Instituto de Investigaciones Agropecuarias

Genetic transformation in Prunus persica genotypes could add single horticultural traits in existing cultivars without modifying their commercial characteristics. Despite this opportunity, the final setting of transformation protocols in the species endures two major limiting factors preventing the development of new varieties: (a) explants are recalcitrant in regenerating adventitious transformed shoots and (b) have a limited regeneration capability, usually extended to just a few genotypes (i.e., cultivar dependence). This protocol illustrates a procedure that has allowed the establishment of transformation methodologies in several varieties of the species and is presented here for Red Top and Elegant Lady; this methodology could help extend technical baselines for successful transformation procedures in other, potentially more recalcitrant, and newly developed cultivars or genus members.

Drought stress is a significant abiotic factor that limits plant growth and has led to widespread tree mortality worldwide. As climate change predicts longer, more severe, and unpredictable drought periods in subtropical regions, understanding how forest ecosystems cope with such stress becomes critical. This study focuses on Neltuma alba, a drought-tolerant tree species commonly found in the Gran Chaco Americano region of South America. We investigated the coexistence of different behaviors to cope with drought stress in N. alba and searched for signals of local adaptation in its populations. Using a combination of macroscopic leaf morphological traits and genetic (molecular) information in common garden experiments, we identified four behaviors in N. alba plants for coping with drought stress. These behaviors were associated with the timing of leaf senescence and survival under drought stress. Genetic markers revealed high levels of diversity within populations, providing potential for adaptive responses to changing environmental conditions. Furthermore, we observed local adaptation, with populations exhibiting distinct leaf morphological traits related to water use efficiency and transpiration rates. These traits reflect the natural selection imposed by different water regimes in each population. In conclusion, this study enriches our understanding of N. alba’s adaptive responses to drought stress and highlights the importance of considering intraspecific functional diversity and local adaptation in forest management and conservation efforts. The findings can guide the selection of drought-tolerant provenances for reforestation projects and contribute to maintaining the evolutionary resilience of forest populations in the face of climate change.

The disruptive impact of the COVID-19 pandemic on food supply has underscored the need for localized household assessments of food insecurity, particularly in developing countries where such data may be limited. Consequently, this study aims to assess the economic access to food for Chilean households in the pre- and post-pandemic scenarios. We utilized an Almost Ideal Demand System, leveraging Household Consumption Surveys to estimate the cross and own expenditure elasticities among food categories. And, to gauge the potential impact of prices on food security the quantities of food that households acquired were nutritionally scored by income quintile. Our findings pre- and post-pandemic revealed a prioritization of Meats, Grains & Cereals and Fruit & Vegetables across all households, irrespective of their socioeconomic quintile. Moreover, post-pandemic is observed a tendency towards lower-income households experiencing a higher price increment than higher-income households (p-value < 0.0001). The implementation of social protection policies, plus the articulation of agrarian, food and nutritional policies, is observed as vital for addressing food insecurity and alleviating poverty.

Placental samples for RNA extraction are collected via non-recovery (euthanasia) or invasive (surgery) methods in small ruminants, such as sheep. Alternatively, delivered placentas could be used, but the feasibility of obtaining high-quality RNA from this tissue is unknown in sheep. We aimed to evaluate the possibility of extracting RNA from naturally delivered ovine placenta, comparing two preservation methods. Twenty-seven single-pregnant sheep were monitored 24/7 from gestational day 140 to parturition. Tissue was collected after placental delivery, preserved using snap frozen (SF, n = 27) and RNAlater® (LTR, n = 27) techniques, and processed for RNA extraction using a commercial kit. RNA concentration (ng/µL), A260/280, and RNA quality number (RQN) were measured. Concentration was higher (p < 0.001) in LTR (70.39 ± 6.3) than in SF (49.77 ± 10.5), A260/280 was higher (p = 0.045) in SF (2.06 ± 0.01) than in LTR (2.03 ± 0.01), and RQN was higher (p < 0.0001) in SF (6.81 ± 0.24) than in LTR (2.84 ± 0.24) samples. Timing of placental delivery did not affect the evaluated indicators. Results indicate that extracting high-quality RNA from delivered placentas preserved via the snap-frozen technique is possible, supporting a method that aligns with the refinement principle of animals used in research.

In Chile, most potato crops are cultivated under rainfed systems, frequently facing temperature increases and water defcits during the growing season. This feld study aimed to evaluate the physiological responses and genotypic variations between the Chilean native potato variety Chona Negra and commercial varieties (Karú INIA and Desiree) when exposed to moderately high temperatures (+5.0 to+5.9 °C) for 40 days during the tuber bulking phase under diferent hydro- (or water availability) conditions. Four treatments were applied: (i) ambient temperature with rainfed conditions (T0H0), (ii) high temperature with rainfed conditions (T1H0), (iii) ambient temperature with irrigation (T0H1), and (iv) high temperature with irrigation (T1H1). The results showed that lower water availability and a moderate temperature increase (+5 °C) afected the leaf pigment content, photosynthetic performance and, chlorophyll fuorescence in both commercial and native potato genotypes. While moderately high temperatures and water defcits generally did not have stronger combined efects than each condition alone, our fndings highlight the critical role of water availability in environments like southern Chile. Notably, the native potato, Chona Negra, exhibited enhanced photosynthetic performance under higher temperatures with irrigation, associated with increases in specifc leaf area, stomatal conductance, photochemical quenching, and chlorophyll content. These findings suggest that Chona Negra may possess adaptive traits that improve its tolerance to heat stress when adequate water is available. In contrast, commercial varieties appeared more susceptible to limitations in photosynthetic activity under higher or prolonged periods of elevated temperatures.

Salinity negatively affects flower production and fertility in tomato but the underlying mechanisms are not fully understood. One hypothesis is that salinity affects sugar partitioning by reducing photosynthesis, which in turn affects source–sink relationships and hence the development of reproductive structures. This study investigates how salt stress alters sugar composition in leaves, flowers, and phloem sap of Solanum lycopersicum and its halophyte relative Solanum chilense, and how this may explain the effects on flower production and fertility. Salt stress increased flower abortion and reduced sepal length in S. lycopersicum, while decreasing pollen grain number in S. chilense. Photosynthetic nitrogen use efficiency was also reduced in S. lycopersicum. Salinity raised myo-inositol and sucrose concentrations in S. lycopersicum leaves but only slightly altered sugar concentrations in flowers. The concentration of sucrose in the foliar exudates was higher in S. chilense as compared to S. lycopersicum, suggesting a higher export of sucrose from the leaves. These findings suggest that S. lycopersicum maintains better metabolic function under salt stress, while S. chilense sustains sugar import to sink organs. Correlations between reproductive traits and sugar dynamics indicate that sugar distribution contributes to reproductive development under salinity stress.

Chile holds ~50% of temperate forests in the Southern Hemisphere, thus constituting a genetic–ecological heritage. However, intense anthropogenic pressures have been inducing distinct forest structural-regeneration patterns. Accordingly, we evaluated 22 soil properties at 0–5 and 5–20 cm depths in two protected sites, with similar perturbation records but contrasting post-disturbance regeneration stages: long-term secondary forest (~50 y) (SECFORST) (dominated by Chusquea sp.-understory) and a short-term forest after disturbance (~5 y) (FADIST) within a Nothofagus spp. forest to determine the potential of these soils to promote nutrient availability, water cycling, soil organic carbon (SOC) sequestration (CO2→SOC), and microbiome. Results detected 93 correlations (r ≥ 0.80); however, no significant differences (p < 0.05) in physical or chemical properties, except for infiltration velocity (+27.97%), penetration resistance (−23%), SOC (+5.64%), and % Al saturation (+5.64%) relative to SECFORST, and a consistent trend of suitable values 0–5 > 5–20 cm were estimated. The SOC→CO2 capacity reached 4.2 ± 0.5 (FADIST) and 2.7 ± 0.2 Mg C y⁻¹ (SECFORST) and only microbial abundance shifts were observed. These findings provide relevant insights on belowground resilience, evidenced by similar ecosystem services provision capacities over time, which may be influenced progressively by opportunistic Chusquea sp.

The objective of this study was to evaluate the effect of four cycles of six biannual rotations and four levels of incorporation of residues for each crop on the chemical properties of a volcanic soil from central-southern Chile. Methods: After six biannual rotations (canola–bread wheat, bean–bread wheat, canola–durum wheat, bean–durum wheat, canola–corn, and bean–corn) and four levels of residue incorporation (0, 50, 100, and 200%), we evaluated the chemical properties of a volcanic soil through eight years of cultivation. Results: The chemical properties of the soil were affected mainly by crop rotation and to less extent by the dose of residue incorporated. Beans showed a positive relation with soil pH, unlike canola with a negative effect (p < 0.05). Corn was also noticeably negative for available P. The application of increasing doses of residue positively affected the exchangeable K and Mg (p < 0.01). There were also positive correlations between pH and exchangeable Ca, exchangeable Ca and Mg, and available S and exchangeable Al and negative correlations between pH and exchangeable Al, pH and available S, and available S with exchangeable Ca and Mg. Conclusions: Carrying out different crop rotations seems to be a boost for chemical properties of the soil, while the incorporation of residues allows higher concentrations of exchangeable K and Mg.

Extreme maximum temperatures in summer present a significant risk to agroindustry as crops and their ecological interactions have critical thermal limits that can affect their performance and microorganisms-related. Gray mold disease caused by Botrytis cinerea is the most critical disease affecting crops worldwide. In this sense, the impact of temperature on agricultural productivity is well documented in the Northern Hemisphere; the risk of extreme temperatures on the infection rate of B. cinerea in Central Chile is limited. This study analyzes historical climate data from January and February between 1951 and 2023 for the cities of Santiago, Talca, Chillán, and Los Ángeles. The aim was to examine trends in extreme maximum temperatures (EMTs) and develop a simple model to estimate the infection rate of B. cinerea. Linear trend analyses were conducted, as was analysis of the probability of occurrence. Additionally, five-year averages were calculated, and a generic model was presented to assess the effects of warming on the infection rate. The analysis shows positive growth in extreme maximum temperatures in January and February, with projections for 2024, 2025, and 2026 at 70%, 80%, and 80%, respectively. February showed the most significant thermal increase among all stations, with Chillán and Los Ángeles recording higher increases than Santiago and Talca. Projections suggest temperatures near 40–41 °C. The five-year averages for Chillán and Los Ángeles exceeded 37 °C in the 2016–2020 period, the highest values during the analyzed time frame. Trends for 2021–2026 indicate upper limits above 38 °C. These trends, combined with dry summers, could increase the severity of infections and modify the optimal thermal conditions for the pathogen. The results suggest that thermal changes could reduce the infection risk by B. cinerea on fruit crops in Central Chile, and a theoretical approach is proposed to develop predictive tools to facilitate risk assessment in a warming environment.

Diatomaceous earth (DE) is composed mainly of fossilized diatoms; its use is generally limited as an insecticide due to its abrasive nature. DE is rich in silica dioxide, so it is also considered a bioavailable source of soluble silicon (Si), known to enhance plant defense mechanisms. This has been most extensively investigated in crops such as wheat or rice, however there is not much information on the response in fruit trees. The study investigated the effects of DE application on hazelnut trees, analyzing its impact on morphological, chemical and antioxidant characteristics of the plants, as well as on the reduction of oxidative stress in roots, leaves and nuts. Two experiments in La Araucanía during season 2021/2022 were carried out, Experiment 1, under controlled conditions (Campo Experimental Maquehue, Freire) and Experiment 2 in the field (GADI Orchard, Perquenco), both using Tonda di Giffoni and Barcelona cultivars, the most common planted in Chile. DE application improved plant growth, leaf silicon concentration, antioxidant activity and lipid peroxidation. These findings suggest that DE could be a sustainable tool to improve hazelnut production and quality, with important implications for nutritional management and sustainable nut production. The research addressed key aspects such as nut yield, tree growth, silicon concentration, antioxidant properties and oxidative stress, providing information relevant to the agronomic management and quality of hazelnut crops.

In humans as well as in animals, the toxic contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) stimulates immunosuppression and increases responsiveness to infectious diseases. The relationship between environmental contaminants and different infectious diseases, including COVID-19, has been described. Nevertheless, reports about the potential impact of TCDD on coronaviruses (CoVs) are limited. In this study, the impact of TCDD (0–100 pg/mL) was assessed during infection in vitro with canine coronavirus (CCoV-II), the alphaCoV causing moderate enteric disease in dogs, although genetic alterations may surprisingly generate new dangerous strains. For instance, outbreaks of lethal infections in dogs were related to highly virulent CCoV strains, and cases of pneumonia and malaise in humans were associated with new canine–feline recombinant strains of CCoV, underlining the cross-species spread capability of CoVs. Herein, during CCoV infection, TCDD induced a substantial growth in virus yield and in the expression of viral nucleocapsid protein in infected groups. Infected cells exhibited alterations in cell morphology, extensively enhanced by TCDD. Moreover, in infection, TCDD modulated the protein levels of aryl hydrocarbon receptor (AHR), a signaling responsive to both environmental contaminant and CoVs infections. Overall, our findings showed that TCDD, playing a role in AHR signaling, may worsen CCoV infection.

The use of extended light spectra, including UV-A, green, and far-red, has been scarcely explored in vertical farming. This study evaluated the effects of full spectra under two intensities (90 and 180 µmol m⁻² s⁻¹) on the growth and antioxidant properties of green and purple leaf lettuce. Three light spectra were tested: Blue-White (BW), Red-White (RW), and Red-Blue (RB). Fresh weight (FW), dry weight percentage (DWP), chlorophyll concentration (NDVI), and antioxidant parameters (total phenolic content (TPC), antioxidant capacity by DPPH and FRAP and total flavonoid content (TFC)) were assessed. Spectrum-intensity interactions significantly influenced FW, with RW-180 µmol m⁻² s⁻¹ yielding the highest FW (78.2 g plant⁻¹ in green and 48.5 g plant⁻¹ in purple lettuce). BW-90 µmol m⁻² s⁻¹ maximized DWP in green lettuce, while PAR intensity of 180 µmol m⁻² s⁻¹ favored DWP in purple lettuce. Chlorophyll concentration increased under PAR intensity of 180 µmol m⁻² s⁻¹, and leaf color varied with spectrum, with RW producing lighter leaves. Antioxidant parameters declined over time, but a PAR intensity of 180 µmol m⁻² s⁻¹, particularly under RW, boosted TPC and TFC contents in both lettuce cultivars during early stages (days 0 and 15). Conversely, a lower PAR intensity of 90 µmol m⁻² s⁻¹, mainly under RW, enhanced antioxidant capacity by FRAP at 15 days and by the end of the cycle for both cultivars. Overall, RW-180 µmol m⁻² s⁻¹ interactions promoted the best characteristics in lettuce. Nonetheless, the findings emphasize the significance of fine-tuning both light spectrum and intensity to enhance lettuce growth and quality in vertical farming systems considering the cultivar, time and variable to be evaluated.

This study evaluated the impact of deficit irrigation during preharvest on the physiological and productive responses of ‘Regina’/Gisela 6 sweet cherry. After harvest, deficit-irrigated trees were water recovered, and physiological variables were measured. Fruit condition was evaluated after 45 days of cold storage. The experiment was carried out during the 2023–2024 season in an orchard located in La Araucanía, Chile. At 37 days after starting treatment (DAST), deficit irrigation (DI) depressed stem water potential (Ψs), photosynthesis (Asat), stomatal conductance, and intercellular CO2 concentration with respect to controls (WI). Findings suggest that stomatal behavior was near-anisohydric on a temporal scale. Carbon partitioning into sorbitol was favored over sucrose in DI leaves, indicating improved osmoprotection. At 51 DAST, water-recovered DI trees had a Ψs equivalent to WI trees but lower Asat. Chlorophylls (SPAD) remained unaffected throughout the trial. Treatments produced similar yields, whereas DI inhibited trunk cross-sectional area growth. The DI treatment had no effect on any of the fruit quality traits other than size. Similarly, fruit condition following 45 days of cold storage was not influenced by reduced irrigation. The physiological and productive responses of ‘Regina’/Gisela 6 sweet cherry trees to preharvest deficit irrigation increased water productivity in the field.

Decisions about the level of pesticide residues in fresh vegetables are part of the pesticide evaluation and their approval process for its distribution and commercialization in Chile. The improper and excessive use of pesticides including the overuse and harvesting before the residues have washed off can lead to a high amount of residues and pesticide metabolites. The Chilean government have adopted policies to reduce the pesticide concern although the enforcement and implementation is limited due to the lack of coordination of some public institutions related to agriculture, environment and public health. The data from the surveillance system of fresh vegetables has been published since 2016 reporting evidences of pesticide residues above the Maximum Residue Levels (MRLs) of Chile. The risk and uncertainty of this data report the dietary intakes of pesticide residues within acceptable levels should not exceed the statutory established by governments and international organizations. There is a relevant need to support the official authorities with high quality scientific information to support the decision making process for modify and regulate the use of pesticides in the agriculture decreasing their impacts in the human health and environment. This chapter aims to evaluate current data related to chemical food safety and dietary risk assessment due to pesticide residues in fresh vegetables from Chile.

The entire agri-food value chain is facing today a great challenge, which means to move towards a sustainable and more efficient, clean production and trends of consumers under risks and uncertainties of climate change. Good Agricultural Practices (GAP) are necessary to produce fresh vegetables in optimal conditions securing their quality, traceability, and safety. However, the overuses of agrochemicals in the agriculture have increased the levels of contaminants in water bodies generating hazards and risks throughout the agri-food value chain. In Chile, the national surveillance system have reported several notifications of chemical contaminations, due to the presence of pesticide residues exceeding the Maximum Residues Levels (MRLs) and unauthorized pesticides for several crops. Nevertheless, from the perspective of microbial safety, there are no evidences of risks. Therefore, there is a necessity to use sustainable technologies in the agriculture to reduce the presence of pesticide residues in fresh vegetables. In the last decade, the nanotechnology is evolving as a relevant tool in modern agri-food industry, which is significantly advancing to contribute with solutions for production and processing of fresh vegetables. The nanotechnology research fields have generated new agrochemical agents and new delivery mechanisms to improve crop productivity, and it promises to reduce pesticide use. Additionally, novel DNA-based application/devices of nanosensors/nanobiosensors in crop protection have been developed for the plant disease diagnostics and chemical residues. Also, some of these nanobiosensors have been validated with success for traceability and authenticity of fresh vegetables. Novel advances in nanostructures and nanoparticles have demonstrated to be effective in removal of pesticide residues from fresh vegetables, water bodies and soils. Furthermore, nanotechnology is actively contributing in the development of a new generation of intelligent and active packaging together to nanomaterials for storage and transportation of fresh vegetables. This chapter aims to provide a perspective for the further challenges and opportunities that nanotechnology can face to enhance food safety of fresh vegetables in Chile.

Circular economy (CE) is an economic model that use efficiently resources through waste minimization and seeks to maximize the utility and value of products, components and raw materials, always. It is an opposite model to lineal economy that have been predominately in the last decades. CE limits the exploitation resources and dependence on fossil fuels and the transition to a circular economy requires actions and policies. Different countries have dissimilar ways of adopting and promoting goals to move towards CE. The following chapter summarizes information, governance and research in Europe, South America and Chile in agriculture waste management, including Food donations law. Reuse of plastics from agriculture; reuse of agricultural waste in agriculture; reuse of waste from other sources in agriculture. Future research to reduce agriculture waste and food waste have been identified.

Chile has become a significant producer of hazelnuts (Corylus avellana L.) due to its favorable conditions for off-season production to meet global market demand. Efficient light interception is crucial for optimizing the hazelnut yield and quality, as it directly influences the plant’s photosynthetic capacity. The goal was to assess the impact of intercepted photosynthetically active radiation (PAR) at upper, middle, and lower canopy levels in hazelnut trees grown at different planting densities and the canopy management of yield and quality parameters. The percentage of vain, sucker, double, bug, and healthy hazelnuts, including the number of fruits, total fruit weight, and grams per fruit was evaluated. The upper canopy levels intercepted the highest PAR, significantly enhancing the number and weight of fruits. The lower canopy levels received considerably less PAR, reducing the productivity. Production pruning in dense planting systems (5 × 3 m) improved the light penetration compared to a less dense planting density (5 × 6 m). Strong positive correlations were observed among PAR, fruit weight, and fruit number, emphasizing the importance of the light distribution within the canopy in hazelnut production. Production pruning and optimized planting densities are essential for maximizing light interception, improving yield, and ensuring high-quality hazelnut production.

Intercropping has been widely studied owing to its potential to increase crop production and improve soil properties. The combination of wheat (Triticum aestivum L.) with chickpea (Cicer arietinum L.) and lupin (Lupinus albus L.), along with P fertilization, has shown promising results in enhancing wheat yield. This study investigated the effects of intercropping wheat with chickpea and lupin, as well as P fertilization, on wheat yield, soil properties, and root morphological characteristics. A field experiment was conducted to evaluate chemical properties, basal soil respiration, and enzymatic activity. The results revealed that intercropping with chickpea and lupin, along with the addition of P, significantly increased the relative wheat yield compared with monoculture. The land equivalent ratio (LER) was also influenced by P fertilization, with wheat/lupin showing higher values than wheat/chickpea. Furthermore, aerial biomass exhibited significant differences between cropping systems and P fertilization, with the P+ treatment (220 kg ha-1) resulting in 24% higher aerial biomass during anthesis in the wheat/chickpea intercropping system than in wheat monocrops. The findings of this study indicate that the cropping system did not have a substantial impact on soil chemical properties. However, the interaction between cropping system and P fertilization had a significant effect on soil basal respiration. Although phosphatase activity remained unchanged by the cropping system and P fertilization, urease activity was significantly influenced by both factors, with a notable interaction effect.

The global tendency of higher production of fish has naturally led to more available derivatives of this industry such as hydrolysates, whose elevated percentage of proteins and mineral nutrients allows them to be used as a fertilization complement in agriculture. One of these products is salmon hydrolysate fertilizer, with unknown fertilizing value. This study determined the dynamics and delivery rate of N and P from a salmon hydrolysate fertilizer produced in Chile. Under controlled laboratory conditions using volcanic soil, a conventional fertilization treatment (urea and triple superphosphate) and control without fertilization were applied. The soil was incubated at 25 °C and 80% of usable humidity at times of 0, 7, 14, 21, 56 and 112 d. The results indicated that the salmon hydrolyzed fertilizer presented a rapid and high N delivery rate (104.2% availability), and its net N delivery value was higher than that obtained with urea. The P applied with salmon hydrolysate presented a high net delivery rate (68.4% availability) compared to triple superphosphate (6.6% availability) but showed erratic delivery dynamics. Soil pH and electrical conductivity were not affected. These results allow us to promote the idea that the use of salmon hydrolyzed fertilizer constitutes a good alternative to the use of conventional fertilizers.