Chongqing Three Gorges Academy of Agricultural Sciences

ABSTRACT This study investigated the changes in the volatile metabolome of C. reticulata cv. “Dahongpao” (Chuanchenpi) after aging for 1, 2, and 3 y. Using Headspace Solid-Phase Microextraction coupled with Gas Chromatography-Mass Spectrometry, we analyzed Chenpi samples aged for 1 (CR1), 2 (CR2), and 3 (CR3) years. A total of 782 distinct volatile metabolites were provisionally identified, with terpenoids (28.52%), esters (14.45%), ketones (9.97%), heterocyclic compounds (8.44%), and alcohols (8.18%) being the predominant classes. Multivariate statistical analyses (PCA and OPLS-DA) revealed clear differentiation in volatile profiles among the three aging groups. Comparative analysis showed a net decrease in volatiles from CR1 to CR2, but a significant net up-accumulation of diverse compounds from CR1 to CR3, and particularly from CR2 to CR3. The 3 y Chenpi exhibited the most complex and enriched volatile signature, characterized by significantly higher levels of specific terpenoids (bicyclo[3.1.1]hept-3-en-2-one, 4,6,6-trimethyl-; 2-methyl-6-methyleneocta-2,7-dien-4-one), phenols (phenol, 2-propyl-), aldehydes (2-nonenal (Z)), and unique nitrogen (acetonitrile, 2,2’-iminobis-) and sulfur-containing compounds. KEGG pathway analysis highlighted significant enrichment in secondary metabolite biosynthesis, especially terpenoid pathways, which intensified with aging. These findings demostrate that 3 y of aging substantially enhances the aromatic complexity of Dahongpao Chenpi, offering strategies for quality standards, processing, and industrial application.

Objective Citrus reticulata cv. ‘Dahongpao’ is an ancient Chinese cultivar whose by-products, peel, flower, and leaf remain underexplored. This study aimed to conduct a comprehensive comparative characterization of the volatilomic profiles, odor-active signatures, and antioxidant activities of the essential oils (EOs) extracted from these three tissues to establish a scientific basis for their differentiated valorization. Methods Essential oils were obtained from the three tissues using ultrasound-assisted hydrodistillation. The volatile metabolomes were analyzed using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. Antioxidant capacities were evaluated using spectrophotometric assays to determine total phenolic content, ferric reducing antioxidant power, and scavenging activities against superoxide and hydroxyl radicals. Results A total of 985 volatile metabolites were identified, dominated by terpenoids (25.99%), esters (15.63%), and heterocyclic compounds (9.44%). Tissue-specific chemical signatures were observed: peel EOs were enriched in terpenoids such as α-citral and (1α,3β,4β)-p-menthane-3,8-diol; flower EOs accumulated oxygenated monoterpene like linalool and nerolidol; leaf EOs were characterized by green-note aldehydes and alcohols, including (Z)-3-hexen-1-ol and phytol. Antioxidant profiling revealed functional divergence: leaf EO showed the highest superoxide scavenging, flower EO exhibited the strongest hydroxyl radical scavenging and reducing power, while peel EO had the highest total phenolic content. Differential metabolite analysis highlighted extensive divergence, with 834 metabolites differing between peel and flower EOs (815 upregulated in peel). Notably, 2-Methoxy-3,5-dimethylpyrazine, a potent odorant with a 0.4 ppb threshold was significantly enriched in peel EO, along with high-impact volatiles like α-citral, 2,4-decadienal, and 2-octanol acetate. Conclusion Red mandarin tissues possess distinct metabolite architectures. The peel is a rich reservoir of phenolics and high-impact odorants, making it a prime candidate for the food and fragrance industries. The flower and leaf EOs harbor unique aromatic and bioactive traits suitable for specialized nutraceutical or cosmetic applications. These findings strongly support the differentiated, value-added utilization of all three by-products.

Clubroot, caused by Plasmodiophora brassicae Woronin, poses a major threat to Chinese cabbage (Brassica rapa subsp. pekinensis) production worldwide, significantly impacting crop yield, quality, and economic value. Biological control represents a promising approach since it is non-toxic and eco-friendly, and it reduces the risk of pathogen resistance development. In this study, our objective was to screen for actinomycetes that can effectively inhibit clubroot. We screened 13 actinomycete strains, identifying 2, XDS3-6 and CD1-1, with substantial in vivo inhibitory effects, achieving infection suppression rates above 64% against P. brassicae. Phylogenetic analysis classified XDS3-6 and CD1-1 as Streptomyces virginiae and Streptomyces cinnamonensis, respectively. Both strains exhibited protease and glucanase production capabilities, essential for pathogenic suppression. Additionally, these strains induced host defense responses, as evidenced by increased jasmonic acid (JA) and salicylic acid (SA) accumulation and elevated activities of defense-related enzymes. Colonization studies of XDS3-6 and CD1-1 mutant strains in cabbage roots indicated sustained root colonization, with peak colony-forming units (CFUs) at 20 days post-inoculation, reaching 11.0 × 104 CFU/g and 8.5 × 104 CFU/g, respectively, and persisting for at least 30 days. Overall, these findings underscore the potential of Streptomyces strains XDS3-6 and CD1-1 as effective biocontrol agents, providing a theoretical foundation for their application in managing clubroot in Chinese cabbage.

Higher standards for elementary and secondary school students' education have emerged in response to the expansion of the education sector, which has intensified educational competitiveness. Once implemented, the "double reduction" program successfully manages macro society as a whole and pushes for educational institution change. One of the biggest challenges that elementary and secondary school students have when trying to improve the quality of their education is determining whether or not the institutions that teach these subjects are being adequately transformed. A student's natural talent is only one of several contextual elements contributing to their scientific achievement. This article aimed to find high-achieving students' most salient contextual traits in scientific literacy. This article looks at how the "double reduction" strategy has affected educational institutions from both the student and parent points of view. According to the findings, schools will again be the centre of attention under the "double reduction" program, which aims to improve education. The expectations of schools, parents, and students continue to limit the transformation of elementary and secondary educational institutions even though the government and educational institutions have implemented some steps to alleviate the "double reduction" strategy. According to the research, the factors that were found to have the greatest impact on the target students' exceptional accomplishments in science were the following: the quality of teachers' educational materials practices, the disciplinary climate, the amount of time and effort put into learning; the resources available to students through school media; the number of teachers on staff; and students' belief in their abilities. The knowledge gained from this study may be useful in future research on students' scientific literacy abilities

Decadally cycling soil carbon (dSOC) is the main component of the terrestrial soil carbon (C) pool. The response of dSOC to warming largely determines the feedback between climate warming and the C cycle. However, there is a lack of investigations about the effect of warming on the relative change in turnover rate (RCT) of dSOC and annually cycling SOC (aSOC) in dissolved organic carbon (DOC), microbial biomass carbon (MBC) and CO2. We clarified this issue by incubating two C3-C4 vegetation switch soils (23 years switch, HA soil and 55 years switch, GG soil) at 20°C and 30°C in the recently improved continuous airflow CO2 trapping system for 1 year. Warming increased the contribution of dSOC (C3-C) by 21℅ (soil HA) and 8℅ (soil GG) in MBC, and 38℅ (soil HA) and 15℅ (soil GG) in CO2, while only 2%–3℅ increase in DOC at the final stage of the incubation. Furthermore, warming increased the RCT in MBC and CO2 by 5.3- and 4.1-fold, respectively, but had no significant influence on the RCT in DOC, indicating that soil microbes may be an important engine to accelerate dSOC-derived CO2 emission in a warming world.

To explore the occurrence dynamics and infection characteristics of citrus target spot, and screen effective fungicides and provide data support for citrus safe production. Two orchards with different altitudes and different management levels in Shuangshi community and Baiyan Village of Wanzhou District Chongqing city were selected to follow up the occurrence of citrus target spot. At the same time, the inhibition effects of 6 compound fungicides to Pseud of abraea Citricarpa (Citrus Target spot) were determined by the mycelial growth rate inhibition method. The results showed that, in December of 2021 to March of 2022, in the 2 orchards, the average disease spot, number of falling leaf showed a trend of reduce after the first rise, and incidence and disease index were characterized by rising gradually along with the passage of time. From late to the end of January, there were more rainy and foggy days, and the temperature dropped sharply, which aggravated the defoliation. Orchard 1 was with higher altitude 750 m and loose management, and the disease outbreak came more rapidly and severely. While in orchard 2, the lower altitude, higher management level and stronger tree made the disease be later and lighter than orchard 1. Further studies of compound fungicide screening showed that the EC50 against Ps. Citricarpa, from low to high, was 40% Tebuconazole·Prochloraz (0.03295)<13% Thifluzamide·Hexaconazole (0.03634)<30% Difenoconazole·Propiconazole (0.03881)<40% Difenoconazole·Pyraclostrobin (0.30849)<30% Thifluzamide·Tebuconazole (0.90167)<33 % Kasugamycin·Copper Quinoline (2.92935). These fungicides can be used for further research in the field test.

In order to overcome the problems of low precision and speed in the existing fast fusion methods of virtual image of product shape, a new fast fusion method of virtual image of product shape based on progressive fill line algorithm is proposed in this paper. The progressive filling line algorithm is used to fill the virtual image holes of product shape, and dibr technology is introduced to reconstruct the image position and restore the image colour. Finally, the fuzzy minimum error threshold algorithm and Ostu algorithm are used to calculate the optimal threshold and global threshold of the product shape virtual image features, so as to realise the rapid fusion of product shape virtual image. The experimental results show that the design method can ensure the fusion accuracy and clarity of virtual image of product shape, and the shortest fusion time is 7 ms.