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The presence of genotype-by-environment interactions (GE) remains a major issue for crop improvement. The aims of this work were: i) to compare the efficiency of parametric and non-parametric methods to test the presence of crossover (COI) and non-crossover GE (NCOI), ii) visual examination of the relationships between environments and genotypes tested, and iii) to test the effectiveness of dividing the peach season evaluations into mega-environments (ME) using the biplot based on AMMI and SREG. Non-parametric ANOVA was more useful than the parametric approach because it can distinguish between the presence of COI and NCOI. Three test methods, suitable for investigating two-factor interactions, were used to show that interactions between genotypes and environment involve significant changes in rank order. The Yang test based on mixed model theory combined with interaction-wise error rate was the most sensitive to detect COI, while the Gail and Simon, as well as the Azzalini and Cox methods were conservative. Which-won-where pattern was followed with four and two ME were found with AMMI and SREG, respectively. Entries G16 (Hermosillo P), G21 (Maria Emilia N), G2 (84.351.029 N) and G8 (Cotogna del Berti P) showed specific adaptability to ME-1, ME-2, ME-3 and ME-4 generated by AMMI, respectively; while G28 (Sunprince P) exhibited specific adaptation to ME-1 and G16 in ME-2 which were created by SREG. Average environment coordination (AEC) view of the GGE biplot involving the seven environments identified G10 (Flameprince P) as the most stable and high-yielding genotype across environments, unlike G8 and G28, which showed only high yields. Results indicated that AMMI and GGE biplots are informative methods to explore stability and adaptation patterns of genotypes in practical plant breeding and in subsequent variety recommendations. In addition, finding ME helps identify the most suitable peach genotypes that can be recommended for areas within a specific ME in either one or more test locations.

Identification of genotypes with acceptable yield and yield stability in different environments is an important issue in plant breeding. Genotype-by-environment interaction (GEI) can alter genotypes performances making the selection of superior material a tedious task for breeders. Consequently, it is necessary to assess the usefulness of different available methods and identify the most suitable for understanding GEI. The objectives of this work were to compare three methods to study genotype stability considering incomplete data sets: (i) Di Rienzo, Guzmán and Casanoves' test (DGC), (ii) relative yield (RY) and (iii) Piepho's method. In addition, AMMI (additive main effect and multiplicative interaction) analysis and eight AMMI stability measures SIPC, EV, ASV, Da, FP, B, FA and Za were computed to explore their advantages and disadvantages to select stable entries. The usefulness of the genotype selection index (GSI) and the rank-sum (RS) procedures to identify stable and high-yielding genotypes were evaluated and then compared with the superiority (P) and reliability indexes (I). The association between yield variation and climatic factors as frosts, chilling, heat, rainfall and the interactions among them were also analyzed. 29 peach entries were assessed in four to seven seasons in a completely randomized design with three replications. DGC and RY tests agreed on classifying Fireprince as a stable and high-yielding peach, RY classified 25 entries as stable, while Piepho's method did not separate the tested genotypes as DGC and RY did. The results of AMMI indicated that 25.06% of total variability was justified by genotypes, 9.76% by environments and 58.97% by GEI. The first five interaction principal components could explain 94.82% of GEI and showed the efficiency of AMMI model to study and understand GEI. The AMMI parameters showed no association with fruit yield, therefore, they could be useful to indicate stable entries but they would not be appropriate to select stable and high-yielding genotypes. The EV and Za indicated static stability while ASV, SIPC, Da, FA and FP pointed out the dynamic stability concept. The performance of the best entries selected by GSI, RS, P and I procedures were not different, therefore, any of them can be used to select superior peach genotypes. Rainfall during endodormancy, rainfall from floral bud endo- to ecodormancy - and heat accumulation during fruit development period showed significant correlation with yield variation across seasons. Fil: Maulión, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentina Fil: Arroyo, Luis. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria San Pedro; Argentina Fil: Daorden, María Elena. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria San Pedro; Argentina Fil: Valentini, Gabriel Hugo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria San Pedro; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentina

Trichloris crinita y T. pluriflora son gramíneas perennes nativas de Argentina que presentan potencialidad productiva como forrajeras para regiones áridas y semiáridas. Los objetivos del presente trabajo fueron analizar para ambas especies las variaciones en la distribución y densidad estomática foliar ante dos regímenes hídricos diferentes y su asociación con las precipitaciones en el lugar de origen. Se caracterizaron seis introducciones para cada especie, implantando dos ensayos, uno en ambiente húmedo y otro en ambiente seco, realizándose mediciones de dimensiones foliares y recuentos estomáticos en cada material para cada ambiente. El Análisis de Componentes Principales representó el 73,3% de la variación sobre los dos primeros ejes, respondiendo al efecto del ambiente de evaluación sobre los parámetros estomáticos y a las diferencias entre especies para las dimensiones foliares. Para T. crinita se observaron diferencias significativas entre introducciones para la mayoría de las variables analizadas en ambos ambientes. Para T. pluriflora, las variaciones entre introducciones fueron evidentes solamente en ambiente húmedo. Las variaciones observadas presentaron correlación con las precipitaciones en el sitio de colecta únicamente para T. crinita. Las variables aquí empleadas resultaron de utilidad para la caracterización de los materiales analizados; se discute su implicancia para la conservación del recurso fitogenético. Analisys of distribution and stomatal density in Trichloris (Chloridoideae, Poaceae), under different water regimes. Trichloris crinita and T. pluriflora are perennial grasses native from Argentina that have productive potential as forage for arid and semi-arid regions. The objectives of the present work were to analyze in both species the variations in leaf stomatal distribution and density under two different water regimes and their association with rainfall at the place of origin. Six introductions for each species were characterized. Two trials were implemented, one in a humid environment and the other in a dry environment. Measurements of foliar dimensions and stomatal counts in each material for each environment were made. The Principal Component Analysis represented 73.3% of the variation on the first two axes, responding to the effect of the evaluation environment on stomatal parameters and to the differences between species for their foliar dimensions. Significant differences were observed between introductions of T. crinita in both environments for most of the variables analyzed. Variations between introductions of T. pluriflora were observed only in humid environment. The observed variations correlated with rainfall at the collection site only for T. crinita. The variables used here were useful for the characterization of the materials analyzed; their implications for the conservation of this plant genetic resource are discussed. Fil: Trod, María Amalia. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Tomas, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Zabala, Juan Marcelo. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Marinoni, Lorena del Rosario. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Giavedoni, Julio Alberto. Universidad Nacional del Litoral; Argentina

Sudden death syndrome (SDS) of soybean can be caused by at least four distinct Fusarium species, with F. tucumaniae being the main causal agent in Argentina. The fungus is a soil-borne pathogen that is largely confined to the roots, but damage also reaches aerial part of the plant and interveinal chlorosis and necrosis, followed by premature defoliation can be observed. In this study, two genetically diverse soybean cultivars, one susceptible (NA 4613) and one partially resistant (DM 4670) to SDS infection, were inoculated with F. tucumaniae or kept uninoculated. Leaf samples at 7, 10, 14 and 25 days post-inoculation (dpi) were chosen for analysis. With the aim of detecting early markers that could potentially discriminate the cultivar response to SDS, gas chromatography–mass spectrometry (GC–MS) analyses and biochemical studies were performed. Metabolic analyses show higher levels of several amino acids in the inoculated than in the uninoculated susceptible cultivar starting at 10 dpi. Biochemical studies indicate that pigment contents and Rubisco level were reduced while class III peroxidase activity was increased in the inoculated susceptible plant at 10 dpi. Taken together, our results indicate that the pathogen induced an accumulation of amino acids, a decrease of the photosynthetic activity, and an increase of plant-specific peroxidase activity in the susceptible cultivar before differences of visible foliar symptoms between genotypes could be observed, thus suggesting that metabolic and biochemical approaches may contribute to a rapid characterization of the cultivar response to SDS. Fil: Rosati, Romina Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentina Fil: Lario, Luciana Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentina Fil: Hourcade, Mónica E.. Universidad Nacional de Rosario; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentina Fil: Luque, Alicia G.. Universidad Nacional de Rosario; Argentina Fil: Scandiani, María Mercedes. Universidad Nacional de Rosario; Argentina Fil: Spampinato, Claudia Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentina

A quantitative trait locus (QTL) analysis of grain yield and yield-related traits was conducted on 93 durum wheat Recombinant Inbred Lines (RIL) derived from the cross UC1113 × Kofa. The mapping population and the parental lines were evaluated in environments of Argentina for 19 traits, including grain yield (Yld), heading date (Hd), flowering time (Flt), plant height (Ph), biomass per plant (Bpp), and spikelet number per ear (Sne). A total of 223 QTLs with LOD ≥ 3 and 47 additional QTLs with LOD > 2.0 were detected. These QTLs were clustered in 36 regions with pleiotropic QTLs and 12 genomic regions each associated with only one phenotypic trait. The regions with highest number of pleiotropic and stable QTLs were 3BS.1, 3BS.2,2BS.1, 1BL.1, 3AL.1, 1AS and 4AL.3. In addition, effects of epistatic QTLs and QTL x environment interactions were detected. Fil: Roncallo, Pablo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; Argentina Fil: Akkiraju, Pavan C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosinteticos y Bioquimicos. Universidad Nacional de Rosario. Facultad de Cs.bioquímicas y Farmaceuticas. Centro de Estudios Fotosinteticos y Bioquimicos; Argentina Fil: Echenique, Carmen Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; Argentina

Chilling and heat requirements for breaking dormancy and flowering were studied in 63 nectarine and118 peach genotypes (Prunus persica (L.) Batsch) for seven years. We compared two methods for estima-tion of requirements and four models for calculation of chill accumulation: Chilling Hours (CH), ChillingUnits (CU), Positive Chilling Units (PCU) and Dynamic, while heat accumulations were estimated in grow-ing degree hours (GDH). Additionally, correlations between chilling requirements, heat requirements andflowering date were established. Our results suggest that the Luedeling model is better than the Alonsomodel to estimate chilling and heat requirements in our field conditions. Moreover, it is recommend-able to calculate the chill accumulation in accordance with the Chilling Hours or Positive Utah models.Additionally, since chilling requirements were positively correlated with flowering dates, they seem tobe important to regulate blooming in nectarine and peach genotypes. Fil: Maulión, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina Fil: Valentini, Gabriel Hugo. Instituto Nacional de Tecnologia Agropecuaria. Centro Reg.buenos Aires Norte. Estacion Exptal.agrop.san Pedro; Argentina Fil: Kovalevski, Leandro. Universidad Nacional de Rosario. Facultad de Cs.economicas y Estadistica. Escuela de Estadistica; Argentina Fil: Prunello, Marcos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina Fil: Monti, Laura Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina Fil: Daorden, María Elena. Instituto Nacional de Tecnologia Agropecuaria. Centro Reg.buenos Aires Norte. Estacion Exptal.agrop.san Pedro; Argentina Fil: Quaglino, Marta. Universidad Nacional de Rosario. Facultad de Cs.economicas y Estadistica. Escuela de Estadistica; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina

Pre-harvest sprouting (PHS) in Sorghum bicolor is one of the main constrains for its production in the central region of Argentina, as grain maturation often coincides with rainy or high environmental humidity conditions. The obtention of more dormant genotypes with higher PHS resistance has always been a desirable trait for breeders but the typical quantitative nature of seed dormancy makes its manipulation difficult through classical breeding. Dissecting this quantitative variability into quantitative trait loci (QTL) is a main concern especially in cereal species. In this work, a sorghum segregating population including 190 families was genotyped with microsatellite markers and the SbABI5 candidate gene. A genetic map encompassing 96 markers and a total length of 1331 cM was built. Seed dormancy was phenotyped in F3 and F4 panicles in two contrasting Argentinean environments (Castelar and Manfredi). Six seed dormancy QTL for mature grains were identified (qGI-1, qGI-3, qGI-4, qGI-6, qGI-7 and qGI-9) with the aid of QTL Cartographer and QTLNetwork, three of them (qGI-3, qGI-7 and qGI9) being co-localised by both approaches. No epistasis was detected for the identified QTL but QTL-byenvironment interaction was significant for qGI-7 and qGI-9. Interestingly, seed dormancy candidate genes SbABI3/VP1 and SbGA20ox3 were located within qGI-3, which makes them noteworthy candidate genes for this QTL. Fil: Cantoro, Renata. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Fernandez Galdeano, Jorge Luis. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosinteticos y Bioquimicos. Universidad Nacional de Rosario. Facultad de Cs.bioquímicas y Farmaceuticas. Centro de Estudios Fotosinteticos y Bioquimicos; Argentina Fil: Rodríguez, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Jorge Omar, Gieco. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi; Argentina. Universidad Nacional del Litoral; Argentina Fil: Paniego, Norma Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Heinz, Ruth Amelia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Benech-Arnold, Roberto Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cultivos Industriales; Argentina

Nowadays, although there are several studies based on peach phenotypic diversity and adaptability, there is no current research regarding associations among characters using multivariate statistical methods which provide more trustable conclusions than bivariate analysis. For this reason, we evaluated not only the adaptability of the accessions but also the relationships among qualitative and quantitative traits applying Multiple Correspondence Analysis and Factor Analysis, respectively. The study was carried out on seventy-seven nectarine and one hundred and thirty-two peach accessions grown in Argentina that were characterized with 35 fruit quality, agronomic and phenological traits during 3 seasons. Multiple Correspondence Analysis revealed that freestone trait would be associated with strong anthocyanin coloration of the flesh around the brown dark stone while semi-freestone trait would be related to weak or no anthocyanin coloration of the flesh around the light brown stone. Then, Factor Analysis enabled us to identify positive relationships between blooming and sprouting date; harvesting period and yield and among fruit development period, harvesting date, fruit weight and soluble solid content. In addition, 'phenology traits', 'productivity' and 'fruit quality and reaping time' would be unrelated to each other. Furthermore, the agglomerative hierarchical cluster analysis grouped the accessions in accordance to their similarities and allowed the identification of the most adapted cultivars. We have demonstrated that this approach is a powerful tool that should be considered for further studies on peach germplasm and it has also the possibility to be applied for other fruit species. Finally, the results of this study provide valuable information for germplasm characterization and for breeding practices aiming to develop accessions adapted to the climatic conditions of the northern of Buenos Aires province. Fil: Maulión, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentina Fil: Arroyo, Luis Enrique. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria San Pedro; Argentina Fil: Daorden, María Elena. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria San Pedro; Argentina Fil: Valentini, Gabriel Hugo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria San Pedro; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentina

Paspalum notatum Flugge is a grass species organized as an agamic complex. The objective of the current research was to survey the frequencies and variation of cytosine methylation at CCGG sequences in diploid and tetraploid genotypes, and to determine the occurrence of methylation changes associated with tetraploidization by using methylation-sensitive amplification polymorphism (MSAP) markers. No differences were found in the average proportions of methylated CCGG sites between cytotypes, but methylation patterns were significantly more variable in tetraploids. In both groups of plants, epigenetic and non-epigenetic variation correlated significantly when compared by Mantel tests. The evaluation of 159 common MSAP markers showed that 18.86 % of them differed in their methylation status in the different ploidies. Dendrogram analysis, reflecting epigenetic distances, showed that the four diploids and one experimentally-obtained sexually-reproducing tetraploid, grouped together. MSAP analysis performed on a diploid plant and its autotetraploid derivative showed that new epialleles emerged after tetraploidization. Sequencing of several MASP markers showed homologies with low copy genes, non-coding sequences and transposon/retrotransposon elements.

The soybean cyst nematode (SCN) is one of the most economically important pathogens of soybean. Molecular mapping of quantitative trait loci (QTL) for resistance to SCN is a proven useful strategy in order to assist in the development of resistant soybean cultivars. In the present study, a Bayesian modeling approach was performed to map QTL controlling genetic resistance to SCN races 3 and 14. For this purpose, a population of recombinant inbred lines derived from the cross between line Y23 (susceptible) and cv. Hartwig (resistant) was used. A total of 144 microsatellites markers (Simple Sequence Repeats) were selected and synthesized for mapping purpose. Posterior marginal parameter distributions were computed using the Reversible Jump Markov Chain Monte Carlo (RJ-MCMC) algorithm. It was determined the existence of four QTLs on three linkage groups (LG); that is LG A2 for race 3, LG C2 for race 14, and LG G for both races. The estimates of posterior modes of the heritability were 0.038 and 0.53 for the LGs A2 and G respectively (race 3). For the race 14 the posterior modes of the heritability were 0.044 and 0.05 for the LGs C2 and G. The identified QTLs explained about 57 and 9 % of the total phenotypic variance, for the races 3 and 14, respectively. These results confirm the effectiveness of the Bayesian method to map QTL controlling resistance to SCN in soybean. Accordingly, integrating QTL mapping with Bayesian methods will enable response to selection for quantitative traits of interest in soybean to be improved.

Quality, specifically protein content and gluten strength are among the main objectives of a durum wheat breeding program. The aim of this work was to validate quantitative trait loci (QTLs) associated with grain protein content (GPC) and gluten strength measured by SDS sedimentation volume (SV) and to find additional QTLs expressed in Argentinean environments. Also, epistatic QTL and QTL x environmental interactions were analyzed. A mapping population of 93 RILs derived from the cross UC1113 x Kofa showing extreme values in gluten quality was used. Phenotypic data were collected along six environments (three locations, two years). Main effect QTLs associated with GPC were found in equivalent positions in two environments on chromosomes 3BS (R 2 = 21.0-21.6%) and 7BL (R 2 = 12.1-13%), and in one environment on chromosomes 1BS, 2AL, 2BS, 3BL, 4AL, 5AS, 5BL and 7AS. The most important and stable QTL affecting SV was located on chromosome 1BL (Glu-B1) consistently detected over the six environments (R 2 = 20.9-54.2%). Additional QTLs were found in three environments on chromosomes 6AL (R 2 = 6.4-12.5%), and in two environments on chromosomes 6BL (R 2 = 11.5-12.1%), 7AS (R 2 = 8.2-10.2%) and 4BS (R 2 = 11-16.4%). In addition, pleiotropic effects were found affecting grain yield, test weight, thousand-kernel- weight and days to heading in some of these QTLs. Epistatic QTLs and QTL x environment interactions were found for both quality traits, mostly for GPC. The flanking markers of the QTLs detected in this work could be efficient tools to select superior genotypes for the mentioned traits. Fil: Conti, Veronica Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Bordenave; Argentina Fil: Roncallo, Pablo Federico. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina Fil: Beaufort, Valeria. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentina Fil: Miranda, Ruben. Asociación de Cooperativas Argentinas; Argentina Fil: Jensen, Carlos A.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Barrow; Argentina Fil: Echenique, Carmen Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur; Argentina

The objective of this work was to identify major and minor-effect quantitative trait loci (QTL) for resistance to races 3, 9, and 14 of soybean cyst nematode (SCN) in Hartwig cultivar; to map new resistance QTLs for these races; and to check for the existence of epistatic interactions between QTLs. Cultivar Hartwig is an important resistance source to SCN. Recombinant inbred lines (RIL) obtained from a cross between 'Hartwig' (resistant) and Y23 (susceptible) were evaluated regarding resistance to the three races. New genomic regions for resistance to SCN were identified by microsatellites. Four QTLs, which explained between 12 and 34% of phenotypic variance, were detected for resistance to race 3 in linkage groups (LG) A2, G, J, and M. The QTL in LG G is also important for resistance to race 9. Epistatic interactions were detected between loci, which indicate resistance to races 9 and 14. There are high and low-effect resistance QTLs to SCN. O objetivo deste trabalho foi identificar locos associados a características quantitativas (QTL) de efeito maior e menor para a resistência às raças 3, 9 e 14 do nematoide do cisto da soja (NCS) na cultivar Hartwig, mapear novos QTLs de resistência para estas raças e verificar a existência de interações epistáticas entre QTLs. A cultivar Hartwig é uma importante fonte de resistência ao NCS. Linhagens endogâmicas recombinantes (LER) obtidas do cruzamento entre 'Hartwig' (resistente) e Y23 (suscetível) foram avaliadas quanto à resistência às três raças. Novas regiões genômicas de resistência ao NCS foram identificadas por microssatélites. Quatro QTLs, que explicaram entre 12 e 34% da variância fenotípica, foram detectados para a resistência à raça 3 nos grupos de ligação (GL) A2, G, J e M. O QTL no GL G também é importante para a resistência à raça 9. Interações epistáticas foram detectadas entre loci, o que indica resistência às raças 9 e 14. Há QTLs de maior e menor efeito para a resistência ao NCS. Fil: Ferreira, Marcia Flores da Silva. Universidade Federal do Espírito Santo; Brasil Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina. Universidad Nacional de Rosario; Argentina Fil: Ferreira, Adésio. Universidade Federal do Espírito Santo; Brasil Fil: Schuster, Iván. Cooperativa Central de Pesquisa Agrícola; Brasil Fil: Santana, Fernanda Abreu. Universidade Federal de Viçosa; Brasil Fil: Pereira, Waldir Dias. Embrapa Soja; Brasil Fil: Barros, Everaldo Gonçalves de. Universidade Federal de Viçosa; Brasil Fil: Moreira, Maurilio Alves. Universidade Federal de Viçosa; Brasil

O objetivo deste trabalho foi avaliar, em soja, as heranças da resistência ao nematóide de cisto da soja, raças 3 e 14. As seguintes populações foram avaliadas: uma linhagem endogâmica recombinante (RILs) [Hartwig (resistente) x Y23 (suscetível)], para as raças 3, 14 e 9; uma população de famílias F2:3 [(M-SOY 8001 (resistente) x MB/BR 46 – Conquista (suscetível)], para a raça 3; e uma população de famílias F2:3 [S5995 (resistente) x BRSMG Renascença (suscetível)], para a raça 14. Foram identificados nas populações RILs quatro genes epistáticos que condicionaram resistência à raça 14 e três genes epistáticos para a resistência às raças 3 e 9. A falta de um dos genes proporcionou resistência moderada em todas as situações. Na população F2:3 de M-SOY 8001 x MB/BR 46 – Conquista, foi identificado um gene recessivo para resistência moderada à raça 3 e dois genes recessivos para a resistência completa. Na população F2:3 do cruzamento S5995 x BRSMG Renascença foram identificados dois genes recessivos que condicionaram resistência moderada à raça 14. Estes resultados visam contribuir no delineamento de cruzamentos, que envolvem estes parentais, com maior possibilidade de acumular genes que conferem resistência às diversas raças do nematóide de cisto da soja. The objective of this work was to evaluate the soybean inheritance of resistance to cyst nematode races 3 and 14. The following populations where evaluated: one population of recombinant inbred lines (RILs) [Hartwig (resistant) x Y23 (susceptible line)] for races 3, 14 and 9; one population of families F2:3 [M-SOY 8001 (resistant) x MB/BR 46 – Conquista (susceptible)] for race 3; and one population of families F2:3 [(S5995 (resistant) x BRSMG Renascença (susceptible)] for race 14. In RIL populations, four epistatic genes were identified which conditioned resistance to race 14, and three epistatic ones for resistance to races 3 and 9. The lack of one gene provided moderate resistance under all situations. The highest number of genes for resistance to race 14 points out that genes responsible for lower effects might be involved. In population F2:3 from M-SOY 8001 x MB/BR 46 – Conquista, one recessive gene for moderate resistance and two recessive genes complete resistance to race 3 were identified. Two recessive genes conditioning moderate resistance to race 14 were identified in population F2:3 from the crossing S5995 x BRSMG Renascença. These results will be useful in designing crossings, involving these parentals, with higher possibility to accumulating genes that provide resistance to several SCN races.

Soybean germplasm exhibits various levels of resistance to Fusarium tucumaniae, the main causal agent of sudden death syndrome (SDS) of soybean in Argentina. In this study, two soybean genotypes, one susceptible (NA 4613) and one partially resistant (DM 4670) to SDS infection, were inoculated with F. tucumaniae. Disease symptoms were scored at 7, 10, 14, and 25 days post-inoculation (dpi). The greatest difference in the area under the disease progress curve (AUDPC) values among genotypes was observed at 25 dpi. In order to detect early metabolic markers that could potentially discriminate between susceptible and resistant genotypes, gas chromatography–mass spectrometry (GC-MS) analyses of root samples were performed. These analyses show higher levels of several amino acids and the polyamine cadaverine in the inoculated than in the uninoculated susceptible cultivar at 7 dpi. Principal component analysis (PCA) revealed that the metabolic profile of roots harvested at the earliest time points from the inoculated susceptible genotype was clearly differentiated from the rest of the samples. Furthermore, variables associated with the first principal component were mainly amino acids. Taken together, the results indicate that the pathogen induced the susceptible plant to accumulate amino acids in roots at early time points after infection, suggesting that GC-MS-based metabolomics could be used for the rapid characterization of cultivar response to SDS. Fil: Scandiani, María M.. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina Fil: Luque, Alicia G.. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina Fil: Razori, María V.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina Fil: Ciancio Casalini, Lucila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina Fil: Aoki, Takayuki. Genetic Resources Center; Japón Fil: O´Donnell, Kerry. United States Department Of Agriculture; Estados Unidos Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina Fil: Spampinato, Claudia Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina

The purpose of this work was to identifymicrosatellite markers linked to a gene forresistance to Heterodera glycinesIchinohe (Soybean Cyst Nematode – SCN) insoybean cultivar Hartwig. ABC1F2 mapping population derivedfrom a cross between Hartwig (resistant)and the Brazilian soybean line Y23(susceptible) was used. About 200microsatellite or simple sequence repeat(SSR) primer pairs were tested in a bulkedsegregant analysis (BSA). Those thatshowed clear polymorphisms were amplifiedin the BC1F2 population, whichhad been previously inoculated andevaluated for resistance/susceptibility toSCN Race 3. Three SSR markers linked toSCN resistance were detected in thepopulation. Two of them, Satt 038 and Satt163, flanking a dominant resistant gene(d/a = –0.90), explained 37% of thephenotypic variance. This gene was mappedat the edge of molecular linkage group G. Broad and narrow sense heritabilities wereestimated to be 50.54% and 37.73%,respectively. A selection efficiency of91.18% was obtained with the simultaneoususe of the two markers. The identified SSRmarkers will be useful tools for assistingthe selection of homozygous genotypes andfor expediting the introgression of the SCNresistance locus from cv. Hartwig tosoybean elite cultivars.

Transgenic wheat plants without the selectable marker gene were obtained either in the presence or in the absence of selective pressure during the transformation protocol. When using hygromycin as selective agent in a co-transformation experiment involving a mixture of plasmids pGL2, containing the hpt gene, and pAI1Gus, containing the uidA gene, 3 out of 19 transgenic wheat plants had the uidA gene alone as shown by Southern blots. The gene was transmitted to the progeny following Mendelian rules. Segregation and loss of the selectable marker gene was also found in three out of six events from other experiments where high-molecular-weight glutenin genes were expressed or over-expressed. On the other hand, in 7 experiments where no selective pressure was applied and that involved 1016 bombarded explants, 23 transgenic wheat plants were obtained. The uidA gene was stably integrated as suggested by its transmission to the progeny.

Sclerotinia Head Rot (SHR), a disease caused by Sclerotinia sclerotiorum, is one of the most limiting factors in sunflower production. In this study, we identified genomic loci associated with resistance to SHR to support the development of assisted breeding strategies. We genotyped 114 Recombinant Inbred Lines (RILs) along with their parental lines (PAC2 ?partially resistant?and RHA266 ?susceptible?) by using a 384 single nucleotide polymorphism (SNP) Illumina Oligo Pool Assay to saturate a sunflower genetic map. Subsequently, we tested these lines for SHR resistance using assisted inoculations with S. sclerotiorum ascospores. We also conducted a randomized complete-block assays with three replicates to visually score disease incidence (DI), disease severity (DS), disease intensity (DInt) and incubation period (IP) through four field trials (2010?2014). We finally assessed main effect quantitative trait loci (M-QTLs) and epistatic QTLs (E-QTLs) by composite interval mapping (CIM) and mixed-model-based composite interval mapping (MCIM), respectively. As a result of this study, the improved map incorporates 61 new SNPs over candidate genes. We detected a broad range of narrow sense heritability (h2) values (1.86?59.9%) as well as 36 M-QTLs and 13 E-QTLs along 14 linkage groups (LGs). On LG1, LG10, and LG15, we repeatedly detected QTLs across field trials; which emphasizes their putative effectiveness against SHR. In all selected variables, most of the identified QTLs showed high determination coefficients, associated with moderate to high heritability values. Using markers shared with previous Sclerotinia resistance studies, we compared the QTL locations in LG1, LG2, LG8, LG10, LG11, LG15 and LG16. This study constitutes the largest report of QTLs for SHR resistance in sunflower. Further studies focusing on the regions in LG1, LG10, and LG15 harboring the detected QTLs are necessary to identify causal alleles and contribute to unraveling the complex genetic basis governing the resistance. Fil: Zubrzycki, Jeremías Enrique. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina Fil: Maringolo, Carla Andrea. Universidad Nacional de Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Filippi, Carla Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina Fil: Quiroz, Facundo José. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Nishinakamasu, Verónica. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina Fil: Puebla, Andrea Fabiana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina Fil: Di Rienzo, Julio Alejandro. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Departamento de Desarrollo Rural. Area de Estadística y Biometría; Argentina Fil: Escande, Alberto Raul. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina Fil: Lia, Verónica Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Heinz, Ruth Amelia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Hopp, Horacio Esteban. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosinteticos y Bioquimicos. Universidad Nacional de Rosario. Facultad de Cs.bioquímicas y Farmaceuticas. Centro de Estudios Fotosinteticos y Bioquimicos; Argentina Fil: Paniego, Norma Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina

In peach breeding, suitable identification methods for performance stability studies as well as the associations between stability parameters are poorly understood. Therefore, the aims of this work were to compare parametric (S2 ij , biS2 xi, Wi, i and Ii) and non-parametric (S(1) i , S(2) i , S(3) i and Pi) stability measures, evaluate the level of association among them, select superior accessions and identify major environmental variables as causes of yield variation among years. Fruit yield stability was studied using data of fruit yield from 25 peach genotypes under three environments, arranged in a completely randomized design with three replications. Frosts, chilling, heat, rainfall and the interactions among them were considered as explanatory variables of yield variation through years. Crossover was the main effect of genotype-byenvironment interaction indicating that the selection of high-yielding and stable peach genotype would be a laborious task for breeders. The interaction between rainfall and heat accumulation during fruit development period explained 96.7% of yield variation among years. Yield (Yi) exhibited negative correlation with Wi and i, while Wi showed negative association with Pi. S(1) i , S(2) i , and S(3) i were positively associated with each other, showing that just one of these three statistics would be sufficient to select stable accessions although they were not correlated with Yi. Fruit yield was positively correlated with Pi and Ii, these two measures were also positively associated with each other, and therefore, only one of them would be enough for selection of superior peach accessions. Both, Pi and Ii statistics revealed that accessions Sunprince, Flameprince, María Aurelia, Vega, Starlite and Flavorcrest were the most stable and high-yielding genotypes across environments Fil: Maulión, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosinteticos y Bioquimicos. Universidad Nacional de Rosario. Facultad de Cs.bioquímicas y Farmaceuticas. Centro de Estudios Fotosinteticos y Bioquimicos; Argentina Fil: Valentini, Gabriel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria San Pedro; Argentina Fil: Ornella, Leonardo Alfredo. NIDERA S.A; Argentina Fil: Pairoba, Claudio Fabián. Universidad Nacional de Rosario. Facultad de Psicología. Secretaria de Ciencia y Tecnología; Argentina Fil: Daorden, María Elena. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria San Pedro; Argentina Fil: Cervigni, Gerardo Domingo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosinteticos y Bioquimicos. Universidad Nacional de Rosario. Facultad de Cs.bioquímicas y Farmaceuticas. Centro de Estudios Fotosinteticos y Bioquimicos; Argentina

Corn is one of the world’s most important cereals and a major source of calories for humanity, along with rice and wheat. Climate change and the use of marginal land for crop production require the development of genotypes adapted to stressful environments, particularly drought tolerant plants. Among the new technologies currently available for accelerate the releasing of new genotypes there is an emerging discipline called Machine Learning (ML). A primary goal of ML algorithms is to automatically learn to recognize complex patterns and make intelligent decisions based on data. This work reviews several strategic applications of ML in maize breeding. Quantitative trait loci mapping, heterotic group assignment and the popular genome-wide selection are some of the key areas currently addressed by the literature. Results are encouraging and propose ML algorithms as a valuable alternative to traditional statistical techniques applied in maize, even the more recently introduced linear mixed models.

In many species polyploidization involves rearrangements of the progenitor genomes, at both genetic and epigenetic levels. We analyzed the cytosine methylation status in a ‘tetraploid-diploid-tetraploid’ series of Eragrostis curvula with a common genetic background by using the MSAP (Methylation-sensitive Amplified Polymorphism) technique. Considerable levels of polymorphisms were detected during ploidy conversions. The total level of methylation observed was lower in the diploid genotype compared to the tetraploid ones. A significant proportion of the epigenetic modifications occurring during the tetraploid–diploid conversion reverted during the diploid–tetraploid one. Genetic and expression data from previous work were used to analyze correlation with methylation variation. All genetic, epigenetic and gene expression variation data correlated significantly when compared by pairs in simple Mantel tests. Dendrograms reflecting genetic, epigenetic and expression distances as well as principal coordinate analysis suggested that plants of identical ploidy levels present similar sets of data. Twelve (12) different genomic fragments displaying different methylation behavior during the ploidy conversions were isolated, sequenced and characterized.

The objective of this work was to determine soybean resistance inheritance to Heterodera glycines Ichinohe (soybean cyst nematode - SCN) races 3 and 9, as well as to evaluate the efficiency of direct and indirect selection in a soybean population of 112 recombinant inbred lines (RIL) derived from the resistant cultivar Hartwig. The experiment was conducted in a completely randomized design, in Londrina, PR, Brazil. The estimated narrow-sense heritabilities for resistance to races 3 and 9 were 80.67 and 77.97%. The genetic correlation coefficient (r g = 0.17; p

The concentration of yellow carotenoid pigments in durum wheat grain is an important quality criterion and is determined both by their accumulation and by their degradation by lipoxygenase enzymes (Lpx loci). The existence of a duplication at the Lpx-B1 locus and the allelic variation for a deletion of the Lpx-B1.1 copy is reported. This deletion was associated with a 4.5-fold reduction in lipoxygenase activity and improved pasta color (P

A transferência de alelos de resistência a doenças em plantas pode ser facilitada pelo uso de marcadores moleculares do DNA. Se proximamente ligados a alelos de resistência, eles podem ser usados na seleção assistida por marcadores (S.A.M.). Uma aplicação concreta dos marcadores na S.A.M. é durante o processo de piramidação de alelos de resistência. Por meio da S.A.M., em três gerações de retrocruzamento, o Programa de Melhoramento do Feijoeiro do BIOAGRO, Universidade Federal de Viçosa (Minas Gerais, Brasil), obteve linhagens de feijoeiro (Phaseolus vulgaris) com características fenotípicas similares às da cultivar Rudá (recorrente), contendo alelos de resistência à antracnose, ferrugem e mancha-angular. No momento, sementes das linhagens RC3F4, homozigotas para os locos de resistência estão sendo multiplicadas para serem submetidas a inoculações com os patógenos de interesse e a testes agronômicos. O Programa de Melhoramento da Qualidade da Soja do BIOAGRO vem usando marcadores moleculares para identificar "quantitative trait loci" (QTLs) associados à resistência ao nematóide de cisto da soja (NCS). Foram identificados dois marcadores microssatélites (Satt038 e Satt163) flanquendo o alelo de resistência rhg1 e também marcadores ligados a um QTL que confere resistência à raça 14 do NCS. Esse QTL explica mais de 40% da resistência da soja (Glycine max) cultivar Hartwig, uma das principais fontes de resistência ao NCS. A S.A.M. é uma realidade em diversos programas de melhoramento no mundo inteiro que visam ao desenvolvimento de cultivares resistentes a doenças. O seu uso efetivo no melhoramento depende de uma maior sintonia entre o melhorista e o biólogo molecular de plantas. Transfer of disease resistance alleles in plants can be expedited by the use of DNA molecular markers. If the markers are tightly linked to the resistance alleles they can be used for marker assisted selection (M.A.S.). One effective use of M.A.S. is found in the process of pyramiding resistance alleles. By using M.A.S., in three backcross generations, the Bean Breeding Program of BIOAGRO, Federal University of Viçosa (Minas Gerais, Brazil), has obtained bean (Phaseolus vulgaris) lines phenotypically similar to cultivar Rudá (recurrent) and resistant to anthracnose, rust and angular leaf spot. Seeds of BC3F4 lines currently are being multiplied to undergo inoculation with specific pathogens and agronomic performance tests. The Soybean Quality Breeding program of BIOAGRO used molecular markers to identify quantitative trait loci (QTLs) associated with resistance to soybean cyst nematode (SCN). Two microsattelite markers (Satt038 and Satt163) flanking the allele rhg1 were identified. Markers linked to a QTL that confers resistance to SCN race 14 were also identified. This QTL explains more than 40% of the resistance present in soybean (Glycine max) cultivar Hartwig, one of the most import resistance sources for SCN. The use of M.A.S. is a reality in several breeding programs around the that are trying to develop disease resistant cultivars. The effective use of this tool depends on a greater understanding between the breeder and the plant molecular biologist.

A highly efficient method for stable wheat transformation using hygromycin resistance as a selectable marker is described. Young embryogenic calli growing from immature wheat embryos were transformed using a gunpowder-driven microparticle accelerator. Transgenic wheat plants were determined by PCR amplification of transgene fragments and confirmed by Southern hybridization, activity of the transgene expression and by analysis of the progeny. The hpt gene was as good as or a better selectable marker than the bar gene with an average efficiency (number of transgenic plants relative to the number of bombarded calli) of 5.5% compared with 2.6% for the bar gene.

The objective of this work was to identify major and minor?effect quantitative trait loci (QTL) for resistance to races 3, 9, and 14 of soybean cyst nematode (SCN) in Hartwig cultivar; to map new resistance QTLs for these races; and to check for the existence of epistatic interactions between QTLs. Cultivar Hartwig is an important resistance source to SCN. Recombinant inbred lines (RIL) obtained from a cross between 'Hartwig' (resistant) and Y23 (susceptible) were evaluated regarding resistance to the three races. New genomic regions for resistance to SCN were identified by microsatellites. Four QTLs, which explained between 12 and 34% of phenotypic variance, were detected for resistance to race 3 in linkage groups (LG) A2, G, J, and M. The QTL in LG G is also important for resistance to race 9. Epistatic interactions were detected between loci, which indicate resistance to races 9 and 14. There are high and low? effect resistance QTLs to SCN. QTLs de resistência ao nematoide do cisto da soja, raças 3, 9 e 14 na cultivar Hartwig: O objetivo deste trabalho foi identificar locos associados a características quantitativas (QTL) de efeito maior e menor para a resistência às raças 3, 9 e 14 do nematoide do cisto da soja (NCS) na cultivar Hartwig, mapear novos QTLs de resistência para estas raças e verificar a existência de interações epistáticas entre QTLs. A cultivar Hartwig é uma importante fonte de resistência ao NCS. Linhagens endogâmicas recombinantes (LER) obtidas do cruzamento entre 'Hartwig' (resistente) e Y23 (suscetível) foram avaliadas quanto à resistência às três raças. Novas regiões genômicas de resistência ao NCS foram identificadas por microssatélites. Quatro QTLs, que explicaram entre 12 e 34% da variância fenotípica, foram detectados para a resistência à raça 3 nos grupos de ligação (GL) A2, G, J e M. O QTL no GL G também é importante para a resistência à raça 9. Interações epistáticas foram detectadas entre loci, o que indica resistência às raças 9 e 14. Há QTLs de maior e menor efeito para a resistência ao NCS.

The objective of this work was to evaluate the soybean inheritance of resistance to cyst nematode races 3 and 14. The following populations where evaluated: one population of recombinant inbred lines (RILs) [Hartwig (resistant) x Y23 (susceptible line)] for races 3, 14 and 9; one population of families F2:3 [M-SOY 8001 (resistant) x MB/BR 46 – Conquista (susceptible)] for race 3; and one population of families F2:3 [(S5995 (resistant) x BRSMG Renascença (susceptible)] for race 14. In RIL populations, four epistatic genes were identified which conditioned resistance to race 14, and three epistatic ones for resistance to races 3 and 9. The lack of one gene provided moderate resistance under all situations. The highest number of genes for resistance to race 14 points out that genes responsible for lower effects might be involved. In population F2:3 from M-SOY 8001 x MB/BR 46 – Conquista, one recessive gene for moderate resistance and two recessive genes complete resistance to race 3 were identified. Two recessive genes conditioning moderate resistance to race 14 were identified in population F2:3 from the crossing S5995 x BRSMG Renascença. These results will be useful in designing crossings, involving these parentals, with higher possibility to accumulating genes that provide resistance to several SCN races. RESUMO- O objetivo deste trabalho foi avaliar, em soja, as heranças da resistência ao nematóide de cisto da soja, raças 3 e 14. As seguintes populações foram avaliadas: uma linhagem endogâmica recombinante (RILs) [Hartwig (resistente) x Y23 (suscetível)], para as raças 3, 14 e 9; uma população de famílias F2:3 [(M-SOY 8001 (resistente) x MB/BR 46 ? Conquista (suscetível)], para a raça 3; e uma população de famílias F2:3 [S5995 (resistente) x BRSMG Renascença (suscetível)], para a raça 14. Foram identificados nas populações RILs quatro genes epistáticos que condicionaram resistência à raça 14 e três genes epistáticos para a resistência às raças 3 e 9. A falta de um dos genes proporcionou resistência moderada em todas as situações. Na população F2:3 de M-SOY 8001 x MB/BR 46 ? Conquista, foi identificado um gene recessivo para resistência moderada à raça 3 e dois genes recessivos para a resistência completa. Na população F2:3do cruzamento S5995 x BRSMG Renascença foram identificados dois genes recessivos que condicionaram resistência moderada à raça 14. Estes resultados visam contribuir no delineamento de cruzamentos, que envolvem estes parentais, com maior possibilidade de acumular genes que conferem resistência às diversas raças do nematóide de cisto da soja. Made available in DSpace on 2017-06-09T23:51:50Z (GMT). No. of bitstreams: 1 Inheritanceresistance.pdf: 392613 bytes, checksum: fa0cabff747b1e185e14c992d27ae11f (MD5) Previous issue date: 2004-11-09