Contribution of autochthonous maize populations for adaptation to European conditions

Early 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 sensitive.Research supported by the Ministry of Science and Technology (Ref. HF1999-0138), the Ministère de l’Education Nationale et de la Recherche, the Committee for Science and Technology of Spain (Project AGL2004-06776), the Autonomous government of Galicia (PGIDIT04RAG403006PR), the Excma. Diputación Provincial de Pontevedra, and the European Union (RESGEN 88 CT96).Peer reviewe

Defensive changes in maize leaves induced by feeding of Mediterranean corn borer larvae

[Background] Plants can respond to insect attack via defense mechanisms that reduce insect performance. In this study, we examined the effects of several treatments applied to two maize genotypes (one resistant, one susceptible) on the subsequent growth and survival of Sesamia nonagrioides Lef. (Mediterranean corn borer, MCB) larvae. The treatments were infestation with MCB larvae, application of MCB regurgitant upon wounding, wounding alone, or exposure to methyl jasmonate, and they were applied at the V6–V8 stage of maize development. We also monitored changes in the concentrations of compounds known to be involved in constitutive resistance, such as cell wall-bound hydroxycinnamates and benzoxazinoids.[Results] In both maize genotypes, the leaves of plants pre-infested with MCB larvae were less suitable for larval development than those from untreated plants. Application of MCB regurgitant upon wounding, and wounding itself, resulted in leaf tissues becoming less suitable for larval growth than those of pre-infested plants, suggesting that there could be herbivore-associated effector molecules that suppress some wounding responses. A single application of MCB regurgitant did not seem to mimic feeding by MCB larvae, although the results suggested that regurgitant deposited during feeding may have enhanced ferulates and diferulates synthesis in infested vs. control plants. Jasmonic acid may play a role in mediating the maize response to MCB attack, but it did not trigger hydroxycinnamate accumulation in the leaves to a level comparable to that induced by larval leaf feeding. The EP39 maize genotype showed an increase in leaf cell wall strength by increasing hemicellulose cross-linking in response to MCB attack, while induced defenses in the EP42 plants appeared to reflect a broader array of resistance mechanisms.[Conclusions] The results indicated that leaf feeding by MCB larvae can increase leaf antibiosis against MCB in two maize genotypes with contrasting levels of resistance against this borer. Also, the larval regurgitant played a positive role in eliciting a defense response. We determined the effects of the plant response on larval growth, and detected defense compounds related to borer resistance.This research was supported by the National Plan for Research and Development of Spain (AGL2012-33415, AGL2015-67313-C2-1-R, and AGL2015-67313-C2-2-R) co-financed by the European Social Fund (FEDER). R. Santiago acknowledges postdoctoral contract “Ramón y Cajal” financed by the Ministry of Economy and Competitiveness (Spain), Vigo University, and the European Social Fund.Peer reviewe

El nabicol: un recurso fitogenético de interés para Galicia

100 páginas.- Memoria para optar al grado de licenciado en Biología por la Universidad de Vigo1. Las poblaciones locales de Brassica napus var. pabularia que se cultivan en Galicia, presentaron una gran homogeneidad para los distintos caracteres tanto cuantitativos como cualitativos analizados, agrupándose la gran mayoría en un único grupo. 2. La variedad de nabicol más adecuada para la producción hortícola fue MBG-BRS0063, que presentó los mayores rendimientos en fresco y seco en todos los ambientes, si bien la variedad MBG-BRS0337 fue más adecuada para su cultivo en zonas del interior. En cuanto a la obtención de semilla, las variedades más productivas fueron MBG-BRS0029 y MBGBRS0134. 3. Aunque las plantas alcanzaron un desarrollo normal en la siembra de primavera, ésta supone una pérdida de rendimiento, tanto en seco como en fresco, frente a la siembra de otoño (siembra tradicional). Además, las plantas se ven más afectadas por el ataque de plagas de lepidópteros, por lo que el nabicol no parece ser un cultivo adecuado para la siembra de primavera. 4. Todas las variedades presentaron una buena aceptación por parte del panel de catadores equivalente al de la variedad comercial. Además, debido a los niveles de fibra ácido detergente y proteína bruta, las variedades locales gallegas de nabicol podrían también utilizarse en la alimentación del ganado, al igual que ocurre con otros cultivos de brásicas presentes en la agricultura gallega. De este modo se obtendría un doble aprovechamiento: hortícola y ganadero.Peer reviewe

Importance of Daily Rhythms on Brassicaceae Phytochemicals

© 2021 by the authors.The circadian clock serves to coordinate metabolism and physiology with the diurnal cycles derived from the daily rotation of the earth. In Brassicaceae, circadian rhythms contribute to the temporal daily variation in diverse phytochemicals and, hence, to both resistance to biotic stress and edible crop health value. Understanding the temporal variation in the specialized metabolites present in Brassica crops can improve selection and future breeding strategies. In this review, we focus on the importance of daily rhythms in the phytochemical biochemistry of the main bioactive compounds present in Brassicaceae plants. We provide a general overview of the mechanisms that can drive the daily variation in phytochemical levels and then provide specific examples of compounds that show daily variation. Finally, we discuss how these rhythmic patterns in plant phytochemicals may impact plant protection against biotic stress, the content of nutraceuticals, and the longevity of post-harvest crops.This effort was funded by the grants RTI2018-094650-J-I00 and RYC2019-027834-I by the Spanish Ministry of Science, Innovation and Universities to Marta Francisco.Peer reviewe

Maximizing the Reliability of Genomic Selection by Optimizing the Calibration Set of Reference Individuals: Comparison of Methods in Two Diverse Groups of Maize Inbreds (Zea mays L.)

Genomic selection refers to the use of genotypic information for predicting breeding values of selection candidates. A prediction formula is calibrated with the genotypes and phenotypes of reference individuals constituting the calibration set. The size and the composition of this set are essential parameters affecting the prediction reliabilities. The objective of this study was to maximize reliabilities by optimizing the calibration set. Different criteria based on the diversity or on the prediction error variance (PEV) derived from the realized additive relationship matrix–best linear unbiased predictions model (RA–BLUP) were used to select the reference individuals. For the latter, we considered the mean of the PEV of the contrasts between each selection candidate and the mean of the population (PEVmean) and the mean of the expected reliabilities of the same contrasts (CDmean). These criteria were tested with phenotypic data collected on two diversity panels of maize (Zea mays L.) genotyped with a 50k SNPs array. In the two panels, samples chosen based on CDmean gave higher reliabilities than random samples for various calibration set sizes. CDmean also appeared superior to PEVmean, which can be explained by the fact that it takes into account the reduction of variance due to the relatedness between individuals. Selected samples were close to optimality for a wide range of trait heritabilities, which suggests that the strategy presented here can efficiently sample subsets in panels of inbred lines. A script to optimize reference samples based on CDmean is available on request.This research was jointly supported as “Cornfed project” by the French National Agency for Research (ANR), the German Federal Ministry of Education and Research (BMBF), and the Spanish Ministry of Science and Innovation (MICINN). R. Rincent is jointly funded by Limagrain, Biogemma, Kleinwanzlebener Saatzucht AG (KWS), and the Association Nationale de la Recherche et de la Technologie (ANRT).ANRBMBFMICINNKWSANRTPeer reviewe

Valor hortícola de las variedades gallegas de Brassica rapa L.

4 páginas, 1 figura y 1 tabla -- Trabajo presentado en el II Congreso de Mejora Genética de Plantas, celebrado en León (España) del 21 al 24 de septiembre de 2004.En los años 80 se inició en la Misión Biológica de Galicia (CSIC) una recolección de variedades locales de Brassica oleracea L., Brassica napus L. y B. rapa (Ordás y Baladrón 1985), que actualmente se está completando con muestras de aquellas zonas de la geografía gallega que no estaban inicialmente representadas. Actualmente se conservan 284 variedades de B. oleracea, 220 de B. rapa y 50 de B. napus, lo que hace un total de 554 entradas. Con las primeras variedades recolectadas se realizaron estudios citológicos (Ordás y Baladrón 1985) e isoenzimáticos (Arús et al. 1987) y una caracterización morfológica que únicamente incluyó 30 variedades de B. rapa (Baladrón y Ordás 1989). El objetivo de este trabajo es hacer una caracterización morfológica y agronómica de las 120 variedades de B. rapa que se conservaban en el banco de germoplasma de la Misión Biológica de Galicia en el momento de iniciarlo con el fin de seleccionar aquellas que presenten buenas aptitudes para su cultivo como nabizas y grelos para incluirlas en futuros programas de mejora, así como conocer la diversidad genética de la especie en el germoplasma gallego y establecer relaciones entre variedades.Agradecimientos al Cabildo Insular de La Palma y al Ministerio de Ciencia y Tecnología.Peer reviewe

Caracterización agronómica de variedades locales gallegas de Brassica rapa L

Comunicación presentada al X Congreso Nacional de Ciencias Hortícolas, celebrado en Pontevedra en mayo de 2003.Peer reviewe

Evaluación de variedades gallegas de nabicol (B. napus var. pabularia) en siembra precoz

Comunicación presentada al X Congreso Nacional de Ciencias Hortícolas, celebrado en Pontevedra en mayo de 2003.Peer reviewe

Evaluation of European maize germplasm under cold conditions

Maize (Zea mays L.) is a tropical crop with low tolerance to cold conditions and has to be planted late in temperate areas due to low temperatures. The objective of this research was to identify new cold tolerant populations among the European germplasm useful for improving adaptation to early sowing. For that, the European Union Maize Landraces Core Collection (EUMLCC) was evaluated under cold conditions. After a preliminary screening of 95 populations the 11 populations with best germination and early growth under cold conditions were multiplied and evaluated in a cold chamber and in early field sowings at two locations during 2 years. The cold tolerant populations from the EUMLCC were not significantly different from the cold tolerant checks in the cold chamber. In early field sowing, some EUMLCC populations had similar emergence than the commercial checks and the coldest tolerant hybrids, and higher vigor than all the hybrids and the yield of some of the populations surpassed the yield of the cold tolerant hybrids. Altogether, Aranga1 emerged as the most promising candidate as base population for improving adaptation to early sowing.Research was supported by the Spanish National Plan for Research and Development (AGF2004-06776, AGL2007-64218), the Autonomous Government of Galicia (PGIDIT04RAG403006PR) and the Excma. Diputacion Provincial de Pontevedra.Peer reviewe

The nabicol: a horticultural crop in northwestern Spain

Nabicol (B. napus L. var. pabularia) is a traditional crop in the Northwest of Iberian Peninsula (South of Galicia and North of Portugal) where it is grown during the winter season on small farms and gardens using traditional varieties. A collection of 36 populations of nabicol from Galicia (northwestern Spain) was evaluated during 2002 and 2003 in two locations and two growing seasons (spring/summer and autumn/spring) for 28 agronomic and morphological traits. The objectives of this study were to: (i) evaluate a collection of nabicol landraces from northwestern Spain, (ii) determine the suitability of this germplasm as a summer crop and (iii) study the genetic diversity among local populations. Significant differences were observed among populations for most traits. Genotype × environment interaction was significant for most of them. Spring/summer growing season could be recommended for growing nabicol but resistance to Lepidoptera pests attacking Brassica crops should be improved. Most populations had an agronomic value similar to the commercial variety. The most promising variety for horticultural use was MBG-BRS0063, which showed the highest yield. Morphological and agronomic data were subjected to cluster analysis and four groups were defined with a group clustering most populations. The low genetic diversity could be explained because populations were collected in close geographical areas and the selection made by farmers was always for a horticultural use. These results give information about the diversity and breeding value of the nabicol Spanish germplasm, which could be useful in breeding programsResearch was supported by the National Plan for Research and Development (AGL2002-03057), Autonomous Government of Galicia, INIA, and Excma. Diputación Provincial de Pontevedra. V.M. Rodríguez acknowledges a fellowship from the Ministry of Science and Technology from Spain. G. Padilla acknowledges a fellowship from the Cabildo Insular de la Palma.MCYTXunta GaliciaDiputación Provincial de PontevedraCabildo insular de La PalmaPeer reviewe