Tomato brown rugose fruit virus (ToBRFV) is considered an emerging disease and a viral pandemic for tomato consumers. The objectives of this research were to analyze the biological and physicochemical characteristics of ToBRFV in tomato and tobacco plants, as well as to evaluate its natural host range. Inoculant seeds were recovered from ToBRFV-infected tomato samples in Coahuila, Mexico, and confirmed by RT-PCR. In the first greenhouse experiment, tomato plants of the F1 hybrid variety 172–300 (Yüksel), infected with ToBRFV, were used to evaluate viral inclusions (VI), dilution endpoint (DEP), the incubation period (IP), and latency period (LP). In a greenhouse experiment, Nicotiana longiflora plants were inoculated with ToBRFV to determine the in vitro longevity (IVL) and thermal inactivation (TI) of the virus in sap. Finally, the inoculation of tomato plants grown in open fields was carried out to evaluate transmission to natural hosts. The plants tested for possible ToBRFV reservoirs near the inoculum source were inspected and confirmed by a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The results indicate that the VIs on tomato leaves manifested as X-bodies and rounded, stacked plaques within epidermal cells. The DEP required to induce the infection in plants was from a ToBRFV concentration of 1 × 10^−5.5, the IP of ToBRFV occurred 9 to 12 days post-inoculation, and LP could be detected one day after inoculation. The TI of ToBRFV in N. longiflora plants occurred at 85 °C for 30 min. Ipomoea purpurea, Mirabilis jalapa, Clematis drummondii, and Solanum tuberosum were newly identified hosts of ToBRFV. The results found contribute to a better understanding of the impact of ToBRFV, managing and preventing the spread of ToBRFV in diverse environments.

Domesticated tomato (Solanum lycopersicum L.) crops have presented an increased susceptibility to pests under field and greenhouse conditions. Among these pests is tomato/potato psyllid, Bactericera cockerelli Sulc (Hemiptera: Triozidae), a major pest in solanaceous crops. In this study, we evaluated volatile organic compound (VOC) emissions from the headspace in three healthy varieties of tomato plants (Floradade, Micro-Tom and wild) under greenhouse conditions using solid-phase microextraction and gas chromatography–mass spectrometry (SPME/GC-MS). Later, independent bioassays were performed to evaluate VOC emissions with three varieties infested with nymphs of B. cockerelli. The results in healthy plants showed markedly different VOC profiles in each variety (14 compounds for wild, 17 for Floradade and 4 for Micro-Tom). Plants infested with nymphs showed changes in VOC emissions distinctly in Floradade and wild varieties. We suggest that these qualitative differences in VOC profiles by the degree of domestication could explain the preferences of B. cockerelli.

Tomato brown rugose fruit virus (ToBRFV), being a mechanically transmitted disease, is usually difficult to control; therefore, an effective alternative to reduce transmission and replication in the crop is by spraying with chlorine dioxide (ClO₂) during routine crop management. In this research, the efficacy of chlorine dioxide (ClO₂) for ToBRFV management in a greenhouse and open field was determined. The phytotoxicity of ClO₂ and its effective concentration against ToBRFV in Nicotiana longiflora plants were evaluated. Subsequently, the effect of ClO₂ on ToBRFV was evaluated in tomato plants grown in an open field. Finally, the effectiveness of ClO₂ on plants inoculated with ToBRFV under greenhouse conditions was evaluated and the number of necrotic local lesions (NLLs) was quantified. The results revealed that ClO₂ at 760 mg L⁻¹ did not show phytotoxicity and reduced the number of NLLs in N. longiflora plants. It also decreased ToBRFV transmission and replication in field- and greenhouse-grown tomato plants, improving agronomic parameters. ClO₂ reduced replication in plants inoculated with different amounts of ToBRFV inoculum in a greenhouse. N. longiflora leaves expressed lower numbers of NLLs when inoculated with ClO₂-treated tomato plant extracts. Finally, the results demonstrate that ClO₂ represents an effective management alternative when used by direct application to plants. To our knowledge, this is the first study where the use of an antiviral compound is carried out under field and greenhouse conditions.

Soybean, Glycine max (L.), in the field is very susceptible to infestation by sweetpotato whitefly, Bemisia tabaci (Gennadius). Preference for oviposition by whitefly in two soybean genotypes was evaluated, and a profile of volatile compounds in healthy plants was obtained. The average number of eggs per square centimeter was 4.1 to 13.7 in ‘Nainari’ variety and 15.1 to 28.4 in an experimental line. Trichome averaged 6.5 per square centimeter in Nainari and 6.8 in the experimental line. The average length of trichomes of Nainari was 311 microns and in the experimental line was 342. Solid-phase microextraction and gas chromatography-mass spectrometry were used to obtain the profile of volatile compounds in two Nainari soybean genotypes and one experimental line: cis-3-hexenyl acetate; cis-3-methyl-1,3-pentadiene; 4-methyl-1,3-pentadiene; cis-3-hexenyl valerate; cis-2-hexen-1-ol; 9-ethyl-9-heptyloctadecane; tetradecane; tridecane; and 2,6-bis(1,1-dimethylethyl)-4-(1-oxopropyl) phenol. In plants infested with whitefly eggs and nymphs, eight compounds were identified in Nainari and seven in the experimental line: M-xylene; 1-octen-3-ol; d-limonene; cedrene; propanoic acid, 2-methyl-, 2-methyl propyl ester; 3-methylnonane; longifolene; caryophyllene; 2,5-cyclohexadiene-1,4-dione, 2,6-bis (1,1-dimethylethyl)-; alpha-farnesene; pentanoic acid, 2,2,4-trimethyl-3-carboxyisopropyl, isobutyl ester, and 2,6-bis(1,1-dimethylethyl)-4-(1-oxopropyl) phenol. Differences in the profile of volatile compounds in healthy Nainari plants might explain oviposition repellency.

A novel rhizobacteria Bacillus was isolated from rhizosphere of soil associated with tomato (Solanum lycopersicum L.) under open field conditions. The Bacillus amyloliquefaciens strain MHR24 (MHR24) is a promising biocontrol agent against several fungal phytopathogens. In this research, MHR24 was characterized by an effective antagonistic ability against Alternaria alternata (Aa), Botrytis cinerea (Bc), Fusarium oxysporum F1 (F1), F. oxysporum F2 (F2), F. oxysporum R3 (F3), and Sclerotinia sclerotiorum (Sc). In particular, MHR24 showed a strong inhibition via airborne volatiles against Bc, F3, Aa, and F2 fungal strains. MHR24 also showed elevated saline stress tolerance at 1% and 25% to NaCl and KCl. The molecular sequence analysis of 16S rDNA confirmed the identity of the isolate as Bacillus amyloliquefaciens strain MHR24. Bioassays on Arabidopsis thaliana Col-0 inoculated with MHR24 showed in in vitro conditions that MHR24 significantly increases the foliar and root area, while in growth chamber conditions, it strongly increases the dry shoot biomass of A. thaliana. The observed results indicate that B. amyloliquefaciens MHR24 has a broad-spectrum biocontrol against fungal phytopathogens and can be used as a biofertilizer and biocontrol agent to improve horticultural crops.

Interactions between plants and insects have been widely studied. Plants develop numerous strategies to avoid establishment and/or feeding by insects. The aim of this research was to evaluate oviposition preference, nymphal development, and survival of Bactericera cockerelli Sulc on ‘Floradade’, ‘Micro-Tom’, and ‘Wild’ varieties of tomato (Solanum lycopersicum L.). Free-choice assays showed B. cockerelli oviposited twice more on ‘Floradade’ than ‘Micro-Tom’ with 1,000 and 479 eggs, respectively. Nymphal stages as well as adults of the pest developed much better on Floradade’ variety to emerge 3 days earlier than in ‘Micro-Tom’ and ‘Wild’ varieties. Adult emergence percentage was 52, 36, and 18% for ‘Floradade’, ‘Micro-Tom’, and ‘Wild’. Results in a greenhouse showed the degree of domestication of tomato varieties affected oviposition preference and survival of the insect.