In order to clarify the alleviating effect of heterologous double-root on coffee continuous cropping obstacle, the soil of the continuous cropping obstacle garden of coffee was used to cultivate Caffea liberica, No. 1 and C. canephora, Reyan No. 1 heterologous double-root grafting coffee seedling. The mechanism of heterologous double-root alleviating continuous cropping obstacle was clarified through different root separation ways, and the differences and synergies of heterologous double-root in alleviating continuous cropping obstacle were discussed. Compared with non-rhizosphere soil, the seedling quality index and plant biomass of heterologous double-root coffee or homologous double-root coffee decreased significantly after culturing in rhizosphere soil. After non-rhizosphere soil culture, there were no significant differences in the seedling quality index or plant biomass between heterologous double-root coffee and homologous double-root coffee. The seedling quality index, root biomass of C. liberica and C. canephora, and total plant biomass of heterologous double-root coffee were significantly higher than those of homogenous double-root coffee after rhizosphere soil culture. Continuous cropping obstacle inhibited the growth of coffee, but had more effect on homologous double-root coffee. Heterogenous double-root coffee alleviated the growth obstacle of continuous-cropping coffee by C. liberica roots. The seedlings quality of the heterologous double-root coffee separated root by nylon net was better than that of root undivided or separated root by double pot under continuous cropping, and the root growth of C. canephora was the best in nylon net separation. Root allelochemicals of C. liberica promoted the root growth of C. canephora. There was no significant difference in the seedlings quality of heterologous double-root coffee between root undivided and separated root by double pot, and the C. liberica root growth of root undivided was worse than that of double pot separation. The root growth of C. canephora inhibited the root growth of C. liberica when the heterologous double-root were in contact with each other, but this inhibition was not related to the allelopathic substances in the C. canephora rhizosphere. The root growth of C. liberica had no significant difference in nylon net separation and double pot separation. There was no effect on the root growth of C. liberica with or without the allelopathic substances. of C. canephora. The root system of C. liberica alleviated the continuous cropping obstacle by reducing the inhibition of allelopathic environment and promoting the root growth of C. canephora by its allelopathic substances. The results would provide a theoretical basis for the application of heterologous double-root grafting in the field.

To clarify the effects of short-term high temperature stress on the developmental, reproductive characteristics and offspring fitness of Eotetranychus sexmaculatus females, the females were exposed to 33 ℃, 36 ℃, 39 ℃, 42 ℃, 45 ℃ for 1 h, 2 h, 4 h, respectively. The longevity, fecundity, offspring developmental period and sex ratio of E. sexmaculatus females were observed. The results showed that the oviposition period of E. sexmaculatus was prolonged and the fecundity was increased exposed to from 33 ℃ to 42 ℃ for 1 h, 2 h, 4 h and 45 ℃ for 2 h and 4 h. The population growth of E. sexmaculatus was the most favorable exposed to 39 ℃, the oviposition period was the longest exposed to 39 ℃ for 1 h, which was 12.67 d, and the fecundity of single female was the highest, which was 32.65. The intrinsic rate of increase (r_m) of E. sexmaculatus was the highest exposed to 39 ℃ for 1 and 4 h, which was 0.29, and the population doubling time was shorter, which was 2.42 d and 2.38 d, respectively. Exposed to short-term high temperature stress, there was no significant effect on the offspring sex ratio of E. sexmaculatus. The survival rate of E. sexmaculatus was decreased, the fecundity was decreased, the longevity was prolonged, and the r_m value was decreased exposed to 45 ℃ for 1 h. Therefore, the population development of E. sexmaculatus was inhibited at 45 ℃ high temperature stress for 1 h.

The study was aimed to cope with the rapid increase in demand for patchouli [Pogostemon cablin (Blanco) Benth.] and to solve the problems of lack of patchouli medicinal materials, germplasm degradation, confusion of germplasm sources, and vulnerability to diseases and pests. Callus, cluster buds and rooting seedling of patchouli were irradiated with a gradient dose of ⁶⁰Co-γ rays. The appearance and morphology of regenerated plants were observed, the mutated plants were screened, the agronomic traits and physiological and biochemical indicators were measured, and the content of pogostone and patchouli alcohol, the main volatile components, were determined by gas chromatography-mass spectrometry (GC-MS). The results showed that calluses and cluster buds were more sensitive to ⁶⁰Co-γ rays and had higher mortality rate, while rooting seedlings were more tolerant to ⁶⁰Co-γ rays and had lower mortality. The best way to breed mutagenesis is ⁶⁰Co-γ treated rooting seedlings with irradiation doses of 100 Gy with a mutagenesis rate of up to 10%. In this experiment, 29 patchouli variant plants were obtained, which were divided into seven morphological types, namely three-leaf whorls, heteromorphic leaves, deep-split leaves, narrow leaves, coiled leaves, undercoiled leaves and purple leaves. The contents of osmotic conditioning substances [soluble sugar, soluble protein and free proline (Pro)], antioxidant substances [malondialdehyde (MDA), peroxidase (POD), catalase (CAT)], pogostone and patchouli alcohol were compared and analyzed. According to the analysis results of the above determination indicators, 15 potential plants were finally screened, namely: stress-resistant plants with high effective components SY7 and ZY1; environmentally sensitive plants with high effective components SY15, SY18 and XY1; stress-resistant plants SY2, SY6, SY19, YY2, YY9 and XJY1; high active ingredient plants SY10 and SY17; “pogostone-type” patchouli plants SY3 and JY1. Among them, SY7 and ZY1 are new germplasms with double excellent characteristics, and the two “pogostone-type” patchouli plants have application value for solving the problems of the lack of authentic medicinal materials and the degradation of germplasm. In this study, patchouli variant plants bred by the ⁶⁰Co-γ ray irradiation mutagenesis method have the advantages of strong stress resistance and high active ingredients, which would provide mature methods and potential germplasm for patchouli mutagenesis breeding and new variety breeding.

In order to explore a method to protect Orah from frost damage, Orah harvested early from 2021—2022 were used as the materials, and prochloraz+ambient temperature storage and CK + ambient temperature storage were used to determine the sugar, acid, vitamin C and other quality indicators, as well as the weight loss, decay, electrical conductivity and other storage resistance indicators during the storage period. SPSS analysis software was used to cluster seven indicators in two years. The results showed that prochloraz could effectively inhibit the growth of the rot pathogen of citrus during storage, and prolong the occurrence time of fruit rot; At the same time, it could maintain the content of soluble solids in fruits to the level before harvest. During the 150 d storage period, the titratable acid content of the two treatments decreased gradually with the extension of storage time. The titratable acid content in prochloraz treatment group decreased faster than that in CK. Therefore, the solid acid ratio of prochloraz treatment group was higher than that of CK. As the solid acid ratio increased with the increase of storage time, the flavor quality of the two treatments also gradually improved. During the storage period, there was no significant difference in vitamin C content between the two; At 150 days of storage, it could still be maintained at about 20.90 mg/100 g (2021) and 14.50 mg/100 g (2022). In terms of fruit storage resistance, the weight loss rate of prochloraz treatment group was slightly lower than that of the CK in 2022 (prochloraz was significantly lower than that of the CK in 2021); On the contrary, the peel conductivity of prochloraz treatment group was higher than that of the CK in 2022 (in 2021, prochloraz treatment was significantly higher than that of the CK). The seven indexes of the two treatments in two years were clustered into two categories by the cluster analysis. The first category were CK of 0, 15, 30, 45, 60, 90 d and prochloraz treatments of 0, 15, 30, 45, 60 d; The second category were CK of 120, 150 d and prochloraz treatments of 90, 120, 150 d. To sum up, prochloraz can effectively reduce the occurrence of rot rate of Orah, improve the fruit flavor of early fruit picking, and maintain good total soluble solids and vitamin C content of fruits. According to the comprehensive indicators and cluster analysis results, the orah can be harvested early, treated with prochloraz and other preservatives, and stored at ambient temperature for 60 days or 60 days before being refrigerated, or stored at ambient temperature for 90 days before being released from the market.

In this study, the rhizosphere soil of jasmine was used as the material under the condition of artificial greenhouse to analyze and compare the effects of two fungicides (fluazinam and tebuconazole) on soil physical and chemical properties, soil enzyme activities in addition to carbon source metabolic diversity of soil microbial community. The indexes of soil physical and chemical properties were different under the application of the two fungicides of different concentration. The pH value and organic matter content of soil decreased by 14.8% and 18.8%, respectively, after application of 50% fluazinam. The content of organic matter increased by 76.8% after treatment with 50% tebuconazole. 50% of tebuconazole had the most significant effect on total nitrogen, available phosphorus and available potassium, and the highest increase of total nitrogen was 77.8%. The maximum available phosphorus increased by 1.3 times while the content of available potassium increased by 2.1 times. The effects of fungicides on the activities of sucrase, urease and acid phosphatase in jasmine rhizosphere soil were significant. The sucrase activity was significantly decreased by 92.8% after treated with 50% fluazinam. The urease activity decreased significantly after spraying 50% tebuconazole, which was 41.9% lower than that before spraying. At the same time, the acid phosphatase activity showed increasing trends after treated with fungicides. To compare the carbon source metabolic diversity of soil microbial community after application of the fungicides found that the value of average well color development (AWCD) in CK was the lowest. After the treatment of the two fungicides, AWCD decreased compared with that before spraying, among which the inhibitory effect of tebuconazole on AWCD was the most significant. In general, the Shannon diversity index (H) and evenness index (U) of soil microorganisms showed a decreasing trend with fungicide treatment. However, there was no significant difference in the dominance index (D) among all treatments. Soil microbial community had a certain inhibitory effect on the metabolic diversity of six kinds of carbon sources after fungicides application. In addition, principal component analysis of soil microbial community carbon source metabolic diversity revealed that amino acids and carbohydrates had similar utilization rates. In addition, polymers and carboxylic acids were similar. This study analyzed and compared the effects of fluazinam and tebuconazole on the microbial characteristics and carbon source metabolic diversity in jasmine rhizosphere soil, and the results would provide a scientific basis for evaluating the ecological function in rhizosphere soil microorganisms of jasmines under the influence of two fungicides.

The effects of different fertilizer combinations on the growth and nutrition of Camellia oleifera were studied to select the fertilizer combination that is conducive to the growth of C. oleifera. Ten-year-old common C. oleifera Cenruan 3 was used as the material. Ten experimental treatments with different N∶P∶K ratio and dosage, and different dosage of organic fertilizer were set. The physiological indexes of fruit traits, leaf traits and nutrition of C. oleifera at different growth stages were measured, and the analysis of variance, multiple comparisons and correlation analysis were performed. The results show that 0.5 kg N∶P∶K (20∶8∶17) +5 kg organic fertilizer+0.25 kg medium elements water-soluble fertilizer (Ca+Mg≥10.0%) had the best growth effect on C. oleifera. This fertilizer combination could effectively increase the fruit size, leaf area, net photosynthetic rate, transpiration rate and contents of nitrogen, phosphorus, potassium, calcium and magnesium in trees, which is conducive to the storage and distribution of tree nutrition. In conclusion, 0.5 kg compound fertilizer N∶P∶K=2∶1∶2 and 5 kg organic fertilizer applied together twice one year in the Spring and Autumn had a better effect on the growth and nutrition of C. oleifera.

Bacillus subtilis Czk1 is a rhizosphere antagonist with a very broad-spectrum antagonistic, growth promotion and induction of plant resistance. In order to fully utilize organic nutrients in agricultural wastes and promote biological control of soil-borne plant diseases, Czk1 was used as the research object in this study, chicken manure as the base fertilizer, corn straw, mushroom bran and coconut bran compost were used as the raw materials, and the liquid-solid two-phase fermentation process was adopted. The total number of viable bacteria and the number of spores were determined by the dilution plate colony counting method. The formula, process parameters and culture conditions of Czk1 solid fermentation materials were determined by the single factor and orthogonal experiment method. The results showed that the optimal conditions for solid fermentation of Czk1 are raw material was mushroom bran and chicken manure compost with the inoculated weight of Czk1 at 10%, the added amount of soybean powder at 10%, the water content at 40%, the fermentation temperature at 37 ℃ and the turning once every 72 h. Under the conditions, the total number of viable bacteria in Czk1 strain could reach 8.63×10⁸CFU/g. The number of spores was 8.37×10⁸CFU/g. The best fermentation material was corn straw and chicken manure compost, Czk1 inoculation amount of 10%, adding 5% soybean powder, 40% water content, fermentation temperature of 37 ℃, turning once every 72 h, the total number of viable bacteria in Czk1 inoculation strain could reach 6.53×10⁸CFU/g. The number of spores was 5.97×10⁸CFU/g. The total number of viable bacteria and the number of spores of Czk1 strain could reach 8.70×10⁸CFU/g and 6.90×10⁸CFU/g, respectively, when 30% mushroom bran was added. The physical and chemical properties of four fermentation biological fertilizer raw materials were determined, and significant differences were observed in their organic matter content and carbon to nitrogen ratio. Among them, chicken manure had the highest pH, total phosphorus, and total potassium content, while the carbon to nitrogen ratio was the lowest. The total content of nitrogen, phosphorus, and potassium was higher than that of corn straw, coconut bran, and mushroom bran; Corn straw has the highest electrical conductivity and organic matter content as the raw material; Coconut bran has the highest total nitrogen content, while mushroom bran has the highest carbon to nitrogen ratio. The seed germination index of bio-organic fertilizer with different combinations of chicken manure, mushroom bran, corn straw, and coconut bran is greater than 80%. Therefore, high quality bioorganic fertilizer can be prepared from agricultural waste by selecting suitable fermentation production conditions. B. subtilis Czk1 has good development and utilization value.

Salt stress is the most prevalent abiotic stress globally, severely affecting crop growth. Rice is an important food crop, it is important to improve the salt tolerance of rice through chemical control technology. To further provide the theoretical basis for the application of hemin to rice cultivation under salt stress, it is important to study the adverse effects of NaCl on rice seedling growth and to understand how hemin regulating the physiological process to alleviate stress. A pot experiment was carried out with the rice varieties Huanghuazhan and Xiangliangyou 900 as the materials. During the three leaves and one heart period, after 48 hours of 5 μmol/L hemin treatment, 50 mmol/L NaCl was applied to the corresponding cultivated soil. Each variety had three treatments, (1) control group: distilled water, (2) S group: 50 mmol/L NaCl solution; and (3) SH group: 50 mmol/L NaCl +5 μmol/L hemin solution. Measurements of seedlings growth characteristics, gas exchange parameters, and physiological indicators were taken after the 3^rd, 6^th, 9^th and 12^nd days after NaCl treatment, respectively. NaCl stress inhibited the seedling growth of the two rice varieties, reduced the photosynthetic rate, and increased reactive oxygen species. Compared with CK, the antioxidant enzymes activities of S group increased significantly in the early stage, but decreased significantly as the extension of stress time. Among them, the inhibitory effect of NaCl stress on Huanghuazhan was stronger than that of Xiangliangyou 900. Compared with NaCl treatment, exogenous hemin increased plant height, stem base width, biomass, total root length, root surface area, root volume, and root tip number of the two rice varieties. Hemin inhibited reactive oxygen species (O₂·^- and H₂O₂) accumulation, decreased malondialdehyde (MDA) content, and electrolyte leakage (EL). The photosynthetic capacity and SPAD were enhanced. The activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) were increased. Meanwhile, the ascorbic acid (AsA) and soluble protein levels were up-regulated in leaves. The results of this experiment indicate that NaCl stress inhibit rice seedlings, and the application of hemin can mitigate the damage caused by NaCl stress on rice seedlings by enhancing the net photosynthetic rate, increasing antioxidant activity or content, and reducing membrane lipid peroxidation.

The study was aimed to explore the effects of applying different organic fertilizers on the yield, quality, soil fertility of sweet potato. Five different organic fertilizer treatments with no fertilization as the control were set up and sweet potato variety Qianshu 6 was used. The results showed that the application of organic fertilizer could effectively promote the growth of sweet potato vines and the expansion of root tubers. The yield of Shangcanli biological organic fertilizer (T₄) was the highest, which was 19.9% higher than that of the control. The effects of different organic fertilizers on the nutritional quality of sweet potato were different, but the accumulation of dry matter was not obvious. In addition, planting sweet potato significantly reduces the nutrient content of soil, while applying different organic fertilizers could supplement part of the nutrient requirements of sweet potato, but had no significant impact on soil pH value. Organic fertilization significantly increased the contents of soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN). Organic fertilization significantly increased the activities of urease (URE), acid phosphatase (ACP), N-acetylglucosidase (NAG) and cellobiase (CBH), but significantly decreased the activities of nitrate reductase (NR) and-Glucosidase (BG), while did not significantly affected the activityof other enzymes. Correlation analysis showed that the effects of different components of organic fertilizer on the yield and quality of sweet potato root tubers were quite different. The pH value of fertilizer and the amount of organic matter input mainly affected the quality of root tubers, while the amount of pure nitrogen input was closely related to the yield and quality of root tubers. The physical and chemical properties of soil were mainly affected by the pH value of organic fertilizer, the input amount of organic matter and pure nitrogen, but had little correlation with the input amount of pure phosphorus and pure potassium. The correlation between organic fertilizer and soil MBC, soil URE, ACP, NR, PPO and LAP was stronger than that of soil microbial biomass nitrogen (MBN), N-acetylglucosidase (NAG), cellobiase (CBH) and polyphenol oxidase (PPO). Different organic fertilizers promoted the growth of sweet potato, increased the yield of sweet potato, increased the nutrient content of soil, and changed the microbial environment of soil to a certain extent. Therefore, the correlation analysis results of indicators could provide references for sweet potato production.

In order to explore the effects of N, P and K fertilizers on the growth and nutrient uptake of areca nut seedlings and provide a scientific fertilizer application in field management, areca nut seedlings were used to conduct the “3414”fertilizer ratio in pots at the greenhouse. Fertilization significantly increased biomass and fertilizer utilization of areca nut seedlings. In balanced nitrogen, phosphorus and potassium fertilization, N and P fertilizers had the maximum utilization. Balanced nitrogen and potassium fertilization without phosphate fertilizer, K fertilizers had the maximum utilization. The N content was the main factor affecting the stem and leaf biomass, while the P content was the main factor affecting root biomass. Correlation and path analysis indicated that N and P could synergistically improve the growth of areca nut seedlings, but they were affected by the application of K fertilizer. However, N, P and K fertilizers could reach balance and synergy to improve the growth of seedlings. In conclusion, N, P and K fertilizers in a rational proportion was beneficial for the nutrient uptake and utilization of areca nut seedlings, and N∶P∶K=2∶2∶2 (T₆) was the most suitable fertilization ratio.