In order to investigate characterization and the differences of volatile substances in different types of flue-cured tobacco, the volatile components (VOCs) and relative contents of six varieties of flue-cured tobacco were analyzed by headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS) and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). Combined with the relative odor activity value (ROAV), important flavor substances were determined and different aroma components were screened by multivariate statistical analysis. The results showed that 93 and 80 kinds of compounds, such as esters, alcohols, and aldehydes, were detected by GC-IMS and HS-SPME-GC-MS in six flue-cured tobacco varieties, respectively. A total of 19 volatile flavor compounds, such as benzaldehyde, acetic acid, valeraldehyde, and methyl acetate, were selected as compounds to distinguish the aroma of different toasted tobaccos by orthogonal partial least-squares discrimination analysis (OPLS-DA). In this study, more comprehensive information about volatile flavor components of six flavor types of flue-cured tobacco has been obtained by the synergistic analysis of two distinct analytical instruments. Meanwhile, this study clarified the composition and differences of aroma components of six types of flue-cured tobacco, which lays a foundation for the flavor control of different types of flue-cured tobacco.

Excellent properties of plastics, such as tensile strength, durability and chemical resistance, have made them an important part of our daily lives and led to their widespread use in packaging, automotive, electronics, construction, agricultural production, and other fields (Xanthos and Walker 2017, Stubbins et al. 2021, Kaandorp et al. 2023, Shaaban et al. 2024). In agriculture, plastics are extensively used in mulching films, irrigation pipes, greenhouses, and fertiliser packaging, and their intensive application generates considerable plastic residues directly in farmland environments. For example, China alone generated approximately 126 500 tons of agricultural plastic waste in 2022 (Tang 2023). The common plastic waste mainly includes polyethylene terephthalate (PET), polyethylene (PE), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyvinyl chloride (PVC), polypropylene (PP), polycarbonate (PC), polyamide (PA) and polyurethane (PU) (Jin et al. 2022, Yibo et al. 2024). This plastic waste can be converted into microplastics (MPs, particle size: 1 μm-5 mm) and nanoplastics (NPs, particle size: < 1 μm) through multiple pathways, such as photodegradation, physical wear, hydrolysis and biodegradation (

Tobacco Fusarium root rot, caused mainly by Fusarium oxysporum and F. solani, poses a major threat to tobacco production by severely impairing root function and reducing yield and quality. In the context of sustainable agriculture, biological control has gained increasing attention as an environmentally friendly and effective alternative to chemical pesticides. This study evaluated four tobacco rhizosphere Bacillus strains to clarify how key biological traits relate to field performance in controlling Fusarium root rot. Strains were assessed for antifungal activity, indole-3-acetic acid (IAA) production, chemotaxis toward root exudates, biofilm formation, and colonization capacity. Significant differences were observed, with G12 and G51 exhibiting the most favorable profiles. Both showed strong antifungal activity (42.42%-57.50%), robust chemotaxis toward root exudates from healthy tobacco plants (RCI up to 35.86), efficient biofilm formation, and successful colonization of tobacco tissues. Greenhouse assays demonstrated that G12 and G51 reduced disease indices to below 10.00 and achieved control efficacy above 90%, approaching that of chemical treatment. Multi-location field trials in 2024-2025 further confirmed their effectiveness, with both strains reducing disease incidence by more than 60% and consistently improving agronomic traits. G51 provided the most stable yield benefits across years and sites, while G12 and G51 also accelerated the decline of chlorophyll and leaf nitrogen content at later stages, suggesting a role in promoting earlier maturation. Overall, this study establishes a link between chemotaxis, biofilm formation, colonization, and field efficacy, underscoring the importance of integrating multiple biological traits when screening biocontrol agents. These findings provide scientific support for the application of tobacco rhizosphere Bacillus strains in the sustainable management of Fusarium root rot.