Scielo RSS <![CDATA[Chilean journal of agricultural research]]> vol. 78 num. 4 lang. en <![CDATA[SciELO Logo]]> <![CDATA[Selection of superior genotype of sweet-potato in Indonesia based on stability and adaptability]]> ABSTRACT Sweet-potato (Ipomoea batatas [L.] Lam.) is the 3rd most important root and tuber plant in the world, after potatoes and cassava. The knowledge of the structure of Genotype × Environment interaction (GEI) could assist in the development of cultivars of sweet-potato. The objective of this research was to select superior sweet-potato genotypes in Indonesia based on Finlay-Wilkinson regression, additive main effect and multiplicative interaction (AMMI) analysis, AMMI stability value (ASV), and Genotype plus Genotype × Environment (GGE) biplot methods. Genetic materials evaluated in this research were 10 Indonesian superior genotypes developed by the Plant Breeding and Seed Technology Lab., Faculty of Agriculture, University of Padjadjaran, Bandung. The research was arranged in randomized block design, with 16 genotypes as treatments. Data analysis of the yield characters was performed by using combined variance analysis: Finlay-Wilkinson regression, ASV, AMMI, and GGE Biplot. The GEI significantly influenced the tested genotypes at three sites. However, they did not show any significant differences in the GEI. Ayamurasaki, Beniazuma, Awachy2, 15(112), Awachy4, Awachy5, 80(109), 54(160), 35(180) were specific adaptation genotypes of marginal land based on Finlay-Wilkinson analysis; whereas, Rancing, AC Putih, Ayamurasaki, Naruto Kinotoki, Awachy1, Awachy2, 15(112), Awachy4, 57(97), 80(109), 54(160), 68(120) and 35(180) performed as stable genotypes based on ASV. Ayamurasaki, Naruto Kinotoki, Awachy1, Awachy2, 57(97), 80(109) and 68(120) were stable genotypes based on AMMI analysis. However, based on GGE Biplot analysis Ayamurasaki, Awachy1, 80 (109) and 68 (120) were stable genotypes. ASV analysis provided effective stable genotype selections of 87.50% greater than other stability methods. Ayamurasaki, Awachy1, 80(109) and 68(120) were stable genotypes based on AMMI, ASV, and GGE biplot analysis. <![CDATA[Behavioral and physiological response of male <em>Callisphyris apicicornis</em> (Coleoptera: Cerambycidae) to virgin con-specific females’ extracts]]> ABSTRACT Callisphyris apicicornis (Fairmaire &amp; Germain) (Coleoptera: Cerambycidae: Necydalinae) is a native, xylophagous, and polyphagous longhorned beetle, currently having the status of an increasing pest in some fruit orchards in Chile which needs a control strategy. However, no efficient methods have been developed against C. apicicornis. Since pheromone- based strategies are promissory against these types of pests, it is necessary to understand the chemical communication within this species in order to collect and identify the pheromonal compounds as the first step to develop pheromone- based control tactics. The objectives of this work were to study behavioral and electrophysiological responses of males to con-specific females and its extracts, to seek out evidence of chemical communication in the intraspecific relationship of C. apicicornis. In field, we collected 112 males using 8 baited traps with alive females in two separate experiments. However, neither males nor headspace (HS) extracts were attractive for either sex in field, no males were captured in those treatments (16 traps). On the other hand, in laboratory bioassays males showed significant electroantennographic responses to females’ volatiles extracts (1.46 mV) and gland extracts (1.15 mV). Likewise, behavioral bioassay showed significant olfactometric preference for females’ volatiles and gland extracts. Our results strongly suggest a female- produced sex attractant occurs within this species, so further studies should attempt to identify and quantify the chemicals compounds with this role <![CDATA[Roselle ( <em>Hibiscus sabdariffa</em> L.) cultivars calyx produced hydroponically: Physicochemical and nutritional quality]]> ABSTRACT The chemical constituents of roselle (Hibiscus sabdariffa L.) vary by environmental stimuli and cultivar. The effect of cultivars produced under hydroponic and greenhouse conditions on the mineral composition, chemical and nutraceutical quality of the calyx was evaluated. An experiment was conducted in greenhouse and hydroponic conditions, in a randomized complete design with three replicates and four plants per experimental unit. Treatments were formed by a six roselle cultivars: Cruza Negra, Criolla Huajicori, UAN25-1, UAN16-2, 4Q4, and UAN6-Puga. Principal component analysis (PCA) showed that ‘Cruza Negra’ is the best cultivar because it presents the highest values of total and insoluble fiber (395 and 260 g kg-1 dry basis [db]), total phenols (29.178 mg kg-1 db), anthocyanins (18.133 mg kg-1 db), 2,2-diphenyl- 1-picrylhydrazyl (DPPH; 645 mg kg-1 db), and the absorption capacity of oxygen radicals (ORAC; 240 mg kg-1 db). The highest contribution of minerals was observed in ‘Cruza Negra’ (K, Na, Zn, and Cu) and ‘Criolla Huajicori’ (Ca, Mg, S, and Mn), contributing significantly to the recommended daily intake (RDI). Variability was evident in all the quality characteristics evaluated in the greenhouse roselle calyx. Ash, total and insoluble fiber, phenols, anthocyanins, DPPH, and ORAC contributed the most to the nutritional and nutraceutical quality of the roselle calyx. These variables were influenced by the cultivar <![CDATA[Growth and nutrient balance of <em>Asystasia gangetica</em> (L.) T. Anderson as cover crop for mature oil palm ( <em>Elaeis guineensis</em> Jacq.) plantations]]> ABSTRACT Nutrient recycling and mineral balance are important factors affecting nutrient budgets in oil palm (Elaeis guineensis Jacq.) plantations. The nutrient budget includes processes such as plant uptake, removal by harvesting, accumulation or storage in the standing plant, and recycling through decomposition of cover crop Asystasia gangetica (L.) T. Anderson can be utilized as cover crops in mature oil palm plantations with appropriate management. This study aimed to examine the growth of A. gangetica in 17 yr old oil palm plantations with different populations, understanding the contribution of A. gangetica to improve available nutrient in the plantation on the nutrient balance, and to study its role as cover crop in the mature oil palm plantation. The experiment was conducted in an experiment field of 17 yr old of mature oil palm at Bogor, Indonesia. Results showed that A. gangetica can be used as cover crops in mature oil palm plantations because it meets several conditions such as rapidly covering the land (11 wk after planting), and able to increase the available N, P, K as much as 18.49%, 9.20%, 38.36%, respectively, based on the nutrient balance with the optimum population is 1 000 000 plants ha-1 <![CDATA[Physical properties of sesame seeds harvested at different maturation stages and thirds of the plant]]> ABSTRACT The quality of sesame (Sesamum indicum L.) seeds is directly influenced by their physical characteristics, which are seldom studied notwithstanding their extreme importance in the entire production chain. Therefore, the objective of this study was to quantify the physical properties of two types of sesame seeds, collected at three points in the plant with different maturation levels, measured with digital caliper, and to evaluate the feasibility of using a digital image to determine their physical characteristics. The seeds were initially evaluated for water content and mass of 1000 seeds, and later with the data of the characteristic dimensions A (length), B (width), and C (thickness), obtained by a caliper and digital images, we determined their sphericity, circularity, projected area, and geometric diameter. We observed that water content did not affect the physical properties of the cream (CNPA G4) and black sesame cultivars. In addition, seeds of the black cultivar presented higher results than the seeds of the cream cultivar for the mass of 1000 seeds (2.7 ± 0.08 g), sphericity (58.8 ± 0.47%), projected area (4.03 ± 0.12 mm2), and geometric diameter (1.65 ± 0.03 mm). Seed batches harvested after 70% maturation had the highest mass of 1000 seeds (2.7 ± 0.12 g). The results of the physical analyses of sesame seeds performed with caliper and digital image are equivalent, which shows that digital images can be used as tools to obtain the physical properties of seeds. <![CDATA[Influence of increased doses of detoxified castor bean meal on chemical composition and characteristics of sugarcane silage]]> ABSTRACT Sugarcane (Saccharum officinarum L.) ensilage presents serious limitations due to the conversion of soluble carbohydrates into ethanol, thus, it is necessary to use additives that reduce losses of DM during the ensilage process. The aim of this study was to evaluate the effect of increasing levels of detoxified castor-bean (Ricinus communis L.) meal (DCBM) on the nutritive value, fermentation pattern, stability and losses of sugarcane silages. Twenty mini-silos with sugarcane and five different concentrations of DCBM (0, 50, 100, 150 and 200 g kg-1 fresh matter) were prepared in a completely randomized design with five replicates per treatment. After 60 d, silage was sampled to determine chemical-bromatological composition, fractionation of carbohydrates and protein content, ammoniacal N (N-NH3) and losses through gases and effluents. The addition of DCBM increased (P &lt; 0.05) DM content, crude protein, fraction A + B1 of the total carbohydrates. However, it reduced (P &lt; 0.05) the levels of neutral and acid detergent insoluble fiber, fraction B1 + B2 of total N and N-NH3. The addition of DCBM reduced the losses of total DM but decreased silages aerobic stability. The addition of 150 g kg-1 DBCM improved the nutritional value, fermentation pattern and reduced losses of sugarcane silages <![CDATA[Modeling the leaf area of <em>Ormosia paraensis</em> Ducke by statistical models and artificial neural networks]]> ABSTRACT The leaf is a very important plant structure because it allows gas exchange and transformation of light energy into chemical energy. The objective of this research study was to test artificial neural networks (ANNs) to estimate the leaf area (LA) of Ormosia paraensis Ducke and compare their performance with adjusted statistical models. One hundred forty leaves were selected from seedlings of the species at the leaf age of 100 days after sowing (DAT). The LA was calculated by indirect estimation with ImageJ software, and the linear length (L) and width (W) dimensions were measured with a ruler graduated in centimeters. Afterward, 90 leaves were randomly separated to generate mathematical equations of LA (Y) as a function of linear dimensions (L and W), and 50 leaves to validate the equations. Similarly, 100 networks of the multilayer perceptron (MLP) type were trained with the backpropagation algorithm and the best networks were selected for later validation. The choice of the best equations and ANNs was based on precision and dispersion statistics. The quadratic equation obtained from model (4) demonstrated consistent statistics with the coefficient of determination (R²aj = 87.39) and a low result for the standard error of estimate (SEE = 12.07%). For the ANNs, a correlation coefficient (Ryŷ), varying between 0.9316 and 0.9521, was obtained in the training phase, while it ranged from 0.8522 to 0.8825 in the validation phase, generating lower residues. It is concluded that the ANN performance was higher compared with the conventional regression technique. <![CDATA[Association between arbuscular mycorrhizal fungi and <em>Pratylenchus brachyurus</em> in maize crop]]> ABSTRACT Maize (Zea mays L.) is one crop of major relevance in Brazil; however, nematodes are limiting factors in maize growth and productivity due to the difficulty to control them. Studies point out that arbuscular mycorrhizal fungi (AMF) increase plant tolerance to nematodes. Thus, the aim of this study was to assess the association between AMFs and Pratylenchus brachyurus in maize growth. Six AMF species (Rhizophagus clarus, Claroideoglomus etunicatum, Gigaspora rosea, G. margarita, Scutellospora calospora, S. heterogama), as well as a control treatment free of mycorrhizae, were assessed under two different nematode inoculum conditions (presence and absence). Plants were collected and analyzed 60 d after inoculation. The nematode population was higher in the treatments inoculated with AMFs. On the other hand, just the plants inoculated with R. clarus did not present improved development in comparison to the control. Nematodes increased AMF spore density, but despite the fact that AMFs have presented different root colonization capacity (ranging from 2.3% to 95.0%), such capacity was not affected by the nematodes <![CDATA[Next-generation sequencing of root fungal communities in continuous cropping soybean]]> ABSTRACT Soybean root rot is a major disease of soybean (Glycine max [L.] Merr.) under continuous cropping, which leads to dramatic variations in the rhizosphere microflora. Soybean was sown in a different field after year zero, and continuous cropping was applied for 1 or 2 yr. The objectives were to investigate the variation in fungal populations present or inhabiting soybean roots during 3 yr of monocropping using next-generation sequencing to compare the three sets of root samples and provide a theoretical basis for the following inoculation study of the different pathogens involved in root rot disease in soybean, variation in fungal populations, and incidence of root rot. Results showed that operational taxonomic units (OTUs) of the three samples were divided into 19 phyla, 169 families, and 235 genera. Ascomycota and Basidiomycota were the dominant phyla in the continuous cropping root samples. Continuous cropping could increase the relative abundance of some fungi, namely Fusarium, Rhizoctonia, and Thelebolus, which are associated with soybean root rot for 2 and 3 yr of cropping. Continuous cropping could also increase the abundance of Gymnoascus, Chrysosporium, Ctenomyces, Aphanoascus, and Aspergillus, which are soil pathogenic fungi that can cause other plant diseases <![CDATA[Effects of brassinolide application on antioxidant characteristics and endogenous hormones of <em>Leymus chinensis</em> (Trin.) Tzvelev under different light intensity regimes]]> ABSTRACT Different light and shade intensities are the main constraints to achieve potential biomass accumulation in Leymus chinensis (Trin.) Tzvelev. An experiment was conducted to explain the physiochemical and morphological adversity triggered by various light intensities. Adverse impacts were lessened with exogenous brassinolide (BR). Treatments consisted of 100% natural light (T0), 100% natural light + 0.1 mg L-1 BR (BT0), light shade (70% natural light) (T1), light shade + BR (70% natural light + 0.1 mg L-1 BR) (BT1), moderate shade (50% natural light) (T2), and moderate shade + BR (50% natural light + 0.1 mg L-1 BR) (BT2). These were completely randomized design treatments with five replicates. Results showed that dry biomass production and endogenous hormone levels (abscisic acid [ABA], zeatin riboside [ZR], gibberellic acid [GA], and indole acetic acid [IAA]) increased, while osmolyte accumulation (soluble sugars and proteins, free amino acids, and proline), antioxidant activity (peroxidase [POD], superoxide dismutase [SOD], and catalase [CAT]), and lipid peroxidation decreased under shade at T0. Treatment T1 depicted the most promising results for these attributes. However, biomass accumulation (33%-56%), osmotic substances (soluble sugars,13%-38%; soluble proteins, 9%-41%; free amino acids, 8%-16%; proline, 11%-41%), and antioxidant enzyme activities (POD, 11%-14%; SOD, 3%-33%; CAT, 4%-23%) increased. On the other hand, lipid peroxidation was reduced by BR application, as indicated by decreased malondialdehyde (MDA) content (7%-31%) and relative conductivity (7%-19%) under both natural and shade conditions. Likewise, the biosynthesis of ABA (2%-22%), ZR (11%-24%), and GA (30%-50%) improved under exogenous BR compared with the control. The IAA contents (22%-28%) decreased under foliar-applied BR compared with the control. Results suggested that light to moderate shade improved the biomass production and physiological performance of L. chinensis, while BR application exhibited further improvement <![CDATA[Effects of biochar on seedling root growth of soybeans]]> ABSTRACT Biochar application is an effective method for agriculture production. In order to study the biochar effect on soybean (Glycine max [L.] Merr.) seedling root growth, this study was conducted in a sand culture experiment using two soybean cultivars with different P efficiencies. Soybean was pot-grown at four biochar rates (0%, 0.15%, 0.75% and 1.5%, w/v). The results showed no difference in Cultivar × Biochar interaction on root morphologic characteristics. At 7 d after germination (DAG), biochar slightly enhanced root growth; at 10 DAG, biochar significantly increased total root length (TRL) and total root surface area (TRSA) highest by 48.4% and 27.4% (P &lt; 0.05) at 1.5% biochar rate, respectively, compared to the control. The positive effects on root morphology by biochar were especially concentrated on fine roots (&lt; 0.5 mm). In addition, root vitality and leaf soluble sugar content were significantly increased by both 0.75% and 1.5% biochar; shoot biomass increased maximally by 65.6% at 1.5% biochar rate compared to the control; inversely, root/shoot ratio significantly reduced by 32.3% and 23.5% at 1.5% biochar rate, respectively, at 7 and 10 DAG. We suggest that biochar had positive effects on soybean seedling growth through improving root morphology and root vitality, regardless of different P efficient cultivars <![CDATA[Occurrence of Septoria tritici blotch ( <em>Zymoseptoria tritici</em> ) disease on durum wheat, triticale, and bread wheat in Northern Tunisia]]> ABSTRACT Wheat (Triticum aestivum L.) is the most important cereal crop in Tunisia, nonetheless production is highly affected by drought and diseases mainly Septoria tritici blotch (STB) caused by Zymoseptoria tritici (Roberge ex Desm.) Quaedvl. &amp; Crous anamorph and Mycosphaerella graminicola (Fuckel) J. Schröt. 1894 teleomorph; that has become an inherent disease of durum wheat (Triticum turgidum L. subsp. durum (Desf.) van Slageren) but rarely observed on bread wheat (Triticum aestivum L. subsp. aestivum) and on triticale (×Triticosecale spp.) The main objective of this work was to study the prevalence and geographical distribution of Z. tritici on triticale, durum wheat and particularly on bread wheat in different cereal growing regions of North and Northwestern Tunisia to confirm its presence/absence on bread wheat. For this study, 126 wheat fields were surveyed in North and Northwestern Tunisia during 2015-2016 and 2016-2017 cropping seasons. STB on durum wheat was present in the majority of inspected durum wheat fields, where high mean incidence (60%) and severity (40%) were recorded at Jendouba, Bizerte, Beja, and Kef. The survey data revealed low risk on bread wheat with an incidence of 23% and 29% at Bizerte and Beja, respectively. However high incidence of 84% and 52% was recorded at Cap Bon in 2016 and 2017, respectively and mainly at El Haouaria where STB severity was relatively high on bread wheat landrace of unknown origin but called by local farmers as ‘Farina arbi’. Sporadic incidence was recorded on Triticale of 100% at Jendouba (in 2016), and 33% at Bizerte (in 2016 and 2017) and absence at all other surveyed sites; likewise for severity at same locations where 13% and 42% were recorded in 2016. The survey data revealed low risk on bread wheat except at El Haouaria where STB severity was relatively high on a bread wheat landrace; while it was considered as high risk at all durum wheat fields in Beja, Bizerte, Jendouba, Zaghouan and Kef regions, such distinct occurrence could lead to clarify host specificity in Z. tritici <![CDATA[Implications of genetic diversity in the improvement of silkworm <em>Bombyx mori</em> L.]]> ABSTRACT Improvement programs depend on characterizing genetic resources, this process being the fundamental basis for determining the diversity and genetic divergence of such resources and thereby enabling a rigorous, efficient selection of the parentals that, through hybridization, will go on to enhance heterosis. The aim was to use the resulting hybrids to improve population mean with respect to genetic parameters used for the qualitative and quantitative traits that affect commercial natural silk production. Bombyx mori L. is a domesticated insect of global economic importance, mainly due to the production of natural silk but also for its relevance in rural agro-industry in tropical and subtropical regions. Non-textile uses currently being developed are also to the fore. These relate to such fields as science and academia, biomedicine, biotechnology, the pharmacological industry and cosmetics. With this in mind, the aim of the current article was to provide a general context for sericulture and in so doing give an overview of the silk production scenario nationally and go on to describe the importance of genetic diversity to silkworm breeding programs and to demonstrate how genetic drift, inbreeding, and artificial selection contribute to loss of genetic diversity in B. mori <![CDATA[Effects of bud nodal position along the cane on bud fertility, yield component and bunch structure in ‘Carménère’ grapevines]]> ABSTRACT Carménère is an important grapevine (Vitis vinifera L.) variety from the Chilean wine industry, which has a low fertility in their basal buds, affecting negatively yield. Due to this, the aim of this work was to characterize and evaluate technological maturity, percentage of bud break, practical bud fertility, yield components, bunch structure and yield index by practical fertility reached in each nodal position in buds along Carménère canes. Bud break reached an average of 79.9% along the cane, with extreme values from 57.3% to 98.7%. Bud fertility reached an average of 1.3 bunch per bud, with extreme values from 0.9 to 1.7. According to this, ‘Carménère’ showed a low fertility in basal buds. Weight of bunch varied from 108.0 to 214.7 g. Number and weight of berries was higher in the buds from distal nodal positions. Bunch structure parameters, such as stalk length, number and length of primary wings, and yield index by practical fertility was also higher in the bud from distal nodal positions. Moreover, large size berries represent 50% of berries and 80% of weight of berries. Due to this, ‘Carménère’ productivity is limited by small size berries. These findings are important to determine the viticultural managements that should be performed in ‘Carménère’ vineyards