Osmotic stress tolerance in forage oat varieties (Avena Sativa L.) based on osmotic potential trials

Received: April 1st, 2022 ; Accepted: December 12th, 2022 ; Published: February 7th, 2023 ; Correspondence: [email protected]; [email protected] oats (Avena sativa L.) are globally important for milk and meat production, and, to a lesser extent, for the human diet. In Mexico, oats are a strategic crop, occupying the fourth place in cultivated area, only after maize for grain, bean, and sorghum for grain. Droughts are the main problem for oat production in Mexico. This study evaluated the germination and seedling growth of several oat varieties in response to drought stress simulated by PEG-6000 treatments of different osmotic pressure in order to identify drought-resistant genotypes. The Teporaca genotype was the most outstanding in the three levels of OP compared to its control with 0.0 of Osmotic Potential (OP). The Teporaca genotype showed the largest root length and the lowest diminishment of root length under osmotic stress conditions. This genotype also had the largest shoot length in the three osmotic stress levels. Regarding root fresh weight, Babicora stands out with 98.5% and Teporaca with 43% in the most severe level. Teporaca, Menonita, and Babicora showed the outstanding root dry weights of 346.5%, 327.2%, and 251.2%, respectively. These varieties had higher root dry weight than their own controls in water in the most severe level of OP. In conclusion, the Teporaca, Menonita, and Karma genotypes showed the highest osmotic stress tolerance and could be used as sources of favorable alleles to improve oat drought tolerance

Maíz para pan en agricultura ecológica

Maize (Zea mays L.) bread is increasingly appreciated by consumers from the northwest of the Iberian Peninsula. However, the ancient maize varieties specifically selected for those uses have been replaced by hybrids with higher yield and lower flour quality. Besides, maize available comes from intensive agriculture, involving herbicides, insecticides and other potentially dangerous products. Organic production of traditional maize varieties for human consumption could be valuable for raising the returns of small local farmers in the northwest of Spain and the north of Portugal, and for matching the demands of consumers. Autochthonous varieties have been evaluated under organic farming and the quality of those with higher yield for bakery. Four autochthonous varieties were identified with the best performance under organic conditions and adequate quality for making bread and other traditional maize foods. Those varieties are "Tuy" (yellow kernel and medium growing cycle), "Sarreaus" (yellow kernel and early cycle), "Meiro" (black kernel and late cycle), and "Rebordanes" (white kernel and medium-early cycle). Traditional white, yellow and black maize varieties have been identified, and a selection program for increasing yield and quality is being performed for each.El pan de maíz (Zea mays L.) es cada vez más apreciado por los consumidores del noroeste de la Península Ibérica. Sin embargo, las antiguas variedades de maíz específicamente seleccionadas para esos usos han sido reemplazadas por híbridos con mayor rendimiento y menor calidad harinera. Además, el maíz disponible procede de agricultura intensiva, donde se usan herbicidas, insecticidas y otros productos potencialmente peligrosos para la salud. La producción ecológica de variedades tradicionales de maíz para consumo humano puede ser útil para aumentar los beneficios de los pequeños agricultores locales en el noroeste de España y norte de Portugal, así como para satisfacer las demandas de los consumidores. En este trabajo hemos evaluado variedades autóctonas en condiciones de agricultura ecológica y la calidad panificable de las variedades con mayores rendimientos. Hemos identificado cuatro variedades autóctonas con el mayor valor agronómico en condiciones de agricultura ecológica y calidad satisfactoria para hacer pan de maíz y otros alimentos tradicionales de maíz. Estas variedades son "Tuy" (grano amarillo y ciclo medio), "Sarreaus" (grano amarillo y temprana), "Meiro" (grano negro y tardía), y "Rebordanes" (grano blanco y ciclo medio). Estas variedades tradicionales de maíz blanco, amarillo y negro están siendo mejoradas para aumentar el rendimiento harinero

Evaluación agronómica de poblaciones dulces de maíz derivadas de cruzamientos entre maíz dulce y maíz grano

The adaptation of sweetcorn (Zea mays L.) to Spanish growing conditions needs to be improved, something that could be achieved by incorporating traits from field corn populations. The aim of the present study was to analyse the performance of sweetcorn populations carrying the genes sugary1 (su1) or shrunken2 (sh2), as well as sugary enhancer double mutants (su1 se1), produced by crosses between sweetcorn donor populations and the Spanish field corn populations Lazcano, Oroso and Rastrojero. The three field corn populations plus the su1, su1 se1 and sh2 populations derived from them, as well as the su1, su1 se1, and sh2 donor populations used in the crosses with the field corn populations, were evaluated for their agronomic performance. Several hybrids were used as controls. Assessments were made in Zaragoza (NE Spain) and Pontevedra (NW Spain) over two years. The ability of the field corn populations to improve the sweetcorn varieties was not greatly affected by the sweetcorn mutant involved. The field corn populations chosen as donors for improving sweetcorn must depend on the growing conditions in mind. Sweetcorn populations derived Oroso would appear to be the most favourable for northern Spain, while those derived from Rastrojero would appear to be the most suitable for inland Spain, although other field corn populations are still to be examined.La adaptación del maíz dulce (Zea mays L.) a las condiciones españolas debe ser mejorada y esto se puede realizar mediante la incorporación de factores de adaptación de las poblaciones locales. El objetivo del presente estudio fue evaluar el resultado de las poblaciones de maíz dulce sugary1 (su1), sugary enhancer (su1 se1), y shrunken2 (sh2) derivadas de las poblaciones de maíz grano Lazcano, Oroso y Rastrojero. Las tres poblaciones originales junto con las su1, su1 se1 y sh2 convertidas y las tres poblaciones utilizadas como donantes de los genes su1, su1 se1, y sh2, fueron evaluadas para comportamiento agronómico, utilizando varios híbridos como testigos. Los ensayos se realizaron en dos localidades españolas (Zaragoza y Pontevedra) durante dos años. La capacidad de las poblaciones de maíz grano para mejorar el maíz dulce no se vio en gran medida afectada por el tipo de mutante incorporado. Las poblaciones de maíz grano utilizadas como donantes dependen de las condiciones de crecimiento, siendo Oroso la más favorable para el Norte de España. Las poblaciones de maíz dulce derivadas de Rastrojero parecen ser las más convenientes para la España interior, no obstante pueden explorarse otro tipo de poblaciones de maíz grano

Heterotic patterns among french and spanish maize populations

E-mail : [email protected] audienceThe objective of this work was to identify heterotic patterns among maize (Zea mays L.) populations representing the variability of Southwestern Europe. Six Spanish and six French maize populations were crossed in a complete diallel without reciprocals. The average yield of hybrids and populations was 6.1 t ha-1; mid-parent heterosis for yield was 22.0%, ranging from 12.2% to 51.9%. The population Lazcano produced the hybrids with highest yield, followed by Tuy, Rastrojero and Millette du Lauragais (ML). The environment × population interaction was significant for yield, therefore each environment was analyzed separately in order to determine the best heterotic pattern for each environment. The heterotic patterns suggested were Tuy × Rastrojero (Pontevedra), Rastrojero × ML (Zaragoza), Bade × Millette Montagne Noire (Mauguio), and Tuy × Lazcano (Saint Martin de Hinx). The most promising early heterotic pattern was Bade × Esterre. The most promising combination across sites was Lazcano × ML with the highest yield (7.7 t ha-1) and a mean heterosis of 30.7%. The cluster analysis based on mid-parent heterosis showed three clusters, corresponding to the dry areas of Spain, northern Spain, and southern France. These clusters are consistent with previous knowledge based on history, isozymes, and RFLP. The potential heterotic patterns are dry Spain × humid Spain or dry Spain × south France, although within these groups there were also some favorable combination

Contribution of autochthonous maize populations for adaptation to European conditions

E-mail: [email protected] audienceEarly vigor, earliness and cold tolerance are the main potential contributions of European maize (Zea mays L.) for breeding programs for adaptation to areas with short growing seasons and cold springs. The objective of this research was to determine the potential contributions of populations from different European regions to breeding for adaptation. Six Spanish and six French maize populations differing on variability for earliness, vigor and cold tolerance were crossed in a complete diallel without reciprocals. The populations and their crosses were evaluated in the field and in a cold chamber. Minimum temperatures were the main environmental trait affecting genotype · environment interaction, probably due to the cold sensitivity of the genotypes with the best performance in the field. The best population cross, based on specific heterosis for adaptation-related traits in the field, was Viana · Rastrojero, but this cross was cold sensitive. Tuy · Lazcano should be the best choice for a breeding program for adaptation, based on performance in the field and cold tolerance. As conclusions, there was variability for earliness, vigor and cold tolerance among the populations and crosses involved in this study, being tolerant to cold conditions the populations with medium growing cycle originated in areas with short growing seasons. The highest yielding crosses were cold sensitiv

Performance of crosses among French and Spanish maize populations across environments

International audienceHeterotic patterns among European maize (Zea mays L.) populations are strongly affected by genotype X environment (GE) interactions and no single heterotic pattern has been identified so far that is not influenced by GE interaction. The objectives of this work were to study (i) the mean performance and stability of the heterotic patterns 'Humid Spain X Southern France' and 'Dry Spain X Humid Spain' and (ii) the influence of some environmental and genotypic covariates on G and E main effects and their interaction. We studied the GE interaction for grain yield in eight environments using Sites Regression (SREG) and factorial regression models. The biplot obtained from the SREG model allowed visual cultivar evaluation. The factorial regression model incorporated genotypic and environmental covariates that enhanced biological interpretation of GE interaction. The heterotic patterns Humid Spain x Southern France and Dry Spain X Humid Spain had similar mean performance across environments, but the former, represented by the cross Lazcano x Millette du Lauragais, was more stable. Effects of G, E, and GE for grain yield were mainly due to earliness, vigor effects, and/or environmental factors related to cold stress. An adequately long vegetative cycle along with early vigor had a great influence on the mean grain yield performance of Lazcano × Millette du Lauragais. Additionally, its intermediate number of days to silking and tolerance to temperature stresses could be related to its stability. Breeding for tolerance to temperature stresses could render more stable maize genotypes

Cross resistance of Diamondback moth implies altered interactions with domain II of Bacillus thuringiensis toxins

We compared responses to six insecticidal crystal proteins from Bacillus thuringiensis by a Cry1A-resistant strain (NO-QA) and a susceptible strain (LAB-P) of the diamondback moth, Plutella xylostella. The resistant strain showed > 100-fold cross-resistance to Cry1J and to H04, a hybrid with domains I and II of Cry1Ab and domain III or Cry1C. Cross-resistance was sixfold to Cry1Bb and threefold to Cry1D. The potency of Cry1I did not differ significantly between the resistant and susceptible strains. Cry2B did not kill resistant or susceptible larvae. By combining these new data with previously published results, we classified responses to 14 insecticidal crystal proteins by strains NO-QA and LAB-P. NO-QA showed high levels of resistance to Cry1Aa, Cry1Ab, and Cry1Ac and high levels of cross- resistance to Cry1F, Cry1J, and H04. Cross-resistance was low or nil to Cry1Ba, Cry1Bb, Cry1C, Cry1D, Cry1I, and Cry2A. Cry1E and Cry2B showed little or no toxicity to susceptible or resistant larvae. In dendrograms based on levels of amino acid sequence similarity among proteins, Cry1F and Cry1J clustered together with Cry1A proteins for domain II, but not for domain I or III. High levels of cross-resistance to Cry1Ab-Cry1C hybrid H04 show that although Cry1C is toxic to NO-QA, domain III or Cry1C is not sufficient to restore toxicity when it is combined with domains I and II of Cry1Ab. Thus, diamondback moth strain NO-QA cross-resistance extends beyond the Cry1A family of proteins to at least two other families that exhibit high levels of amino sequence similarity with Cry1A in domain II (Cry1F and Cry1J) and to a protein that is identical to Cry1Ab in domain II (H04). The results of this study imply that resistance to Cry1A alters interactions between the insect and domain II