Oil Crop Science最新文献

In order to grasp the distribution of Aspergillus flavus in the soil of peanut production areas in China, A. flavus biomarkers were tested on 555 soil samples from 37 sampling points in 17 provinces, peanut fields in four agroecological zones (Southern area, Yangtze River Basin, Northern area, Northeast area). The results showed that (1) the cultivation amount of A. flavus per gram of soil in the Yangtze River Basin is 1.30 times that of the southern area, 1.56 times that of the northern area, and 6.20 times that of the northeast area, with obvious regional characteristics. (2) In the Yangtze River basin, the change of longitude in the east-west direction has no direct impact on the cultivation amount of A. flavus per gram of soil. (3) In the east coast, the A. flavus cultivated per gram of soil increased first and then decreased with the increase of latitude from south to north. (4) A. flavus can be isolated in the soil samples above 1000 ​m. Field pollution is an important source of aflatoxin contamination in peanut. The study on the distribution of A. flavus in soil in China could provide theoretical support for the early warning and prevention and control measures of aflatoxin contamination in peanut.

In 2020, diseased seedlings of winter oilseed rape (Brassica napus) with cankered taproots as well as abundant sclerotium-like structures in the soil surrounding the roots were found in Longxi County of Gansu province of northwestern China. A fungus with production of pycnidia was isolated from the diseased roots, and it was identified based on morphological characteristics, molecular phylogeny (ITS, LSU) and PCR detection with the specific primers. The fungus was identified as Leptosphaeria sclerotioides Gruyter, Aveskamp & Verkley [anamorph: Phoma sclerotioides (Preuss) ex Sacc.]. Re-inoculation of isolates of P9 and P10 of L. sclerotioides on winter oilseed rape (B. napus cultivar ‘Zhongshuang No. 9’) in Wuhan caused formation of abundant sclerotium-like structures in soil surrounding the roots, but failed to produce root cankers as those observed in Gansu possibly due to lack of long peroid of low-temperature conditioning in Wuhan. In spite of this, plant height, pod number and seed yield of oilseed rape were significantly reduced in the treatment with L. sclerotioides P9 and P10, compared to the control treatment. To the best of our knowledge, this is the first report of L. sclerotioides on B. napus in China and the finding broadened our understanding about the natural distribution of this psychrophilic fungus.

In recent years, peanut yield and quality are more seriously affected by pod rot disease in China. However, managing this disease has proven challenging due to the wide host range of its pathogens. In this study, four soil samples were collected from fields with pod rot disease in Hebei Province, and 454 pyrosequencing was used to analyze the fungal communities structure within them. All 38 490 ITS high-quality sequences were grouped into 1203 operational taxonomic units, the fungal community diversity of four soil samples was evaluated and compared using Shannon index and Simpson index. The results showed that members of Ascomycota were dominant, followed by Basidiomycota. According to the BLAST results at the species level, Guehomyces had the highest abundance, accounting for about 7.27%, followed by Alternaria, Fusarium, and Davidiella. The relative abundance of Fusarium oxysporum isolated from rotting peanuts in soil with peanut rot was higher than that in the control, indicating that Fusarium oxysporum might be one of the main pathogenic fungus of peanut rot in this area. This study delved into the broader fungal community associated with peanut pod rot, providing a theoretical foundation for preventing and treating this disease in agriculture.

In order to understand the pathogenic mechanisms of Sclerotium rolfsii on peanut and to analyze the variation of virulence in S. rolfsii strains, the highly virulent strain (ZY2) and weakly virulent strain (GP3-1) were investigated under both in vivo and in vitro conditions. The results indicated that S. rolfsii directly infected peanut by producing infection cushions. ZY2 formed infection cushions earlier than GP3-1, and ZY2 produced a greater number of infection cushions compare to GP3-1. Both strains could utilize cellulose, xylose, or polygalacturonic acid in the Czapek medium. The activities of cellulase (CL) and polygalacturonase (PG) in the inoculated peanut stems increased significantly at 9 ​h after inoculation. The activities of CL and PG produced by ZY2 in the inoculated stems were significantly higher than that produced by GP3-1. Both strains could produce oxalic acid (OA), and the content of OA produced by ZY2 in the inoculated stems was higher than that produced by GP3-1. In summary, it suggested that S. rolfsii destroyed peanut cells through physical and biochemical factors by secreting a large amount of OA, CL and PG during the formation of infection cushions. The difference in OA content, activity of CL and PG produced by highly and weakly virulent strains played important roles in variation of virulence.

WRKY transcription factors (TFs) have been identified as important core regulators in the responses of plants to biotic and abiotic stresses. Cultivated peanut (Arachis hypogaea) is an important oil and protein crop. Previous studies have identified hundreds of WRKY TFs in peanut. However, their functions and regulatory networks remain unclear. Simultaneously, the AdWRKY40 TF is involved in drought tolerance in Arachis duranensis and has an orthologous relationship with the AhTWRKY24 TF, which has a homoeologous relationship with AhTWRKY106 TF in A. hypogaea cv. Tifrunner. To reveal how the homoeologous AhTWRKY24 and AhTWRKY106 TFs regulate the downstream genes, DNA affinity purification sequencing (DAP-seq) was performed to detect the binding sites of TFs at the genome-wide level. A total of 3486 downstream genes were identified that were collectively regulated by the AhTWRKY24 and AhTWRKY106 TFs. The results revealed that W-box elements were the binding sites for regulation of the downstream genes by AhTWRKY24 and AhTWRKY106 TFs. A gene ontology enrichment analysis indicated that these downstream genes were enriched in protein modification and reproduction in the biological process. In addition, RNA-seq data showed that the AhTWRKY24 and AhTWRKY106 TFs regulate differentially expressed genes involved in the response to drought stress. The AhTWRKY24 and AhTWRKY106 TFs can specifically regulate downstream genes, and they nearly equal the numbers of downstream genes from the two A. hypogaea cv. Tifrunner subgenomes. These results provide a theoretical basis to study the functions and regulatory networks of AhTWRKY24 and AhTWRKY106 TFs.

The optimal process conditions for solvent-free microwave extraction (SFME) of essential oils from Cinnamomum longepaniculatum deciduous leaves after moisture conditioning were established by response surface methodology (RSM). A Box-Behnken design (BBD) was applied to evaluate the effects of three independent variables: moisture content (A: 54%–74%), microwave power (B: 300–500 ​W) and microwave time (C: 20–40 ​min), on the extraction yield of essential oil. The compounds of the essential oils obtained by SFME, hydro-distillation and microwave-assisted hydro-distillation (MADE) were identified by gas chromatography-mass spectrometry (GC-MS), and the total lipids of C. longepaniculatum fresh leaves and deciduous leaves were analyzed. The correlation analysis of the response regression model indicated that quadratic polynomial model could be employed to optimize the extraction of essential oil. The optimal extraction condition was A: 58%, B: 400 ​W and C: 28 ​min. In the optimal condition, the maximum extraction yield was 4.475 mL/100 ​g dw and higher than that by MADE. The main compound of the essential oil was eucalyptol (63.54%), and total oxygenated compounds was 78.95%, mainly caused by SFME and the metabolism of endophytic bacteria with decreasing content of phospholipids and fatty acids. Analysis of variance under the extraction condition illustrated high fitness of the model and the success of RSM for optimizing and reflecting the expected process condition. SFME combined with moisture regulation was an effective method for extracting essential oil from C. longepaniculatum deciduous leaves.

Land suitability analysis of Moringa oleifera tree cultivation is important to enhance its product, as the demand for this tree for medicinal values and food sources is increasing worldwide. Therefore, this study aimed to assess suitable land for Moringa oleifera tree cultivation by using the integration of multi-criteria evaluation with geospatial technologies in the Dhidhessa catchment, western Ethiopia. Five parameters, namely: slope, land use and land cover (LULC), soil texture, land surface temperature, and rainfall data, were used in this study. The land suitability evaluation of Moringa oleifera is classified into three classes as highly suitable, moderately suitable, and not suitable. The results revealed that, about 344.4 ​km² (12.2%) of the area is categorized into highly suitable, and 2343.7 ​km² (83%) is moderately suitable for Moringa tree, whereas, 137.2 ​km² (4.9%) is categorized as not suitable for Moringa oleifera tree cultivation. Hence, based on the finding of the study, we suggested that farmers and other stakeholders can cultivate Moringa oleifera trees in the Dhidhessa catchment.

As important supplementary to major edible oils, comparative chemical advantages of minor edible oils decide their development and usage. In this study, chemical composition of 13 kinds of specific edible vegetable oils were investigated. The comparative advantages of chemical compositions of these edible oils were obtained as follows: (1) camellia, tiger nut and almond oil were rich in oleic acid, the contents of which accounted for 79.43%, 69.16% and 66.26%, respectively; (2) safflower oil contained the highest content of linoleic acid (76.69%), followed by grape seed (66.85%) and walnut oil (57.30%); (3) perilla seed, siritch, peony seed and herbaceous peony seed oil were rich in α-linolenic acid (59.61%, 43.74%, 40.83% and 30.84%, respectively); (4) the total phytosterol contents of these oils ranged from 91.46 mg/100 ​g (camellia oil) to 506.46 mg/100 ​g (siritch oil); and (5) The best source of tocopherols was sacha inchi oil (122.74 mg/100 ​g), followed by perilla seed oil (55.89 mg/100 ​g), peony seed oil (53.73 mg/100 ​g) and herbaceous peony seed oil (47.17 mg/100 ​g). The comparative advantages of these specific edible oils indicated that they possess the high potential nutritional values and health care functions.

Oil from Camellia oleifera Abel. seed is a popular edible oil in Asia, which has gained much attention for its medicinal applications on relieving various inflammation, however, the mechanism is still unknown. The present study was to investigate the gastroprotective effect of camellia oil against ethanol-induced gastric mucosal injury in mice. The results showed that camellia oil pretreatment significantly reduced gastric ulcer injury. A remarkable inhibited oxidative stress by reducing the concentration of malondialdehyde and a significant decrease of the levels of pro-inflammatory factors in gastric tissue were observed in camellia oil pretreated group. In addition, camellia oil improved the diversity of gut microbiota and changed the community structure and composition by increasing Bacteriodes and Dorea. And the feces metabolomics found that metabolism of cofactors and vitamins, and lipid, carbohydrate and amino acid metabolism were modulated by admiration of camellia oil. Taken together, the findings of this study suggested that camellia oil could ease the ethanol-induced gastric mucosal injury via the improvement of anti-oxidant and anti-inflammatory status, as well as the regulation of gut microbiota and its metabolites.

There is a constant search for biomaterials from natural products like plants for food and industrial applications. The work embodied in this report aimed at investigating the effects of microwave-assisted and soxhlet extraction (MAE and SE) techniques on the functional physicochemical quality characteristics of Moringa oleifera seed oil and proteins extracts. M. oleifera ​seeds were ground to fine powders and oil was extracted by microwave-assisted and soxhlet extraction techniques using petroleum ether. Quality attributes including yield percent, moisture content, iodine, saponification, specific gravity, viscosity, pH, thiobarbituric acid, acid and peroxide values were measured. Mineral and vitamin contents, chemical/functional groups, fatty acid (FA) composition, and reducing power of the oil were evaluated. Metabolomics of protein extracted from the defatted powders were analyzed by nuclear magnetic resonance (NMR). M. oleifera ​oil from MAE and SE methods had good yield (34.25 ​± ​0.0%, 28.75 ​± ​0.0%), low moisture content (0.008 ​± ​0.0%, 0.011 ​± ​0.0%), non-drying and unsaturated, moderately saponified, less dense (0.91 ​± ​0.01, 0.92 ​± ​0.02 g mL⁻¹), had Newtonian flow, were weakly acidic, showed good content of FAs, recorded strong potential for long shelf-life, showed stability against oxidative rancidity and enzymatic hydrolysis, had very rich deposits of micro- and macro-nutrients as well as water-soluble and lipid-soluble vitamins, and functional groups in the oil were reflective of its content of long- and medium-chain triglycerides (LCT and MCT). Monounsaturated and saturated fatty acids (MUFA and SFA) were detected and the oil has excellent ferric ion reducing power. NMR metabolomic assay revealed the presence of nine essential amino acids (EAAs) in the protein extract. MAE technique is a feasible and acceptable alternative for high throughput extraction of ​M. oleifera ​oil with high yield and excellent quality attributes. The study revealed that MAE did not impart any remarkable advantage(s) on the physicochemical properties of ​M. oleifera ​seed oil and protein compared to SE technique.