Scientia Agropecuaria

Construction of an integral index based on macroinvertebrates to determine the quality of water with agro-industrial influence

Resumen Los índices fisicoquímicos y biológicos se vienen utilizando de manera aislada, si los parámetros de estos índices se aplicaran de manera integral, reunirían en una única medida la variabilidad funcional y estructural de los componentes bióticos y abióticos de la calidad del agua. Por ello en esta investigación se realizó un análisis integral de la calidad del agua; se utilizaron variables abióticas y macroinvertebrados acuáticos para la construcción del índice integral. Para ello se establecieron 11 puntos de muestreo que fueron seleccionados considerando distintos grados de intervención agroindustrial. Se midieron 21 variables abióticas y 27 métricas biológicas. Los macroinvertebrados fueron recolectados cuantitativamente e identificados hasta nivel taxonómico de familia. Mediante un ACP, previa estandarización y exclusión de variables no correlacionadas (VIF ≤ 10) se determinó el gradiente abiótico, que representó a las variables abióticas que explicaron las perturbaciones en el agua; con el gradiente abiótico y las métricas biológicas se realizó una correlación de Pearson, y se seleccionaron aquellas métricas biológicas que presentaron una correlación elevada y no redundante (Pearson 0.6 ≤ r ≤ 0,8); con las métricas biológicas seleccionadas se procedió a formular y categorizar el índice; finalmente, mediante una regresión lineal simple, el índice propuesto fue comparado con otros cinco índices (ICA, ICOMO, EPT, BMWP/col. y ASPT). Los resultados mostraron que el gradiente abiótico fue definido por el CP 1 que explicó el 65,5% de la varianza acumulada, representado por la altitud (r = 0,411), hierro (r = 0,345) y oxígeno disuelto (r = 0,329). Las métricas biológicas utilizadas para el diseño del índice fueron: % de raspadores, % de nadadores, NEF de orden 2, tolerancia de Ephemeroptera y Trichoptera. Se concluyó que el índice integral presenta mayor nivel predictivo (R2 = 0,87) de la calidad del agua, frente a los demás índices: ASPT (R2 = 0,79), BMWP/col. (R2 = 0,68), EPT (R2 = 0,61), ICOMO (R2 = 0,35) e ICA (R2 = 0,27).

Abstract The physicochemical and biological indices have been used in isolation; if the parameters of these indices were applied in an integrated manner, they would bring together in a single measure the functional and structural variability of the biotic and abiotic components of water quality. Therefore, in this research an integral analysis of water quality was carried out; abiotic variables and aquatic macroinvertebrates were used for the construction of the integral index. For this purpose, 11 sampling points were established and selected considering different degrees of agro-industrial intervention. 21 abiotic variables and 27 biological metrics were measured. Macroinvertebrates were quantitatively collected and identified to family taxonomic level. Using a PCA, after standardization and exclusion of uncorrelated variables (VIF ≤ 10), the abiotic gradient was determined, which represented the abiotic variables that explained the disturbances in the water; with the abiotic gradient and the biological metrics, a Pearson correlation was performed, and those biological metrics that presented a high and non-redundant correlation were selected (Pearson 0.6 ≤ r ≤ 0.8); with the selected biological metrics, we proceeded to formulate and categorize the index; finally, by means of simple linear regression, the proposed index was compared with five other indexes (ICA, ICOMO, EPT, BMWP/col. and ASPT). The results showed that the abiotic gradient was defined by CP 1 which explained 65.5% of the accumulated variance, represented by altitude (r = 0.411), iron (r = 0.345) and dissolved oxygen (r = 0.329). The biological metrics used for the index design were: % scrapers, % swimmers, NEF of order 2, Ephemeroptera and Trichoptera tolerance. It was concluded that the integral index presents a higher predictive level (R2 = 0.87) of water quality, compared to the other indices: ASPT (R2 = 0.79), BMWP/col. (R2 = 0.68), EPT (R2 = 0.61), ICOMO (R2 = 0.35) and ICA (R2 = 0.27).

Selection of stable and high-yielding lines of purple corn (Zea mays L.) var. popcorn using multi-trait stability index (MTSI)

Resumen Un enfoque novedoso para fortalecer las estrategias de mejoramiento genético de maíz es el uso del índice de estabilidad de múltiples caracteres (MTSI), este índice permite identificar genotipos más estables y de alto rendimiento con mayor confiabilidad que los métodos anteriores. Con el objetivo de seleccionar líneas S1 sobresalientes de maíz morado reventón basado en el MTSI, 80 líneas S1 de maíz morado reventón fueron evaluados en tres ambientes. Se estudiaron 11 características: volumen de expansión (VE), pericarpio pigmentado (PP), rendimiento de grano (GY), porcentaje de expansión (PE), floración masculina (FM) longitud de mazorca (LM), humedad del grano (HG), altura de planta (AP), peso de 100 granos (PG), volumen de 100 granos (VG) y tamaño del grano expandido (TG). Los resultados indicaron que las diferencias ambientales contribuyeron en mayor medida a la variación total, seguido de las diferencias genotípicas, ambos fueron significativas para todas las variables, además, la interacción genotipo x ambiente fue significativa en 10 de 11 características evaluadas. De acuerdo con el MTSI y con una presión de selección del 15%, 12 líneas S1 de maíz morado reventón fueron seleccionados como las más estables y de alto rendimiento entre los 80 genotipos evaluados. Las líneas S1 seleccionadas serán convertidas en líneas dobles haploides y evaluadas por sus habilidades combinatorias general y específica, así mismo, se determinará la capacidad antioxidante que no se conoce.

Abstract A novel approach to strengthen maize breeding strategies is the use of the multi-trait stability index (MTSI), this index allows the identification of more stable and high-yielding genotypes with greater reliability than previous methods. To select outstanding purple popcorn S1 lines based on the MTSI, 80 purple popcorn S1 lines were evaluated in three environments. 11 characteristics were studied: expansion volume (VE), pigmented pericarp (PP), grain yield (GY), expansion percentage (PE), male flowering (FM), ear length (LM), grain moisture (HG), plant height (AP), weight of 100 grains (PG), volume of 100 grains (VG) and expanded grain size (TG). The results indicated that the environmental differences contributed to a greater extent to the total variation, followed by the genotypic differences, both were significant for all the variables, in addition, the genotype x environment interaction was significant in 10 of 11 characteristics evaluated. According to the MTSI and with a selection pressure of 15%, 12 purple popcorn S1 lines were selected as the most stable and high yielding among the 80 genotypes evaluated. The selected S1 lines will be converted into double haploid lines and evaluated for their general and specific combinatorial abilities, likewise, the unknown antioxidant capacity will be determined.

Spatial and temporal evolution of olive cultivation due to pest attack, using remote sensing and satellite image processing

Resumen El cambio climático, así como la aparición de plagas y enfermedades, están afectando las plantaciones de olivos (Olea europaea L.) y la producción de aceitunas en el mundo, por lo tanto, urge la necesidad de contar con herramientas que nos ayuden a identificar la evolución espacial y temporal de los olivares, respecto al ataque de plagas, como la Orthezia olivicola y el barrenillo del olivo Phloeotribus scarabaeoides. En este trabajo utilizamos información de imágenes satelitales de libre disposición que permitieron realizar el análisis espacial y temporal y la combinación de índices de vegetación. Para la zona de estudio, según los valores del NDVI (Normalized Difference Vegetation Index) se identificó que la superficie de plantas enfermas va de 42% a 68%, plantas moderadamente sanas de 2% a 18%, y el estado de la plantación considerado como plantas muy sanas con tendencia a 0%, lo que significa que prácticamente el 100% de los olivos se encuentran con algún nivel de afectación. La variación temporal de los índices NDVI, DVI, SAVI, GNDVI, EVI2 y MSAVI, permitieron establecer los estados de afectación como leve, ataque de plagas moderado, severidad del ataque de las plagas sumado al déficit hídrico y ataque de plagas muy fuerte asociado al punto de marchitez permanente.

Abstract Climate change, as well as the appearance of pests and diseases, are affecting olive plantations (Olea europaea L.) and the production of olives in the world, therefore, there is an urgent need for tools to help us identify the spatial and temporal evolution of the olive groves, regarding the attack of pests, in this case, the Orthezia olivicola and the olive borer Phloeotribus scarabaeoides. In this work, we use information from freely available satellite images that allowed us to carry out spatial and temporal analysis and the combination of vegetation indices. For the studied area, according to the values of the NDVI (Normalized Difference Vegetation Index), it was identified that the surface of diseased plants ranges from 42% to 68%, moderately healthy plants from 2% to 18%, and the state of the plantation considered as very healthy plants with a tendency to zero, which means that practically 100% of the olive trees are affected by some level. The temporal variation of the NDVI, DVI, SAVI, GNDVI, EVI2, and MSAVI indices, allowed us to establish the states of affectation as mild, moderate pest attack, the severity of the pest attack added to the water deficit, and very strong pest attack and state of permanent wilting.

Automatic counting of fish larvae using computer vision based on neural networks

Resumen El conteo de larvas de peces es una técnica aplicada en la acuicultura para determinar la eficiencia de la etapa de inducción y conocer la cantidad de larvas fecundadas. Por esta razón, el objetivo de este trabajo fue mejorar el conteo de larvas bajo 3 pilares fundamentales: precisión, error y tiempo. Para esto realizamos una investigación experimental bajo un diseño completo al azar con dos sistemas de conteo: tradicional y de visión artificial; cada una con 10 repeticiones, con 2000 larvas; posteriormente realizamos el conteo mediante visión artificial utilizando una cámara que capturaba las imágenes de una pecera con peces en movimiento. Los resultados muestran que el método propuesto es factible para el conteo de larvas, con un 92,65% de precisión, 7,41% de error y un tiempo promedio de 61 segundos por repetición en relación al sistema de conteo tradicional: precisión 64,44%, error 35,61% y tiempo 2009,3 s. El sistema desarrollado puede ser replicado en el sector acuícola por su efectividad y costo.

Abstract Fish larvae counting is a technique applied in aquaculture to determine the efficiency of the induction stage and to know the number of fertilized larvae. For this reason, the research aims to improve the count of larvae under 3 fundamental pillars: precision, error and time. For this, we carried out an experimental investigation under a completely randomized design with two counting systems: traditional and artificial vision; each one with 10 repetitions, with 2000 larvae; Later, we carried out the count by means of artificial vision using a camera that captured images of a fish tank with moving fish. The results show that the proposed method is feasible for counting larvae, with 92.65% accuracy, 7.41% error and an average time of 61 seconds per repetition in relation to the traditional counting system: accuracy 64.44%, error 35.61% and time 2009.3 s. The developed system can be replicated in the aquaculture sector due to its effectiveness and cost.

Chia (Salvia hispanica) seeds degradation studied by fuzzy-c mean (FCM) and hyperspectral imaging and chemometrics - fatty acids quantification

Abstract Chia seeds are nutritious food because they have a high content of protein, polyunsaturated fatty acids (omega-3 and omega-6) and phenolic compounds. During storage, fatty acids are degraded, by oxidative and hydrolytic reactions, forming free fatty acids (FFA). In this work, we used Near Infrared Hyperspectral Imaging (NIR- HSI) and chemometrics to predict FFA acid value and fatty acids concentrations in chia seeds during storage. First, we explore the hyperspectral images by Fuzzy c-means (FCM), where it is possible to observe as chemical compounds are formed or degraded during storage. Second, PLSR models were developed to predict FFA value and fatty acids concentration. RPD values reached values higher then 2.0, indicating a good ability to estimate these chemical compounds, especially polyunsaturated fatty acids omega-3 and omega-6. Finally, NIR-hyperspectral imaging coupled with chemometrics allowed us to show the chemical degradation process of chia seeds during storage, mainly associated with polyunsaturated fatty acids degradation. Besides NIR-HSI showed to be a powerful technique to quantify the main fatty acids with high accuracy.

Classification, technical efficiency, and economic performance of producers in the main productive region of quinoa in Peru

Abstract Classifying small agricultural producers based on their technical efficiency and economic performance allows us to gauge the potential to improve yield in the quinoa crop, promote local food security, and improve rural incomes. Consequently, the objective of this study was to characterize and classify quinoa producers at the Peruvian Altiplano based on their productive, economic, and social attributes, so the technical efficiency and economic performance of the identified groups can be analyzed. Hence, 409 surveys conducted among quinoa producers in the Puno region were used to run the statistical analysis using two-stage cluster techniques, stochastic frontier, linear regression, and ANOVA tests. The results revealed that three groups of producers exhibited discriminating variables in the use of fertilizers, organic fertilizers, weed control, application of fungicides, production of quinoa, the total area of all crops, and achievement of economic benefits. It was evidenced that the use of seeds and fertilizers, in optimal quantities, increased yield, and in combination with quinoa sales, were the significant variables to differentiate technical efficiency. The high Andes are characterized by smallholdings, subsistence agriculture and, agrobiodiversity conservation and, although cultivation practices are predominantly low technical efficient, it would be possible to rapidly increase agricultural performance with a better allocation of external inputs. However, this could be done to regional limits, for this reason, the role of public policy is very important so that producers can get broader access to production inputs and technical services.

Extraction of proteins secreted by the phytopathogen Macrophomina phaseolina: Selection of an efficient method that includes stimulation with its host tissue

Resumen El hongo necrotrófico, mundialmente distribuido, Macrophomina phaseolina es el agente causal de enfermedades de cultivos de importancia económica como la podredumbre carbonosa de la soja. Este hongo secreta una amplia variedad de proteínas y metabolitos que le permiten invadir la planta e iniciar el proceso de infección. La contribución de las proteínas con actividad hidrolítica secretadas por este hongo en el proceso de infección ha sido ampliamente estudiada, las proteínas sin actividad enzimática también podrían poseer un papel importante en este proceso. El análisis de proteínas totales permitiría ampliar el conocimiento sobre este patógeno, y establecer estrategias más eficientes para su control. El objetivo del presente trabajo fue evaluar tres métodos de extracción de proteínas secretadas por M. phaseolina. El hongo fue crecido en medio líquido PDB y Czapek-Dox (CZP) con y sin suplemento de hojas de soja. Las proteínas fueron extraídas del filtrado liofilizado del medio PDB utilizando tres métodos de extracción, y analizadas mediante SDS-PAGE. Se seleccionó el método de precipitación de proteínas con ácido tricloroacético en acetona ya que mostró una mejor resolución del perfil proteico. El filtrado de M. phaseolina crecido en PDB suplementado con hojas de soja (MpPDBs) presentó un mayor rendimiento de extracción de proteínas secretadas entre todas las condiciones evaluadas. Los perfiles proteicos del medio PDB con y sin suplemento, presentaron siete bandas diferenciales, una de ellas específica, detectada en MpPDBs. Estos resultados constituyen una base para estudios sobre el papel de proteínas secretadas por el hongo en el proceso de infección.

Abstract The globally distributed necrotrophic fungus Macrophomina phaseolina is the causal agent of economically important crop diseases such as soybean charcoal rot. This fungus secretes a wide variety of proteins and metabolites that allow it to invade the plant and initiate the infection process. The role of fungi secreted proteins with hydrolytic activity in the infection process has been extensively studied; proteins without enzymatic activity could also play an important role in this process. The analysis of total proteins would allow to broaden the knowledge about this pathogen and establish more efficient strategies for its control. The objective of the present work was to evaluate three methods for the extraction of proteins secreted by M. phaseolina. The fungus was grown in potato dextrose broth (PDB) and Czapek-Dox (CZP) with and without soybean leaf supplementation. Proteins were extracted from the lyophilized filtrate of PDB medium using three extraction methods and analyzed by SDS-PAGE. The protein precipitation with trichloroacetic acid in acetone was selected because it showed a better resolution of the protein profile. The filtrate of M. phaseolina grown in PDB supplemented with soybean (MpPDBs) presented the highest yield of protein extraction of secreted proteins among all conditions evaluated. The protein profiles of PDB medium with and without supplementation showed seven differential bands, one of the specific, detected in MpPDBs. These results constitute a basis for studies on the implication of proteins secreted by the fungus in the infection process.

Technological advances in obtaining, identifying and producing protein hydrolysates from fish residues by enzymatic action: bioactive and techno-functional properties, application in food, market and regulation

Resumen En la actualidad, se han desarrollado numerosas metodologías para obtener el máximo aprovechamiento de proteínas del pescado, con la finalidad de satisfacer la demanda nutricional humana, este aprovechamiento se ha realizado tanto, a partir de pescado entero como de sus residuos o subproductos (hígado, cabeza, piel, gónadas, esqueleto y vísceras) los que representan hasta el 60% del pescado entero. Potencialmente el pescado entero y los subproductos pueden utilizarse como fuentes de aminoácidos esenciales, colágeno, gelatina, lípidos poliinsaturados y enzimas. Mediante el uso de la tecnología enzimática se han obtenido hidrolizados proteicos con amplio potencial para su aplicación como ingredientes en el desarrollo y producción de alimentos fortificados, debido a sus propiedades funcionales (antihipertensivos, antioxidantes, antimicrobianos e inmunomoduladores) los que pueden reducir los riesgos de cáncer, envejecimiento, diabetes y enfermedades cardiovasculares. Además, estos hidrolizados presentan importantes propiedades tecno-funcionales (formación de espuma, solubilidad, emulsificación, gelificación, retención de agua y aceite) que proveen características tecnológicas deseables para el procesamiento, almacenamiento y calidad del producto, así como para el comportamiento durante el procesamiento y almacenamiento. Esta revisión analiza los avances en la tecnología de obtención, identificación y producción de hidrolizados proteicos de pescado (FPH) por acción enzimática, con énfasis en residuos de pescado destacando la aplicación de los FPH en alimentos, el análisis de mercado y las regulaciones globales. Se recomienda continuar los estudios de optimización de producción enzimática de FPH a fin de lograr mejorar el sabor y su aplicación en la fortificación de alimentos de consumo masivo.

Abstract At present, numerous methodologies have been developed to obtain the maximum use of fish proteins, to satisfy human nutritional demand, this use has been made both from whole fish and from its residues or by-products (liver, head, skin, gonads, skeleton, and viscera) which represent up to 60% of the whole fish. Whole fish and by-products can potentially be used as sources of essential amino acids, collagen, gelatin, polyunsaturated lipids, and enzymes. Using enzymatic technology, protein hydrolysates have been obtained with ample potential for their application as ingredients in the development and production of fortified foods, due to their functional properties (antihypertensive, antioxidant, antimicrobial and immunomodulatory), which can reduce the risk of cancer, aging, diabetes, and cardiovascular diseases. In addition, these hydrolysates have important techno-functional properties (foaming, solubility, emulsification, gelation, water, and oil retention) that provide desirable technological characteristics for processing, storage and product quality, as well as for behavior during processing. and storage. This review analyzes the advances in the technology for obtaining, identifying, and producing fish protein hydrolysates (FPH) by enzymatic action, with an emphasis on fish residues, highlighting the application of FPH in food, market analysis and global regulations. It is recommended to continue the studies to optimize the enzymatic production of FPH to improve the flavor and its application in the fortification of mass consumption foods.