2024 Vol.31(6): 1–8    [Abstract] ( 133 )    [PDF 1919 KB ] ( 18 )

In order to explore the effects of combined application of sulfur and iron on the growth and physiological characteristics of broccoli seedlings under stress, two kinds of combined application solutions of sulfur and iron（7 mmol/L Na2SO4+0.5 mg/L FeCl2 and 7 mmol/L Na2SO4+20 mg/L EDTA-Fe）were sprayed on the leaves of broccoli seedlings, and 150 mmol/L NaCl solution and 15% PEG6000 solution were used to simulate salt and drought stress. Xanthomonas campestris was inoculated on the leaves of broccoli seedlings by acupuncture method to simulate the stress of black rot fungus. The antioxidant enzyme activities, malondialdehyde, osmotic adjustment substances and glucosinolate contents of broccoli seedlings in each group were determined. The results showed that: under salt and drought stress, the broccoli seedlings of salt control（CKs）and drought control（CKd）both appeared the phenomenon of yellow leaves and wilting, and the broccoli seedlings treated with sulfur and iron fertilizer had a better growth state, without obvious wilting or leaf abscission. Under salt stress, the activities of SOD, POD and soluble protein content of T1s and T2s treatment groups were significantly higher than those of CKs; The content of glucosinolate in T1s treatment group was significantly higher than that in CKs, and the content of malondialdehyde in T2s treatment group was significantly lower than that in CKs. Under drought stress, POD activity in T1d treatment group was significantly higher than that in CKd; The proline content in T2d group was significantly higher than that in CKd; The content of MDA in T1d and T2d treatment groups was significantly lower than that in CKd. Under the stress of black rot fungus, the control（CKb）treatment of black rot fungus showed obvious yellowing, black spots and leaf rot; The growth status of broccoli seedlings in T1b and T2b treatment groups was better, only the local phenomenon of leaf etiolation occurred and the black spot was smaller. The activities of SOD, POD and CAT in T1b treatment group were not significantly different from those in CKb, but they all increased in varying degrees; The activities of SOD and POD in T2b group were significantly higher than those in CKb group; The contents of soluble protein and proline in T1b and T2b treatment groups were significantly higher than those in CKb, and the content of malondialdehyde was significantly lower than that in CKb. The membership function analysis showed that the combined application of 7 mmol/L Na2SO4+0.5 mg/L FeCl2 could alleviate the stress damage of broccoli seedlings and effectively improve their comprehensive stress resistance.

2024 Vol.31(6): 9–14    [Abstract] ( 30 )    [PDF 445 KB ] ( 22 )

With ‘Lanxin’ ‘Guixigua’ ‘Lingtong’ ‘Jinxing’ ‘Jingmei 8K’ ‘F57M’ as experimental materials, the treatments were set up: Nutrient solution + sprayed with water（CK）, nutrient solution containing 200 mmol/L NaCl+sprayed with water（T1）, nutrient solution containing 200 mmol/L NaCl+sprayed with 150 μmol/L melatonin（T2）. The growth indexes, chlorophyll, MDA contents and antioxidant enzyme activities of the nutrients were determined. The results showed that compared with CK, the plant height, stem diameter, biomass and chlorophyll content of watermelon seedlings under NaCl treatment were significantly reduced, and the growth was inhibited. Melatonin spray alleviated the growth inhibition induced by salt stress. After NaCl treatment, the MDA content in the leaves increased significantly. Compared with T1, the MDA content in the leaves decreased significantly after spraying with melatonin. Compared with CK, NaCl treatment significantly increased the activities of POD, CAT and APX in leaves, and the activities of SOD, POD, CAT and APX in leaves were significantly increased after melatonin spray. Exogenous 150 μmol/L melatonin spray can alleviate the damage caused by NaCl, improve the salt tolerance of watermelon seedlings of different varieties, and effectively promote the growth of watermelon seedlings.

2024 Vol.31(6): 15–20    [Abstract] ( 23 )    [PDF 1465 KB ] ( 8 )

In order to screen out the most suitable concentration of tebuconazole in controlling strawberry seedling growth, ‘Hongyan’ strawberries were sprayed with five different concentrations of tebuconazole（C1 : 2.52×10-6 mol/L, C2 : 5.04×10-6 mol/L, C3 : 7.56×10-6 mol/L; C4 : 1.01×10-5 mol/L, C5 : 1.26×10-5 mol/L）, and with water as the control, the effects of different treatments on plant height, stem diameter, leaf area, chlorophyll content, net photosynthetic rate and biomass of strawberry were measured at 5,10,15,20,25 and 30 days after spraying. The results showed that the growth of plant height and leaf area of strawberry was significantly inhibited after treatment with different concentrations of tebuconazole, and C4 had the best inhibitory effect. The total net increment was 78.32% and 83.55% lower than that of CK, respectively. Within a certain range of concentration, the stem diameter could be increased, but the difference was not significant. C1 had the best promotion effect on stem diameter, and the total net increment increased by 36.95% compared with CK. In terms of physiological indexes, the chlorophyll content of C2 increased the most compared with CK at 30 d, but there was no significant difference between C2 and CK. C4 significantly increased the net photosynthetic rate. The application of tebuconazole reduced the dry and fresh weight of the plant, but increased the root-shoot ratio. The root-shoot ratio of C2 was the largest, but the difference is not significant. The seedling index of C2 was the highest, which was 10.69% higher than that of CK. The comprehensive analysis of membership function showed that C2（tebuconazole 5.04×10-6 mol/L）had the best control effect on strawberry growth.

2024 Vol.31(6): 21–27    [Abstract] ( 20 )    [PDF 9302 KB ] ( 14 )

To investigate the effects of exogenous salicylic acid（SA）on the growth of watermelon seedlings under drought stress, with watermelon as the research material, foliar spraying of SA was used to study the effects of different concentrations [0 mmol/L（T0）, 0.5 mmol/L（T1）, 1 mmol/L（T2）, 2 mmol/L（T3）, and 3 mmol/L（T4）]of SA on the growth of watermelon seedlings under drought stress conditions. The results showed that under drought stress, the growth status of watermelon seedlings was significantly inhibited, with a significant increase of 40.50% and 52.10% in malondialdehyde（MDA）and relative conductivity, an increase in total photosynthetic pigment content, soluble protein and proline content, and an increase in peroxidase（POD）and catalase（CAT）activities. With the increase of SA concentration, the growth and physiological characteristics of watermelon seedlings were significantly affected. Plant height, stem thickness, leaf width, leaf length, proline content, soluble protein content, photosynthetic pigment content, stomatal conductance, and antioxidant enzyme activity（CAT and POD）showed a trend of first increasing and then decreasing; The content of malondialdehyde, relative conductivity, and transpiration rate showed a trend of first decreasing and then increasing. Compared with drought stress, the T1 group of watermelon seedlings had the highest plant height, leaf width, CAT activity, photosynthetic pigments, and proline content, with increases of 56.02%, 2.46%, 32.20%, 23.30%, and 40.70%, respectively; The T2 group of watermelon seedlings showed the highest stem diameter, POD activity, and soluble protein content, with increases of 24.03%, 12.80%, and 10.00%, respectively; The growth and physiological characteristics of T4 group watermelon seedlings were severely inhibited. In summary, the application of low to medium concentrations of exogenous SA can alleviate the damage caused by drought stress to watermelon seedlings. T1 treatment in this experiment is the most suitable concentration to improve the drought resistance of watermelon seedlings.

2024 Vol.31(6): 28–33    [Abstract] ( 19 )    [PDF 2235 KB ] ( 13 )

In order to investigate the effects of exogenous glutathione（GSH）on the metabolism of glucosinolates, brocolli seedlings treated with 25 mg/L GSH were taken as experiment materials. The contents of glucosinolates and sulforaphane and the activity of myrosinase were detected, and the transcriptional expression characteristics of the genes related to glucosinolate metabolism in brocolli seedlings, including bolMAM1, bolUGT74B1, bolMYB28, bolMyr, and bolPEN2 were evaluated at different time points after GSH treatment. The results showed that at 12 h of exogenous GSH treatment, the content of glucosinolate in brocolli seedlings was significantly higher than that in the control. Consistent with this, the transcriptional expression levels of key genes for glucosinolates synthesis, bolMAM1 and bolUGT74B1 were significantly higher than those in the control. Although the transcriptional expression level of bolMYB28 was higher than that in the control, it did not reach a significant level. Further analysis revealed that the expression levels of the myrosinase genes bolMyr and bolPEN2, as well as the myrosinase activity, reached their maximum at 24 h of exogenous GSH treatment and were significantly higher than those in the control. With the increase of myrosinase activity, after 36 h of exogenous GSH treatment, the content of sulforaphane in the treatment group reached its highest value and was significantly higher than that in the control group. In summary, exogenous application of GSH has a positive effect on the synthesis of glucosinolates and the generation of the bioactive substance sulforaphane in brocolli seedlings. The research results provide important data support for the use of exogenous treatment methods to increase the content of glucosinolates, especially its hydrolysis product sulforaphane, in cruciferous plants such as broccoli.

2024 Vol.31(6): 34–38    [Abstract] ( 24 )    [PDF 733 KB ] ( 14 )

Using agricultural waste as eco-organic soilless culture substrate has far-reaching significance for reducing production cost, reducing input of water, fertilizer and medicine, and improving crop yield. In this study, eggplant was pot-planted with substrate materials including different ratio of mushroom residue, corn stalk and vermiculite, and the pH value, EC value and nutrient contents of different substrate ratios were analyzed, as well as the effect of substrate to growth and yield of eggplant. The results showed that the nutrient content of each compound substrate was always significantly higher than that of soil（control）before and after eggplant cultivation, and the order of superiority of each treatment was as follows:vermiculite:mushroom residue:corn stalk=5:3:2（volume ratio）, vermiculite:mushroom residue:corn stalk=4:3:3, and vermiculite: mushroom residue: corn stalk=6:2:2, soil. The morphology, yield and single weight of eggplant fruit under substrate cultivation were significantly higher than those in soil, and the ratio of vermiculite:mushroom residue:corn stalk=5:3:2 was the best composite matrix ratio in this experiment. This study provides scientific basis and technical reference for facility eggplant cultivation and full utilization of agricultural waste resources.

2024 Vol.31(6): 39–43    [Abstract] ( 15 )    [PDF 1124 KB ] ( 16 )

Using the stem segments with dormant shoots of axillary buds of annual silk cotton wood as materials, the effects of different disinfection times, different basic media, selection of exogenous hormones and ratio between hormones on the culture in vitro of silk cotton wood were studied, and the existing tissue culture rapid propagation system of silk cotton wood was optimized. The test results showed that the pollution rate was the lowest and the survival rate was the highest when the axillary bud stem segment of silk cotton wood was disinfected with 70% alcohol for 30s, and then disinfected with 2% sodium hypochlorite for 12min. Using MS medium and adding 5.0 mg/L GA3+125 mg/L carboxybenzicillin sodium as the primary medium, axillary bud germination rate was the highest and growth status was the best. The suitable subproliferation medium for axillary buds of silk cotton wood was 1/2MS+0.5 mg/L IAA+1.0 mg/L BA, and the effective proliferation coefficient was the highest after 30 days, which was 4.2, and the optimal rooting culture conditions were 1/2MS+0.5 mg/L NAA. The substrate of grass peat:vermiculite:perlite=1:1:1（v/v）was used in the transplanting stage, and 87 silk cotton trees grew well and had intact root systems after 30 days of transplanting, and the survival rate of transplanting was 96.67%.

2024 Vol.31(6): 44–50    [Abstract] ( 23 )    [PDF 4253 KB ] ( 11 )

Taking shuangyong park in tianjin as a representative sample plot, the daily and seasonal changes of air ion concentration in the park and its different plant communities were measured to study the correlation between negative ions concentration and environmental factors. According to the unipolar coefficient and Abe air quality evaluation index the optimal time period of air quality in the park were selected to guide the surrounding residents to exercise outdoors in a suitable period of time. The results showed that from the observation results of negative ions concentration in the whole year, the negative ions concentration of evergreen conifer community showed spring>autumn>summer>winter; The performance of deciduous broad-leaved plant community was spring>summer>autumn>winter; The daily change of air ions concentration in urban parks showed a “U” shape change trend with the minimum value mostly between 13：30 and 15：30 and slight difference among different plant configurations. According to the assessment of the air quality CI of the park in spring, summer and fall, the optimal time period of the park’s air quality mainly distributed at 8：00-11：00 and 17：00, when the air reached the clean air standard and was more suitable for outdoor exercise for the surrounding residents; Whereas at 12：00 and 14：00 in the afternoon, the air was slightly pollutedI and it was not recommended to carry out outdoor activities for a long period of time.

2024 Vol.31(6): 51–56    [Abstract] ( 22 )    [PDF 4183 KB ] ( 25 )

Based on the health theme of salt reduction-, a healthy salt-reduced red oil radish pickle recipe was developed. Using radish salt blanks as raw materials, supplemented by potassium chloride, calcium chloride and yeast extract as variables, the impact of various factors on the sensory quality of pickles was studied through single factor experiments and response surface optimization, and electronic tongue and fast gas phase electrons were used. The flavor and taste changes in full-salt pickles（QY）, direct salt-reduced 28% pickles（ZJJY）, and auxiliary salt-reduced pickles（FZJY）were measured. The experiment determined that the optimal compound formula of auxiliary salt-reduction pickles was 19% potassium chloride, 14% calcium chloride, and 39% yeast extract. At this time, the sensory evaluation score of the product was 90.56 points, which was similar to the value of the theoretical model. The bitterness of the pickles in the salt group was minimized, the saltiness was significantly reduced, and the flavor component was increased with 2-ethyl-6-methylpyrazine, which has a pleasant aroma. The salt-reduced red oil radish pickles developed in this experiment not only meet the public's demand for low-salt diet, but also increase the added value of white radish products. This research has important practical significance and economic value.

2024 Vol.31(6): 57–63    [Abstract] ( 13 )    [PDF 4585 KB ] ( 12 )

Pholiota microspora is an edible fungus that is rich in nutrients and has a variety of effects. In order to increase the nutritional value of melts, the production process of Pholiota microspora flavor melts was studied. The traditional roasting process was adopted with Pholiota microspora powder, egg white and egg yolk as the main raw materials. On the basis of single factor test, the response surface design test was used to determine the optimal process formula of Pholiota microspora flavor melts through sensory evaluation. The results showed that the optimal process formula was as follows: egg white 69 g, egg yolk 65 g, Pholiota microspora powder 10 g, white sugar 6 g, corn starch 10 g, white granulated sugar 12 g, corn starch 10 g, lemon juice 1 g, baking temperature 100 ℃, baking time 60 min, under these conditions, the sensory score of the Pholiota microspora flavor melts was 83.08 points, and the protein content increased by 6.33%, the fat content decreased by 4.60% and the dietary fiber content was 3.7 times that of common melts. It can be seen that the melts prepared by this technical formula are more in line with people's pursuit of healthy food.

2024 Vol.31(6): 64–74    [Abstract] ( 11 )    [PDF 15222 KB ] ( 7 )

The crude polysaccharides of Tremella fuciformis were extracted from dried and fresh Tremella fuciformis, and the extraction technology and antioxidant activity were compared by single factor and response surface tests. The results showed that the optimal extraction conditions of crude polysaccharide from dried tremella fuciformis were as follows: ratio of solid to liquid 1:49（g:mL）, extraction temperature 71 ℃, extraction time 3 h, and ultrasonic time 40 min. The extraction rate of crude polysaccharide was（20.07±0.43）%; the optimal extraction conditions of crude polysaccharide from fresh Tremella fuciformis were as follows: ratio of solid to liquid 1:32（g: mL）, extraction temperature 71 ℃, extraction time 4 h, ultrasonic time 40 min, and extraction rate of crude polysaccharide was（44.13±0.79）%. The extraction rate of crude polysaccharide from dried Tremella fuciformis was only 45.48% of that from fresh Tremella fuciformis. The superoxide anion and hydroxyl radical scavenging rates of crude polysaccharides from dried and fresh Tremella fuciformis were measured. The IC50 values were 5.12, 4.01, 3.59, and 3.63 mg/mL, respectively. At the mass concentration of 5 mg/mL, the FRAP values of crude polysaccharides from dried and fresh Tremella fuciformis were 0.36 and 0.51, respectively. The antioxidant activity of the two crude polysaccharides increased with the increase of mass concentration, and the antioxidant activity of crude polysaccharides from fresh Tremella fuciformis was higher than that from dried Tremella fuciformis.

2024 Vol.31(6): 75–78    [Abstract] ( 11 )    [PDF 1206 KB ] ( 14 )

To enhance the catalytic ability of porcine pancreas lipase, it was immobilized on wheat bran by physical adsorption in a column glass bottle at 37 ℃ and 160 r/min, and used to catalyze the non-aqueous transesterification between hexanol and vinyl acetate as well as the hydrolysis of peanut oil at 37 ℃ and 160 r/min. It was found that the suitable mass ratio of wheat bran and lipase was determined to be 20:10（mg:mg）. At this ratio, the immobilized lipase behaved the highest non-aqueous activity, being more than10-fold activity of 10 mg native lipase. The activity decreased less than 0.2% after the immobilized lipase was reused 5 times in the organic system, each time for 8 h, which showed that it had a good catalytic stability. In hydrolysis of peanut oil, the immobilized lipase could hydrolyze peanut oil 4.7 folds of that accomplished by the native lipase with equal mass, which means that it has potential as a feed additive to assist animal digestion.

2024 Vol.31(6): 79–84    [Abstract] ( 20 )    [PDF 4178 KB ] ( 10 )

A qualitative and quantitative method for the detection of carbaryl pesticide residues on the surface of vegetable leaves was developed by combining fluorescence spectroscopy with chemometrics. Taking carbaryl pesticide on the surface of spinach leaves as the research object, spinach leaves of uncoated and coated with carbaryl pesticide at different concentrations（1.0×10-3 g/L~1.0×10-1 g/L）were prepared. The fluorescence spectra of all samples were collected by LS-55 fluorescence spectrophotometer produced by Perkin Elmer Company. All spectra were preprocessed using S-G smoothing and S-G smoothing + orthogonal signal correction（OSC）methods, respectively. On this basis, the mathematical models for qualitative and quantitative analysis of carbaryl pesticide residues on spinach leaf surface were established based on the partial least squares（PLS）method. Comparing the results of different models, it was found that the partial least squares discriminant（PLS-DA）model and the PLS quantitative model could provide the better results using S-G smoothing+OSC preprocessed spectra. For PLS-DA model, the discriminant accuracies were 100% for calibration and prediction sets. For PLS quantitative model, the correlation coefficients R2 were 0.98 for calibration and prediction sets, and the root-mean-square errors of calibration and prediction were 5.2×10-3 g/L and 6.1×10-3 g/L, respectively.

2024 Vol.31(6): 85–89    [Abstract] ( 17 )    [PDF 1865 KB ] ( 9 )

High quality fuel requires deep desulfurization in exquisite processes, mainly to remove the sulfur of thiophene compounds contained in the fuel. In order to explore catalysts for deep desulfurization of fuel, a one-pot synthesis method was used to prepare AEO-7 substituted cobalt phthalocyanine, which is amphiphilic to water and oil, for catalytic removal of sulfur from sodium sulfide and thiophene. And its catalytic desulfurization performance was compared with three water-soluble sulfonic acid amino substituted cobalt phthalocyanine desulfurization catalysts, based on the oxygen consumption kinetics of the reaction system. It was found that in the catalytic removal of sulfur from sodium sulfide solution, after 1 minute, the oxygen consumption of the AEO-7 substituted cobalt phthalocyanine catalytic reaction system was only 1/12 of the optimal water-soluble desulfurization catalyst. However, after 30 minutes of desulfurization of thiophene in isooctane, the oxygen consumption of AEO-7 substituted cobalt phthalocyanine catalytic system was about 10 times as high as that of water-soluble phthalocyanine catalytic systems. It can be seen that AEO-7 cobalt phthalocyanine has the potential to be applied in the deep desulfurization process of fuel.

2024 Vol.31(6): 90–93    [Abstract] ( 13 )    [PDF 1012 KB ] ( 8 )

The purpose of this study is to evaluate the methane production potential of campus cafeteria catering waste through anaerobic digestion by using the theoretical and experimental methods. Based on the principle of conservation of chemical oxygen demand, the theoretical methane production rate of campus catering waste was estimated to be 446.7 mL/gVS（Volatile solid）, with dissolved carbohydrates and proteins contributing 33.8% of methane production. Using the experimental method, anaerobic batch fermentation experiments with campus catering waste as substrate obtained the cumulative methane yield of 363.5 mL/gVS, which was lower than the theoretical estimation value. According to the estimation results with the experimental method, it was calculated that the methane production of campus catering waste in Tianjin city could reach 2 264.2 m3/d, indicating that the potential for methane production through anaerobic digestion of campus catering waste is enormous and has practical value.

2024 Vol.31(6): 94–98    [Abstract] ( 19 )    [PDF 1960 KB ] ( 11 )

In order to cultivate the innovation ability of college students, an innovation experiment was designed based on an innovation training program of college students, namely, analysis of small and medium molecule metabolites in the process of maize seed germination. Gas chromatography mass spectrometry technology was used, combined with partial least squares discriminant analysis, to determine the medium and small molecule metabolites of corn seed germination and differential metabolites. The results showed that in the process of maize seed germination, there were different metabolites including 15 species, among which were 6 kinds of organic acid, 4 kinds of amino acids, 1 carbohydrate and its derivatives and 4 other compounds. By the practice, the students mastered the frontier field of differential metabolite analysis in the process of maize seed germination, stimulated their innovative thinking and expanded their scientific horizon. In addition, the innovative experiment integrated instrumental analysis, plant physiology, and biostatistics and improved students’ experimental skills and deepened their understanding of theoretical knowledge.

2024 Vol.31(6): 99–102    [Abstract] ( 19 )    [PDF 828 KB ] ( 16 )

Through the work of Tianjin teachers to Huangnan Vocational and Technical School to support the construction of major in ecological environmental protection, research was carried out from talent training, reform of curriculum system, personnel training, in-depth connection with industrial development, in order to improve the level of school-enterprise collaboration, to continuously improve the quality of local education, to consolidate the foundation of vocational education development. The work could better serve the local economic and social development, improve the level of vocational education in Qinghai province, and provide skilled talents to support the high-quality development.