Objectives: Antibiotic-resistant bacterial infections are a growing global concern. A natural remedy for bacterial infections could be available in the Selenicereus undatus fruit, but its antibacterial and biochemical properties are not fully known. Methods: In this study, the biochemical composition and antibacterial, antioxidant, and cytotoxic activities of the Jindu No. 1 (JD) and Bird’s Nest (YW) dragon fruit varieties and their potential effects against E. coli, Pseudomonas sp., and Staphylococcus sp. were scrutinized. Results: The JD fruit extract showed higher antibacterial activity than the YW variety against E. coli, Pseudomonas sp., and Staphylococcus sp. in vitro. Additionally, the JD variety demonstrated more significant antioxidant activity than the YW variety and showed less cytotoxic activity. The JD variety had a higher glucose content, while the YW variety had a higher fructose content, and the phytoconstituents analysis confirmed 659 metabolites in total from the two varieties. Through in silico analyses, phytoconstituents were evaluated to identify potential drug molecules against the selected bacterial strain. Moreover, the molecular docking study revealed that riboprobe and Z-Gly-Pro might be effective against E. coli, 4-hydroxy retinoic acid, and that succinyl adenosine may target Pseudomonas sp., and xanthosine and 2′-deoxyinosine-5′-monophosphate may be effective against Staphylococcus sp. These results were further validated by 100 ns Molecular Dynamics (MD) simulation, and all of the selected compounds exhibited acceptable ADMET features. Conclusions: Therefore, phytoconstituents from S. undatus fruit varieties could be employed to fight human bacterial diseases, and future studies will support the continuation of other biological activities in medical research.

Okra (Abelmoschus esculentus (Linn.) Moench), a globally cultivated vegetable crop valued for its nutrient-rich pods, is facing emerging threats from seedling damping-off and blight in subtropical regions of South China. In 2022, fungal isolates representing five genera (Trichoderma, Rhizoctonia, Rhizopus, Macrophomina, and Rhizomucor) were obtained from symptomatic seedlings in Guangdong Province. The pathogenicity test revealed that three Rhizoctonia isolates (ACCC 35247, ACCC 35460 and ACCC 35461) could induce typical damping-off symptoms, inhibit seed germination and cause hypocotyl necrosis, consistent with symptoms observed under natural field conditions. Based on morphological and molecular characterization, along with phylogenetic analysis of the ITS region, the pathogen was identified as Rhizoctonia solani (teleomorph: Thanatephorus cucumeris (Frank) Donk). The mycelial and sclerotia lethal temperature of the pathogen was 45 °C and 48 °C respectively, and the optimal temperature (T_opt) for mycelial growth was 28.22 °C. Sensitivity of the pathogen to seven fungicides was evaluated in vitro using a mycelial radial growth assay, the EC₅₀ values for each fungicide were estimated. According to the EC₅₀ values of seven fungicides, there was significant difference in the inhibitory effect of each fungicide on the pathogen, and the pathogen was most sensitive to trifloxystrobin + tebuconazole (1:2), with the mean EC₅₀ value being 0.43 mg·L⁻¹. This study provides critical insights into the disease management of R. solani induced damping-off in okra.

In this study, we applied eight different light quality treatments and investigated their effects on the proliferation and physiological characteristics of Aquilaria sinensis group-cultivated seedlings in order to screen the best light quality for optimizing group-cultivation fast multiplication technology. The results showed that the highest multiplication rates were obtained with blue light and red light, which were significantly higher than those of white light. Blue light was the most effective in promoting the synthesis of photosynthetic pigments, while red light and blue violet light were favorable for the accumulation of soluble sugars. Correlation analysis showed that the multiplication rate was significantly and positively correlated with plant height, chlorophyll b, total chlorophyll, and soluble sugar content. The comprehensive evaluation indicated that blue light, blue-violet light, and red light was most suitable for fostering proliferation of, and physiological status improvement in, group-cultivated A. sinensis seedlings, with their superior performance likely attributable to the combined effects of specific spectral properties and appropriate photosynthetic photon flux density (PPFD) levels. The results of this study provide technical support for light environment regulation for the efficient and rapid propagation of group-cultured A. sinensis seedlings.