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Abstract [Objective] The woody stems of plants are difficult to obtain satisfactory microscopic image in both freehand and paraffin sections due to the high content of secondary vascular tissues and high degrees of lignification of cell walls. Microtome cryostat can section the tissue with a certain hardness. It will be one of the effective tools for the section of plant woody stems. [Methods] Some woody stems with uniform texture and high water content can be sectioned by cryo-sectioning without chemical fixation. For stems with hard wood and less water content, observation was performed after fixation with FAA and other fixation, OCT embedding, (-30) - (-25) ℃ sectioning, and staining with 0.1% toluidine blue staining solution. [Results] For tree or shrub stems with a diameter of less than 6 cm, cryo-sectioning method could be used to quickly obtain complete structure and clear and colorful microstructure images. [Conclusion] The microtome cryostat can be used for microstructure sectioning of woody stems combined with toluidine blue staining, which has the advantage of simplicity, efficiency, and ease of operation.

Objective: To better control the growth of spoilage microorganisms, and ensure the food safety of Xiangwei Luodou dry. Methods: The putrefactive microorganisms in Xiangwei dried tofu were identified by plate scribing method, colony morphology observation, Gram staining, 16S rDNA and ITS sequence. Results: A total of 9 strains were isolated andscreened. KZ2780-3 and KZ2780-4 are Bacillus subtilis, NZ2559-1 is Bacillus cereus, and JZ2559-5 is Bacillusamylolyticus amyloliquefaciens, FZ2559-2 for Klebsiella pneumoniae, SZ2641-5 for Enterococcus faecium, RZ2641-7 for Staphylococcus haemolyticus, BZ2780-1 for Acinetobacter baui, CZ2780-5 for Penicillium citri. Conclusion: The strains causing dry rot of Xiangwei bean are Bacillus subtilis, Bacillus cereus, Bacillus amyloliquefaciens, Klebsiella pneumoniae, Enterococcus faecium, Staphylococcus hemolyticus, Acinetobacter baui and Penicillium citri. The control methods of Xiangwei stewed bean dry are ultra-high temperature instantaneous sterilization technology, plasma sterilization technology, natural antibacterial substances combined with biological preservatives, vacuum packaging, air conditioning preservation and so on.

Cadmium (Cd) contamination in rice has been a serious threat to human health. To investigate the effects of arbuscular mycorrhizal fungi (AMF) on the Cd translocation in rice, a controlled pot experiment was conducted. The results indicated that AMF significantly increased rice biomass, with an increase of up to 40.0%, particularly in root biomass by up to 68.4%. Notably, the number of prominent rice individuals also increased, and their plasticity was enhanced following AMF inoculation. AMF led to an increase in the net photosynthetic rate and antioxidant enzyme activity of rice. In the AMF treatment group, the Cd concentration in the rice roots was significantly higher (19.1%‒68.0%) compared with that in the control group. Conversely, the Cd concentration in the rice seeds was lower in the AMF treatment group, indicating that AMF facilitated the sequestration of Cd in rice roots and reduced Cd accumulation in the seeds. Path coefficients varied across different treatments, suggesting that AMF inoculation reduced the direct impact of soil Cd concentration on the total Cd accumulation in seeds. The translocation of Cd was consistently associated with simultaneous growth dilution and compensatory accumulation as a result of mycorrhizal effects. Our study quantitatively analyzed this process through path analysis and clarified the causal relationship between rice growth and Cd transfer under the influence of AMF.

Abstract [Objective] This study aims to investigate the impact of Streptomyces pactum Act12 broth on growth and physiological characteristics of Medicago sativa seedlings under petroleum stress. [Methods] The effects of different concentrations (0, 1%, 10%, and 100%) of Act12 broth under a petroleum stress level of 3% (W/W ) were examined by determining seedling growth, root morphology, photosynthetic characteristics, osmoregulatory substance content, and antioxidant capacity in M . sativa. [Results] The 3% petroleum significantly hindered photosynthesis and biomass accumulation of M . sativa seedlings, compared to the control group (CK). Moreover, it resulted in elevation in malondialdehyde level, decrease in soluble sugar and soluble protein content, as well as alteration in the activities of superoxide dismutase (SOD) and peroxidase (POD). Compared to the absence of Act12 broth, solutions with low and medium concentrations (1% and 10%) effectively mitigated the toxic effects of petroleum, with 10% Act12 broth exhibiting the most significant effect. The seedlings treated with Act12 broth exhibited significant enhancements in plant height, above-ground dry mass, underground dry mass, stem tolerance index, root tolerance index, total root length, root surface area, root volume, and number of root tips. Additionally, the level of MDA was decreased by 42.49% and 56.45%, soluble sugar was increased by 79.25% and 89.83%, while soluble protein was increased by 167.63% and 256.15% in the above-ground and underground parts, respectively. Moreover, SOD and POD activity were increased by 35.81% and 57.33%, respectively. [Conclusion] The fermented liquid with low/medium concentration effectively modulates antioxidant enzyme activity and osmotic regulation ability of seedlings, resulting in reduced MDA content, enhanced photosynthesis ability, increased biomass, and eventually alleviates the inhibition effects of petroleum stress on seedling growth.