (Finlay–Wilkinson slope) and stability (deviations from regression) were calculated. Two commercial cultivars (Harrington and Baronesse) were used as checks in all environments. Marker-quantitative trait associations were identified using 47 simple sequence repeats (SSRs) and the general linear model (GLM) implemented in TASSEL. The mean plant height and grain yield of the 80 RCSLs differed greatly across environments, reflecting differences in water availability. In all environments, there were significant differences (P

Ancestral germplasm may be a useful source of genetic variation for crop improvement. Genetic variation in developmental traits that contribute to heading date may be useful in developing varieties that are uniquely tailored to specific stress environments. Hordeum vulgare subsp. spontaneum (K. Koch) A. & Gr. is the ancestor of cultivated barley and useful developmental trait alleles may have been lost in the domestication process. Accordingly, we surveyed a sample of 16 subsp. spontaneum accessions for vernalization requirement, photoperiod sensitivity, photoperiod response, and relative earliness. We compared the subsp. spontaneum accessions to four H. vulgare L. subsp. vulgare accessions representing spring, facultative, and winter growth habit. Thirteen subsp. spontaneum accessions originating from the Fertile Crescent and the one subsp. spontaneum accession from the Caucasus region required vernalization; they were responsive to long photoperiods and most were very early. Two subsp. spontaneum accessions from the Himalayan region had no vernalization requirement but were extremely sensitive to short photoperiods. We used a clustering procedure to define two groups of subsp. spontaneum accessions, a group of subsp, spontaneum that included the two subsp. vulgare accessions of spring and facultative growth habit, and a fourth group comprised of the two subsp. vulgare winter habit cultivars. These data indicate that subsp. spontaneum may be a source of novel alleles for growth habit.

The ancestor of barley (Hordeum vulgare subsp. spontaneum) may be a source of novel alleles for crop improvement. We developed a set of recombinant chromosome substitution lines (RCSLs) using an accession of H. vulgare subsp. spontaneum (Caesarea 26-24, from Israel) as the donor and Hordeum vulgare subsp. vulgare 'Harrington' (the North American malting quality standard) as the recurrent parent via two backcrosses to the recurrent parent, followed by six generations of selfing. Here we report (i) the genomic architecture of the RCSLs, as inferred by simple sequence repeat (SSR) markers, and (ii) the effects of H. vulgare subsp. spontaneum genome segment introgressions in terms of three classes of phenotypes: inflorescence yield components, malting quality traits, and domestication traits. Significant differences among the RCSLs were detected for all phenotypes measured. The phenotypic effects of the introgressions were assessed using association analysis, and these were referenced to quantitative trait loci (QTL) reported in the literature. Hordeum vulgare subsp. spontaneum, despite its overall inferior phenotype, contributed some favorable alleles for agronomic and malting quality traits. In most cases, the introgression of the ancestral genome resulted in a loss of desirable phenotypes in the cultivated parent. Although disappointing from a plant breeding perspective, this finding may prove to be a useful tool for gene discovery.Key words: Hordeum vulgare subsp. vulgare, Hordeum vulgare subsp spontaneum, association analysis, QTLs, genetic resources.

Association mapping has been proposed to identify polymorphisms involved in phenotypic variations and may prove useful in identifying interesting alleles for breeding purposes. Using this approach, a total of 382 cultivars and advanced lines of spring wheat obtained from three breeding programs (Chile, Uruguay and CIMMYT) were evaluated for plant height (PH), kernels per spike (KS), 1,000 kernel weight (TKW), grain yield and carbon isotope discrimination (Δ13C) and tested for genotyping-by-sequencing-derived SNP markers across the hexaploid wheat genome. A Bayesian clustering approach via Markov chain Monte Carlo was performed to examine the genetic differentiation (F ST) among different genetic groups. The results indicated the existence of two distinct and strongly differentiated genetic groups. Cluster I contained 215 genotypes (56.3 %), over 60 % (137/215) of which were collected from CIMMYT. Cluster II showed the highest F ST value, according to 95 % credible interval. Linkage disequilibrium (LD) among SNPs was calculated for the A, B and D genomes and at the whole-genome level. LD decayed over a longer genetic distance for the D genome than for the A and B genomes. In the A and B genomes, LD declined to 50 % of its initial value at about 2 cM. In the D genome, LD was much more extensive, declining to 50 % of its initial value only at 22 cM. In the whole genome, LD declined to 50 % of its initial value at an average of 4 cM. Important genomic regions associated with complex traits in spring wheat were identified. Selection on these regions may increase the efficiency of the current breeding programs. Although most of the associations were environment specific, some stable associations were detected for Δ13C, KS, PH and TKW. Chromosomes 1A, 3A, 4A and 5A were the most important chromosomes, as they comprised quantitative trait loci (QTL) for Δ13C, a trait that can be used as an indirect tool for increased water-use efficiency in wheat. Environment-specific genomic regions were detected, indicating the presence of QTL-by-environment interaction. To produce suitable genotypes under contrasting water availability conditions, QTL × E interactions (and genotype-by-environment interaction) should be considered in the current spring wheat breeding program.

A collection of 368 advanced lines and cultivars of spring wheat (Triticum aestivum L.) from Chile, Uruguay, and CIMMYT (Centro Internacional de Mejoramiento de Maíz y Trigo), with good agronomic characteristics were evaluated under the Mediterranean conditions of central Chile. Three different water regimes were assayed: severe water stress (SWS, rain fed), mild water stress (MWS; one irrigation around booting), and full irrigation (FI; four irrigations: at tillering, flag leaf appearance, heading, and middle grain filling). Traits evaluated were grain yield (GY), agronomical yield components, days from sowing to heading, carbon isotope discrimination (Δ(13) C) in kernels, and canopy spectral reflectance. Correlation analyses were performed for 70 spectral reflectance indices (SRI) and the other traits evaluated in the three trials. GY and Δ(13) C were the traits best correlated with SRI, particularly when these indices were measured during grain filling. However, only GY could be predicted using a single regression, with Normalized Difference Moisture Index (NDMI2: 2,200; 1,100) having the best fit to the data for the three trials. For Δ(13) C, only individual regressions could be forecast under FI (r(2): 0.25-0.37) and MWS (r(2): 0.45-0.59) but not under SWS (r(2): 0.03-0.09). NIR-based SRI proved to be better predictors than those that combine visible and NIR wavelengths.

Se estudio el rendimiento de grano (GY) y la tolerancia a la sequia de lineas recombinantes con substitucion de cromosomas (RCSLs), provenientes de la cruza entre Hordeum vulgare L. subsp. spontaneum (K. Koch) Thell y H. vulgare L. subsp. vulgare, en dos ambientes contrastantes, uno con estres hidrico (WWS) y otro sin estres hidrico (NWS), durante tres temporadas de crecimiento, 2004-2005, 2005-2006 y 2006-2007. En la primera temporada se establecieron 80 RCSLs y en las siguientes se evaluo una seleccion de 13 RCSLs. Se utilizo un diseno a-latice en todos los experimentos. Con los datos de GY obtenidos en los sitios WWS y NWS se calculo el indice de sensibilidad a la sequia (DSI). Durante la temporada 2004-2005, el GY vario ampliamente entre localidades, reflejando las diferencias en la disponibilidad de agua. El GY promedio de las 80 RCSLs fue 4,4 y 8,0 Mg ha-1 en los sitios WWS y NWS, respectivamente. El DSI vario ampliamente entre genotipos, desde 0,24 hasta 1,53. Ademas, el DSI se correlaciono negativa y significativamente con el rendimiento de grano en el ambiente WWS y permitio seleccionar un grupo de genotipos tolerantes y otro de sensibles a la sequia. El grupo de genotipos tolerantes a sequia mostro en el sitio WWS un rendimiento de grano promedio de 18, 12 y 7% superior al de los no tolerantes, en las temporadas 2004-2005, 2005-2006 y 2006-2007, respectivamente.

Aguacero-INIA es un cultivar de triticale (X Triticosecale Wittmack) de primavera creado por el Proyecto Trigo del Instituto de Investigaciones Agropecuarias, en el Centro Regional de Investigación Quilamapu, Chillán, a partir de un cruzamiento efectuado en 1992. El grano es de color rojo y de forma elíptica. La altura de la planta varía entre 105 y 120 cm, y la espiga es blanca y barbada. Su rendimiento en ensayos ha variado entre 7,0 y 12,0 t ha-1. La dureza del grano, el valor de sedimentación y el glúten húmedo varían entre 30-40%, 15-20 cm³ y 15-20%, respectivamente. Estas características corresponden a un grano suave, en la escala usada para el trigo. La proteína y niveles de energía del grano indican que es apropiado para alimentación animal. Aguacero-INIA is a spring triticale (X Triticosecale Wittmack) cultivar created by the Wheat Project at Quilamapu Regional Research Center of the National Agricultural Research Institute (INIA), Chillán, Chile, from a cross made in 1992. The grain is red and it has an elliptical shape. The plant height varies between 105-120 cm and the spike is white and awned. Its yield in trials has varied between 7.0 and 12.0 t ha-1. Its grain hardness, sedimentation value and wet gluten ranged between 30-40%, 15-20 cm³ and 15-20%, respectively. These characteristics correspond to a soft grain in the scale used for wheat. Protein and energy levels of the grain indicate that is appropriate for animal feeding

This chapter reviews diversity in agronomic traits, diversity in malting quality traits, and the current status of Quantitative Trait Loci (QTL) analysis in barley and the application of QTL tools to the analysis of genetic diversity in barley and crop improvement. Agronomic and quality traits were undoubtedly key issues for the domesticators of barley. Crop productivity would clearly have been an attribute of key interest, and the selection of shattering-resistant mutants probably led to a quantum leap in yield. Because barley has been used both as a food and as a principal ingredient of fermented beverages from the earliest times, there may well have been conscious selection for end-use properties. The selection of hull-less mutants in areas of the world where barley was a principal foodstuff underscores the importance of end-use properties in domestication. The malting and brewing properties of wild barley accessions and landraces have not been welldescribed and are, in fact, extremely difficult to measure. Plant breeding efforts are directed primarily at traits exhibiting quantitative variation. Breeders and geneticists were now able to collaborate in developing and testing hypotheses regarding the number, location, effect, and interactions of genes influencing quantitative traits.

In Chile, durum wheat is cultivated in high-yielding Mediterranean environments, therefore breeding programs have selected cultivars with high yield potential in addition to grain quality. The genetic progress in grain yield (GY) between 1964 and 2010 was 72.8 kg ha&minus, 1 per year. GY showed a positive and significant correlation with days to heading, kernels per unit ground area and thousand kernel weight. The gluten and protein content tended to decrease with the year of cultivar release. The correlation between the &delta, 13C of kernels and GY was negative and significant (&minus, 0.62, p &lt, 0.05, for all cultivars, and &minus, 0.97, p &lt, 0.001, excluding the two oldest cultivars). The yield progress (genetic plus agronomic improvements) of a set of 40&ndash, 46 advanced lines evaluated between 2006 and 2015 was 569 kg ha&minus, 1 per year. Unlike other Mediterranean agro-environments, a longer growing cycle together with taller plants seems to be related to the increase in the GY of Chilean durum wheat during recent decades.