El cultivo de ajipa. Una posible alternativa para la producción de hidratos de carbono, proteína y aceite en un sistema de agricultura sostenible

28 páginas, 6 figuras, 2 tablas, 14 referencias. Colección: Agricultura. Serie: Cultivos industriales.Puede descargarse online en https://www.juntadeandalucia.es/servicios/publicaciones/detalle/49368.htmlLa ajipa, cuyo nombre científico es Pachyrhizus ahipa (Wedd.) Parodi, es una planta de la familia Leguminosas ya cultivada por los Incas durante el período precolombino, junto con especies muy habituales y mucho más conocidas para nosotros, como el maíz y el pimiento. De la importancia de la ajipa durante el período Inca dan cuenta los hallazgos arqueológicos de restos de raíces en enterramientos humanos (Paracas-Necrópolis), y las representaciones en cerámica y bordados de distintas culturas (Mochica, Nasca).Los trabajos realizados fueron financiados mayoritariamente con fondos del proyecto de la Unión Europea AHIPA (FAIR6 CT98-4297)Peer reviewe

A Set of Lotus japonicus Gifu × Lotus burttii Recombinant Inbred Lines Facilitates Map-based Cloning and QTL Mapping

Model legumes such as Lotus japonicus have contributed significantly to the understanding of symbiotic nitrogen fixation. This insight is mainly a result of forward genetic screens followed by map-based cloning to identify causal alleles. The L. japonicus ecotype ‘Gifu’ was used as a common parent for inter-accession crosses to produce F2 mapping populations either with other L. japonicus ecotypes, MG-20 and Funakura, or with the related species L. filicaulis. These populations have all been used for genetic studies but segregation distortion, suppression of recombination, low polymorphism levels, and poor viability have also been observed. More recently, the diploid species L. burttii has been identified as a fertile crossing partner of L. japonicus. To assess its qualities in genetic linkage analysis and to enable quantitative trait locus (QTL) mapping for a wider range of traits in Lotus species, we have generated and genotyped a set of 163 Gifu × L. burttii recombinant inbred lines (RILs). By direct comparisons of RIL and F2 population data, we show that L. burttii is a valid alternative to MG-20 as a Gifu mapping partner. In addition, we demonstrate the utility of the Gifu × L. burttii RILs in QTL mapping by identifying an Nfr1-linked QTL for Sinorhizobium fredii nodulation

Efecto de la fuente de nitrógeno en la distribución de asimilados y composición de savia en ajipa (Pachyrhizus ahipa (Wedd.) Parodi)

7 páginas, 4 figuras, 1 tabla y 17 referencias. Trabajo presentado en el VI Simposium Nacional - II Ibérico sobre nutrición mineral de las plantas, Sevilla, del 12 al 15 de Noviembre de 1996. Entidades colaboradoras Junta de Andalucía, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Sociedad Española de Fisiología Vegetal, El Monte, Caja de Huelva y Sevilla y Gat Fertiliquidos. Editores Científicos: Rafael Sarmiento Solís, Eduardo O. Leidi Montes y Antonio Troncoso de Arce. (Instituto de Recursos Naturales y Agrobiología de Sevilla).[EN]:Ahipa (Pachyrhizus ahipa (Wedd.) Parodi) is a legume root crop of Andean origin which accumulates carbohydrates of industrial interest in its tuberous roots and rotenone in leaves and seeds. The aim of this work was the study of lhe effect of N source (nitrate vs symbiotic N2, fixation) on growth, assimilate partitioning and xylem sap composition. The treatments consisted in: (a) plants inoculated with an specific Rhizobium strain irrigated wilh a N free nutrient solution (T-N2); and (b) non inoculated plants irrigated with a nutrient solution contai ning 4 mM NO3K (T-NO3). Main differences in growth and assimilate allocation were observed between plants grown in different treatments: N2,-fixing plants showed an increased earliness and reduced tuberous root growth in comparison with NO3-fed plants . Dry matter allocation into leaves and shoots was higher in NO -fed plants lhan in N2-fixing plants. Nitrogen concentration in leaves, stems and roots was higher in N2-fixing plants than in NO3-fed plants. At early growth stages, main xylem sap nitrogenous solutes were amino acids and amides. At flowering, N2-fixing plants showed high concentratÍon ofureides (allantoin+allantoic acid) and the amino acid L-canavanine[ES]:La ajipa (PachyrhiZlls ahipa (Wedd) Parodi), leguminosa de origen andino, se caracteriza por la acumulación de hidratos de carbono de interés industrial en sus raíces tuberosas y la presencia de rotenona en hojas y semillas. En este trabajo hemos estudiado el efecto de la nutrición nitrogenada (fijación simbiótica de N2 ó N mineral) sobre el crecimiento, partición de asimilados y composición de savia de xilema. Los tratamientos consistieron en: (a) plantas inoculadas con una cepa especifica de Rhizobium spp. (T-N2) y (b) plantas no inoculadas (T-NO3). Las planta se cultivaron en perlita/vermiculit y se regaron con solución de Hewitt sin N (T-N2) o 4 mM NO3K (T-NO3). Se observaron importantes diferencias debidas a la fuente de N: las plantas T-N, presentaron una mayor precocidad en la floración y fructificación y un menor desarrollo de la raíz tuberosa en comparación con las plantas T-NO2. La acumulación de materia seca en hojas y tallos de las plantas también fue superior en las plantas T-NO3. La concentración de N en hojas, tallos y raices fue superior en la plantas T-N2. En estadios tempranos de crecimiento, los componentes principales de savia de xilema, en ambos tratamientos. eran aminoácidos y amidas. En floración, las plantas T-N2, presentaban altas concentraciones de ureidos (alantoina+ácido alantoico) y el principal aminoácido transportado era L-canavanina.Sección de Nutrición Mineral de la Sociedad Española de Fisiología Vegetal y Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC.Peer reviewe

Sinorhizobium fredii Strains HH103 and NGR234 Form Nitrogen Fixing Nodules With Diverse Wild Soybeans (Glycine soja) From Central China but Are Ineffective on Northern China Accessions

Sinorhizobium fredii indigenous populations are prevalent in provinces of Central China whereas Bradyrhizobium species (Bradyrhizobium japonicum, B. diazoefficiens, B. elkanii, and others) are more abundant in northern and southern provinces. The symbiotic properties of different soybean rhizobia have been investigated with 40 different wild soybean (Glycine soja) accessions from China, Japan, Russia, and South Korea. Bradyrhizobial strains nodulated all the wild soybeans tested, albeit efficiency of nitrogen fixation varied considerably among accessions. The symbiotic capacity of S. fredii HH103 with wild soybeans from Central China was clearly better than with the accessions found elsewhere. S. fredii NGR234, the rhizobial strain showing the broadest host range ever described, also formed nitrogen-fixing nodules with different G. soja accessions from Central China. To our knowledge, this is the first report describing an effective symbiosis between S. fredii NGR234 and G. soja. Mobilization of the S. fredii HH103 symbiotic plasmid to a NGR234 pSym-cured derivative (strain NGR234C) yielded transconjugants that formed ineffective nodules with G. max cv. Williams 82 and G. soja accession CH4. By contrast, transfer of the symbiotic plasmid pNGR234a to a pSym-cured derivative of S. fredii USDA193 generated transconjugants that effectively nodulated G. soja accession CH4 but failed to nodulate with G. max cv. Williams 82. These results indicate that intra-specific transference of the S. fredii symbiotic plasmids generates new strains with unpredictable symbiotic properties, probably due to the occurrence of new combinations of symbiotic signals.España, Junta de Andalucía P11-CVI-7500España Ministerio de Economía y Competitividad BIO2016-78409-

Sinorhizobium fredii Strains HH103 and NGR234 Form Nitrogen Fixing Nodules With Diverse Wild Soybeans (Glycine soja) From Central China but Are Ineffective on Northern China Accessions

Sinorhizobium fredii indigenous populations are prevalent in provinces of Central China whereas Bradyrhizobium species (Bradyrhizobium japonicum, B. diazoefficiens, B. elkanii, and others) are more abundant in northern and southern provinces. The symbiotic properties of different soybean rhizobia have been investigated with 40 different wild soybean (Glycine soja) accessions from China, Japan, Russia, and South Korea. Bradyrhizobial strains nodulated all the wild soybeans tested, albeit efficiency of nitrogen fixation varied considerably among accessions. The symbiotic capacity of S. fredii HH103 with wild soybeans from Central China was clearly better than with the accessions found elsewhere. S. fredii NGR234, the rhizobial strain showing the broadest host range ever described, also formed nitrogen-fixing nodules with different G. soja accessions from Central China. To our knowledge, this is the first report describing an effective symbiosis between S. fredii NGR234 and G. soja. Mobilization of the S. fredii HH103 symbiotic plasmid to a NGR234 pSym-cured derivative (strain NGR234C) yielded transconjugants that formed ineffective nodules with G. max cv. Williams 82 and G. soja accession CH4. By contrast, transfer of the symbiotic plasmid pNGR234a to a pSym-cured derivative of S. fredii USDA193 generated transconjugants that effectively nodulated G. soja accession CH4 but failed to nodulate with G. max cv. Williams 82. These results indicate that intra-specific transference of the S. fredii symbiotic plasmids generates new strains with unpredictable symbiotic properties, probably due to the occurrence of new combinations of symbiotic signals

LEGU-MED: Developing Biodiversity-Based Agriculture with Legume Cropping Systems in the Mediterranean Basin

Environmental degradation and the decrease of ecosystem service provision are currently of major concern, with current agricultural systems being a major driver. To meet our future environmental and sustainability targets a transformation of the agro-food systems and current agricultural value chain are crucial. One approach to redesign farming systems is the concept of biodiversity-based agriculture (BBA) which relies on sustainable diversification of biological components and their natural interactions in farming systems to maximize fertility, productivity, and resilience to external perturbations. Despite minimizing anthropogenic inputs, BBA is not yet able to meet all beneficial environmental objectives. BBA applied in the Mediterranean basin requires urgent innovation in approaches, methodologies, and models for small-holder traditional farming systems to ensure a stable provision of ecosystem services and better resilience to environmental stresses linked to climate change. Legumes are the backbone of the Mediterranean agro-ecosystems from ancient times, but their unique and wide biodiversity was not sufficiently valorized, especially by North-African countries. Here, we present LEGU-MED, a three-year international project funded by PRIMA initiative 2019. An international consortium was established involving five universities, 5 research institutes, and one private company from 8 countries: Italy, Germany, Spain, Algeria, Tunisia, Turkey, Lebanon, and Croatia. The main objective of this project is to put forward an international and well-integrated plan to valorize the legume agrobiodiversity of the Mediterranean in biodiversity-based farming systems and consequently enhance agro-ecosystem functions and services in the Mediterranean basin. The successful completion of LEGU-MED will have the following impacts on Mediterranean legume-based farming systems: (1) improve water use efficiency, (2) reduce the use of anthropogenic inputs through the maintenance of soil fertility, (3) enhance pollination and improve ecological connectivity with flora and fauna, (4) protect close-by wildland ecosystems, (5) enhance other ecosystem services (e.g., pest, disease, and weed suppression), and (6) provide healthier and safer protein-rich food. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

The Sinorhizobium fredii HH103 Lipopolysaccharide is not only relevant at early soybean nodulation stages but also for symbiosome stability in mature nodules

In this work we have characterised the Sinorhizobium fredii HH103 greA lpsB lpsCDE genetic region and analysed for the first time the symbiotic performance of Sinorhizobium fredii lps mutants on soybean. The organization of the S. fredii HH103 greA, lpsB, and lpsCDE genes was equal to that of Sinorhizobium meliloti 1021. S. fredii HH103 greA, lpsB, and lpsE mutant derivatives produced altered LPS profiles that were characteristic of the gene mutated. In addition, S. fredii HH103 greA mutants showed a reduction in bacterial mobility and an increase of auto-agglutination in liquid cultures. RT-PCR and qPCR experiments demonstrated that the HH103 greA gene has a positive effect on the transcription of lpsB. Soybean plants inoculated with HH103 greA, lpsB or lpsE mutants formed numerous ineffective pseudonodules and showed severe symptoms of nitrogen starvation. However, HH103 greA and lps mutants were also able to induce the formation of a reduced number of soybean nodules of normal external morphology, allowing the possibility of studying the importance of bacterial LPS in later stages of the S. fredii HH103-soybean symbiosis. The infected cells of these nodules showed signs of early termination of symbiosis and lytical clearance of bacteroids. These cells also had very thick walls and accumulation of phenolic-like compounds, pointing to induced defense reactions. Our results show the importance of bacterial LPS in later stages of the S. fredii HH103-soybean symbiosis and their role in preventing host cell defense reactions. S. fredii HH103 lpsB mutants also showed reduced nodulation with Vigna unguiculata, although the symbiotic impairment was less pronounced than in soybean

Estudios fisiológicos y genéticos de estirpes de Rhizobium meliloti con vistas a la producción de inoculantes

Universidad de Granada, Facultad de Ciencias. Leída el 12-07- 198

Nitrogen and phosphorus availability limit N2 fixation in bean

Availability of nitrogen (N) and phosphorus (P) might significantly affect N2 fixation in legumes. The interaction of N and P was studied in common bean (Phaseolus vulgaris), considering their effects on nodulation and N2 fixation, nitrate reductase activity, and the composition of N compounds in xylem sap. The effect of N on the uptake of P by plants was estimated by analysing rhizospheric pH and P concentration in xylem sap and in plant shoots. Inoculated bean plants were grown in pots containing perlite/vermiculite in two experiments with different amounts of P and N. In a third experiment, bean plants were grown on two soil types or on river sand supplied with different concentrations of N. At harvest, shoot growth, number of nodules and mass, and nitrogenase activity were determined. Xylem sap was collected for the determination of ureides, amino acids, nitrate and phosphate concentration. At low nitrate concentration (1 mM), increasing amounts of P promoted both nodule formation and N2 fixation, measured as ureide content in the xylem sap. However, at high nitrate concentration (10 mM), nodulation and N2 fixation did not improve with increased P supply. Glutamine and aspartate were the main organic N compounds transported in the xylem sap of plants grown in low nitrate, whereas asparagine was the dominant N compound in xylem sap from plants grown in high nitrate. Nitrate reductase activity in roots was higher than in shoots of plants grown with low P and high N. In both soils and in the sand experiment, increased application of N decreased nodule mass and number, nitrogenase activity and xylem ureides but increased the concentration of asparagine in xylem sap. Increasing P nutrition improved symbiotic N2 fixation in bean only at low N concentrations. It did not alleviate the inhibitory effect of high nitrate concentration on N2 fixation. A decrease in plant P uptake was observed, as indicated by a lower concentration of P in the xylem sap and shoots, correlating with the amount of N supplied. Simultaneously with the specific inhibition of N2 fixation, high nitrate concentrations might decrease P availability, thus inhibiting even further the symbiotic association because of the high P requirement for nodulation and N2 fixation.This work was partially supported by Project SC93–070 (INIA-MAPA).Peer Reviewe