Repositorio Nacional

Context: Wheat crop growth models from all over the world have been calibrated on the Groot and Verberne (1991) data set, collected between 1982 and 1984 in the Netherlands, in at least 28 published studies to date including various recent ones. However, the recent use of this data set for calibration of potential yield is questionable as actual Dutch winter wheat yields increased by 3.1 Mg ha-1 over the period 1984 – 2015. A new comprehensive set of winter wheat experiments, suitable for crop model calibration, was conducted in Wageningen during the growing seasons of 2013–2014 and of 2014–2015. Objective: The present study aimed to quantify the change of winter wheat variety traits between 1984 and 2015 and to examine which of the identified traits explained the increase in wheat yield most. Methods: PCSE-LINTUL3 was calibrated on the Groot and Verberne data (1991) set. Next, it was evaluated on the 2013–2015 data set. The model was further recalibrated on the 2013–2015 data set. Parameter values of both calibrations were compared. Sensitivity analysis was used to assess to what extent climate change, elevated CO2, changes in sowing dates, and changes in cultivar traits could explain yield increases. Results: The estimated reference light use efficiency and the temperature sum from anthesis to maturity were higher in 2013–2015 than in 1982–1984. PCSE-LINTUL3, calibrated on the 1982–1984 data set, underestimated the yield potential of 2013–2015. Sensitivity analyses showed that about half of the simulated winter wheat yield increase between 1984 and 2015 in the Netherlands was explained by elevated CO2 and climate change. The remaining part was explained by the increased temperature sum from anthesis to maturity and, to a smaller extent, by changes in the reference light use efficiency. Changes in sowing dates, biomass partitioning fractions, thermal requirements for anthesis, and biomass reallocation did not explain the yield increase. Conclusion: Recalibration of PCSE-LINTUL3 was necessary to reproduce the high wheat yields currently obtained in the Netherlands. About half of the reported winter wheat yield increase was attributed to climate change and elevated CO2. The remaining part of the increase was attributed to changes in the temperature sum from anthesis to maturity and, to a lesser extent, the reference light use efficiency. Significance: This study systematically addressed to what extent changes in various cultivar traits, climate change, and elevated CO2 can explain the winter wheat yield increase observed in the Netherlands between 1984 and 2015.

Light Use Efficiency Potential Yield CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CROP MODELLING LIGHT PHENOLOGY MAXIMUM SUSTAINABLE YIELD TRITICUM AESTIVUM WINTER WHEAT

An anion conductance, the essential component of the hydroxyl-radical-induced Ion current in plant roots

IGOR POTTOSIN ALBERTO ISAAC ZEPEDA JAZO JAYACUMAR BOSE (2018, [Artículo])

Oxidative stress signaling is essential for plant adaptation to hostile environments. Previous studies revealed the essentiality of hydroxyl radicals (HO•)-induced activation of massive K+ efflux and a smaller Ca2+ influx as an important component of plant adaptation to a broad range of abiotic stresses. Such activation would modify membrane potential making it more negative. Contrary to these expectations, here, we provide experimental evidence that HO• induces a strong depolarization, from −130 to −70 mV, which could only be explained by a substantial HO•-induced efflux of intracellular anions. Application of Gd3+ and NPPB, non-specific blockers of cation and anion conductance, respectively, reduced HO• induced ion fluxes instantaneously, implying a direct block of the dual conductance. The selectivity of an early instantaneous HO•-induced whole cell current fluctuated from more anionic to more cationic and vice versa, developing a higher cation selectivity at later times. The parallel electroneutral efflux of K+ and anions should underlie a substantial leak of the cellular electrolyte, which may affect the cell’s turgor and metabolic status. The physiological implications of these findings are discussed in the context of cell fate determination, and ROS and cytosolic K+ signaling

BIOQUÍMICA Anions Membrane potentials (Electrophysiology) Patch-clamp techniques (Electrophysiology) Oxidative stress Anion conductance Electrolyte leakage Hydroxyl radical

Carbon sequestration potential, challenges, and strategies towards climate action in smallholder agricultural systems of South Asia

ML JAT Debashis Chakraborty Jagdish Ladha C.M. Parihar Ashim Datta Hari Sankar Nayak Dharamvir Singh Rana Bruno Gerard (2022, [Artículo])

Carbon Stock Global Warming Potential CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA BALANCED FERTILIZATION CARBON SEQUESTRATION CONSERVATION AGRICULTURE GLOBAL WARMING

PROPUESTA DE MANEJO DE LA PESQUERÍA EMERGENTE DE MERLUZA DEL PACÍFICO NORTE Merluccius productus EN EL GOLFO DE ULLOA, BAJA CALIFORNIA SUR

PABLO MORA ZAMACONA (2023, [Tesis de doctorado])

"La merluza del Pacífico Merluccius productus se distribuye desde Alaska hasta el sur de México, con una población particular descrita al sur de la península de Baja California conocida como merluza enana, de la que poco se sabe. Dicha población actualmente no es pescada comercialmente, por lo que representa un recurso con potencial de explotación. Las pesquerías potenciales y emergentes crean desafíos y oportunidades para los administradores pesqueros que necesitan tomar decisiones sobre cómo gestionar de forma sostenible una pesquería previa a su inicio. Este trabajo propone y analiza posibles medidas alternativas de gestión pesquera para esta potencial pesquería, bajo incertidumbre biológica y de mercado. Debido al desconocimiento de diversos aspectos de la biología del recurso primeramente se analizó el crecimiento individual del stock y posteriormente se realizó un análisis bioeconómico de la potencial pesquería.

Para el análisis del crecimiento individual se utilizó un total de 240 otolitos y datos de longitud patrón de 932 especímenes muestreados de mayo a diciembre de 2015. La formación anual de incrementos en los otolitos se verificó mediante la relación de incremento marginal y el análisis de borde. La edad se estimó a partir de recuentos de anillos en secciones sagitales de otolitos y el crecimiento se analizó mediante un enfoque de inferencia multimodelo. Se consideraron los modelos de crecimiento de von Bertalanffy (VBGM), VBGM generalizado, Gompertz, Logístico y Johnson, los cuales se ajustaron a conjuntos de datos de talla a la edad observados y retrocalculados agrupados por sexo. Según el criterio de información de Akaike, el VBGM generalizado fue el más apropiado para las hembras (L∞= 31.36 cm, k= 0.15 cm año-1), mientras que el VBGM proporcionó el mejor ajuste para los machos (L∞= 25.35 cm, k= 0.28 cm año-1).

El análisis bioeconómico de alternativas de manejo para una potencial pesquería de merluza enana indicó que una nueva pesquería de dicho stock podría ser biológicamente sostenible y económicamente rentable, bajo un conjunto de estrategias de gestión y reglas de control. Se recomienda un acceso limitado con bajo esfuerzo pesquero ya que resulta más redituable por barco y biológicamente precautorio, considerando la alta incertidumbre asociada con la explotación de una población virgen..."

"The Pacific hake Merluccius productus is distributed from Alaska to southern Mexico, with a particular population described south of the Baja California peninsula known as dwarf hake, about which little is known. This population is not currently commercially fished; hence it represents a resource with potential for exploitation. Potential and emerging fisheries create challenges and opportunities for fishery managers who need to make decisions about how to sustainably manage a fishery prior to its initiation. This work proposes and analyzes possible alternative fishery management measures for this potential fishery, under biological and market uncertainty. Due to the lack of knowledge of various aspects of the biology of the resource, the individual growth of the stock was first analyzed and subsequently a bioeconomic analysis of the potential fishery was carried out.

A total of 240 otoliths and standard-length data from 932 specimens sampled from May to December 2015 were used for the analysis of individual growth. The annual formation of otolith increments was verified using the marginal increment analysis and the edge analysis. Age was estimated from annuli counts in sagittal sections of otoliths and growth was analyzed using a multi-model inference approach. The von Bertalanffy growth models (VBGM), generalized VBGM, Gompertz, Logistic and Johnson growth models were considered, which were fitted to observed and back calculated length-at-age data sets grouped by sex. According to Akaike's information criterion, the generalized VBGM was the most appropriate for females (L∞= 31.36 cm, k= 0.15 cm year-1), while the VBGM provided the best fit for males (L∞= 25.35 cm, k= 0.28 cm year-1).

The bioeconomic analysis of management alternatives for a potential dwarf hake fishery indicated that a new fishery for said stock could be biologically sustainable and economically profitable, under a set of management strategies and control rules. Limited access with low fishing effort is recommended as it is more profitable by boat and biologically precautionary, considering the high uncertainty associated with the exploitation of an unfished stock. Despite the combination of high fishing costs and low prices, the fishery could still be profitable in the long term, although there is risk of overexploitation if high fishing effort is allowed..."

Merluza enana, stock no explotado, crecimiento individual, análisis bioeconómico, pesquería potencial Dwarf hake, unexploited stock, individual growth, bioeconomic analysis, potential fishery CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS PECES Y FAUNA SILVESTRE REGLAMENTACIÓN Y CONTROL REGLAMENTACIÓN Y CONTROL