Fumigation Treatment Research Articles

Economic framework to assess the impact of banning pesticides, with application to sulfuryl fluoride for drywood termites (Blattodea: Kalotermitidae) in California.

Sulfuryl fluoride (SF) is a fumigant used to eliminate drywood termites (DWT: Kalotermitidae; Froggatt) and other structural pests. Because of its global warming potential, it has been suggested that SF be restricted as a greenhouse gas (GHG). We present an economic model to assess the net social cost of restricting SF. We consider 3 approaches to address DWT control- no treatment, allowing SF fumigation and localized treatments, and only local treatment. Each approach generates private and public benefits and costs. We estimate that the annual damage and home equity loss by DWT in California is US$4.5-16.8 billion without treatment. If fumigation is used on 20% of the houses and local treatments on the others, the combined social cost of treatment, damage, and GHG emissions are between US$1-US$2 billion annually. The annual cost of local treatments only would be between US$3.2 and US$4.9 billion. If the application of SF is severely restricted or banned, the social costs will increase between US$1.43 and US$4.31 billion annually. The implied cost per ton of CO2 eliminated is between US$624 and US$1,465, much above the price range of CO2 in other applications. The restriction/ban has significant equity and environmental effects, impacting low-income individuals living in rented properties and replacing damaged wood in housing will increase GHG emissions. We further recommend the continued use of SF until a comparable whole-structure alternative is developed that fits the parameters of our model.

Shelf life quality retention and decay inhibition of winter jujube (Zizyphus jujuba Mill. cv. Dalidongzao) using 1-methylcyclopropene

Winter jujube is susceptible to cold stress during cold storage, resulting in quality deterioration. Shelf life of winter jujube after cold storage has not been investigated. This study investigated the effects of 1.0 μL L−1 1-methylcyclopropene (1-MCP) fumigation treatment for 24 h on the quality characteristics of jujube fruits (Zizyphus jujuba Mill. cv. Dalidongzao) during cold storage. The jujubes from the early experimental stage (0 d) were stored at room temperature (20 ± 1 °C) to estimate the shelf life. The remaining jujubes were transferred to cold storage at 0 ± 1 °C and were removed during the middle (40 d) and the later (60 d) stages of the experiment. The decay rate, firmness, color, titratable acidity, total phenolics and flavonoids, antioxidant activity, and antioxidant enzyme activity of winter jujube were measured every 3 days until the end of shelf life. The results indicated that the application of 1-MCP treatment extended the time for jujube to exceed a decay rate of more than 10 % by three days after 40 and 60 days of cold storage. 1-MCP treatment effectively retard the decrease of total phenolic and flavonoid content in jujube, and maintain high free radical scavenging ability and antioxidant enzyme activity throughout shelf life storage.

Exploration of the Biocontrol Activity of Bacillus atrophaeus Strain HF1 against Pear Valsa Canker Caused by Valsa pyri.

Valsa pyri-induced pear Valsa canker is among the most prevalent diseases to impact pear quality and yields. Biocontrol strategies to control plant disease represent an attractive alternative to the application of fungicides. In this study, the potential utility of Bacillus atrophaeus strain HF1 was assessed as a biocontrol agent against pear Valsa canker. Strain HF1 suppressed V. pyri mycelium growth by 61.20% and induced the development of malformed hyphae. Both culture filtrate and volatile organic compounds (VOCs) derived from strain HF1 were able to antagonize V. pyri growth. Treatment with strain HF1-derived culture filtrate or VOCs also induced the destruction of hyphal cell membranes. Headspace mixtures prepared from strain HF1 were analyzed, leading to the identification of 27 potential VOCs. Of the thirteen pure chemicals tested, iberverin, hexanoic acid, and 2-methylvaleraldehyde exhibited the strongest antifungal effects on V. pyri, with respective EC50 values of 0.30, 6.65, and 74.07 μL L-1. Fumigation treatment of pear twigs with each of these three compounds was also sufficient to prevent the development of pear Valsa canker. As such, these results demonstrate that B. atrophaeus strain HF1 and the volatile compounds iberverin, hexanoic acid, and 2-methylvaleraldehyde exhibit promise as novel candidate biocontrol agents against pear Valsa canker.

Impact of Phosphine Fumigation Treatments on the Vitality of Wheat Grains at Different Storage Periods

Impact of Phosphine Fumigation Treatments on the Vitality of Wheat Grains at Different Storage Periods

Analysis of Key Points of Technical Review of Traditional Chinese Medicine Fumigation Treatment Device

Traditional Chinese medicine fumigation device is the carrier of traditional Chinese medicine fumigation treatment. In recent years, with the rapid development of new technology and new materials, the development of fumigation device changes with each passing day, and a variety of new products continue to emerge. However, at present, the lack of corresponding evaluation norms, resulting in some difficulties in the registration, marketing, quality control, evaluation scale and other aspects of the product. Some products have many disadvantages in clinical use. From the perspective of technical review, this paper elaborates and analyzes the main concerns in technical review, such as product structure, main risks, performance requirements, clinical evaluation, etc., in order to provide a basis for the design, development, production, registration, use and post-marketing supervision of the devices.

Effects of Fumigation on the Reduction of Salmonella enterica in Soil.

Due to the phaseout of methyl bromide (MeBr), there is a need for broad-spectrum soil fumigation alternatives for pest management. Little is known about the impact of fumigation alternatives on foodborne pathogens, such as Salmonella, in agricultural soils. This study investigated the effect of MeBr alternative fumigants on Salmonella reduction in soil. Sandy loam soil was collected from a conventional farmed vegetable field and inoculated with either Salmonella Newport J1892 or Typhimurium ATCC 14028 (5.9 ± 0.3 log10 colony-forming unit [CFU]/g). Each of the four fumigants labeled for pest management (1,3-dichloropropene, chloropicrin, dimethyl disulfide, and metam sodium) was applied at labeled maximum application field levels to soil in pots and stored for a 2-week period. Sterile water was used as a control. Following the 2-week period, Salmonella concentrations in soil samples were enumerated at 1, 7, 14, and 21 days postfumigation. The mean concentration of Salmonella Newport was significantly higher than that of Salmonella Typhimurium 1 day after fumigation (p = 0.015). Fumigation using 1,3-dichloropropene or dimethyl disulfide significantly reduced Salmonella Newport and Salmonella Typhimurium concentrations, compared with the sterile water control. The rate of Salmonella reduction in soil treated with dimethyl disulfide was higher (0.17 ± 0.02 log10 CFU/g/day), compared with soil treated with the other fumigants (0.10-0.12 log10 CFU/g/day). Due to the reduction of Salmonella, alternative fumigation treatments may mitigate potential Salmonella contamination in soil within farm environments.

Development of a novel 1-octen-3-ol-loaded agar/curdlan hydrogel for inhibiting peach fruit diseases

Our previous study found that 1-octen-3-ol fumigation treatment could effectively induce the resistance of peach fruit diseases. However, 1-octen-3-ol is a liquid fumigant, which is not conducive to storage and application. Herein, the gel of 1 % agar compound with 1 % curdlan was used as a novel material for covering 1-octen-3-ol. The interaction of agar and curdlan was promoted by adding 1-octen-3-ol, leading to a higher thermostability compared to single-component antibacterial gels. Moreover, 1-octen-3-ol resulted in changes in the internal structure and mechanical properties of gel to form a pore-like structure, which is beneficial to the retention and release of 1-octen-3-ol. Additionally, the 2 % agar gel containing 1-octen-3-ol had the best inhibitory effect on the mycelial growth of Monilinia fructicola and Rhizopus stolonifer in vitro, and the compound hydrogel of 1 % agar and 1 % curdlan with 1-octen-3-ol could most effectively inhibit brown rot and soft rot caused by these two pathogens in vivo. Overall, the data indicated that the novel 1-octen-3-ol-loaded agar/curdlan hydrogels could effectively retain and release 1-octen-3-ol, and induce the resistance of peach fruit diseases.

Ethanol fumigation combined with modified atmosphere packaging delays potato greening under light

Potato greening under light causes post-harvest loss and compromises progress being made in the potato industry. In this study, we investigated the inhibiting effects of ethanol fumigation treatment on potato greening and water loss under light. This paper also examined the different treatments on the relationship between starch granule size and potato greening. Our results suggested that ethanol fumigation combined with modified atmosphere packaging have an effective in improving the overall visual quality and maintained a higher a* value and lower chlorophyll concentration. Ethanol fumigation combined with modified atmosphere packaging treatment deterred greening and water loss compared to the alone treatment. This was due to the larger starch granule size and fewer grana lamellae around the amyloplasts. Our results provide an effectively strategy that treating potatoes with 600 μL L−1 ethanol combined with modified atmosphere packaging to delay potato greening and explain the underlying mechanism of ethanol inhibition of potato greening.

Long-term effects of chloropicrin fumigation on soil microbe recovery and growth promotion of Panax notoginseng.

Panax notoginseng is a precious Chinese medicinal material. Soil fumigation can control soil-borne disease and overcome the continuous cropping obstacles of P. notoginseng. However, chloropicrin (CP) fumigation can kill non-target soil microorganisms and reduce microbial diversity, but the long-time impacts of CP fumigation on soil microbial are less reported. We studied the long-term effects of CP fumigation on soil microbes with high-throughput gene sequencing, and correlated the changes in the composition of microbial communities with environmental factors like soil physicochemical properties and soil enzyme activities. This study mainly focuses on the recovery characteristics of soil microbe after soil fumigation by evaluating the ecological restoration of P. notoginseng soil, its sustained control effect on plant diseases, and its promotion effect on crop growth by focusing on the CP fumigation treatment. The results showed that CP fumigation significantly increased soil available phosphorus (P) to 34.6 ~ 101.6 mg/kg and electrical conductivity (EC) by 18.7% ~ 34.1%, respectively. High-throughput gene sequencing showed that soil fumigation with CP altered the relative abundance of Trichoderma, Chaetomium, Proteobacteria, and Chloroflexi in the soil while inhibiting a lot of Fusarium and Phytophthora. The inhibition rate of Phytophthora spp. was still 75.0% in the third year after fumigation. Fumigation with CP enhanced P. notoginseng's survival rate and stimulated plant growth, ensuring P. notoginseng's healthy in the growth period. The impact of fumigation on microbial community assembly and changes in microbial ecological niches were characterized using normalized stochasticity ratio (NST) and Levins' niche breadth index. Stochasticity dominated bacterial community assembly, while the fungal community was initially dominated by stochasticity and later by determinism. Fumigation with CP reduced the ecological niches of both fungi and bacteria. In summary, the decrease in microbial diversity and niche caused by CP fumigation could be recovered over time, and the control of soil pathogens by CP fumigation remained sustainable. Moreover, CP fumigation could overcome continuous cropping obstacles of P. notoginseng and promote the healthy growth of P. notoginseng.

Quality characteristics of white button mushrooms (Agaricus bisporus) affected by gamma irradiation and volatile oils during storage

Abstract Agaricus bisporus mushrooms contain various bioactive substances, the current study aimed to evaluate the effects of gamma-irradiation (1.5, and 2.0 kGy) and essential oils (EOs) fumigation treatments including; geranium (60, and 80 μL L−1) as well as lemongrass (40, and 60 μL L−1) on quality characteristics (color, weight loss, firmness), and microbial properties, as well as total and reducing sugars of mushrooms at 4 °C during storage for 12 days. It was found that 40 μL L−1 lemongrass (L1) showed the highest L* after 12 days of storage so, it gave the greatest impact on reducing browning of mushrooms. Geranium oil (G1) recorded the least increase in weight-loss (3.01 %) after 12 days of storage. Otherwise, the firmness was also significantly inceased in the EOs (60 μL L−1 of geranium and 40 μL L−1 of lemongrass) samples compared to the controls and gamma-rays. The EOs achieved slight increases in TSS% compared with other treatments. Also, total sugar content in all treatments showed an overall reduction with storage time. Gamma-irradiation (1.5, and 2.0 kGy) was more efficient in inhibiting the development of mesophilic and psychrophilic count. While, lemongrass treatment (L2) has the lowest count of fungi at the end of storage (0.5 log10 CFU g−1). The current findings suggest that and EOs (geranium & lemongrass) and gamma-irradiation are a promise process for maintaining the quality of A. bisporus through refrigeration preservation.

Transcriptomic analysis reveals the functions of H2S as a gasotransmitter independently of Cys in Arabidopsis.

Numerous studies have revealed the gasotransmitter functions of hydrogen sulfide (H2S) in various biological processes. However, the involvement of H2S in sulfur metabolism and/or Cys synthesis makes its role as a signaling molecule ambiguous. The generation of endogenous H2S in plants is closely related to the metabolism of Cys, which play roles in a variety of signaling pathway occurring in various cellular processes. Here, we found that exogenous H2S fumigation and Cys treatment modulated the production rate and content of endogenous H2S and Cys to various degrees. Furthermore, we provided comprehensive transcriptomic analysis to support the gasotransmitter role of H2S besides as a substrate for Cys synthesis. Comparison of the differentially expressed genes (DEGs) between H2S and Cys treated seedlings indicated that H2S fumigation and Cys treatment caused different influences on gene profiles during seedlings development. A total of 261 genes were identified to respond to H2S fumigation, among which 72 genes were co-regulated by Cys treatment. GO and KEGG enrichment analysis of the 189 genes, H2S but not Cys regulated DEGs, indicated that these genes mainly involved in plant hormone signal transduction, plant-pathogen interaction, phenylpropanoid biosynthesis, and MAPK signaling pathway. Most of these genes encoded proteins having DNA binding and transcription factor activities that play roles in a variety of plant developmental and environmental responses. Many stress-responsive genes and some Ca2+ signal associated genes were also included. Consequently, H2S regulated gene expression through its role as a gasotransmitter, rather than just as a substrate for Cys biogenesis, and these 189 genes were far more likely to function in H2S signal transduction independently of Cys. Our data will provide insights for revealing and enriching H2S signaling networks.

Effects of three essential oil fumigation treatments on the postharvest control of Botrytis cinerea and their efficacy as preservatives of cherry tomatoes.

Cherry tomatoes (Solanum lycopersicum) are becoming increasingly popular due to their nutrition and delicious flavor. However, cherry tomatoes are highly perishable and susceptible to various pathogenic microorganisms after harvest, such as Botrytis cinerea. In the pretest experiment, we screened out 3 kinds of plant essential oils (Torreya grandis oil, Eriobotrya japonica oil, and Citrus medica oil) that have strong fungicidal activity on B. cinerea from cherry tomatoes. To further evaluate the postharvest preservation application prospect of these three oils for cherry tomatoes, these three oils were extracted from different parts of three plants by hydrodistillation, and their chemical constituents were analyzed by Gas Chromatography - Mass Spectrometry (GC-MS). The main representative components of T. grandis oil, E. japonica oil, and C. medica oil were δ-cadinene (11.76%), trans-nerolidol (9.70%), and 5,7-dimethoxycoumarin (23.22%), respectively. These three EOs effectively inhibited the mycelial growth of B. cinerea in vitro, with EC50 values of 81.672, 144.046, and 221.500 μL/L, respectively. Compared with the blank control and other oil treatments, T. grandis oil (at a concentration of 200 µL/L) fumigation treatment was more effective at inhibiting the growth rate of the pathogen. In addition, the phenolic content and phenylalanine ammonia lyase (PAL), β-1,3-glucanase, chitinase, and peroxidase (POD) activities of tomatoes significantly increased on the 7th day due to T. grandis oil treatment. The present study shows that these three oils with high extraction rates have preservation potential for cherry tomatoes. Among these three essential oils (EOs), T. grandis oil can be used to further develop preservative products as a fumigant.

Fungal community analysis of hot spots in bulk maize under different storage conditions

Maize is one of the main cereals used for food and livestock feed. During storage, maize is easily infected by fungi to form mildew or cause hot spots, resulting in maize quality loss and potential safety hazards. We collected maize samples from normal spots and hot spots in three warehouses with different storage conditions (i.e., normal storage, N2-controlled atmosphere storage, and phosphine fumigation treatment storage) and used high-throughput sequencing and traditional culturing methods to investigate the fungal communities inducing hot spots. The results showed that there were large differences in the fungal communities on the maize within the three storage warehouses, and the community compositions of the hot spots and normal spots were different within the same warehouse. The storage conditions were highly associated with the fungal community alpha and beta diversities. Aspergillus penicillioides, A. vitricola, and A. chevalieri were the dominant fungal species inducing hot spots. Furthermore, the grain temperature and moisture content were significantly correlated with fungal community composition in hot spots and normal spots. These data are useful for grain depot managers evaluating the potential risks of fungi-induced hot spots and for optimizing storage conditions to reduce the risks of hot spots during maize storage.

Chemical fumigation combined with soil amendments of contrasting carbon availability alters soil bacterial and fungal community diversity

Chemical fumigation is used to reduce soil-borne diseases in agricultural production systems; however, non-targeted soil microorganisms may also be affected. This study investigated the effects of chemical fumigation and substrate carbon (C) availability on the soil bacterial and fungal community diversity under controlled conditions over 128 days. This study consisted of a 3 × 3 factorial arrangement of three fumigant treatments (fumigation with chloropicrin [CP], metam sodium [MS], or no fumigation) and three soil amendment treatments (amendment with young barley, mature barley, or no amendment). MS fumigation transiently decreased bacterial species evenness when combined with young barley residues; however, it did not affect fungal diversity indices. CP fumigation, regardless of soil amendment or substrate C availability, decreased bacterial species evenness and richness that did not recover over time. However, CP fumigation only decreased fungal species evenness and richness when combined with young or mature barley residues. Although all treatments resulted in a bacterial and fungal community that was significantly dissimilar to the non-fumigated unamended soil, CP fumigated soils had the most dissimilar bacterial and fungal β-diversity after 128 days. This study demonstrated that the addition of young or mature barley residues to chemically fumigated soil did not recover microbial diversity. Instead, the addition of plant residues to chemically fumigated soil had a greater impact on microbial diversity and community composition compared to chemical fumigation used alone, subsequently promoting a less diverse and selective community for both fumigation and organic C additions.

Diversity and function of soybean rhizosphere microbiome under nature farming.

Nature farming is a farming system that entails cultivating crops without using chemical fertilizers and pesticides. The present study investigated the bacterial and fungal communities in the rhizosphere of soybean grown in conventional and nature farming soils using wild-type and non-nodulating mutant soybean. The effect of soil fumigant was also analyzed to reveal its perturbation of microbial communities and subsequent effects on the growth of soybean. Overall, the wild-type soybean exhibited a better growth index compared to mutant soybean and especially in nature farming. Nodulation and arbuscular mycorrhiza (AM) fungi colonization were higher in plants under nature farming than in conventionally managed soil; however, fumigation drastically affected these symbioses with greater impacts on plants in nature farming soil. The rhizosphere microbiome diversity in nature farming was higher than that in conventional farming for both cultivars. However, the diversity was significantly decreased after fumigation treatment with a greater impact on nature farming. Principal coordinate analysis revealed that nature farming and conventional farming soil harbored distinct microbial communities and that soil fumigation significantly altered the communities in nature farming soils but not in conventional farming soils. Intriguingly, some beneficial microbial taxa related to plant growth and health, including Rhizobium, Streptomyces, and Burkholderia, were found as distinct microbes in the nature farming soil but were selectively bleached by fumigant treatment. Network analysis revealed a highly complex microbial network with high taxa connectivity observed under nature farming soil than in conventional soil; however, fumigation strongly broke it. Overall, the results highlighted that nature farming embraced higher microbial diversity and the abundance of beneficial soil microbes with a complex and interconnected network structure, and also demonstrated the underlying resilience of the microbial community to environmental perturbations, which is critical under nature farming where chemical fertilizers and pesticides are not applied.

Research Progress in Diagnosis and Treatment of Postpartum Depression by Traditional Chinese Medicine

In this paper, by analyzing a large number of domestic and foreign literatures on the treatment of postpartum depression in recent years, the research progress of traditional Chinese medicine (TCM) in the treatment of postpartum depression was systematically reviewed. Sum up after a postpartum depression of the most common etiology and pathogenesis, from the compound Chinese medicine, acupuncture, needle medicine use, massage, music therapy and traditional Chinese medicine fumigation treatment, according to the basic theory of TCM in detail its historical source, choose party on the basis of TCM syndrome differentiation, acupuncture and moxibustion therapy in a variety of acupuncture and moxibustion treatment of forms, and other characteristics of traditional Chinese medicine therapy. Literature review shows that: The doctor of traditional Chinese medicine in the treatment of postpartum depression, with overall concept as guiding ideology, thus improve the systemic symptom of patients, improve the quality of life, and there are diversified TCM therapies, patients and their families have high acceptance, small side effects, make up the deficiency of western medicine, not only in the clinical practice to improve the curative effect of treatment of postpartum depression, also for the general medical compatriots to broaden the diagnosis and treatment method of postpartum depression, provide evidence for the selection of treatment for such patients.

Soil nitrification process played a key role in alleviating continuous cropping limitation induced by fumigation

Continuous cropping causes enormous crop produce reduction, and soil fumigation is an effective approach to alleviate the limitation. Understanding the impacts of agriculture management on microbial community and its association with nutrient availability would provide strong supports for alleviating continuous cropping limitation. However, the mechanisms of fumigants in enhancing plant growth and alleviating continuous cropping barriers was not clear. In this study, fumigation treatments including chloropicrin (CP), dazomet (DZ), and untreated control (CK) were carried out at field scale, and rhizosphere bacterial community and plant phytochrome were analyzed. The results showed that fumigation had strong effects on rhizosphere bacterial community and soil properties. Fumigation treatment caused significantly reduction in rhizosphere bacterial diversity. The nitrifiers (Nitrospira and Nitrospirillum) and functional gene (ammonia oxidizing bacterial AOB amoA) were significantly inhibited by fumigation treatment, which caused significant reduction in nitrification potential (PNF). The inhibition of nitrifiers, AOB amoA gene and PNF led to significant reduction of soil NO3−-N, but increase of NH4+-N. Subsequently, plant photosynthesis was enhanced as a result of increasing leaf chlorophyll a content caused by fumigation treatment. Therefore, fumigation treatment would promote crop growth through increasing the photosynthetic pigment. The study indicated the key mechanisms fumigation promoting plant growth and alleviating cropping limitation were closely related to soil nitrifiers and nitrogen nutrients.

Application of microbial organic fertilizers promotes the utilization of nutrients and restoration of microbial community structure and function in rhizosphere soils after dazomet fumigation.

Soil fumigant dazomet is a broad-spectrum nematicide and fungicide that can kill non-target microbes. Fungicides or organic fertilizers are often added after fumigation to improve the recovery of soil microbes. However, the effect of adding microbial organic fertilizers (MOF) after fumigation on the structure and function of rhizosphere soil microbial communities of crops is unclear. Therefore, we investigated the effects of adding Junweinong and Junlisu MOFs after dazomet fumigation on the structure and function of rhizosphere microbial communities and its relationship with soil properties and enzyme activities. The results showed that the addition of these two MOFs after dazomet fumigation significantly reduced the rhizosphere soil available phosphorus, available potassium, organic matter content, and urease, alkaline phosphatase, and catalase activities, but increased the soil pH compared with the fumigation treatment. The application of MOFs after fumigation resulted in significant enrichment of bacteria such as Gaiella, norank_f_Vicinamibacteraceae, and Flavisolibacter and fungi such as Peroneutypa, Olpidium, and Microascus in the rhizosphere soil of the crop and increased the relative abundance of functional genes of 13 kinds of amino acids metabolism, pyruvate metabolism, TCA cycle, and pentose phosphate pathway as well as endophytic and epiphytic functional groups in the rhizosphere soil. In particular, NH4 +-N, pH, and AK had the greatest effect on rhizosphere microorganisms. Overall, the addition of MOFs after fumigation promoted crop root nutrient uptake, enhanced rhizosphere soil microbial metabolism, allowed more beneficial communities to colonize the roots, and promoted soil microbiological health.

Comparative Analyses of Ripening, Texture Properties and Cell Wall Composition in Three Tropical Fruits Treated with 1-Methylcyclopropene during Cold Storage

Regulation of fruit ripening is one of the most important topics in postharvest storage. Effects of 1-methylcyclopropene (1-MCP) greatly depend on the responsiveness of fruit cultivar to this molecule. Although 1-MCP has been used in postharvest preservation of many fruit species, its effects on ripening process, including ethylene production, and softening of banana, mango, and papaya are still not very clear. In the present study, we comparatively investigated the effects of 1-MCP fumigation treatment (1 μL L−1 for 20 h) on ripening behavior and texture qualities of the three fruits during storage at 15 °C. Results showed that 1-MCP treatment not only suppressed the production but also delayed the peak points of ethylene in banana and mango. However, it only significantly delayed the emergence of peak, but didn’t suppress the production of ethylene in papaya. Meanwhile, 1-MCP treated papayas showed the lowest malondialdehyde (MDA) content, cell membrane permeability (CMP) and activities of polygalacturonase (PG) and cellulose (CX), accompanied by the highest firmness and protopectin content. Furthermore, 1-MCP treatment slowed down the changes of pulp cell structure in three kinds of fruit. Thus, the findings suggest that postharvest application of 1-MCP has potential in banana and mango fruits due to both prolonging storage-life and ensuring the texture quality, whereas it is not suitable for papaya fruit because of the abnormal softening and the poor texture.

Antifungal activity of diacetyl, a volatile organic compound, on Trichoderma lixii F2 isolated from postharvest Lanzhou lily bulbs

The most severe fungal disease is postharvest gray mold, which might cause massive losses in Lanzhou lily bulbs. Some microorganism-produced volatile organic compounds (VOCs) have been proven to have antifungal action and can be employed as fruit and vegetable preservation. Our most recent research discovered that diacetyl (2, 3-butanedione) produced by Bacillus subtilis CL2 could significantly prevent some pathogens. The goal of this investigation was to see if diacetyl had antifungal properties against Trichoderma lixii F2, one of the most common postharvest rot pathogens of Lanzhou lily bulbs. The results indicated that diacetyl (1.587 μL/mL) fumigation treatment significantly inhibited the hyphal growth, modified hyphal morphology, and disrupted the cell membrane integrity. In vivo tests the antifungal mechanisms of diacetyl on T. lixii F2 were performed in Lanzhou lily bulbs. The results indicated that the content of total phenols and flavonoids increased, while malondialdehyde decreased under different treatment by diacetyl. Meanwhile, the activities of peroxidase, polyphenol oxidase, catalase, and superoxide dismutase and phenylalanine ammonia-lyase in Lanzhou lily bulbs were investigated. It was showed that diacetyl could eliminate excessive reactive oxygen species, reduce the damage of plant cells, and improve the resistance of Lanzhou lily bulbs against T. lixii F2. This research reveals that diacetyl could activate antioxidant enzymes and disease-resistant enzymes in Lanzhou lily bulbs to prevent pathogenic fungus from invading and inducing resistance, laying the groundwork for future uses in preserving Lanzhou lily bulbs.