Scielo RSS <![CDATA[Chilean journal of agricultural research]]> vol. 79 num. 1 lang. en <![CDATA[SciELO Logo]]> <![CDATA[Association analysis of four storage protein components using microsatellite markers in a <em>japonica</em> rice collection]]> ABSTRACT Protein content is one of the main nutrition quality traits used to measure nutrition value in rice (Oryza sativa L.) Therefore, improving the protein content is a main target for nutrition quality breeding in rice. Previous studies have mainly focused on the total protein content in brown and polished rice using bi-parental segregating populations. Few researchers have focused on four different protein component traits (glutelin, prolamin, albumin, and globulin) in rice, and little is known regarding association analysis in natural populations. In this study, 329 japonica accessions (Oryza sativa L. subsp. japonica Kato) were collected from worldwide geographic distributions and genotyped using 154 microsatellite markers to detect the association between four protein component traits and relative markers in the tested panel. The Coomassie Brilliant Blue G-250 method was used to measure the phenotype of four protein components. A total of 845 amplified alleles were detected with allele number ranging from 2 to 9. The whole population was divided into three subgroups via software STRUCTURE 2.3.4. The scatterplot showed that the LD (linkage disequilibrium) decay distance was about 30 cM in the whole tested population. A total of 15 simple sequence repeats (SSR) markers were identified by using both the general linear model (GLM) and mixed linear model (MLM). These associated marker loci can provide a higher variety of choices in improving the nutrition quality of rice. In addition, the carrier materials with excellent alleles identified in this study can be used as parental genotypes in rice molecular breeding in the future. <![CDATA[Effect of amino acid biostimulant on the yield and nutraceutical potential of soybean]]> ABSTRACT Advancement in crop cultivation technologies strives to increase the yield and improve the quality of crops under minimized threats posed to the natural environment. Application of biostimulants is a treatment which increases crop yield and quality particularly after plants exposure to stress conditions. The objective of the work was to determine changes in yield and nutraceutical potential of soybean (Glycine max [L.] Merr.) ‘Atlanta’ after application of biostimulant. A field experiment was conducted in three growing seasons (2014-2016). Terra Sorb Complex biostimulant was applied in the growing season in the form of single or double spraying in two concentrations (0.3% and 0.5%). Number of biostimulant applications and its concentration modified yield and quality of crop and also the nutraceutical and antioxidative potential of soybean. Foliar application of biostimulant improved yield of soybean (increased by 25% compared to the control) without any negative effect on the nutritive value of seeds. The application of biostimulant increased (compared to the control) number of pods and seeds (32%), plant height (38%), phenolic content (34%), flavonoids content (74%), and reducing power (210%). Taking into account biometric traits of soybean plants, positive effects were observed in the case of single biostimulant applications with lower concentration. The conducted study demonstrated a significant increase in the soybean yield and antioxidant potential after double application of the tested biostimulant at higher concentration. On the other hand, total fat and protein content was higher in plants treated once with a lower product concentration. <![CDATA[Slow growth <em>in vitro</em> culture for conservation of <em>Chilotanum</em> potato germplasm]]> ABSTRACT To keep potato (Solanum tuberosum L.) germplasm accessions disease-free and available for use, these are conserved as in vitro microplants under tissue culture conditions. The management of in vitro plants is labor intensive due to the necessity of periodic transferring of explants to new containers and fresh medium (sub culturing). The effectiveness of MS medium supplemented with sorbitol or mannitol in conservation of potato germplasm corresponding to different genotypes from Chilean native landraces (Chilotanum group) was investigated. Growth curves for modelling, describing and predicting shoot elongation of in vitro potato plants through the time in different culture media were developed as a tool to plan subculture labor for refreshing explants to new media. In MS medium without osmotic active compounds the rate of shoot elongation (k) was 1.12-1.45 cm wk-1 with 0% mortality. In media supplemented with 20, 40, and 60 g L-1 sorbitol, k value ranged between 0.58-0.35, 0.42-0.27 and 0.09-0.05 cm wk-1 respectively. Mortality was 0%, 13%, and 26% for such treatments. In case of mannitol, k value ranged between 0.14-0.25, 0.065-0.11 and 0.042-0.068 cm wk with 3%, 6%, and 26% mortality for 20, 40, and 60 g L-1, respectively. These data can be used to predict shoot elongation rate in different media that provide several alternatives of speed of growth. The information allows to design an adequate strategy for organizing the work in a potato germplasm bank of S. tuberosum, Chilotanum group. <![CDATA[Changes in phytochemical content and antioxidant activity during inflorescence development in broccoli]]> ABSTRACT This study was performed to monitor glucosinolate (GSL) profile, total phenol, ascorbic acid, total flavonoid contents, and antioxidant activity in florets of six broccoli (Brassica oleracea L. var. italica Plenck) genotypes at three different inflorescence developmental stages. The level of phytochemicals and antioxidant activities varied significantly among genotypes and developmental stages. Out of the eight GSLs identified in this study, only five were present in all genotypes and their respective developmental stages. Glucoraphanin (GRA), a major GSL, was significantly increased towards the later stages of development (1.41 μg g-1 in immature stage of ‘Koyoshi’ to 10.57 μg g-1 in commercial stage of ‘09FA- M295’), whereas glucobrassicin (BRA) showed a reverse accumulation pattern with the highest value at the immature stage (5.10-7.97 μg g-1). Other minor GSLs varied depending on the genotype. Total phenolic and ascorbic acid content increased significantly as maturity progressed in all the genotypes with a relatively higher increment observed in ascorbic acid (65.8%-100.9%) than phenolic content (10.2%-31.2%). Flavonoid content, on the other hand, showed a cultivar- dependent accumulation pattern throughout the developmental stages. However, although antioxidant activity increased with inflorescence development, the increment was higher and lower than in total phenol and ascorbic acid content, respectively. The highest value for GRA (10.57 μg g-1), ascorbic acid (502.3 mg 100 g-1), total phenol (523.7 mg 100 g-1) and antioxidant activities was obtained for ‘09FA-M295’ at the commercial stage. Taken together, these results indicate that phytochemicals in broccoli have a differential accumulation pattern during inflorescence development. Regardless of genotypes and inflorescence developmental stage, total phenolic content showed the highest correlation with antioxidant activity (r = 0.779**), followed by ascorbic acid (r = 0.674**) and flavonoid content (r = 0.602**), whereas total GSLs showed a nonsignificant correlation with antioxidant activity. <![CDATA[Classification of wheat kernels infected with fungi of the genus <em>Fusarium</em> using discriminative classifiers and neural networks]]> ABSTRACT Fusarium head blight (FHB) compromises the processing suitability and nutritional value of grain, and it causes significant crop losses. The aim of the study was to develop models for the classification of wheat (Triticum aestivum L.) kernels infected with fungi and healthy wheat kernels. Wheat kernels were classified with the use of Decision Tree, Rule-based, Bayes, Lazy, Meta and Function classifiers, as well as multilayer perceptron (MLP), radial basis function (RBF) and probabilistic neural networks (PNN). Twenty textures were selected from RGB, Lab, XYZ colour spaces each, for every wheat variety and each kernel side. Accuracy ranged from 82% for the dorsal side of kernels for Naive Bayes and IBk classifiers to 100% for the ventral side of kernels for IBk, FLDA and Naive Bayes classifiers. Classification accuracy was highest in the model based on texture attributes from Lab colour space. The final model of 20 attributes from Lab colour space was applied to a set of kernels from all wheat varieties, analysed on the ventral side. The accuracy of the classification model ranged from 94% to 98%, depending on the applied classifier. The models developed with the use of neural networks were characterised by overall classification accuracy of above 99% for MLP networks, above 96% for RBF networks and above 97% for PNN. The developed models indicate that analyses should be performed on the ventral side of kernels based on textures from Lab colour space. <![CDATA[Genetic evaluation and characterization using cluster heat map to assess NaCl tolerance in tomato germplasm at the seedling stage]]> ABSTRACT Salinity is a serious problem that limits crop growth and yield. The present study used plotting to evaluate 25 tomato (Solanum lycopersicum L.) accessions for various morpho-physiological parameters at the seedling stage and identify significantly salt-tolerant tomato lines at three different salinity levels. The pot experiment had a completely randomized design with three replicates in a factorial arrangement under greenhouse conditions. Tomato plants were exposed to 0 (control), 8, and 12 dS m-1 as NaCl stress at the seedling stage. The morpho-physiological traits, such as root and shoot length, root/shoot ratio, number of leaves, fresh and dry shoot weight, fresh and dry root weight, leaf area, Na+ and K+ concentrations, K+/Na+ ratio, and tolerance index, were recorded to examine salt tolerance. According to principal component analysis (PCA), there were six principal components (PCs) with Eigen values &gt; 1 and 77.2% of total cumulative variability. The PC1 (24.3%) revealed the highest variability followed by PC2 (16.2%). Meanwhile, the PCA biplot and cluster heat map analyses indicated that Subarctic, Raad-Red, Naqeeb, Pakit, Tommy-Toe, and BL-1076 were salt-tolerant, whereas PBLA-1401, PB-017902, CLN-2413, BL-1078, BL-1174, and BL-1079 were the most susceptible accessions based on their performance under stress. <![CDATA[Effects of straw returning on rice growth and yield under water-saving irrigation]]> ABSTRACT Straw returning (SR) is an important means of straw utilization, which has been tested and is helpful for improving soil fertility and crop production. However, the effects of SR on plant growth and yield of paddy rice (Oryza sativa L. subsp. japonica Kato) under water-saving irrigation (WSI) are rarely investigated. In the 2015 and 2016 rice seasons, field experiments were conducted with four treatments, namely controlled irrigation with conventional fertilization (CI- CF), controlled irrigation with straw returning (CI-SR), flooding irrigation with conventional fertilization (FI-CF), and flooding irrigation with straw returning (FI-SR). The objective of the present study was to investigate the response of plant height, number of tillers, biomass, and yield to SR and irrigation management. Results indicated that SR enhanced rice yield on average by 7.9% and 7.5% and improved irrigation water use efficiency (IWUE) by 6.3% and 8.3% in 2015 and 2016, respectively. The CI-SR combination significantly increased IWUE compared with FI-CF. These results suggested that SR could offset the inhibition of rice growth caused by CI, and the CI-SR combination could be an effective measure to enhance soil fertility, maintain the rice field, and increase IWUE. Furthermore, rice growth (plant height, number of tillers, and biomass) was slightly inhibited by SR during the first 20 d of the rice season, but increased after the jointing stage (approximately 40 d after transplanting). This implied that diverting some top-dressed chemical N fertilizer into basal application may be necessary for fertilizer management to better meet crop nutrient uptakes in rice fields with SR application, especially with CI. <![CDATA[Rational water use by applying regulated deficit and partial root-zone drying irrigation techniques in tomato under arid conditions]]> ABSTRACT This study involved exploring the opportunities of using regulated deficit irrigation and partial root zone drying approaches as water-saving irrigation methods in a tomato crop (Solanum lycopersicum L.) based on irrigation scheduling. The Partial Root Zone Drying Irrigation practice simply involved interchanging the wet and dry sides in subsequent irrigations. The field experiment was conducted in the Kingdom of Saudi Arabia, during the fall season of 2014-2015 and 2015-2016. The following three irrigation treatments were tested during both years under a drip irrigation system: (1) full irrigation (FI), as a control treatment; (2) regulated deficit irrigation (RDI); and (3) partial root zone drying irrigation (PRD). Both RDI and PRD treatments received 70% of the irrigation water volume of full irrigation (FI). The obtained results indicated that the soil water content of PRD treatment was higher and conserved more soil moisture than that in the RDI treatment. Data for both years indicated that FI exhibited the highest stomatal conductance (gs) values while PRD exhibited the lowest gs values among all the treatments. Under PRD treatment, the dry fruit yield was the highest when compared with RDI and FI treatments for both years. Deficit irrigation treatments result in higher abscisic acid (ABA) concentration in the xylem when compared to that in FI. The vast majority of most extreme irrigation water use efficiency (IWUE) values were involved with PRD while most of the minimum IWUE values were coupled with FI. These results indicate the effects of deficit level irrigation on IWUE <![CDATA[HortSyst: A dynamic model to predict growth, nitrogen uptake, and transpiration of greenhouse tomatoes]]> ABSTRACT The HortSyst model is a new discrete time model for describing the dynamics of photo-thermal time (PTI), total dry matter production (DMP), N uptake (Nup), leaf area index (LAI), and evapotranspiration (ETc) for greenhouse crops. The first three variables are considered as state variables and the latter two are conceptualized as output variables. This model was developed as a tool for decision support systems in Mexican greenhouses for the application of N and water in tomato (Solanum lycopersicum L.) production. The HortSyst has 13 parameters. It was used to calibrate the model and estimate the correct parameter values for the crop season. An experiment was carried out to test model predictions in a greenhouse during the autumn-winter season in Chapingo, Mexico. Tomato ‘CID F1’ was grown in a hydroponic system and plants were distributed with a density of 3.5 plants m-2. The tomato crop was transplanted on 21 August 2015. A weather station was installed inside the greenhouse to measure temperature, relative humidity, and global radiation. The HortSyst model provides an excellent predictive quality for DMP, Nup, LAI, and ETc according to the statistics. Values for bias (BIAS) were DMP (-3.897), Nup (-0.071), LAI (0.026), and ETc (3.647), values for root mean square error (RMSE) were DMP (14.543), Nup (0.500), LAI (0.100), and ETc (39.330), and values for modeling efficiency (EF)were DMP (0.996), Nup (0.991), LAI (0.998), and ETc (0.815). The model proposed and described in this paper can be integrated as a decision support tool for N supply and irrigation management in greenhouse production systems. <![CDATA[Changes in the physical properties of an Amazonian Inceptisol induced by tractor traffic]]> ABSTRACT With agricultural expansion in Amazonian regions, studies are needed to verify the effect of mechanization on the soils of the regions. This study aimed to assess soil physical attributes under different compaction conditions induced by tractor traffic on a soil of southern Amazonas State, Brazil. Treatments consisted of three compaction levels: conventional soil tillage without additional compaction (CT) and conventional soil tillage with additional compaction with four (CTc4) and eight tractor passes (CTc8). An intense increase in soil aggregate diameter was observed in the superficial soil layer (0.00-0.05 m) from four tractor passes, decreasing in the successive soil layers (0.05-0.20 m). Soil density increased up to a depth of 0.10 m. The reduced macroporosity and soil moisture on the soil surface (0.00-0.05 m) did not significantly alter soil microporosity in the different treatments. For the macroporosity, the 0.00-0.05 m layer was the most impaired, with a reduction of more than 50% for the treatments submitted to compaction (CTc4 and CTc8). The penetration resistance for the 0.00-0.05 m layer was increased by more than 150% between the treatment without compaction (CT = 0.88 MPa) and compaction (CTc4 = 2.25 MPa; CTc8 = 2.50 MPa). These results show a greater caution in the agricultural machinery management in Amazonian soils, which may be aggravated due to the intense water regime in the region. <![CDATA[Sustainability of different production systems papaya ( <em>Carica papaya</em> L.) and sorghum ( <em>Sorghum bicolor</em> [L.] Moench) in the semi-arid region]]> ABSTRACT Agricultural production in the semi-arid region is critically important for ensuring food security and agricultural development in world. However, due to the environmental impact generated by agricultural activity, and the challenge of producing food for a growing demand, agriculture is dependent on a constant flow of non-renewable environmental and economic resources. The aim of this study was to quantify the sustainability of different agricultural production systems papaya (Carica papaya L.) and sorghum (Sorghum bicolor [L.] Moench) in the semi-arid region using emergy analysis. The research was carried out in the Curupati Irrigated Perimeter, located in the municipality of Jaguaribara, Ceará (CE), Brazil, corresponding to the cultivation of the irrigated papaya and in the Lagoa Grande settlement, in the Chapada do Apodi, municipality of Tabuleiro do Norte, CE, referring to sorghum cultivation in the rainfed. The rainfed production system had an emergy value of 1.06E+16 seJ ha-1 yr-1, and was lower than in the irrigated system 1.69E+17 seJ ha-1 yr-1. The following values were obtained for the emergy indicators in the irrigated system: emergy yield ratio (EYR) = 1.51; renewability (R%) = 74.29%; environmental load ratio (ELR) = 0.35, and emergy sustainability index (ESI) = 4.37. Where as in the rainfed system, the EYR = 1.13; R% = 83.81%; ELR = 0.20 and ESI = 5.86. The system of production under the rainfed regime therefore displayed better economic, social and environmental performance in relation to the irrigated production system. Both of the studied production systems contributed to the economic growth of the semi-arid region, with low environmental loads. <![CDATA[Tomato genotype resistance to whitefly mediated by allelochemicals and <em>Mi</em> gene]]> ABSTRACT Allelochemicals and Mi, nematode‑resistant gene, are found in wild tomato species and can provide resistance to insect pests. The aim of this study was to check the resistance of tomato (Solanum lycopersicum L.) genotypes with different foliar allelochemical contents (acylsugar and/or zingiberene) associated with and not associated with the Mi gene against the whitefly (Bemisia tabaci biotype B). Fifteen tomato genotypes were tested for resistance against whitefly (Santa Clara, TOM‑695, TOM‑556, TOM‑584, TOM‑684, TOM‑687, TOM‑688, TOM‑759, TOM‑760, ZGB‑703, ZGB‑704, TOM‑778, TOM‑779, TOM‑780, and PI‑127826). Genotypes with high acylsugar (AS) (TOM‑687 and TOM‑688) as well as those with high zingiberene (ZGB) contents (ZGB‑703 and ZGB‑704) had lower oviposition and a lower number of nymphs when compared with genotypes with low AS and ZGB contents and without the Mi gene (Santa Clara, TOM‑ 695, TOM‑556, and TOM‑584). The genotypes carrying the Mi gene, associated with low allelochemical contents, were less preferred for whitefly oviposition compared with susceptible genotypes with low AS and ZGB contents and without the Mi gene. When both the AS and ZGB allelochemicals were present in the same genotypes (TOM‑778, TOM‑779, and TOM-780), they showed a synergistic effect; the number of whitefly eggs and nymphs decreased in genotypes with high AS and ZGB compared with genotypes that had only one of these allelochemicals. However, the number of whitefly eggs and nymphs of genotypes with high AS and ZGB contents, individually or combined, was less than for genotypes carrying the Mi gene. These results indicate that allelochemicals are more effective than the Mi gene to provide resistance to whitefly. <![CDATA[Principal component and morphological diversity analysis of Job’s-tears ( <em>Coix lacryma-jobi</em> L.)]]> ABSTRACT The diversity analysis of Job’s-tears (Coix lacryma-jobi L.), an ideal healthy food crop, is a prerequisite in breeding programs and germplasm utilization. The aim of this study was to characterize the phenotypic traits of 94 Job’s-tears accessions (40 cultivated and 54 wild) collected from different geographic areas in China. Principal component (PC) and genetic diversity analyses were conducted on 12 morphological characters: stem node number, panicle branch number, primer branch nodes, panicles per plant, grain number per plant, plant height, 100-seed weight, total bract surface characteristics, total bract texture, total bract shape, total bract color, and pericarp color. The results showed a high variation among the studied materials. The relationship among traits indicated that some traits could be used for indirect selection to evaluate accessions. Based on PC analysis, the first seven PCs in the experiment can summarize the vast majority of the information about the agronomic traits of the 94 Job’s-tears accessions. The accumulative contribution rate accounted for 87.31% of the total variation. Cluster analysis grouped all the accessions into seven clusters, and this revealed that genetic variation was based on variety types, geographic distribution, and morphological characteristics. <![CDATA[Effect of spray drying at 150, 160, and 170 °C on the physical and chemical properties of maqui extract ( <em>Aristotelia chilensis</em> (Molina) Stuntz)]]> ABSTRACT Maqui (Aristotelia chilensis (Molina) Stuntz) is a native Chilean berry that has the highest antioxidant level compared with other fruit. Anthocyanins, which are the compound with the highest functional level found in maqui, are relatively unstable and quite susceptible to degradation during processing and storage. In addition, maqui is a highly perishable seasonal fruit and it is necessary to find conservation methods for the developed products. Microencapsulation is one way to protect anthocyanins from degradation reactions; it is defined as a process by which certain bioactive substances are introduced in a matrix or wall systems aimed at impeding their loss and protecting them from the reaction with other compounds and/or prevent them from suffering oxidation reactions caused by light or oxygen. The objective of the present study was to evaluate the effect of drying inlet temperature on the physical properties, total polyphenol content, total anthocyanin content, and antioxidant activity of spray-dried maqui extract. Inlet temperatures were 130, 150, and 170 ºC, while other parameters were constant, such as feed flow (18 mL min-1) and encapsulating agent concentration (maltodextrin and gum Arabic). The best drying inlet temperature was 170 ºC; it produced powders with lower moisture content (1.61%), water activity (0.15), and L* coordinate (11.16), as well as increased hygroscopicity (24.01%) and solubility (92.70%). The lowest total polyphenol content loss (23.05 mg gallic acid equivalents g-1), total anthocyanin content (21.46 mg cyanidin- 3-glucoside g-1), and antioxidant activity (85.76% 2,2-diphenyl-1-picrylhydrazyl inhibition) occurred at 170 °C. The size of the powder particles allowed classifying them as microcapsules. Maqui extract microencapsulation provides powders with adequate stability during storage. <![CDATA[Optimum biochar preparations enhance phosphorus availability in amended Mollisols of Northeast China]]> ABSTRACT Biochar amendment to soils can improve soil P availability, but details on the optimum application of biochar to black soils in Northeast China are limited. Three types of biochar were produced at six pyrolysis temperatures (between 200 and 700 °C) and then added to black soil samples. P adsorption-desorption isotherms were fitted by the Langmuir model to evaluate the changes in soil P adsorption-desorption after biochar amendment. Changes in P adsorption and desorption depended on biochar feedstock type and pyrolysis temperature. When pyrolysis temperature increased up to 400 °C, P sorption maximum (Qm) of soybean pod (SP) and soybean straw (SS) biochar-amended soils were enhanced from 855.65 and 428.84 mg kg-1 to 1666.67 and 1547.62 mg kg-1, respectively, while a further increase in the pyrolysis temperature lowered the adsorption capacity. However, P adsorption of corncob (CC) biochar amended soils declined from 1428.57 mg kg-1 to 556.70 mg kg-1 as pyrolysis temperature increased. Higher P desorption in SP and SS compared with CC indicated that SP and SS biochar produced at higher than 400 °C pyrolysis temperatures were considered to be the optimum biochar to enhance P availability in the black soils of Northeast China. <![CDATA[Behavioral and antennal responses of <em>Lobesia botrana</em> (Lepidoptera: Tortricidae) to volatiles from the non-host plant <em>Schinus molle</em> L. (Anacardiaceae)]]> ABSTRACT Lobesia botrana (Lepidoptera: Tortricidae), the grapevine moth, is one of the major pest on grapes. Current control is based on spraying insecticides and/or mating disruption technique, using female sex pheromone, affecting only adult male’s conduct. Behavioral active compounds as plants kairomones influence the interaction of phytophagous insects with plants, providing chemical cues to feed or lay eggs. Through electroantennography (EAG) and olfactory experiments, we investigated the role of volatiles of the non-host plant Schinus molle L. on behavior of L. botrana. Steam distilled essential oil (EO) from S. molle leaves was characterized by gas chromatography coupled to mass spectrometry (GC-MS). The most abundant compounds were limonene (17.61%), α-phellandrene (14.32%), β-caryophyllene (8.82%) and δ-cadinene (9.39%). Electrical responses of L. botrana at 1×102 μg mL-1 EO were not different from control for females (0.81 mV) and males (1.22 mV). At 1×103 and 1×104 μg mL-1 EO we found a significant increment for females to 1.28 and 1.57 mV, and 1.28 and 1.69 mV for males, respectively. In tube-Y olfactometer, at 1×102 μg mL-1 EO the choice did not differ from the control for females (P = 0.7630) and males (P = 0.4054). Females were attracted to odor source at 1×103 μg mL-1 (P = 0.0043) and at 1×104 μg mL-1 (P = 0.0011). Males were attracted to the dose of 1×103 μg mL-1 (P = 0.0278) and at 1×104 μg mL-1 (P = 0.0017). We found that non-host plant volatiles elicited electrophysiological and behavioral responses and that L. botrana can discriminate between doses.