INTRODUCTION:Synthetic nitrogen (N) fertilizers underpin global food security but drive escalating environmental costs, including greenhouse gas (GHG) emissions and soil degradation. Conventional N-reduction strategies face a fundamental trade-off: lowering fertilizer inputs typically compromises crop productivity and farmer income. Nanotechnology offers a pathway to decouple yield from N dependency, yet scalable, low-cost solutions remain elusive. OBJECTIVES:This study aimed to develop a least-input foliar fertilization strategy using bio-derived nanocarbon (BNC) that enables a 30% reduction in synthetic N input in peanut (Arachis hypogaea L.) without sacrificing crop yield, nutritional quality, or economic returns, while elucidating the underlying physiological and microbiological mechanisms. METHODS:Field trials were conducted with peanut (cv. Huayu 22) over two consecutive growing seasons (2024-2025) in Laixi, Shandong, China, under four treatments: N (conventional N, 100% urea), N-30 (reduced N, 70% urea), N + BNC (100% urea + foliar BNC), and N-30 + BNC (70% urea + 18 g ha-1 foliar BNC). Photosynthetic parameters, oxidative stress markers, and 15N isotope tracing were assessed. Transcriptomic, metabolomic, and 16S rRNA microbiome analyses characterized systemic signaling and rhizosphere responses. GHG emissions were modeled using the DNDC framework, and economic benefits were calculated based on yield and input costs. RESULTS:BNC application under N-30% maintained yield parity with the N control by sustaining photosynthetic electron transport and reducing reactive oxygen species (ROS). This enhanced carbon status upregulated the transcription factor HY5, activating nitrate transporter AhNRT1.2 and ammonium transporter AhAMT1.1 and increasing 15N uptake. Changes in root-exudate composition were accompanied by shifts in the rhizosphere bacterial community, including higher relative abundance of taxa associated with nitrification and nutrient turnover (Nitrospira and Gemmatimonas), and coincided with 21% and 14% higher root NO3--N and NH4+-N contents, respectively. Nitrogen use efficiency (NUE) improved by 16.0%, total GHG emissions decreased by 34.8%, and net profit increased by 27.0%. CONCLUSION:A micro-dosage of upcycled BNC (∼$0.02 ha-1) orchestrates HY5-mediated shoot-to-root signaling and rhizosphere microbiome restructuring to sustain crop productivity under reduced N inputs. This commercially viable, low-input framework offers a scalable route for climate-smart agriculture that reconciles food security with environmental sustainability.

Cylindrocladium black rot of peanut is caused by the fungus Calonectria ilicicola (anamorph: Cylindrocladium parasiticum). This quarantined plants pathogen, causes this diseasethat threatens the healthy production of peanuts. The objective of this study was to screen andexplore the extracts of biocontrol bacteria against C. ilicicola. A bacterial strain XYDY-1 was isolated from saline-alkali soil samples collected near peanut plants and identified as Bacillus velezensis based on morphological characteristics, 16S rDNA, and gyrB sequence analyses. The bacterial suspension of XYDY-1 exhibited significant inhibitory effects on the growth of eight pathogenic fungi, including C. ilicicola, Aspergillus niger, Fusarium pseudograminearum, F. oxysporum, F. neocosmosporiellum, Sclerotium rolfsii, Rhizoctonia solanikühn, and Sclerotinia sclerotiorum. Extracellular enzyme assays revealed that XYDY-1 possessed protease, cellulase, amylase, chitinase, and β-1,3-glucanase activities. Furthermore, genomic analysis confirmed the presence of genes srfAD, fenB, ituA, and bmyA, which encode surfactin, fengycin, iturin, and bacillomycin D, respectively, all of which contribute to the inhibition of hyphal growth. Ultra-high-performance liquid chromatography coupled with quadrupole-electrostatic field orbitrap high-resolution tandem mass spectrometry (UPLC-QE Orbitrap MS/MS) analysis detected antifungal compounds in B. velezensis metabolites, including 8-hydroxyquinoline, tunicamycin, Validamycin A, chloramphenicol palmitate, pyocyanin, and Surfactin C. 8-Hydroxyquinoline, tunicamycin, Surfactin C and Validamycin A exhibited significant antifungal activity in assays conducted with pure compounds. Of these, 8-hydroxyquinoline at a concentration of 10 mg/mL displayed the highest efficacy, yielding an inhibition rate of 98.31

Background The practice of tobacco monoculture usually leads to increased occurrence of soil-borne diseases and reduced yield and quality, posing a significant obstacle to sustainable farming. The soil microbiome is central to soil health, but the mechanisms by which crop rotation alleviates monoculture-related obstacles by reconstructing microbial communities and their interaction networks remain poorly understood.Methods A field study was conducted in two regions to compare tobacco grown on soils after rotation (with wheat or rapeseed) and tobacco grown on soils with continuous tobacco cropping. A comprehensive analysis was performed on soil physicochemical properties, enzyme activities, microbial biomass, 16S rRNA bacterial and ITS fungal gene sequencing, microbial co-occurrence networks and phenotypic data, including tobacco yield, disease index and chemical quality of cured tobacco. A multi-omics coupling framework was constructed to integrate environmental variables, community structure and phenotype.Results Crop rotation notably increased the content of available potassium in the soil and enhanced the activities of key enzymes involved in carbon and phosphorus cycling, such as beta-glucosidase, sucrase and acid phosphatase. These changes led to improved nutrient availability. Across the two regions, crop rotation consistently restructured both bacterial and fungal communities, enriching beneficial taxa, including Chitinophagaceae, Rhodanobacteraceae, Xanthobacteraceae, Cercophora and Montagnula, while suppressing the proliferation of potential fungal pathogens. The microbial co-occurrence networks under rotation conditions were more intricate, cooperative and functionally integrated. Path analysis, incorporating composite variables, revealed a comprehensive causal pathway: crop rotation enhances the abundance of beneficial microbes and increases network complexity, which, in turn, improves the soil health indexes. This ultimately results in higher tobacco yield, reduced disease incidence and superior chemical and sensory quality of the cured tobacco.

Global food security faces immense pressure from population growth and climate change, demanding sustainable agricultural intensification. While biochar offers promise for soil enhancement and carbon sequestration, its large-scale application requires significant biomass feedstock and energy-intensive production, raising economic and carbon footprint concerns. Nano-enabled foliar feeding is gaining momentum, but practical, eco-efficient field use from lab to farm remains challenging. Bridging this gap is essential for realizing nano-enabled agriculture without exacerbating environmental burdens. Here, we demonstrate on-site conversion of ecologically safe flash graphene via flash joule heating. Spraying 18 g/hectare of this graphene, produced from 75 g (<0.001%) of crop residues per hectare, on multi-crops over two seasons increased yields by 9.1%-27.3% through enhanced photosynthesis and alleviated oxidative stress. Compared to biochar, this approach reduces farmers' inputs by 86%-91% and lowers life-cycle carbon emissions by up to 10,000-fold. We offered a self-sufficient, scalable, and climate-smart circular foliar feeding pathway to advance food security sustainably.

Peanut root rot poses a significant threat to global peanut production. In order to identify the new pathogen of peanut root rot in Shandong province, China, and to screen the effective antagonistic biocontrol strains against the identified pathogen, ten symptomatic plants from a peanut field (10% disease incidence) of Rongcheng were sampled for pathogen isolation. The predominant isolate RC-103 was identified as Ceratobasidium sp. AG-A through morphological characterization and phylogenetic analysis of ITS and RPB2 sequences. Pathogenicity was confirmed via Koch’s postulates. Three potent biocontrol strains, namely Bacillus subtilis LY-1, Bacillus velezensis ZHX-7, and Burkholderia cepacia Bc-HN1, were screened for effective antagonism against isolate RC-103 by dual-culture analysis. Their cell suspensions could significantly inhibit the hyphal growth of isolate RC-103, with the percentage inhibition of 54.70%, 45.86%, and 48.62%, respectively. Notably, the percentage inhibition of 10% concentration of the cell-free culture filtrate of B. subtilis LY-1 was as high as 59.01%, and the inhibition rate of volatile organic compounds of B. cepacia Bc-HN1 was 48.62%. Antagonistic mechanisms primarily involved the induction of hyphal abnormalities. In addition, the culture filtrate of these biocontrol bacteria significantly promoted the growth of peanut and increased the resistance of peanut plants to isolate RC-103, with the biocontrol efficiency reaching 41.86%. In summary, this study identified a novel pathogen of peanut root rot, Ceratobasidium sp. AG-A, which was reported for the first time in China, and screened three highly effective antagonistic biocontrol strains against Ceratobasidium sp. AG-A isolate RC-103, providing the scientific basis to study the epidemiology and management of this disease.

Peanut (Arachis hydropoaea L.) demonstrates a prominent adaptability to diverse soil types. However, the specific effects of soil types on peanut growth and bacterial communities remain elusive. This study conducted a thorough examination of the agronomic traits, the corresponding physicochemical properties, and bacterial structure of rhizosphere soil in acidic (AT), neutral (NT), and saline–alkali (ST) soils, elucidating the internal relationship between soil type and peanut yield. Our results showed that different soil types exhibited significant differences in peanut yield, with ST demonstrating the lowest yield per plant, showing an 85.05% reduction compared to NT. Furthermore, available phosphorus content, urease, and invertase activities were substantially reduced in both ST and AT, particularly in ST by 95.35%, 38.57%, and 62.54%, respectively. Meanwhile, metagenomic sequencing unveiled a notable decline in Bradyrhizobium and Streptomyces in these soils, which is crucial for soil improvement. Further metabolic pathway analysis revealed that the reduction in pathways related to soil remediation, fertility improvement, and stress response in AT and ST may lead to slower peanut growth. In conclusion, peanuts cultivated in acidic and saline–alkali soils can increase yield via implementing soil management practices such as improving soil quality and refining micro-environments. Our study provides practical applications for enhancing peanut yield in low- to medium-yield fields.

Peanuts grown in saline alkali soil are also subjected to drought stress caused by water scarcity. Therefore, we used HY25 (peanut variety) as an experimental material to investigate the effects of drought on the height of peanut main stems, length of the first lateral branch, leaf area per plant, SPAD value, net photosynthetic rate, and accumulation and distribution of photosynthetic products in saline alkali soil. The results showed that the combined stress of short-term drought and salt significantly reduced the main stem height, first lateral branch length, single plant leaf area, SPAD value, net photosynthetic rate (Pn), intercellular carbon dioxide concentration (Ci), and dry matter accumulation of peanuts, including a decrease in single plant pod yield, 100-pod weight, 100-kernel weight, and peanut yield. And the impact of drought stress on peanut yield varies at different growth stages. For example, under drought stress alone, the sensitive period is the 40th day after planting (40D) > 60th day after planting (60D) > 30th day after planting (30D). Short-term drought has the greatest impact on peanut yield at 40D, while in contrast, resuming watering after drought at 30D results in a slight but not significant increase in peanut yield in comparison with the control. Under the combined stress of drought and salt, the sensitive period of peanuts was 40D > 30D > 60D, and the single pod weight of peanuts was significantly reduced by 15.26% to 57.60% from the flowering stage to the pod stage under drought treatment compared to salt treatment, indicating a significant interaction between drought and salt stress, reducing the single leaf area and net photosynthetic rate of peanut leaves, ultimately leading to a decrease in peanut yield. Therefore, when planting peanuts in saline alkali soil, drought should be avoided, especially early drought, in order to prevent the combined effects of drought and salt stress from harming peanut yield.

Peanut web blotch is an important leaf disease caused by Phoma arachidicola, which seriously affects the quality and yield of peanuts. However, the molecular mechanisms of peanut resistance to peanut web blotch are not well understood. In this study, a transcriptome analysis of the interaction between peanut (Arachis hypogaea) and P. arachidicola revealed that total 2989 (779 up- and 2210 down-regulated) genes were all differentially expressed in peanut leaves infected by P. arachidicola at 7, 14, 21 days post inoculation. The pathways that were strongly differentially expressed were the flavone or isoflavone biosynthesis pathways. In addition, two 2-hydroxy isoflavanone synthase genes, IFS1 and IFS2, were strongly induced by P. arachidicola infection. Overexpression of the two genes enhanced resistance to Phytophthora parasitica in Nicotiana benthamiana. Knockout of AhIFS genes in peanut reduced disease resistance to P. arachidicola. These findings demonstrated that AhIFS genes play key roles in peanut resistance to P. arachidicola infection. Promoter analysis of the two AhIFS genes showed several defense-related cis-elements distributed in the promoter region. This study improves our understanding of the molecular mechanisms behind resistance of peanut infection by P. arachidicola, and provides important information that could be used to undertake greater detailed characterization of web blotch resistance genes in peanut.

HomePlant DiseaseVol. 106, No. 7First Report of Lasiodiplodia pseudotheobromae Causing Collar Rot of Peanut in Shandong Province, China PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Lasiodiplodia pseudotheobromae Causing Collar Rot of Peanut in Shandong Province, ChinaXia Zhang, Ying Li, Manlin Xu, Zhiqing Guo, Jing Yu, Xinying Song, Kang He, Zhiliang Zhang, and Yucheng ChiXia ZhangShandong Peanut Research Institute, Qingdao, Shandong, China, Ying LiShandong Peanut Research Institute, Qingdao, Shandong, China, Manlin Xuhttps://orcid.org/0000-0002-4266-5110Shandong Peanut Research Institute, Qingdao, Shandong, China, Zhiqing GuoShandong Peanut Research Institute, Qingdao, Shandong, China, Jing Yuhttps://orcid.org/0000-0002-5263-3032Shandong Peanut Research Institute, Qingdao, Shandong, China, Xinying SongShandong Peanut Research Institute, Qingdao, Shandong, China, Kang HeShandong Peanut Research Institute, Qingdao, Shandong, China, Zhiliang ZhangChongqing Academy of Agricultural Sciences, Chongqing, China, and Yucheng Chi†Corresponding author: Y. Chi; E-mail Address: 87626681@163.comShandong Peanut Research Institute, Qingdao, Shandong, China AffiliationsAuthors and Affiliations Xia Zhang1 Ying Li1 Manlin Xu1 Zhiqing Guo1 Jing Yu1 Xinying Song1 Kang He1 Zhiliang Zhang2 Yucheng Chi1 † 1Shandong Peanut Research Institute, Qingdao, Shandong, China 2Chongqing Academy of Agricultural Sciences, Chongqing, China Published Online:16 Jun 2022https://doi.org/10.1094/PDIS-10-21-2309-PDNAboutSectionsPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat In August 2019, a collar rot of peanut was observed in several fields in Qingdao, Shandong Province, China. A disease survey was conducted in several peanut fields. Less than 5% of plants exhibited various symptoms, including brown or black stem rot, pod rot, chlorotic leaves, wilting, and even death. Symptomatic stems were cut into small pieces, surface disinfested with 70% ethanol for 1 min and 1% NaClO for 2 min, rinsed three times with sterile water, and dried on sterile filter paper. Pieces were then plated on potato dextrose agar (PDA) media and incubated at 25°C in darkness. Fungal cultures were initially white, turning gray and eventually black, and aerial hyphae were dense and fluffy. Conidia were ellipsoidal, initially hyaline, unicellular, and 14.3 to 21.1 × 8.7 to 13.2 µm (n = 50), and mature conidia were dark brown with a central septum and longitudinal stripes. Molecular identification was performed by sequencing the ITS with ITS1/ITS4 (White et al. 1990) and the beta tubulin gene with Bt2a/Bt2b (Glass and Donaldson 1995) of a representative isolate ZHX9. The ITS and beta tubulin regions (OK427342 and OK489788) of ZHX9 were 99.62 and 100% similar to Lasiodiplodia pseudotheobromae (KF766193 and EU673111), respectively. Phylogenetic analysis was done using neighbor-joining analysis based on those gene sequences. The isolated microorganism was identified as L. pseudotheobromae based on molecular analysis and morphological characteristics. For a pathogenicity assay, 12 10-day-old peanut ('Zhonghua No. 12') seedlings were each inoculated with one mycelial plug (8 mm in diameter) by placing the inoculum on the base of the stem. Twelve plants were each inoculated with a plug of noncolonized PDA as controls. Plants were incubated in a growth chamber (30°C in the day and 25°C at night with a 12-h photoperiod and 80% RH). Necrotic lesions were observed on stems of all inoculated seedlings 5 days after inoculation, whereas control plants remained asymptomatic, and L. pseudotheobromae was consistently reisolated from symptomatic stems. In Asia, peanut collar rot caused by L. pseudotheobromae has been reported in India, Indonesia, North Vietnam (Nguyen et al. 2006), and China (Guo et al. 2014), but collar rot caused by L. pseudotheobromae has not been reported. To our knowledge, this is the first report of L. pseudotheobromae causing collar rot on peanut in China. These results will provide crucial information for studying the epidemiology and management of this disease.The author(s) declare no conflict of interest.References:Glass, N. L., and Donaldson, G. C. 1995. Appl. Environ. Microbiol. 61:1323. https://doi.org/10.1128/aem.61.4.1323-1330.1995 Crossref, ISI, Google ScholarGuo, H., et al. 2014. Chin. J. Oil Crop Sci. 36: 524. https://doi.org/10.7505/j.issn.1007-9084.2014.04.015 Google ScholarNguyen, C. M. T., et al. 2006. IAN 26:25. Google ScholarWhite, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. Crossref, Google ScholarFunding: Funding was provided by Natural Science Foundation of Shandong Province (ZR2020QC131, ZR2021QD153), National Natural Science Foundation of China (31901940), and Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences (CXGC2021B33).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 106, No. 7 July 2022SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 8 Jul 2022Published: 16 Jun 2022First Look: 21 Dec 2021Accepted: 17 Dec 2021 Page: 1982 Information© 2022 The American Phytopathological SocietyFundingNatural Science Foundation of Shandong ProvinceGrant/Award Number: ZR2020QC131Grant/Award Number: ZR2021QD153National Natural Science Foundation of ChinaGrant/Award Number: 31901940Shandong Academy of Agricultural SciencesGrant/Award Number: CXGC2021B33Keywordscollar rotLasiodiplodia pseudotheobromaepeanutThe author(s) declare no conflict of interest.PDF download

Peanut root rot, caused by Fusarium spp., is a devastating fungal disease. As part of a program to obtain a biocontrol agent to control peanut root rot in the field, a bacterial strain LY-1 capable of inhibiting the growth of the fungus in vitro was isolated from rhizosphere soil samples collected from wild mint by agar disk dilution and dual-culture assay. Strain LY-1 was identified as Bacillus subtilis based on morphological characteristics, 16S rDNA, and gyrA sequence analyses. The bacterial suspension and cell-free culture filtrate of LY-1 could significantly inhibit the growth of Fusarium oxysporum, Fusarium proliferatum and Fusarium solani, but volatile organic compounds from the cultures had only a weak effect on mycelial growth. The percentage inhibition of 20% concentration of the cell-free culture filtrate of LY-1 on conidium production of each of the three Fusarium species was greater than 72.38%, and the percentage inhibition by the culture filtration on the germination of conidia of the three species was at least 62.37%. The production of extracellular enzyme activity by LY-1 was studied in functional assays, showing protease, cellulase, amylase, chitinase, and β-1,3-glucanase activity, while LY-1 contained a gene encoding iturin, an antifungal lipopeptide. In addition, under pot culture in a greenhouse, culture filtrate of LY-1 significantly promoted the growth of peanut, increasing the fresh and dry mass of the plant by 30.77% and 27.27%, respectively, in comparison with the no-filtrate control. The culture filtrate of LY-1 increased the resistance of peanut plants to F. oxysporum, with the biocontrol efficiency reaching 44.71%. In conclusion, B. subtilis LY-1, a plant-growth-promoting rhizobacterium, was able to protect peanuts from Fusarium spp. infection.

Peanut (Arachis hypogaea L.) is one of the most economically important crops as a major source of edible oil and protein. In July 2021, a root rot disease was observed on peanut in Laiwu (36º22' N, 117º67' E), Shandong Province, China. Disease incidence was approximately 35%. Disease symptoms included root rot, vessels with a brown to dark brown discoloration, plus progressive yellowing and wilting of leaves from the base leading to whole plant death. To determine the causal agent, symptomatic roots with typical lesions were cut into small pieces, surface sterilized in 75% ethanol for 30 s, and 2% NaClO for 5 min, rinsed three times in sterile water and placed on potato dextrose agar (PDA) at 25℃ (Leslie and Summerell 2006). After 3 days of incubation, whitish-pink to red colonies growing from the roots were observed. Eight single-spore isolates had identical morphological traits that were similar to those of Fusarium spp. A representative isolate (LW-5) was used for morphological characterization, molecular analysis, and pathogenicity test. On PDA, the isolate formed dense aerial mycelia, which were initially white, then became deep pink with age and formed red pigments in the medium. On carnation leaf agar (CLA), macroconidia with 3 to 5 septa were abundant, relatively slender, curved to lunate, that measured 23.7 to 52.2 × 3.6 to 5.4 μm (n=50). Microconidia were oval, 0 to 1 septa. Chlamydospores were globose with a smooth outer wall in chains or single. Following DNA extraction of isolate LW-5, primers EF1-728F/EF1-986R (Carbone et al., 1999), RPB1U/RPB1R, and RPB2U/RPB2R (Ponts et al., 2020) were used to amplify the partial translation elongation factor 1 alpha (TEF1-α), RNA polymerase II largest subunit (RPB1), and RNA polymerase II second largest subunit (RPB2) regions for DNA sequencing, respectively. BLASTn analysis of TEF1-α (GenBank accession No. OP838084), RPB1 (OP838085), and RPB2 (OP838086) sequences, revealed 99.66, 99.87, and 99.09% identity with those of F. acuminatum (OL772800, OL772952 and OL773104), respectively. Isolate LW-5 was identified as F. acuminatum based on morphology and molecular analysis. Twenty Huayu36 peanut seeds were each planted in a 500-ml sterile pot containing 300 g of autoclaved potting medium (nutritive soil: vermiculite=2:1 in volume). Two weeks after seedling emergence, 1 cm depth of the potting medium was dug around the plants to expose the taproot. Two 5-mm wounds per taproot were scratched with a sterile syringe needle. Potting medium in each pot of 10 inoculated plants was mixed with 5 ml of conidial suspension (106 conidia per ml). The other 10 plants were used as non-inoculated controls and treated with sterile water in the same manner. The seedlings were placed in a plant growth chamber maintained at 25°C, RH >70%, 16-h light per day, and irrigated with sterile water. After 4 weeks, inoculated plants exhibited yellowing and wilting symptoms that were similar to those observed in the field, while non-inoculated control plants had no symptoms. F. acuminatum was re-isolated from diseased roots and confirmed using morphological features and DNA sequence analysis of TEF1-α, RPB1 and RPB2. F. acuminatum was reported to cause root rot on Ophiopogon japonicus (Linn. f.) (Tang et al., 2020), Polygonatum odoratum (Li et al., 2021), and Schisandra chinensis (Shen et al., 2022) in China. To our knowledge, this is the first report of root rot on peanut caused by F. acuminatum in Shandong Province, China. Our report will provide crucial information for studying the epidemiology and management of this disease.

In July 2022, dieback and discoloration were detected on infected stems of peanut in Qijiang District of Chongqing (106.56°E,29.41°N), China, with an incidence up to 5%. These peanut stems had disease symptoms typical of anthracnose with irregular gray-brown spots with dark brown edges, sunken, and necrotic. High temperature and high humidity were favorable for the growth of the pathogen. To isolate the pathogen, we collected 10 typical infected peanuts and cut one piece from each of symptomatic stems, surface sterilized with 0.5% NaClO for 1 min, and 75% ethanol for 30 s, then rinsed three times with sterile distilled water and dried on sterilized filter paper. These pieces were incubated on potato dextrose agar (PDA) at 25°C in the dark. Pure cultures were obtained from hyphal tips of each colony. It was found that isolates with the same colony morphology were isolated from each infected stem. A representative isolate (L7) was used for morphological characterization, molecular analysis, phylogenetic analysis, and pathogenicity tests. The colonies appeared white to gray, with white margins and aerial hyphae, and the reverse of the colonies was gray to brown. Conidia were cylindrical, aseptate, with obtuse to slightly rounded ends, 13.4 to 18.8 × 4.2 to 5.8 μm (n=50). Morphological characteristics were generally consistent with those of Colletotrichum gloeosporioides species complex (Cannon et al., 2012). For molecular identification, genomic DNA was extracted using a CTAB method and partial sequences of β-tubulin (TUB2), actin (ACT) genes, chitin synthase (CHS) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were amplified and sequenced using primers T1/T2, ACT-512F/ACT-783R, CHS-79F/CHS-345R, and GDF1/GDR1, respectively (Damm et al., 2012; Dowling et al., 2020). Using the BLAST, TUB2, ACT, CHS and GAPDH gene sequences (GenBank accession No. OR714793, OP168707, OP168708 and OR714794, respectively) were100% (429 bp out of 429 bp), 99.22% (256 bp out of 258 bp), 99.64% (276 bp out of 277 bp) and 100% (253 bp out of 253 bp) identical to C. gloeosporioides CBS:112999 (JQ005587, JQ005500, JQ005326, and JQ005239), respectively. Using Neighbor-Joining algorithm, phylogenetic analysis was conducted based on the concatenated sequences of published TUB2, ACT, CHS and GAPDH genes. The identified isolate (L7) was closely related to C. gloeosporioides. To evaluate pathogenicity, the stems of ten peanut (Zhonghua12) seedlings (2 weeks) were wounded with a sterile toothpick and mycelial plugs (5 mm in diameter) or 20 μl of conidial suspension (105/ml) were inoculated. Non-colonized agar plugs or 20 μl of sterile distilled water were treated as control. After inoculation, the peanuts were kept in a moist chamber at 28°C with 80% humidity in the dark for 24 h, and subsequently transferred to the moist chamber with 12 h light and darkness cycle for 6 days, similar symptoms were observed on all inoculated peanuts. Controls remained asymptomatic. C. gloeosporioides was reisolated from the diseased stems and confirmed using morphological features and sequence analysis of TUB2, ACT, CHS and GAPDH. Anthracnose caused by C. truncatum and C. fructicola has been reported on peanut leaves in China (Gong et al., 2023; Yu et al., 2019). To our knowledge, this is the first report of anthracnose on peanut stem caused by C. gloeosporioides in Chongqing. Our report will provide crucial information for studying on epidemiology and management of this disease.

In June 2021, a previously unreported leaf blight disease of peanut (Arachis hypogaea) was observed on field-grown peanut (Jinhua19) in Laixi city, Shandong province of China. Approximately 5% of plants showed disease symptoms in the fields we investigated. The symptoms first appeared as yellow round or irregular spots on leaves, and then the spots became brown. As the disease progressed, spots became larger and even converge, which later produced leaf chlorosis and abscission. Symptomatic leaves were cut into small pieces, surface disinfested with 70% ethanol for 30s, 1% NaClO for 60s, rinsed three times in sterile water, dried on sterile filter papers, placed on potato dextrose agar (PDA) media, and incubated at 25°C in darkness. Fungal cultures were initially white, with red pigment, then turned gray, and eventually turned black, and aerial hyphae were dense. Conidia were spherical or slightly ellipsoidal, black, smooth, and 8.6 to 11.5 × 8.7 to 14.5μm (n=50). Morphological characteristics of the isolates matched the description of Nigrospora aurantiaca (Wang et al. 2017). Molecular identification was performed by sequencing beta tubulin gene (TUB) with Bt2a/Bt2b and translation elongation factor 1-alpha (TEF) with EF1-728F/EF1-986R (Wang et al. 2021) of a representative isolate ZHX11. TUB (OK489789) and TEF (OK489790) of ZHX11 obtained 100% (401/401 nucleotides) and 99.64% (279/279 nucleotides) similar to those of N. aurantiaca (MN329935, MN264010), respectively. Alignment was conducted separately for each gene set using Clustal W algorithm implemented in MEGA 7.0 (Kumar et al. 2016), and multi-gene (TUB and TEF) phylogenetic analyses using Neighbor-Joining (NJ) method showed that the isolate was N. aurantiaca. To complete Koch's postulates, nine 2-week-old peanut (Zhonghua 12) seedlings were sprayed with conidia suspensions (106 conidia mL-1 in 0.05% Tween 20 buffer). The same number of seedlings were only treated with 0.05% Tween buffer as controls. The experiment was repeated three times. Plants were incubated in a growth chamber (30°C in the day and 25°C at night, a 12-h photoperiod and 80% RH). Ten days after inoculation, typical symptoms were observed on inoculated leaves but not on the controls. N. aurantiaca was reisolated from the diseased leaves but not from the controls. N. sphaerica was observed on peanut in China (Liu et al. 2020). To our knowledge, this is the first report of N. aurantiaca causing leaf blight on peanut in shandong province, China. These findings will help to develop better preventive measures in accordance with the emergence of the new disease.

Peanut pod rot caused by Pythium myriotylum results in significant economic losses worldwide during peanut production.Biological control is an alternative measure to current chemical control methods,which are often inefficient and have adverse environmental effects.To control this disease,39 endophytic bacterial strains from healthy peanut(Arachis hypogaea)roots were screened for their antagonistic activi-ties against P.myriotylum.Five of which showed efficient biocontrol effects.Results showed,they were all identified as Burkholderia cepacia on the basis of 16S ribosomal RNA and Rec A gene sequences.A-mong the five B.cepacia strains,PRI08 manifested the greatest antagonistic activity against P.myrioty-lum mycelial growth.In greenhouse and field experiments,infected peanut plants with B.cepacia PRI08 inoculation reduced the disease incidence by 29.5％and 11.83％,respectively.Moreover,B.cepacia PRI08 significantly promoted peanut growth by enhancing the main stem length,lateral branch length,pod number,plump pod rate and pod yield by 20.44％,19.98％,26.61％,20.36％and 21.52％,respectively.This study revealed that B.cepacia PRI08 has the potential to be used as an agricultur-al biocontrol agent and plant growth-promoting bacterium.

为获得与花生共生的丛枝菌根真菌(AMF),采用湿筛倾析法从花生根际土壤中分离到一株优势菌株,编号APS-1,利用花生毛状根与APS-1 建立双重培养体系培养APS-1 的菌丝和孢子,并通过盆栽试验研究了APS-1 对花生生长和白绢病抗性的影响.结果显示,结合形态学特征和 SSU-ITS-LSU序列分析,确定APS-1 为异形根孢囊霉(Rhizophagus irregularis).盆栽条件下,APS-1 明显促进了 6 个花生品种的生长,同对照相比,总鲜质量、总干质量分别增加 13.27％～21.63％和 11.24％～47.90％.此外APS-1 还能够提高 6 个花生品种对白绢病的抗性,防效达到 43.76％～89.14％.综上所述,异形根孢囊霉 APS-1 是一株对花生白绢病具有较高防治潜力的生防菌株.

Long-term excessive application of chemical fertilizers can cause many problems, such as soil degradation and environmental pollution. Therefore, we reduced conventional nitrogen fertilization and added organic fertilizers in some cases to investigate the response of photosynthetic characteristics, root nodules and yield on reduced nitrogen fertilization. Compared to conventional nitrogen fertilization, the 25% and 35% nitrogen reduction treatments reduced the leaf area index, net photosynthetic rate, 100-fruit weight, 100-kernel weight and the yield of peanut, but had no significant effect on the kernel rate. With constant N fertilizer, adding organic fertilization alone increased leaf area index, chlorophyll, net photosynthetic rate and yield of peanut. In compounded treatments of nitrogen and organic fertilizer, the highest yields were achieved in the 25% N reduction with the 3000 kg/hm−2 organic fertilizer treatment (T3) and the 4500 kg/hm−2 organic fertilizer treatment (T4); furthermore, the net photosynthetic rate, leaf area index, yield and fertilizer contribution were significantly higher in these two treatments than in the conventional fertilizer treatments. Nitrogen fertilizer had significant effects on the quantity and fresh weight of root nodules. Concretely, nitrogen reduction increased the quantity and fresh weight of root nodules of peanut in the early stage of fertility but decreased them in the harvest stage. Nitrogen reduction with an additional organic fertilizer in the late stage of fertility increased the quantity and fresh weight of root nodules of peanut. Considering the property of root nodules was significantly positively correlated with net photosynthetic rate and yield, the arguments above may be the mechanism of the highest yields found in T3 and T4. This work can provide empirical and instructional support for a balanced fertilization strategy in peanut agriculture and high-yielding and efficient cultivation of peanut.

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.

Biochar has been widely reported to improve soil conditions and affect plant growth. However, its effectiveness is limited by soil type and production technology. Considering the application effect of biochar in saline alkali soil, there is currently a lack of in-depth mechanism explanations in the research. Therefore, we designed an experiment to explore the effect of biochar on plant growth in saline alkali soil and conducted soil column experiments in a greenhouse environment using composite inorganic fertilizer (NPK). The results showed that biochar significantly affected the distribution of soil nutrient content at different depths, with a significant increase in fertility levels in the surface and middle layers and a decrease in fertility levels in deep soils. Compared to using fertilizers alone, the combined use of biochar and fertilizers further expands the enrichment effect and significantly reduces the leaching of fertilizers into deeper layers. At the same time, the application of biochar also improved soil properties, including an increase in electrical conductivity and organic matter content, as well as an increase in soil enzyme activity. On the other hand, the application of biochar also increases the activity of antioxidant enzymes and the content of osmoregulation substances in plants, reducing the environmental stress that plants are subjected to. Therefore, our results indicate that biochar can reduce the leaching of fertilizers into deep soil layers, improve soil properties, and promotes the growth of Miscanthus in saline alkali soils.

Peanut (Arachis hypogaea L.) is a widely grown oilseed crop of great agricultural importance worldwide. In July 2022, disease symptoms were observed on peanut roots in Laixi (36º85' N, 120º54' E), Shandong Province, China. About 25% of the plants showed various symptoms, including stem and root rot and blackening, microsclerotia on the stem, yellowing and wilting of leaves, and even death. Twenty diseased plants were collected to confirm the pathogen. Symptomatic roots were cut into small pieces, disinfested with 75% ethanol for 1 min and 0.5% NaClO for 2 min, rinsed three times with sterile water, dried on sterile filter paper, and then spread on potato dextrose agar (PDA) supplemented with 100 μg/mL chloramphenicol and incubated at 25°C in the dark. At the beginning of growth, the fungus formed sparse, white mycelia, which white, then darkened with age and microsclerotia were formed in the medium after 5 days. The mycelium aggregated into black, round to oblong or irregularly shaped microsclerotia 84 to 163 μm long and 54 to 125 μm wide (n=40). These morphological characteristics were consistent with the description of Macrophomina phaseolina (Holliday and Punithalingam, 1970). Molecular identification was performed by sequencing the internal transcribed spacer (ITS) region with ITS1 and ITS4 and translation elongation factor 1-alpha (TEF) with EF1-728F/EF1-986R (Glass and Donaldson 1995) of a representative isolate SXY183. ITS (OR056369) and TEF (OR098356) of SXY183 showed 100% and 97.74% similarity with M. phaseolina (KF951622, KF951997), respectively. Phylogenetic analysis was performed using Neighbor-Joining (NJ) analysis based on the gene sequences of ITS and TEF. The fungus was identified as M. phaseolina based on molecular analysis and morphological characteristics. The pathogenicity of a representative isolate (SXY183) was tested on peanuts under greenhouse conditions. Two-week-old peanut (Huayu No. 9115) seedlings were inoculated with a mycelial plug (8 mm diameter) at the root base of each plant and cultured in a greenhouse (30°C during the day and 25°C at night, a 12-h photoperiod, and 80% RH). Ten plants were inoculated with a plug of non-colonized PDA as a control. Brown lesions were observed on the stem and root of all inoculated seedlings 7 days after inoculation, but not on the control plants. The experiment was repeated three times. M. phaseolina was re-isolated from the symptomatic root and confirmed based on morphological characteristics and DNA sequence analysis of ITS and TEF. M. phaseolina is a soil-borne fungus that is distributed worldwide and has a broad host range. Disease agent has previously been reported on several host plants such as adzuki bean, faba bean, watermelon, Plukenetia volubilis, Atractylodes lancea and Curcuma longa in China (Cai et al., 2020; Sun et al. 2016; Sun et al., 2019; Sun et al., 2020; Wang et al., 2020; Wu et al., 2022). However, this is the first report in which M. phaseolina was found to cause peanut root rot in Shandong Province, China. Our report will provide important information for studying the epidemiology and management of this disease.

Viral diseases of plants are associated with large health and economic costs. Antiviral agents developed for mammalian organisms have had limited success for plants, necessitating alternative strategies to address this biological and sustainability problem. Here we show that chiral 3 nm Cu 1.96 S nanoparticles can site-selectively cleave capsid in tobacco mosaic virus under sunlight. With d - penicillamine as surface ligands, the nanoparticles display high affinity to the Gln 99 to Ala 105 segment in the capsid via a network of supramolecular bonds and 3,000–10,000 times lower affinity to capsids of other viruses. Illumination with green light leads to polarization-dependent, protease-like hydrolysis of the amide bond between Asn 101 and Pro 102. Nanoparticles inhibited viral infectivity by 98.7% in protoplasts and 92.6% in plants while avoiding hypersensitive response and large environmental impact. These findings show that nanoparticles combining proteolytic activity due to metal ions and site selectivity due to nanoscale chirality can be used as effective antiviral agents.