Peanut hulls, an underutilized nutritious culinary ingredient: valorizing food waste for global food, health, and farm economies-a narrative review.

Peanut hulls (PHs) are an edible food waste that is an underutilized food source for human consumption. While edible and palatable, currently they are mainly diverted to livestock feed or building materials. Here, we describe existing literature supporting human food valorization of PHs, and propose methods to optimize recapturing nutrients (protein, fiber, phenols and other phytonutrients) lost by treating PHs as waste. Incorporated into common foods, PHs could be processed into functional ingredients to improve nutrient-density with anticipated corresponding positive health outcomes associated with increases in plant foods. Valorization of PHs addresses multiple priorities of the UN Sustainable Development Goals using a Food Systems Approach (FSA) including reducing food waste, increasing economic opportunities for farmers, and increasing the availability of healthy shelf-stable foodstuffs to address food security. Recent advances in sustainable food processing technologies can be utilized to safely incorporate PHs into human food streams. We propose future applications that could make meaningful impacts for food availability and the nutritional composition of common foods like bread and plant-based meat alternatives. While the limited literature on this topic spans several decades, no commercial operations currently exist to process PHs for human consumption, and most literature on the topic precedes the technological "green revolution." The approaches outlined in this review may help bolster commercialization of this underutilized and nutritious food potentially improving opportunities for multiple global stakeholders.

Phosphorus and selenium compounding mitigates Cr stress in peanut seedlings by enhancing growth homeostasis and antioxidant properties.

Peanut is an economically important crop, but it is susceptible to Cr contamination. In this study, we used peanut as experimental material to investigate the effects of exogenous P, Se interacting with Cr on the nutrient growth and antioxidant system of peanut seedlings by simulating Cr (0 µM, 50 µM, and 100 µM) stress environment. The results showed that exogenous P, Se supply could mitigate irreversible damage to peanut seedlings by altering the distribution of Cr in roots and aboveground, changing root conformation, and repairing damaged cells to promote growth. When the Cr concentration is 100 µM, it exhibits the highest toxicity. Compared to the control group P and Se (0 MM), the treatment with simultaneous addition of P + Se (0.5 + 6.0) resulted in a significant increase in root length and root tip number by 248.7% and 127.4%, respectively. Additionally, there was a 46.9% increase in chlorophyll content, a 190.2% increase in total surface area of the seedlings, and a respective increase of 149.1% and 180.3% in soluble protein content in the shoot and roots. In addition, by restricting the absorption of Cr and reducing the synthesis of superoxide dismutase SOD (Superoxide dismutase), CAT (Catalase), POD (Peroxidase), and MDA (Malonaldehyde), it effectively alleviates the oxidative stress on the antioxidant system. Therefore, the exogenous addition of P (0.5 MM) and Se (6.0 MM) prevented the optimal concentration of chromium toxicity to peanuts. Our research provides strong evidence that the exogenous combination of P and Se reduces the risk of peanut poisoning by Cr, while also exploring the optimal concentration of exogenous P and Se under laboratory conditions, providing a basis for further field experiments.

Antifungal Activity of Cyperus articulatus, Cyperus rotundus and Lippia alba Essential Oils against Aspergillus flavus Isolated from Peanut Seeds.

Aspergillus flavus is a cosmopolitan saprophytic fungus that infests several foodstuffs and is associated with adverse effects in humans. In Senegal, significant losses of groundnut production are mainly due to contamination caused by this species. This study evaluated in vitro antifungal activities of Cyperus articulatus, Cyperus rotundus and Lippia alba essential oils against A. flavus isolated from peanut seeds. Essential oils obtained by hydrodistillation of rhizomes of the two Cyperus species and leaves of L. alba were analyzed with GC-DIF and GC-MS. The essential oil yields from C. articulatus, C. rotundus and L. alba were 1.1%, 1.3% and 1.7%, respectively. These three samples had the following chemotypes: (i) mustakone (21.4%)/eudesma-4(15)-7-dien-1ß-ol (8.8%)/caryophyllene oxide (5.9%), (ii) caryophyllene oxide (25.2%)/humulene epoxyde 2 (35.0%) and (iii) geranial (46.6%)/neral (34.6%). The three oils tested inhibited the growth of A. flavus at concentrations between 100 and 1000 ppm. The L. alba oil was the most effective with total clearance of A. flavus on PDA. For the essential oils of C. rotundus (93.65%) and C. articulatus (78.11%), the highest inhibition rates were obtained with a 1000 ppm dose. Thus, L. alba oil could be used safely as an effective protector of groundnuts against A. flavus.

Glycaemic Response to a Nut-Enriched Diet in Asian Chinese Adults with Normal or High Glycaemia: The Tu Ora RCT.

Nut-based products are a good source of high-quality plant protein in addition to mono- and polyunsaturated fatty acids, and may aid low-glycaemic dietary strategies important for the prevention of type 2 diabetes (T2D). In particular, they may be advantageous in populations susceptible to dysglycaemia, such as Asian Chinese. The present study aimed to compare effects of a higher-protein nut bar (HP-NB, also higher in total fibre and unsaturated fats, comprising mixed almonds and peanuts) vs. an isoenergetic higher-carbohydrate cereal bar (HC-CB) within the diet of 101 Chinese adults with overweight and normo- or hyperglycaemia. Ectopic pancreas and liver fat were characterised using magnetic resonance imaging and spectroscopy (MRI/S) as a secondary outcome. Participants were randomized to receive HP-NB or HC-CB daily as a 1 MJ light meal or snack replacement, in addition to healthy eating advice. Anthropometry and clinical indicators of T2D risk were assessed fasted and during an oral glucose tolerance test (OGTT), pre- and post-intervention. No significant difference was observed between diet groups for body weight, body mass index, waist or hip circumference, blood pressure, glucoregulatory markers, lipid profile or inflammatory markers over 12 weeks (all, p > 0.05). No difference was observed between glycaemic subgroups or those with normal versus high ectopic organ fat. Although HP-NB can attenuate postprandial glycaemia following a meal, no effects were observed for either fasting or glucose-mediated outcomes following longer-term inclusion in the habitual diet of Chinese adults with overweight, including at-risk subgroups.

Effect of a Higher-Protein Nut versus Higher-Carbohydrate Cereal Enriched Diet on the Gut Microbiomes of Chinese Participants with Overweight and Normoglycaemia or Prediabetes in the Tu Ora Study.

Global increases in metabolic disorders such as type 2 diabetes (T2D), especially within Asian populations, highlight the need for novel approaches to dietary intervention. The Tu Ora study previously evaluated the effects on metabolic health of including a nut product into the diet of a New Zealand cohort of Chinese participants with overweight and normoglycaemia or prediabetes through a 12-week randomised, parallel-group clinical trial. In this current study, we compared the impact of this higher-protein nut bar (HP-NB) versus a higher-carbohydrate cereal bar (HC-CB) on the faecal microbiome by employing both 16S rRNA gene amplicon and shotgun metagenomic sequencing of pre- and post-intervention pairs from 84 participants. Despite the higher fibre, protein, and unsaturated fat content of nuts, there was little difference between dietary groups in gut microbiome composition or functional potential, with the bacterial phylum Firmicutes dominating irrespective of diet. The lack of observed change suggests the dietary impact of the bars may have been insufficient to affect the gut microbiome. Manipulating the interplay between the diet, microbiome, and metabolic health may require a more substantial and/or prolonged dietary perturbation to generate an impactful modification of the gut ecosystem and its functional potential to aid in T2D risk reduction.

Genomic-wide analysis of Salmonella enterica strains isolated from peanuts in Brazil.

Peanut-based products have been associated with Salmonella foodborne outbreaks and/or recalls worldwide. The ability of Salmonella to persist for a long time in a low moisture environment can contribute to this kind of contamination. The objective of this study was to analyse the genome of five S. enterica enterica strains isolated from the peanut supply chain in Brazil, as well as to identify genetic determinants for survival under desiccation and validate these findings by phenotypic test of desiccation stress. The strains were in silico serotyped using the platform SeqSero2 as Miami (M2851), Javiana (M2973), Oranienburg (M2976), Muenster (M624), and Glostrup/Chomedey (M7864); with phylogenomic analysis support. Based on Multilocus Sequence Typing (MLST) the strains were assigned to STs 140, 1674, 321, 174, and 2519. In addition, eight pathogenicity islands were found in all the genomes using the SPIFinder 2.0 (SPI-1, SPI-2, SPI-3, SPI-5, SPI-9, SPI-13, SPI-14). The absence of a SPI-4 may indicate a loss of this island in the surveyed genomes. For the pangenomic analysis, 49 S. enterica genomes were input into the Roary pipeline. The majority of the stress related genes were considered as soft-core genes and were located on the chromosome. A desiccation stress phenotypic test was performed in trypticase soy broth (TSB) with four different water activity (aw) values. M2976 and M7864, both isolated from the peanut samples with the lowest aw, showed the highest OD570nm in TSB aw 0.964 and were statistically different (p < 0.05) from the strain isolated from the peanut sample with the highest aw (0.997). In conclusion, genome analyses have revealed signatures of desiccation adaptation in Salmonella strains, but phenotypic analyses suggested the environment influences the adaptive ability of Salmonella to overcome desiccation stress.

Effect of Peanut Butter Intake on Sleep Health in Firefighters: A Randomized Controlled Trial.

Sleep is often impaired in firefighters due to the psychologically and physiologically intense nature of their work and working shift schedules. Peanut butter is affordable and a substantial source of monounsaturated fatty acids, which may aid sleep health. Thus, this study sought to determine if a daily serving of peanut butter consumed before bedtime for seven weeks altered sleep quality and quantity among full-time firefighters. Forty firefighters (peanut butter group = 20; control group = 20) participated in this eight-week randomized controlled trial. All participants completed a subjective questionnaire on mood, focus, and alertness twice daily and wore an Actigraph wristwatch to measure sleep variables, including latency, efficiency, time in bed, time asleep, wake after sleep onset, number of awakenings, and time spent awake. After a baseline week, the peanut butter group consumed two tablespoons of peanut butter two hours prior to bedtime for seven weeks. Compared to the control group, the peanut butter group did not demonstrate significant changes (p > 0.05) in sleep measures or subjective feelings of mood, focus, or alertness after consuming peanut butter for seven weeks. Therefore, peanut butter as a source of peanuts did not alter sleep quality or quantity in this group of firefighters.

Quantitative detection of aflatoxin B1 in peanuts using Raman spectra and multivariate analysis methods.

Aflatoxin B1 (AFB1), among the identified aflatoxins, exhibits the highest content, possesses the most potent toxicity, and poses the gravest threat. It is commonly found in peanuts and their derivatives. This study employs Raman spectroscopy to monitor the AFB1 levels in moldy peanuts, providing a reliable theoretical basis for peanut storage management. Firstly, different degrees of moldy peanuts are spectrally characterized using a portable Raman spectrometer. Subsequently, a two-step hybrid strategy for feature selection is proposed, combining backward interval partial least squares (BiPLS) and variable combination population analysis (VCPA), aiming to simplify model complexity and enhance predictive accuracy. Finally, partial least squares (PLS) regression models are constructed based on different feature intervals and wavelength points. The research results reveal that the PLS regression model using the optimized feature intervals and wavelength points exhibits improved predictive capability and generalization performance. Notably, the BiPLS-VCPA-PLS model, established through the two-step optimization, selects nine wavelength variables, achieving a root mean square error of prediction (RMSEP) of 33.3147 µg∙kg-1, a correlation coefficient of the prediction set (RP) of 0.9558, and a relative percent deviation (RPD) of 3.4896. These findings demonstrate that the two-step feature optimization method, combining feature interval selection and feature wavelength selection, can more accurately identify optimal variables, thus enhancing detection efficiency and predictive precision.

Efficacy of atoxigenic Aspergillus flavus from southern China as biocontrol agents against aflatoxin contamination in corn and peanuts.

Aspergillus flavus is a ubiquitous facultative pathogen that routinely infects important crops leading to formation of aflatoxins during crop development and after harvest. Corn and peanuts in warm and/or drought-prone regions are highly susceptible to aflatoxin contamination. Controlling aflatoxin using atoxigenic A. flavus is a widely adopted strategy. However, no A. flavus genotypes are currently approved for use in China. The current study aimed to select atoxigenic A. flavus endemic to Guangxi Zhuang Autonomous Region with potential as active ingredients of aflatoxin biocontrol products. A total of 204 A. flavus isolates from corn, peanuts, and field soil were evaluated for ability to produce the targeted mycotoxins. Overall, 57.3% could not produce aflatoxins while 17.15% were incapable of producing both aflatoxins and CPA. Atoxigenic germplasm endemic to Guangxi was highly diverse, yielding 8 different gene deletion patterns in the aflatoxin and CPA biosynthesis gene clusters ranging from no deletion to deletion of both clusters. Inoculation of corn and peanuts with both an aflatoxin producer and selected atoxigenic genotypes showed significant reduction (74 to 99%) in aflatoxin B1 (AFB1) formation compared with inoculation with the aflatoxin producer alone. Atoxigenic genotypes also efficiently degraded AFB1 (61%). Furthermore, atoxigenic isolates were also highly efficient at reducing aflatoxin concentrations even when present at lower concentrations than aflatoxin producers. The use of multiple atoxigenics was not always as effective as the use of a single atoxigenic. Effective atoxigenic genotypes of A. flavus with known mechanisms of atoxigenicity are demonstrated to be endemic to Southern China. These A. flavus may be utilized as active ingredients of biocontrol products without concern for detrimental impacts that may result from introduction of exotic fungi. Field efficacy trials in the agroecosystems of Southern China are needed to determine the extent to which such products may allow the production of safer food and feed.

The potential for reducing aflatoxin B1 contamination of stored peanuts by soil disinfection.

Aflatoxins from the fungus Aspergillus flavus (A. flavus) that contaminate stored peanuts is a major hazard to human health worldwide. Reducing A. flavus in soil can decrease the risk of aflatoxins in stored peanuts. In this experiment, we determined whether peanuts grown on soil fumigated with dazomet (DZ), metham sodium (MS), allyl isothiocyanate (AITC), chloropicrin (PIC) or dimethyl disulfide (DMDS) would reduce of the quantity of A. flavus and its toxin's presence. The results of bioassays and field tests showed that PIC was the most effective fumigant for preventing and controlling A. flavus, followed by MS. PIC and MS applied to the soil for 14 d resulted in LD50 values against A. flavus of 3.558 and 4.893 mg kg-1, respectively, leading to almost 100% and 98.82% effectiveness of A. flavus, respectively. Peanuts harvested from fumigated soil and then stored for 60 d resulted in undetectable levels of aflatoxin B1 (AFB1) compared to unfumigated soil that contained 0.64 ug kg-1 of AFB1, which suggested that soil fumigation can reduce the probability of aflatoxin contamination during peanut storage and showed the potential to increase the safety of peanuts consumed by humans. Further research is planned to determine the practical value of our research in commercial practice.

Nuts and seeds - a scoping review for Nordic Nutrition Recommendations 2023.

Background: Nuts and seeds have been part of diets in most of the world for millenniums, and they have also been consumed in the Nordic and Baltic countries for centuries. Consumption of nuts and seeds is linked with various health outcomes. Therefore, when updating the Nordic Nutrition Recommendations (NNR), summarizing the best evidence on key health outcomes from the consumption of nuts and seeds is essential. Objectives: This study aims to evaluate the updated evidence on the consumption of nuts and seeds and health outcomes regarded relevant for the Nordic and Baltic countries, as well as their dose-response relationship presented in updated systematic reviews and meta-analyses. Method: The scoping review is built on a de novo systematic review and an umbrella review published in 2022 on the consumption of nuts and seeds and its various health outcomes, including cardiovascular disease and diabetes. Results: Intake of nuts and seeds is associated with a lower risk of cardiovascular diseases, with evidence assessed as probable. This conclusion is mirrored by evidence from trials on biomarkers for chronic diseases. An intake of a serving of nuts of 28-30 g/day compared to not eating nuts is estimated to translate into approximately 20% relative reduction in the risks of cardiovascular disease and premature deaths. For cancers, consumption of a serving of nuts is inversely associated with cancer mortality. However, for type 2 diabetes, there are mixed and inconclusive results. Additionally, there are inverse associations between nut consumption and respiratory and infectious disease mortality. Allergies for nuts are seen among 1-2% of the population. Conclusion: Overall, the current evidence supports dietary recommendations to increase nut consumption to a serving of nuts and seeds per day for people without allergies to these foods.

Effect of pre-drying and post-frying holding treatments on the oil absorption and quality of fried batter-coated peanuts.

In this study, the effect of pre-drying and post-frying holding treatments on the oil absorption and the quality of the fried batter-coated peanuts were explored. The results showed that hot air drying and microwave drying induced the gelatinization of starch in the batter before frying. The thermodynamic properties of starch in the batter after frying indicated that pre-drying could protect the orderliness of the starch. CLSM images showed that the pre-drying treatment reduced the number of large oil spots on the surface of batter of fried batter-coated peanuts. SEM observation revealed that the structure of the batter treated with pre-drying was denser and the number of large pores was reduced after frying. The post-frying holding treatment improved the color and texture of the batter-coated peanuts. In conclusion, the pre-drying and post-frying holding treatment can reduce the oil content and improve the fracturability of the fried batter-coated peanuts.

Irrigation and Fertilization Scheduling for Peanut Cultivation under Mulched Drip Irrigation in a Desert-Oasis Area.

The aim of this study was to investigate the impact of water and nitrogen regulation on the characteristics of water and fertilizer demands and the yield, quality, and efficiencies of the water and nitrogen utilization of peanuts cultivated under mulched drip irrigation in a desert-oasis region. The experiment, conducted in Urumqi, Xinjiang, centered on elucidating the response mechanisms governing peanut growth, yield, quality, water consumption patterns, and fertilizer characteristics during the reproductive period under the influence of water and nitrogen regulation. In the field experiments, three irrigation levels were implemented, denoted as W1 (irrigation water quota of 22.5 mm), W2 (irrigation water quota of 30 mm), and W3 (irrigation water quota of 37.5 mm). Additionally, two nitrogen application levels, labeled N1 (nitrogen application rate of 77.5 kg·ha-1) and N2 (a nitrogen application rate of 110 kg·ha-1), were applied, resulting in seven treatments. A control treatment (CK), which involved no nitrogen application, was also included in the experimental design. The results indicate a direct correlation between the increment in the irrigation quota and increases in farmland water-related parameters, including water consumption, daily water consumption intensity, and water consumption percentage. The nitrogen harvest index (NHI) demonstrated a higher value in the absence of nitrogen application compared to the treatment with elevated nitrogen levels. The application of nitrogen resulted in an elevation in both nitrogen accumulation and nitrogen absorption efficiency within pods and plants. When subjected to identical nitrogen application conditions, irrigation proved to be advantageous in enhancing water-use efficiency (WUE), nitrogen partial factor productivity (NPFP), and the yield of peanut pods. The contribution rate of water to pod yield and WUE exceeded that of nitrogen, while the contribution rate of nitrogen to nitrogen-use efficiency (NUE) was higher. The total water consumption for achieving a high yield and enhanced water- and nitrogen-use efficiencies in peanuts cultivated under drip irrigation with film mulching was approximately 402.57 mm. Taking into account yield, quality, and water- and nitrogen-used efficiencies, the use of an irrigation quota of 37.5 mm, an irrigation cycle of 10-15 days, and a nitrogen application rate of 110 kg·ha-1 can be regarded as an appropriate water and nitrogen management approach for peanut cultivation under mulched drip irrigation in Xinjiang.

Weaning, food allergens and potential risk factors for delayed introduction: a cross-sectional study.

Much evidence supports that the early introduction of allergenic foods in weaning is useful to prevent food allergies later in life. Real life is often different, with factors related to mothers and infants. Our study aimed to deepen the timing of introducing the foods responsible for most allergic reactions during the weaning and why parents delay their introduction. 110 mothers participated in the study, compiling a questionnaire. Exclusive breastfeeding was associated with a delayed introduction of allergenic foods at 4 months (r = 0.433, p < 0.01) and 1 year (r = 0.486, p < 0.01). Large-for-gestational age at birth was inversely associated with a delayed introduction of allergenic foods (r=-0.204, p < 0.05). This study demonstrates that introducing many allergens is delayed during the weaning. Parents with infants fed with exclusive breastfeeding could need more information about the correct time of introduction of potential allergens in the weaning.

Peanut (Arachis hypogaea L.) seeds and by-products in metabolic syndrome and cardiovascular disorders: A systematic review of clinical studies.

BACKGROUND: Cardiovascular disease (CVDs) is the leading cause of death worldwide. The main risk factors are hypertension, diabetes, obesity, and increased serum lipids. The peanut (Arachis hypogaea L.), also known as the groundnut, goober, pindar, or monkey nut, belongs to the Fabaceae family and is the fourth most cultivated oilseed in the world. The seeds and skin of peanuts possess a rich phytochemical profile composed of antioxidants, such as phenolic acids, stilbenes, flavonoids, and phytosterols. Peanut consumption can provide numerous health benefits, such as anti-obesity, antidiabetic, antihypertensive, and hypolipidemic effects. Accordingly, peanuts have the potential to treat CVD and counteract its risk factors. PURPOSE: This study aims to critically evaluate the effects of peanuts on metabolic syndrome (MetS) and CVD risk factors based on clinical studies. METHOD: This review includes studies indexed in MEDLINE-PubMed, COCHRANE, and EMBASE, and the Preferred Reporting Items for a Systematic Review and Meta-Analysis guidelines were adhered to. RESULTS: Nineteen studies were included and indicated that the consumption of raw peanuts or differing forms of processed foods containing peanut products and phytochemicals could improve metabolic parameters, such as glycemia, insulinemia, glycated hemoglobin, lipids, body mass index, waist circumference, atherogenic indices, and endothelial function. CONCLUSION: We propose that this legume and its products be used as a sustainable and low-cost alternative for the prevention and treatment of MetS and CVD. However, further research with larger sample sizes, longer intervention durations, and more diverse populations is needed to understand the full benefit of peanut consumption in MetS and CVD.

Peanut Allergy and Component-Resolved Diagnostics Possibilities-What Are the Benefits?

Peanut allergy is a widespread and potentially life-threatening condition that affects both children and adults, with a growing incidence worldwide. It is estimated to affect around 1-2% of the population in several developed countries. Component-resolved diagnostics is a modern approach to allergy diagnosis that focuses on identifying specific allergenic proteins to provide precise diagnoses and personalized treatment plans. It is a technique that enables the analysis of specific IgE antibodies against tightly defined molecules (components) that constitute the allergen. Component-resolved diagnostics is particularly valuable in peanut allergy diagnosis, helping to determine allergen components associated with severe reactions. It also aids in predicting the course of the allergy and enables the development of personalized immunotherapy plans; however, the full application of it for these purposes still requires more precise studies. In this paper, we present the current knowledge about peanut allergy and component-resolved diagnostics possibilities. We discuss the possibilities of using molecular diagnostics in the diagnosis of peanut allergy. We focus on examining and predicting the development of peanut allergy, including the risk of anaphylaxis, and describe the latest data related to desensitization to peanuts.

Peanut sprout tea extract inhibits lung metastasis of 4T1 murine mammary carcinoma cells by suppressing the crosstalk between cancer cells and macrophages in BALB/c mice.

BACKGROUND/OBJECTIVES: As peanuts germinate, the content of the components beneficial to health, such as resveratrol, increases within the peanut sprout. This study examined whether the ethanol extract of peanut sprout tea (PSTE) inhibits breast cancer growth and metastasis. MATERIALS/METHODS: After orthotopically injecting 4T1 cells into BALB/c mice to induce breast cancer, 0, 30, or 60 mg/kg body weight/day of PSTE was administered orally. Angiogenesis-related protein expression in the tumors and the degree of metastasis were analyzed. 4T1 and RAW 264.7 cells were co-cultured, and reverse transcription polymerase chain reaction was performed to measure the crosstalk between breast cancer cells and macrophages. RESULTS: PSTE reduced tumor growth and lung metastasis. In particular, PSTE decreased matrix metalloproteinase-9, platelet endothelial cell adhesion molecule-1, vascular endothelial growth factor-A, F4/80, CD11c, macrophage mannose receptor, macrophage colony-stimulating factor, and monocyte chemoattractant protein 1 expression in the tumors. Moreover, PSTE prevented 4T1 cell migration, invasion, and macrophage activity in RAW 264.7 cells. PSTE inhibited the crosstalk between 4T1 cells and RAW 264.7 cells and promoted the macrophage M1 subtype while inhibiting the M2 subtype. CONCLUSIONS: These results suggest that PSTE blocks breast cancer growth and metastasis to the lungs. This may be because the PSTE treatment inhibits the crosstalk between mammary cancer cells and macrophages and inhibits the differentiation of macrophages into the M2 subtype.

Effects of Different Water and Nitrogen Supply Modes on Peanut Growth and Water and Nitrogen Use Efficiency under Mulched Drip Irrigation in Xinjiang.

The optimization of irrigation and fertilization indexes for peanuts with drip irrigation is urgently needed in Xinjiang. A field experiment was conducted during the 2021 peanut growing season at Urumqi, Xinjiang, in Northwestern China, to evaluate the effects of different water and nitrogen treatments on the growth, yield, and water and nitrogen utilization of peanuts. In field experiments, we set up three irrigation levels (irrigation water quotas of 22.5, 30, and 37.5 mm, respectively, for W1, W2, and W3), two nitrogen application levels (77.5 and 110 kg·ha-1, recorded as N1 and N2), and a control treatment (W2N0) that did not include the application of nitrogen. The results showed that nitrogen application enhanced the growth, physiological indexes, yield, and water use efficiency of the W1, W2, and W3 treatments when the irrigation volume remained the same. In comparison with no nitrogen application (W2N0), the peanut growth, physiological indexes, yield, and water use efficiency improved with increasing irrigation amounts in the N1 and N2 treatments. With an increase in the irrigation volume, the water use efficiency grew; the W3N2 treatment had the highest water use efficiency, which was 1.32 kg·m-3. The total water consumption and reproductive-stage water consumption of the peanuts in all treatments increased with the irrigation volume, and a high yield was achieved at 402.57 mm, which was 5.2974 Mg·ha-1. In the W1, W2, and W3 treatments, the nitrogen partial factor productivity significantly decreased as the nitrogen application increased, with the nitrogen partial factor productivity in the W3N1 treatment being the highest, at 60.61 kg·kg-1. A comprehensive evaluation based on principal component analysis assigned W3N2 the higher score. These findings suggest that irrigation water quotas of 37.5 mm should be coupled with 110 kg·ha-1 nitrogen applications for peanuts using drip irrigation in mulch film in Xinjiang.

Arbuscular Mycorrhizal Fungi Restored the Saline-Alkali Soil and Promoted the Growth of Peanut Roots.

Peanut (Arachis hypogaea L.) is an important oil and cash crop. An efficient utilization of saline-alkali soil resources, the development of peanut planting in saline-alkali soil, and obtaining high and stable yield have become urgent needs to ensure peanut production. Arbuscular mycorrhizal fungi (AMF) have been reported to develop the potential productivity of host plants and improve their salt resistance and tolerance. However, there is still limited research on promoting the growth and morphology of peanut roots. Therefore, in this study, seeds of salt-tolerant peanut variety "HY 25" were coated with commercial AMF inoculant before being planted in saline-alkali and normal soils to investigate the effects of AMF on peanut root growth and rhizosphere soil. The results showed that root morphological characteristics were significantly increased by the use of AMF at the podding stage in saline-alkali soil and from the flowering and pegging stage to the maturity stage in normal soil. Of note, the total root volume of peanut inoculated with AMF significantly increased by 31.57% during the podding stage in saline-alkali soil. Meanwhile, AMF significantly increased the phosphatase and invertase activities in the peanut rhizosphere of saline-alkali soil from the flowering stage to maturity stage and soil CAT activity at the maturity stage (41.16~48.82%). In normal soil, soil phosphatase and urease activities were enhanced by AMF at the flowering stage and the podding stage, respectively. AMF also increased the contents of soil organic matter, available phosphorus, and hydrolysable nitrogen, but decreased soil EC in saline-alkali soil. In addition to the significant increase in soil available phosphorus content, AMF had no significant effect on the physical and chemical properties of the soil and other soil nutrients in normal soil. AMF significantly increased pod biomass and yield in saline-alkali soil and normal soil, and improved their agronomic characteristics. In conclusion, peanut seeds coated with AMF improved the root morphological characteristics of peanuts and improved the physical and chemical properties in peanut rhizosphere, especially in saline-alkali soil. The process of rhizosphere soil nutrient transformation was also enhanced. Finally, AMF improved plant agronomic traits to increase the pod yield (16.5~21.9%). This study provides the theoretical basis and technical support for the application of AMF in peanut production in saline-alkali soil.

GWAS with principal component analysis identify QTLs associated with main peanut flavor-related traits.

Peanut flavor is a complex and important trait affected by raw material and processing technology owing to its significant impact on consumer preference. In this research, principal component analysis (PCA) on 33 representative traits associated with flavor revealed that total sugars, sucrose, and total tocopherols provided more information related to peanut flavor. Genome-wide association studies (GWAS) using 102 U.S. peanut mini-core accessions were performed to study associations between 12,526 single nucleotide polymorphic (SNP) markers and the three traits. A total of 7 and 22 significant quantitative trait loci (QTLs) were identified to be significantly associated with total sugars and sucrose, respectively. Among these QTLs, four and eight candidate genes for the two traits were mined. In addition, two and five stable QTLs were identified for total sugars and sucrose in both years separately. No significant QTLs were detected for total tocopherols. The results from this research provide useful knowledge about the genetic control of peanut flavor, which will aid in clarifying the molecular mechanisms of flavor research in peanuts.