Project description:Lepidopteran pests are major factors limiting soybean productivity in South America. In some cases, effective management of these species requires the use of foliar insecticides. For sustainable use of these insecticides, they should only be applied when insect population size exceeds an economic threshold. Since this estimation requires to determine the consumption of different species, this work aimed to integrate all these factors, studying the consumption of small (less than 1 cm long) and medium (1 to 1.5 cm long) size larvae of major lepidopteran pests to vegetative and reproductive tissues on Bt (M7739IPRO variety, containing the event MON87701 which expresses the Cry1Ac protein from Bacillus thuringiensis) and non-Bt (BMX Desafio RR variety) soybeans. The feeding injury to vegetative tissues was tested in detached-leaf assays in grow chambers, and for reproductive structures the study was conducted in greenhouse with infestations at early (flowering) and mid reproductive (mid grain filling) stages. Based on the feeding behavior of the species tested, they were cast in four groups: a) Anticarsia gemmatalis and Chrysodeixis includens, defoliating only the RR variety with the lowest consumption of foliar area; b) Spodoptera eridania, defoliating both RR and IPRO varieties, consuming twice than the species mentioned above; c) Helicoverpa armigera, defoliating and being the most damaging species to pods in the RR variety; and d) S. cosmioides and S. frugiperda, defoliating and damaging pods in both varieties. The species differed in their ability to feed on IPRO varieties, so a different economic threshold should be considered. Consequently, in cases where more than one species are found simultaneously, the species composition should be considered in estimating the economic threshold. Additionally, our findings may contribute to a better decision-making to control insect feeding injury in IPRO varieties, because a slower larval growth provides more time to ensure the need of control with insecticides. In summary, this clasification contributes to an improved recommendation of sustainable insecticide use, taking into account the behavior of each species that are major soybeans pests in South America.
Project description:Pests and diseases are a major contributor to yield losses in sub-Saharan Africa, prompting smallholder farmers to seek cost-effective, accessible and ecologically friendly alternatives for crop protection. This study explored the management of pests and diseases affecting crops across eight selected villages in Ehlanzeni District, Mpumalanga Province, South Africa. A total of 120 smallholder farmers were purposefully selected utilising the snowball technique. Information on the management of plant pests and diseases was collected through interviews and focus group discussions using semi-structured interview schedules. Ethnobotanical indices, including relative frequency of citation (RFC), use-value (UV) and informant consensus factor (Fic), were used to quantify and rank the plants used for crop protection in the study area. Twenty-three plant species (16 naturalised exotics and seven indigenous plants) belonging to 16 families were used for managing pests (vertebrates and invertebrates) and diseases (fungal and bacterial related) affecting crops in the study area. The dominant (100%) crops cultivated by the participants were Allium cepa L., Mangifera indica L., Solanum lycopersicum L. and Zea mays L. The RFC value ranged from 0.08 to 0.83 and the three most popular plants for crop protection were Capsium annuum L. (0.83), A. cepa (0.63) and Dichrostachys cinerea (L.) Wight & Arn. (0.43). In terms of the UV, the five most promising plants used as biocontrol were Tulbaghia violacea (0.13), A. cepa (0.12), C. annuum L. (0.09), Solanum campylacanthum Hochst. Ex A.Rich.(0.09) and Pinus pinaster (0.08). Based on the Fic, four categories were established and dominated by fungal diseases (0.64). Furthermore, T. violacea and A. cepa were the most often mentioned plants used against fungal conditions. Other categories cited were bacterial diseases (0.3), invertebrate pests (0.11) and vertebrate pests (0.14), an indication that smallholder farmers had limited agreement or common knowledge about the plants used for their management. The preparation methods included maceration (38%), decoction (38%) and burning (24%). Foliar application (67%) and soil drenching (33%) were used for administering plant extracts during the management of crop pests and diseases. The study highlights the importance of botanicals and associated indigenous knowledge among smallholder farmers in Mpumalanga Province, South Africa. It is pertinent to explore the valorisation of these botanicals by generating empirical data on their biological efficacies and phytochemical profiles.
Project description:Knowing the nutrient removal by soybean grain harvest in different varieties, locations, and over time is essential to correctly adjust agronomic recommendations, update farmers' practices, and increase nutrient use efficiency. A field-based research trial was carried out to assess macronutrients [nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), and sulfur (S)] removed in grain by modern soybean varieties from southern Brazil introduced between 2007 and 2016. We examined changes between our set of modern varieties and a dataset of historical values encompassing a wide range of varieties introduced before 2007. Moreover, we undertook a synthesis analysis using scientific literature published after 2007 to investigate nutrient removal by grain among modern Brazilian soybeans and a dataset that included field trials from Argentina, United States, and India. There were no yield gains across the years for modern soybean varieties introduced among 2007 and 2016 in Brazil, although the grain N and Mg concentrations decreased. Modern Brazilian soybeans increased nutrient removal compared with that by soybeans historically planted in Brazil, with 11.1, 26.9, 45.0, and 31.6% more N, P, K, and Mg removed, respectively. Our results indicated that soybean growing in Brazil removed 4.3% less N relative to the values reported in the literature dataset, whereas K removal was 21.4% greater. A significant difference was also recorded for high-yield soybean varieties, and Brazilian varieties removed 11.8% less N and 8.6% more K than varieties in the literature dataset. No differences were found among locations for P removal, averaging 4.9 kg Mg-1 grain. In conclusion, this study indicates that the amounts of nutrients removed by modern soybean varieties were greater relative to the historical values recorded in Brazil, excluding Ca and S. Nonetheless, in the middle to long term (10 years), a significant impact of plant breeding on grain nutrient concentration was recorded only for N and Mg. The difference in nutrient removal patterns between Brazil and other countries indicates an integrated effect of management, genotype, and environment on nutrient removal. These findings provide guidance for optimal nutrient management and specific information for plant breeding programs to understand nutrient variability.
Project description:Soybean compounds have been established to modulate inflammation, but less is known about how whole soybean compositions work together after digestion. The objective was to evaluate and compare the anti-inflammatory responses of different soybean varieties under simulated gastrointestinal digestion, with additional consideration of the glycinin:β-conglycinin ratio (GBR). Soybean colonic digests (SCD) inhibited cyclooxygenase (COX)-2 (25-82%), 5-lipoxidase (LOX) (18-35%), and inducible nitric oxide (iNOS) (8-61%). Varieties 88, GN3, and 93 were the most effective inhibitors. SCD (1 mg/mL) of varieties 81 and GN1 significantly (p < 0.05) reduced nitrite production by 44 and 47%, respectively, compared to lipopolysaccharide (LPS)-stimulated macrophages. SCD effectively reduced pro-inflammatory cytokine interleukin (IL)-6 (50 and 80% for 96 and GN1, respectively). Western blot results showed a decrease in the expression of iNOS, p65, and p50. The GBR was in the range of 0.05-1.57. Higher ratio correlated with higher production of IL-1β (r = 0.44) and tumor necrosis factor-alpha (TNF-α, r = 0.56). Inflammatory microarray results showed a significant decrease in expression of markers granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-6 in cells treated with GN1 SCD compared to LPS. The results suggested that SCD exerted its anti-inflammatory potential through nuclear factor kappa B (NF-κΒ) pathway inhibition by decreasing the levels of NF-κB-dependent cytokines and subunits, and inhibition of pro-inflammatory enzyme activity.
Project description:Widespread adoption of MON 87701 × MON 89788 soybean, expressing Cry1Ac Bt protein and glyphosate tolerance, has been observed in Brazil. A proactive program was implemented to phenotypically and genotypically monitor Cry1Ac resistance in Chrysodeixis includens (Walker). Recent cases of unexpected injury in MON 87701 × MON 89788 soybean were investigated and a large-scale sampling of larvae on commercial soybean fields was performed to assess the efficacy of this technology and the distribution of lepidopteran pests in Brazil. No significant shift in C. includens susceptibility to Cry1Ac was observed eight years after commercial introduction of this technology in Brazil. F2 screen results confirmed that the frequency of Cry1Ac resistance alleles remains low and stable in C. includens. Unexpected injury caused by Rachiplusia nu (Guenée) and Crocidosema aporema (Walsingham) in MON 87701 × MON 89788 soybean was detected during the 2020/21 season, and studies confirmed a genetically based alteration in their susceptibility to Cry1Ac. MON 87701 × MON 89788 soybean remains effective against Anticarsia gemmatalis (Hübner), C. includens, Chloridea virescents (Fabricius) and Helicoverpa armigera (Hübner) in Brazil. However, there is evidence of field-evolved resistance to MON 87701 × MON 89788 soybean by the secondary soybean pests R. nu and C. aporema.
Project description:Plant height and node number are important agronomic traits that influence yield in soybean (Glycine max L.). Here, to better understand the genetic basis of the traits, we used two recombinant inbred line (RIL) populations to detect quantitative trait loci (QTLs) associated with plant height and node number in different environments. This analysis detected 9 and 21 QTLs that control plant height and node number, respectively. Among them, we identified two genomic regions that overlap with Determinate stem 1 (Dt1) and Dt2, which are known to influence both plant height and node number. Furthermore, different combinations of Dt1 and Dt2 alleles were enriched in distinct latitudes. In addition, we determined that the QTLs qPH-13-SE and qPH-13-DW in the two RIL populations overlap with genomic intervals associated with plant height and the QTL qNN-04-DW overlaps with an interval associated with node number. Combining the dwarf allele of qPH-13-SE/qPH-13-DW and the multiple-node allele of qNN-04-DW produced plants with ideal plant architecture, i.e., shorter main stems with more nodes. This plant type may help increase yield at high planting density. This study thus provides candidate loci for breeding elite soybean cultivars for plant height and node number.Supplementary informationThe online version contains supplementary material available at 10.1007/s11032-022-01352-2.
Project description:Termites are distributed throughout the world and often cause economic losses. This study aims to; (1) analyze the relationship between the distribution of termite species and the environmental conditions of Makassar city; (2) determine the level of attack in the Makassar City; and (3) map the risk of termite attack in the Makassar City. Samples of Pinus merkusii (2 × 2 × 20 cm) were placed at 13 observation stations and covered using polyvinyl chloride (PVC) tubes (4? in diameter, 25-cm in length). Samples remained in place for 6 months, at which point the presence of termite attacks as well as their intensity and frequency were analyzed. Three species of termites were found among the 13 stations: Schedorhinotermes sp., Coptotermes gestroi, and Microcerotermes serrula. Their presence was significantly influenced by environmental factors at each station. The study results showed a low rate of attack in several subdistricts of Bontoala, Biring Kanaya, Makassar, Mamajang, Mariso, Manggala, Panakukang, Rappocini, Tallo, Tamalanrea, Tamalate, Ujung Pandang, Ujung Tanah, and Wajo districts. A medium level of attacks was found in subdistricts within Biring Kanaya, Manggala, Mamajang, Panakukang, Rappocini, and Tallo Districts. Finally, a high risk of termite attacks was present in several subdistricts of Biringkanaya, Tamalantera, Rappocini, Manggala, and Tamalate districts.
Project description:BackgroundHepatitis B virus (HBV) infection is a world health problem with an estimated 257 million chronically infected people. Indonesia, with 7.1% prevalence of hepatitis B surface antigen (HBsAg), is classified as a moderately endemic country. Healthcare workers (HCWs) are at high occupational risk for HBV infection and potentially becoming transmitters for further infections. In Indonesia, the extent of hepatitis B among HCWs and specific control strategy are not available. This study evaluated the seroprevalence of HBV infection and associated risk factors in HCWs from four areas in South Sulawesi, Indonesia.MethodsA total of 467 HCWs (median age 28 years, male/female 89/378) were recruited. All HCWs were classified into three age groups (< 20-29, 30-39, and ≥ 40 years old), three work types (administration, non-intervention, and intervention), and three service periods (< 5, 5-9, and ≥ 10 years). Data on socio-demographic characteristics and risk factors were obtained by questionnaire and serum samples were tested for HBV markers (HBsAg, its antibody [anti-HBs], and antibody to core antigen [anti-HBc]. Chi-square or Fisher's exact test was used to determine differences in categorical variables, while risk factors were reported as odds ratios (OR).ResultsThe prevalence of current HBV infection (HBsAg+), exposure to HBV (anti-HBc+), and immunity to HBV (anti-HBs+) was 6.2, 19.2, and 26.1%, respectively. Two thirds (66.17%) of all HCWs did not express any of HBV markers. In relation to the age groups, intervention work-type, and service period of HCWs, increasing trends were observed in the exposure to HBV (p < 0.001, p < 0.001, and p < 0.010, respectively) and the immunity to HBV by natural infection (HBsAg-, anti-HBc+, anti-HBs+) (p = 0.004, p < 0.001, and p < 0.010, respectively). Needlestick injury contributed the highest risk factor (OR = 1.71; 95% CI: 1.05-2.77; p = 0.029) for infection acquisition, which mostly occurred in the intervention group (p = 0.046).ConclusionExposure to HBV showed significant association with HCWs' age, work type, and service period. Needlestick injury was the highest risk factor for the acquisition of HBV, with highest events in the intervention work-type. Two thirds of HCWs were still susceptible to HBV infection. Intervention strategies at the national level are required to mount prevention, control, and management of HBV infection in HCWs.
Project description:Rice leaf folder, Cnaphalocrocis medinalis (Guenée), is one of the most serious pests on rice. At present, chemical control is the main method for controlling this pest. However, the indiscriminate use of chemical insecticides has non-target effects and may cause environmental pollution. Besides, leaf curling behavior by C. medinalis may indirectly reduce the efficacy of chemical spray. Therefore, it is crucial to cultivate efficient rice varieties resistant to this pest. Previous studies have found that three different rice varieties, Zhongzao39 (ZZ39), Xiushui134 (XS134), and Yongyou1540 (YY1540), had varying degrees of infestation by C. medinalis. However, it is currently unclear whether the reason for this difference is related to the difference in defense ability of the three rice varieties against the infestation of C. medinalis. To explore this issue, the current study investigated the effects of three rice varieties on the growth performance and food utilization capability of the 4th instar C. medinalis. Further, it elucidated the differences in defense responses among different rice varieties based on the differences in leaf physiological and biochemical indicators and their impact on population occurrence. The results showed that the larval survival rate was the lowest, and the development period was significantly prolonged after feeding on YY1540. This was not related to the differences in leaf wax, pigments, and nutritional components among the three rice varieties nor to the feeding preferences of the larvae. The rate of superoxide anion production, hydrogen peroxide content, and the activity of three protective enzymes were negatively correlated with larval survival rate, and they all showed the highest in YY1540 leaves. Compared to other tested varieties, although the larvae feeding on YY1540 had higher conversion efficiency of ingested food and lower relative consumption rate, their relative growth was faster, indicating stronger food utilization capability. However, they had a lower accumulation of protein. This suggests that different rice varieties had different levels of oxidative stress after infestation by C. medinalis. The defense response of YY1540 was more intense, which was not conducive to the development of the larvae population. These results will provide new insights into the interaction mechanism between different rice varieties and C. medinalis and provide a theoretical basis for cultivating rice varieties resistant to this pest.