Cold and salt stress regulates the expression and activity of a chickpea cytosolic Cu/Zn superoxide dismutase

A cDNA clone encoding a cytosolic superoxide dismutase (SOD) was isolated from a cDNA library constructed from poly(A) RNA from epicotyls of 5-day-old Cicer arietinum L. etiolated seedlings after a differential screening to select clones whose expression decreases with epicotyl growth. Analysis of its deduced amino acid sequence showed all the typical structural motifs of plant cytosolic SODs (EC 1.15.1.1.). The expression of this clone is always higher in young and growing tissues than in old and storage ones, and diminishes throughout the development of the seedlings. Cytosolic Cu/Zn-SOD activity is also higher in radicles and younger internodes. Under stress conditions only cold increases the gene expression whereas the activity is clearly raised up by a saline medium. The results are discussed in relation to the gene regulation and enzyme activity control that crop plants use to resolve the different stresses that reduce their productivity.This research was supported by grants from the Dirección General de Enseñanza Superior e Investigación Científica (DGESIC), Spain (PB98-0290) and from the Junta de Castilla y León (SA105/01)

Efeito do tamanho das partículas de calcário nos teores de Ca, Mg e K no solo e em plantas forrageiras

Liming increases crop production through improved soil conditions in acidic soils. Among the effects of liming, increased availabilities of alkaline and alkaline-earth cations are worth mention. These availabilities may be affected by the particle size of applied limestone, which influences lime reactivity. The effects of particle size and application schedule of magnesium limestone were investigated on extractable Ca, Mg and K in soil, their concentrations in sward plants and dry-matter yield. Magnesium limestone of various particle sizes was applied to experimental plots at a rate of 3 t ha-1, a grass-clover sward was sown, and the plots were monitored during three years. The finest limestone (< 0.25 mm) in a single application yielded the highest soil Ca and Mg concentrations extracted by Mehlich-3 and NH4Cl. The same limestone split in three annual doses was less effective. Plots treated with the coarsest limestone (2-4 mm) did not differ from control plots. Liming had no effect on potassium, either in soil or plants. Soil concentrations of Ca, Mg and K extracted by Mehlich-3 and NH4Cl were correlated with each other (r = 0.76, 0.75 and 0.67, respectively). NH4Cl extracted more Ca than Mehlich-3, while the latter extracted more Mg and K than NH4Cl. Soil Ca, Mg and K extracted by NH4Cl were also correlated to water extractions. Mg concentration in plants correlated to soil Mg extracted by NH4Cl or by water. Neither the concentrations nor the total contents of Ca and K in plants correlated with extractable soil Ca and K. The total dry matter yield was not affected by liming. The yield of sown species was higher in plots treated with the finest limestone than in plots limed with the coarsest limestone. Cations extracted by water or NH4Cl explained the variance of dry matter yield.A aplicação de calcário em solos ácidos promove aumento da produção agrícola por meio da melhoria das condições do solo. Entre os efeitos da calagem, o aumento da disponibilidade de cátions alcalinos e alcalino-terrosos são dignos de menção. Essas disponibilidades podem ser afetadas pelo tamanho das partículas do calcário aplicado, que influencia a solubilidade do mesmo. Investigaram-se os efeitos da granulometria e épocas de aplicação de calcário magnesiano nos cátions trocáveis Ca, Mg e K extraidos no solo, nas suas concentrações em plantas crescidas cultivadas nesse solo e no rendimento das suas matérias secas. Vários tamanhos de partículas de calcário magnesiano foram aplicadas às parcelas experimentais, a uma taxa de 3 t ha-1, gramíneas e trevo foram plantados e as parcelas foram monitoradas durante três anos. O calcário mais fino (< 0,25 mm) em uma única aplicação proporcionou os maiores teores de Ca e Mg extraídos por Mehlich-3 e por NH4Cl. Este mesmo calcário quando aplicado parcelado em três doses anuais foi menos eficaz. Parcelas tratadas com o clacário mais grosseiro (2-4 mm) não diferiram da testemunha. A calagem não teve efeito sobre o potássio, quer seja no solo ou nas plantas. As concentrações no solo de Ca, Mg e K extraídos por Mehlich-3 e NH4Cl foram positivamente correlacionadas. O NH4Cl extraiu mais Ca do que o Mehlich-3, enquanto o segundo extraíu mais Mg e K do que o NH4Cl. O Ca, Mg e K extraídos pelo NH4Cl foram também correlacionados com extrações por água. Concentrações de Mg em plantas estão relacionadas com concentrações de Mg no solo extraídos pelo NH4Cl ou pela água. Nem as concentrações ou teores totais de Ca e K nas plantas correlacionaram-se com as concentrações extraídas de Ca e K do solo. O rendimento de matéria seca total não foi afetado pela calagem. A produtividade das espécies cultivadas foi maior nas parcelas tratadas com os calcários mais finos do que em parcelas com calcário mais grosseiro. Cátions extraídos pela água ou NH4Cl correlacionaram-se com a variação da produção de matéria seca.This research was supported by autonomous Government of GalicianS

How to identify edible-pod pea varieties in a germplasm collection

In breeding of multi-purpose crops, such as peas (Pisum sativum), there is always a concern about which are the best quantitative descriptors to characterize germplasm for each one of their uses and to apply in multi-trait selection in breeding programs (3, 7). The characterization of the genetic material has to be mostly based upon high heritable traits in order to know the variability within the collection. Only those characters that show consistent genetic versus environmental basis should be taken into account, because those markedly influenced by the environment are unreliable and uneven from one place to another. As many metrical characters (that are important from an agricultural point of view but has not been yet genetically analyzed) either have low stability in different environments or their genetic basis are low, they are not able to be used for breeding programs until they were better known. Instead, reproductive characters less affected by environmental factors and interactions must be considered (2). They are useful along with the habitual quantitative ones when the material is intended for a breeding program.Peer reviewe

El tirabeque: Posibles alternativas en los cultivos hortícolas de Galicia

Xunta de Galicia: proyectos XUGA40301B92 y XUGA40302B94.Peer reviewe

Incremento de azúcares y clorofila en la aclimatación del guisante al frío

4 páginas.- Trabajo presentado en el Seminario organizado por el Area de Genétíca de la Universidad de Santiago de Compostela y la Sociedad Española de Genética (Sección de Mejora de Plantas), con la colaboración de la Sociedad Española de Ciencias Hortícolas (Grupo de Mejora Genética) celebrado en el Campus Universitario de Lugo en octubre de 2000.Está bien establecido que los daños causados por el frío se deben a la desestabilización de las membranas celulares por la deshidratación que experimentan (Thomashow, 1999). El ajuste osmótico contribuye a su estabilización, no sólo por aumentar la capacidad de retención de agua. sino también porque se produce síntesis de moléculas crioprotectoras (Strauss y Hauser, 1986). Los pigmentos fotosintéticos están unidos a las membranas tilacoidales. Cuando se altera la estructura de estas, los pigmentos se liberan y degradan. Por ello, para desarrollar un protocolo que permita identificar líneas de guisante (Pisum sativum) resistentes al frío, medimos su capacidad de síntesis de azúcares y de retención de clorofila tras un tratamiento de bajas temperaturas. Este trabajo se enmarca en un proyecto de selección de líneas puras de guisante adaptadas a las condiciones agroclimáticas del interior de Galicia.Peer reviewe

La fotosíntesis a bajas temperaturas permite detectar plantas tolerantes al frío en guisante

3 páginas.- Trabajo presentado en el Seminario organizado por el Area de Genétíca de la Universidad de Santiago de Compostela y la Sociedad Española de Genética (Sección de Mejora de Plantas), con la colaboración de la Sociedad Española de Ciencias Hortícolas (Grupo de Mejora Genética) celebrado en el Campus Universitario de Lugo en octubre de 2000.El objetivo del trabajo fue desarrollar un protocolo que, de forma rápida y sencilla, permita detectar líneas de guisante (Pisum sativum) tolerantes al frío, con el fin de poder seleccionar líneas puras del banco de germoplasma de la Misión Biológica de Galicia, para utilizarlas en un programa de mejora genética, encaminado a la selección de variedades de alto rendimiento. adaptadas a las condiciones agroclimáticas del interior de Galicia. El frío es un factor muy Iimitante de la fotosíntesis, por lo que la tolerancia al frío debe de incluir algún mecanismo de protección del proceso, del que depende la producción de las cosechas.Peer reviewe

Sources of variation for sustainable field pea breeding

The pea crop (Pisum sativum L.) is a convenient source of plant protein for animal feeding. The objective of this research was to evaluate field pea breeding lines for agronomic performance and seed quality focussed to their use in a sustainable production. Thirty-five field pea breeding lines and six elite cultivars were evaluated for their agronomic value in field in Spain upon 20 traits related to flower, cycle, plant architecture, productivity and seed quality. The lines showed significant differences in all the quantitative traits evaluated and three of them, namely MB-0307, MB-0308, and MB-0319 were chosen to be evaluated, together with the advanced cultivar ZP-1233, in field and in growing chamber for agronomic performance, seed quality and ability for sustainable production. The four accessions displayed high seed protein content that had significant effect of cropping density with averages of 253.6 g kg−1 under low cropping density of 60 plants m−2 and 259.1 g kg−1 under high cropping density of 90 plants m−2, therefore, the low cropping density should be regarded as the most convenient. Average yield of the lines MB-0307, MB-0308 and MB-0319 and the cultivar ZP-1233 was fair (197.5 g m−2), probably due to the absence of fertilizers and irrigation, aiming for the sustainability of the crop. Intercropping with rye and herbicide application resulted in no differences on the seed yield; therefore, the ability of the breeding lines to grow without herbicide seems to be demonstrated, while the germination of the seeds at low temperature was very good. These results indicate that field pea could be a new protein crop in the North of Spain to satisfy the demand of plant protein for animal feed, based upon adapted breeding lines that combine the ability for growing under sustainable conditions with other desirable agronomic traits maintaining an adequate productivityResearch was supported by the INLUDES (Lugo, Spain) and the projects RF95-011-C3-3 from the Spanish Government, and XUGA40302B94 and PGIDIT03RAG19E from the Galician Government. The authors are grateful to Xuncoga SCG and Diputación de Pontevedra (Pontevedra, Spain) for farm facilities, to UNIP (Paris, France) for providing statistics about pea production, to C. Caminero for supplying pea seeds, and to X. Iglesias, M. Güimil, S. Rodríguez, J. Iglesias and M. Rey for technical assistance.INLUDESMAPAXunta de GaliciaPeer reviewe

Cultivo de guisante proteaginoso para alimentación animal: su uso como grano seco proteaginoso es un componente importante en la dieta ganadera

Programa de mejora genética del guisante seco proteaginoso a partir de variedades locales realizado desde 1992 por el Grupo de Investigación de Mejora de Leguminosas del CSIC y la Universidad de Santiago de Compostela, con el fin de potenciar su producción agraria como materia prima necesaria para la fabricación de piensos.Diputación de Lugo (INLUDES) y Xunta de Galicia (proyecto de investigación PGIDT99AGR29102).Peer reviewe