Phoebe bournei （Hemsl.） Yang is an important and precious tree species in China. This study aimed to establish a genetic transformation system for P. bournei， pCAMBIA1300-GFP plasmid was constructed and transformed into seedlings with Agrobacterium rhizogenes. To optimize the transformation process， injection and soaking in bacterial solution were compared. Subsequently， an orthogonal ［L9（3³）］ experiment was employed to determine the optimal combination A. rhizogenes strain type， bacterial solution concentration， and seedling age. In addition， the effects of light intensity on induction and transformational rate of P. bournei hairy roots were also examined. The results showed that hairy roots induction and transformation rate with injection method were 80.0% and 66.7% respectively， whereas only 41.2% and 35.3%with soaking method. The main factors affecting the hairy root induction rate and genetic transformation of P. bournei were strain species. Notably， strain type exhibited a substantial influence on both induction and transformation efficiency of hairy roots. The maximum induction and transformation rates were 87.5% and 70.6% respectively. The optimal strain was K599 with concentration of OD₆₀₀=1.2， and the seedlings at the three-leaf stage was the best The seedlings growth， hairy roots induction and transformation efficiency of P. bournei seedlings under lower light intensity （50 μmol·m^-2·s^-1） were more favorable for seedling growth and transformation than high light intensity （100 μmol·m^-2·s^-1）. This study established an efficient and steady transgenic system for P. bournei mediated by A. rhizogenes， thereby obtained transgenic hairy roots plants. That provided a useful platform for molecular genetic research of P. bournei and laying the foundation for important gene exploration， new germplasm development and genetic improvement of P. bournei.

Mulching technique is a widely used agricultural technology. The traditional plastic film currently in use brings huge economic benefits， but also induces serious ecological pollution problems and affects the sustainable development of agriculture， so the development of environmentally degradable mulching films is an inevitable trend. This study systematically describes the research progress and application status of the preparation materials， preparation technologies and products of photodegradable mulching film， biodegradable mulching film， photo/biodegradable mulching film， liquid mulching film and plant-fiber mulching film at home and abroad， as well as the advantages and shortcomings of the five types of degradable mulching films， and provides an outlook on the research direction and development prospects of plant-fiber mulching film. The results of this study provide a theoretical basis for further development of green， environmentally friendly and completely biodegradable agricultural mulching films to promote green and sustainable development of agriculture.

In order to alleviate the effects of insufficient chilling on abnormal flower bud differentiation in plum which was common in the main plum producing areas in southern China， breeding new varieties of plum with high quality was an urgent need. Sanyueli （Prunus salicina L.）， which had the characteristics of early-maturing and low-chilling-requirement， was selected as the material. The annual branches of Sanyueli were chosen for Cobalt 60-ray （⁶⁰Co-γ） irradiation （50 Gy）， and then single-bud was grafted on the branch of 3-year-old peach （Prunus persica L.）. Among the grafted seedlings， a mutant with obvious variation in color and maturity stage was obtained. It was finally named Fuhong. To evaluate the quality and advantages of Fuhong and breed new varieties， the differences between Fuhong and Sanyueli in morphological characteristics， biological characteristics， quality characteristics， disease resistance， and yield were compared through phenotypic observation， quality analysis and molecular identification. The results showed that Fuhong retained the characteristic of low-chilling-requirement of Sanyueli. Furthermore， its color of peel and flesh were mutated into purple red， and the maturity period was delayed about 40 d. The weight of single fruit of Fuhong increased by 2.67 times， which was significantly higher than that of Sanyueli （P < 0.01）； and the content of soluble solid， the ratio of sugar to acid were also significantly higher than those of Sanyueli （P < 0.01）. The regional test in three ecological areas of Fujian showed that Fuhong had excellent and stable yield performance， higher than that of Sanyueli. This new plum variety Fuhong had the advantages of low-chilling-requirement， red flesh， large fruit weight， high sweetness and better quality. It would be preferable in market promotion.

Irradiation mutagenesis tends to generate chromosome structural variations. So far few studies have been reported using the BSA-seq technique to map radiation-induced mutations. In order to explore the feasibility of using BSA-seq for mapping genes in radiation-induced mutants， this study isolated an Arabidopsis thaliana mutant using irradiation mutagenesis and crossed it with the wild type. Individual plants in the F₂ segregating population were screened based on phenotypes， and two pools of offspring with extreme phenotypes were collected. The two offspring pools and the wild type pool were sequenced using whole genome sequencing， and various strategies including MutMap， QTL-seq， and GPS methods were used to analyze the sequencing data of these three pools. It was found that three strategies generated similar results and the mutated gene was located to an interval of 7 Mb on chromosome 2. With visualizing the genomic region within this interval by IGV software， a 25 189 bp deletion was found in the mutant genome. The deletion region was annotated using the SnpEff annotation program， and 6 genes were found in this region， among which the AT2G28610 gene was identified to be the candidate gene and verified through genetic experiments. This study provided a reference for the application of BSA-seq based approaches to map radiation-induced mutations.

Phosphorus deficiency in the soil is a key factor limiting the growth and development of rice （Oryza sativa L.）. It is of great significance to elucidate the morph-physiological changes of rice in response to low phosphorus stress and further understand the mechanism underlying the phosphorus uptake and transport， which is also crucial to alleviate phosphorus stress on rice yield and quality. This paper mainly reviewed the changes in the morphology of roots and shoots as well as the physiological and molecular mechanisms of phosphorus uptake and utilization of rice under low phosphorus stress， and proposed crop management practices to enhance phosphorus uptake and utilization in rice. The key points for future researches were also discussed， that is， effect of interaction between rice roots and soil on the release of soil organic phosphorus， regulation and mechanism of plant hormones， especially new plant hormones， on phosphorus absorption， transport and distribution in rice plants， and development of rice varieties with high phosphorus utilization efficiency and exploring cultivation techniques to improve phosphorus use efficiency. This review is expected to provide theoretical guidance for screening and breeding rice varieties with tolerance to low phosphorus stress （phosphorus efficient varieties） and the cultivation regulation for improving phosphorus utilization efficiency.

To evaluate the effectiveness of soil restoration measures in erosion-degraded forestlands in red soil region of South China， a typical erosion-degraded Pinus massoniana forestland was selected， which located in Ningdu County， Jiangxi province. Seven treatments were set up in this trial： no restoration measures （CT）， fish scale pit + tree-grass （FG）， fish scale pit + tree-shrubs （FS）， fish scale pit + tree-shrubs-grass （FGS）， small horizontal ditch + tree-grass （FGP）， small horizontal ditch + tree-shrubs （FSP）， small horizontal ditch + tree-shrubs-grass （FGSP）. The response of soil erosion and nutrient loss to different restoration measures in the erosion-degraded forestlands was evaluated using the ⁷Be tracing technique. Results showed that the ⁷Be inventory residual percentage under different restoration measures was -6.84% to -33.13%. Soil erosion rate under different restoration measures ranged from 4.43 to 24.04 t·hm^-2·event^-1. The sediment reduction rate was 21.19%-85.49% compared with the CT， and the maximum were 85.49% and 83.81% under FGSP and FGS respectively. Compared with CT， the percentages of increment of soil organic carbon （SOC）， total nitrogen （TN）， available nitrogen （AN） in each restoration measures were 25.10%-65.71%， 9.79%-46.85%， -30.68%-1.29%， respectively. Under two engineering measures， integrated vegetation measures （i.e. FGSP and FGS） of tree-shrubs-grass significantly reduced soil carbon and nitrogen loss， but there was no significant difference between the two engineering measures. The Pearson correlation and stepwise regression analysis suggested that ⁷Be was significantly and positively correlated with SOC， TN and AN content （P<0.01）. R_Be and VC explained 94.7% of variation of SOC loss； R_Be， TN and VC explained 98.3% of variation of TN loss； and R_Be explained 85.6% of variation of AN loss， which indicated that that SOC， TN and AN were physically transported with ⁷Be during soil erosion process， and soil carbon and nitrogen nutrient loss was influenced by coupling interactions of vegetation-soil-soil and water processes. ⁷Be allowed effective evaluation of short-term soil erosion and nutrient loss by different restoration measures. After 4 years of implementing restoration measures， the effect of integrated vegetation measures with tree-shrubs-grass on reducing soil erosion， carbon and nitrogen loss was more significant than that of soil conservation engineering measures. The results of this study provided scientific basis for assessment of ecological benefits and restoration management of erosion-degraded forestlands.

Flavonol synthase （FLS） is a key enzyme in the flavonol biosynthesis pathway in plants. To investigate the mechanism of flower color formation in different species of Yulania， the flavonol contents of Y. denudata and Y. liliiflora were measured by the ultra-performance liquid chromatography （UPLC） at five key stages of flowering. The FLSs genes were cloned by RNA-seq in Y. denudata and Y. liliiflora. The expression patterns of FLSs genes in different tissues and tepals at five flowering stages were detected using quantitative real-time PCR （qRT-PCR）. Subcellular localization of FLSs proteins were performed by transient transformation technique in onion epidermis. The functions of FLSs genes were verified by heterologous transformed in tobacco， and the difference in flavonol contents in the transgenic tobacco corolla was analyzed by UPLC. The results showed the flavonol content of Y. denudata tepals was first increased and then decreased during flowering， while the flavonol content of Y. liliiflora tepals gradually decreased. YdFLS and YlFLS were conserved in sequence. The highest expression level of the YdFLS gene was found in flowers， and YlFLS had the highest expression level in young leaves. The expression of YdFLS was gradually increased and peaked at the bloom stage， while YlFLS showed a declining expression pattern. Both YdFLS and YlFLS were located in the cytoplasm. Overexpression of YdFLS and YlFLS genes in tobacco caused a light corolla phenotype and flavonol accumulation. In conclusion， this study verified that FLSs genes conservatively functioned on promoting flavonol synthesis in Yulania species. This study revealed the important function of FLS gene in flower color formation of Magnolia.

With the requirement of reducing costs and improving efficiency during industrialization of the Business-end kitchen， and the changes of Custom-end lifestyle， the prefabricated food markets have been growing rapidly. The prefabricated food meets the customer needs for fresh food， healthy eating habits and new retail models. The ready-to-eat foods， one of the prefabricated food which already have sterilization procedure during preparation， occasionally detected the excessive level results of microorganisms and foodborne pathogenic bacteria in market spot check， which has great safety risks for consumers. Food irradiation technology is a non-thermal sterilization new methods， gradually accepted by the Chinese food market. Combined with the HACCP food management system and fence factors， irradiation can be the last and most effective barrier in controlling the spread of pathogenic microorganisms. In the current review， the integration of irradiation technology on prefabricated food processing technology was studied， and the functional relationship between irradiation sterilization and other food preservation methods was explored. The review could provide references for irradiation enterprises and prefabricated food production enterprises in terms of economic benefits and food safety.

In order to improve the functional properties of porcine hemoglobin （Hb） and enhance product value， this study employed an enzymatic-phosphorylation （HP） method for the modification of porcine hemoglobin. To investigate the effects of the synergistic modification on porcine hemoglobin， porcine hemoglobin and enzyme-digested porcine hemoglobin peptides （H-Hb） were used as control groups， and the functional properties and structure of the enzymatic-phosphorylated porcine hemoglobin （HP-Hb） were studied. The analysis of functional properties showed that compared to the control groups， the solubility of HP-Hb was significantly improved with an increased emulsion activity index of 12.42 and 6.30 m²·g^-1 （P<0.05）， as well as increased emulsion stability of 6.37% and 3.04% （P<0.05）. The foamability of HP-Hb increased by 7.59% and 4.42% compared to the control groups （P<0.05）， and the foam stability increased by 3.93% and 4.42% （P<0.05）. Structural analysis showed that enzymatic digestion caused peptide chain breakage in HP-Hb， exposing more amino acid groups. Most of the phosphate groups were linked to the N atoms， and the increased presence of P-N and PO₄^3- resulted in stronger infrared absorption peaks. Furthermore， the thermal stability of HP-Hb was significantly improved by 14.00 and 20.67 ℃ compared to H-Hb and Hb， respectively. Microstructural analysis revealed that dual modification caused a change in protein structure， transforming the molecular structure from compact block-like structure to loosely arranged blocks with smaller particle dispersion. Overall， the results indicated that HP dual modification was a feasible modification method to enhance the functional properties and stability of porcine hemoglobin. This study provides new insights for the modification of porcine hemoglobin and serves as a theoretical basis and reference for further research on the application of porcine hemoglobin in food processing.

To investigate the expression of Collagen1 and Collagen3 in pulmonary fibrosis tissue of yak and clarify the roles of Collagen1 and Collagen3 in pulmonary fibrosis process of yak. The normal and fibrosis lung tissue of yak were collected and divided into control group and experimental group. HE staining， Masson staining and transmission electron microscope were used to observe the pathological changes of lung ultrastructure and fibrosis state； qRT-PCR， Western-blot， immunohistochemistry and immunofluorescence staining were used to detect the expression of Collagen1 and Collagen3 genes and proteins in groups. The results showed that the yak lung tissue structure of the control group was intact， the alveolar septum was normal and there was no inflammatory exudate in bronchial lumen and alveolar cavity. while in experimental group， lung tissue showed necrosis， nuclear fragmentation and dissolution， severe hemorrhage and extensive pulmonary edema. The expression of Collagen1 in experimental group is higher， while the expression of Collagen3 is lower than that in control group. In experimental group， Collagen1 and Collagen3 proteins were proliferated massively and distributed in alveolar septum extensively. The other distributions were basically the same as control group but stronger than in control group. In conclusion， Collagen1 and Collagen3 play important roles in yak pulmonary fibrosis.

In order to investigate the genetical variations in early coloring trait of irradiation-induced mutant Bingtang sweet orange， the early coloring of the fruits and the changes in the intrinsic quality of sugar and acid， and validate whether it was an early-maturing mutant. The mutant and the control Bingtang sweet orange were used as materials， the changes in traits and characteristics such as spring tip length， spring tip leaves， floral organs， fruit size， peel color change， and the main seasonal period were analyzed. Molecular markers were applied to identify the genetic variations， and the changes in the soluble solids， titratable acid， and solid-acid ratio， as well as the expression of the genes related to sucrose and citric acid metabolism in the fruits of the mutant and control Bingtang sweet orange were investigated. The results showed that the mutant had significantly shorter spring tips， larger fruits at maturity， peel and flesh coloring orange-yellow and orange 15 d earlier， and the main seasonal period was 2-5 d earlier than that of the control Bingtang sweet orange. Differential bands were found in the amplification in mutant with both insertion and deletion （InDel） markers and simple sequence repeats （SSR） markers， showing genetically alteration. The external color and internal quality of the early maturing mutant fruit reached normal ripeness at 190 d after flowering， with soluble solids， titratable acidity， and sugar-to-acid ratio of 14.53° Brix， 0.46% and 31.59， respectively. The mutant exhibited low acidity， early acid reduction， high sugar-to-acid ratio， and matured 15 days earlier than the control. Expression analysis of genes related to sucrose and citric acid synthesis， degradation， and transport revealed that the synthesis of sucrose in the early maturing mutant was higher and the transport was early， while the synthesis of citric acid was lower， and the degradation was faster and storage was less. These characteristics were aligned with the fruit quality. In conclusion， the irradiation-induced mutant underwent changes in plant traits， biological characteristics， and DNA. The mutant exhibited early acid reduction， low acidity， high sugar-to-acid ratio， and reached color maturity in early November. This study laid the foundation for further selection and registration of this mutant as new early maturing Bingtang sweet variety.

Abnormal metabolism and inflammation of ruminants such as sheep can cause the risk of ectopic lipopolysaccharides （LPS） which then induce inflammation in other parts of the collective， but the effect of LPS on claudin-1 and occludin， the key proteins of the oviduct epithelial barrier in sheep， is unclear. In this study， adult sheep fallopian tubes were collected and the primary oviduct epithelial cells were cultured in vitro， Hematoxylin-Eosin staining， Immunofluorescence， and Western blotting， and real-time PCR were used to elucidate the effect of LPS on the oviduct epithelium Claudin-1 and Occludin in sheep. The results showed that Claudin-1 and Occludin were expressed in the umbrella， ampulla and isthmus epithelium of the fallopian tubes of sheep， the Claudin-1 and Occludin protein in the umbrella is significantly higher than that in the ampulla and isthmus. With induction of primary ampulla epithelial cells by LPS at concentrations of 0 ng·mL^-1， 10 ng·mL^-1， 50 ng·mL^-1， and 100 ng·mL^-1， LPS was found to promote mRNA expression of TLR4， NFκB， and TNFα， and affect the protein levels of Claudin-1 and Occludin. It was shown that low concentrations of LPS could induce oviduct inflammatory response in a short time and lead to disordered expression of Claudin-1 and Occludin in epithelial cells. It was suggested that LPS translocation caused by abnormal rumen metabolism and inflammation in ruminants may induce oviduct inflammatory response， result in oviduct epithelial barrier damage and physiological dysfunction， which seriously affected sheep economy value. It provides a theoretical basis for the study of systemic inflammation caused by LPS translocation during abnormal rumen metabolism and inflammatory diseases in ruminants.

To investigate the effects of space mutation on the growth and physiological characteristics of four woody flowers， a new generation of manned experimental spacecraft was used to carry the seeds of Delonix regia， Jacaranda mimosifolia， Callistemon speciosus， and Cassia fistula. After returning to the ground， the growth characteristics， leaf morphology， pigment content， and physiological activities of the container seedlings were determined. The results showed that after space mutation the survival rate of D. regia increased by 6.92 percentage points， whereas that of J. mimosifolia and C. speciosus decreased by 8.12 and 10.66 percentage points， respectively， and the survival rate of C. fistula had no significant change. The growth characteristics of D. regia and C. fistula seedlings， such as plant height， ground diameter， leaf number， and leaf （axis） area were decreased by 25.74% and 45.15%， 11.14% and 19.51%， 9.13% and 31.60%， 33.62% and 32.26%， respectively. The plant height， ground diameter， leaf number， and leaf length of C. speciosus seedlings andtheaxis length and axis area of J. mimosifolia seedlings were increased by 64.93%， 37.09%， 118.25%， 18.78%， 26.49%， and 37.29%， respectively. The soluble sugar content of D. regia， J. mimosifolia， and C. speciosus seedlings leaves increased by 36.46%， 16.77%， and 7.23%， respectively. The soluble sugar content and PDHA activity of C. fistula seedling leaves were decreased by 8.59% and 39.83%， respectively. Combined the results of correlation analysis， it was deduced that space mutation inhibited the growth and leaf morphological characteristics of D. regia and C. fistula seedlings， causing negative variation. While space mutation caused positive variations in the growth and leaf shape characteristics of C. speciosus seedlings and the leaf shape characteristics of J. mimosifolia seedlings. It had no significant effect on the pigment content of the four woody flower seedlings. The impacts of space mutation on the physiologically active substances in the leaves of D. regia，J. mimosifolia， and C. speciosus seedlings were more significant than that on C. fistula. These results indicate that space mutation had an vital effect on the growth and development of four woody flower seedlings. The impacts of space mutation varied with the different characteristics of the tree species. It is an effective way to improve the germplasm of woody flowers.

To establish an appropriate method for screening free-living conchocelis mutants of Neoporphyra haitanensis， the conchocelis were exposed to ⁶⁰Co-γ-ray irradiation. Subsequently， the irradiated conchocelis were separately cultured in seawater and on scallop shells to observe the mutation rate of the conchocelis. The results indicated that， after exposure to γ-ray irradiation， conchocelis retained the ability to penetrate scallop shells， and showed rich color mutations. The highest mutation rate was observed at a radiation dose of 1 000 Gy， with the mutation rates of free-living conchocelis being consistently lower than those of shell-borne conchocelis under different radiation intensities. Furthermore， to investigate the optimal growth temperature and culture medium for mutants， pink and green mutants induced by ⁶⁰Co-γ-ray radiation were cultured on scallop shells， agar medium， and in seawater. Four temperature gradients （14， 17， 20， 23 ℃） were set， and the changes in the length， width， and branching of mutant conchocelis cells were observed. The results revealed that the pink and green mutants exhibited relatively stable mutation and the growths were optimum when grown at a temperature of 23 ℃ on scallop shell substrates. In the case of the pink mutant， the conchoceli had a length of 190.35 μm， a width of 12.23 μm， and branches numbers of 10.00. The growth rates for width and branching numbers were approximately 19.43% and 28.21%， respectively. For the green mutant， the conchoceli’s length， width， and branching numbers were 115.89 μm， 11.26 μm， and 3.80， respectively， with a width growth rate of approximately 9.96%. Hence， the results provided a new method for screening free-living conchocelis mutants of N. haitanensis， and could be beneficial for exploring the optimal cultivation temperature and substrates for the growth and development of mutants.

Benefit of strong-gluten variety wheat and non-strong-gluten variety wheat in Yanjin County of Henan province is compared and analyzed with their quality in quantitative terms， so as to provide reference for setting policies to enhance farmers' planting initiative and the yield of strong-gluten variety wheat. 257 copies of production cost of strong-gluten variety wheat and non-strong-gluten variety wheat in Yanjin County were collected， which were processed through distribution and pair analysis. Besides， the wheat samples of Yanjin County harvested in summer of 2019—2021 were collected， whose quality was measured and evaluated， so as to run a comprehensive analysis on the benefit of strong-gluten variety wheat and non-strong-gluten variety wheat in Yanjin County. During 2019—2021， the protein content and stability time of strong-gluten variety wheat were remarkably higher than those of non-strong-gluten variety wheat by 0.8 percentage point and 11.7 min， respectively （P<0.01）. The standard-reaching percent of high-quality strong-gluten wheat were 30.77% and 4.30%， respectively. The seed cost per mu of strong-gluten variety wheat in Yanjin County is significantly higher than that of non-strong-gluten variety wheat by 14 RMB yuan， and there is no significant difference between the two total costs. The yield per mu of strong-gluten variety wheat was significantly lower than that of non-strong-gluten variety by 25 kg， but the price per kg was significantly higher than that of non-strong-gluten variety wheat by 0.28 yuan， and the sales revenue per mu was significantly higher than that of non-strong-gluten variety wheat by 94 yuan. It is concluded that there is no significant difference between the total production cost of strong-gluten variety wheat and non-strong-gluten variety wheat in Yanjin County， while the protein content， dough stability time and sales revenue per mu of strong-gluten variety wheat are much higher than those of non-strong-gluten variety wheat according to the collected data. The price per kg of strong-gluten variety wheat would increase 0.011 yuan if the standard-reaching percent of high-quality wheat of strong-gluten variety wheat increased 1 percentage point. Besides， the hectares of strong-gluten variety wheat would go 1 percentage point higher if the sales revenue per mu of strong-gluten variety wheat went 3 yuan higher than that of non-strong-gluten variety wheat. The results are contribute to formulating policy measures to improve the yield of strong gluten wheat varieties and farmers planting initiative.

To investigate the pattern of chloroplast codon usage in cowpea （Vigna unguiculata）， the complete cowpea genome sequence was downloaded from NCBI and structurally analysed in this study. The sequences were screened to obtain 50 protein-coding sequences （CDS）， which were analysed by CodonW and CUSP to obtain important parameters such as GC1， GC2， GC3， RSCU， CAI， CBI， Fop， ENc， RFSC， and further analysed by neutral plot analysis， PR2-plot analysis， ENc-plot analysis， correspondence analysis， optimal codon analysis and comparative analysis of other species. The results showed that cowpea chloroplast gene codons preferred to end at A or U（T）， and G and C were lower in all positions of codons， with a mean value of 36.31%. The mean value of the effective codon number ENc was 44.903， with weak codon preference； there was correlation between GC1 and GC2 and GC3， indicating that base mutations also had an effect on codon selection. From the neutral plot， PR2-plot and ENc-plot， it is clear that cowpea chloroplast codon usage bias is influenced by both base mutations and natural selection. In this study， totally 20 optimal codons were successfully screened. Compared with other species， cowpea and tomato have high similarity in codon usage frequency. This study provides a reference for improving the efficiency of cowpea chloroplasts genes as an exogenous gene expression.

In order to establish an analytical method for simultaneous detection of multiple pesticide residues in tea samples， the hydrophilic deep eutectic solvent （HP-DES） was used as the extractant of the dispersive liquid-liquid microextraction （DLLME） to extract and enrich pesticides in tea samples， and pesticide residues were analyzed by high-performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS）. The results showed that impurities in the tea samples could be effectively removed and the target substances were enriched after HP-DES extraction， vortex and centrifugation. The calibration curves of 65 pesticide residues had good linearity in the range of 1~500 ng·mL^-1， the correlation coefficient （r²） was larger than 0.996， and the limits of quantification （LOQ） ranged from 0.12 to 9.76 μg·kg^-1. In addition， the average recoveries were in the range of 64.44% to 110.15% at three spiked levels （10 μg·kg^-1， 50 μg·kg^-1 and 100 μg·kg^-1） and the relative standard deviation （RSD） was lower than 15%. It is a fast， simple， green， low cost method with good performance， which provides technical support for the detection of pesticide residues in tea matrix.

We studied the nifH-gene communities and physico-chemical properties of rhizosphere soils from flue-cured tobacco amended with plant growth promoting Lysinibacillus sp.， Streptomyces phaeochromogenes and Aspergillus niger in Huili， Liangshan， China， strains to assess the connections between nitrogen cycling， fertilizer regimes and soil quality. In conventional fertilization， the application of plant growth promoting strains resulted in lower pH higher available phosphorus content and nitrogenase activity （P<0.05）. Generally， the application of plant growth promoting strains increased the diversity of nifH-gene community. Proteobacteria， Firmicutes and Cyanobacteria were the dominant phyla， and Bradyrhizobium， Geobacter and Azospirillum were the dominant genera. In the redundancy analysis （RDA）， soil pH and the contents of soil available potassium and available nitrogen were correlated with the nifH-gene containing bacterial community. In conclusion， the results suggested that a plant growth promoting strain inoculum could affect the nutritional status of flue-cured tobacco cultivation soil， increase the nitrogenase activity and modify the nifH-gene community composition and diversity.

To investigate the impact of exogenous selenium fertilizer on selenium accumulation and nutritional quality of ginger （Zingiber Officinale Roscoe）， a field experiment was conducted to determine the effects of two types of selenium-containing conditioners （potassium silicate and maifanstone） and their application rates on the selenium content， growth and development indicators， antioxidant enzyme parameters， nutritional quality， yield of ginger， soil pH， and selenium form changes. The results indicate that both selenium-containing conditioners significantly increased the selenium content of ginger. As the application rate of the conditioners increased， so did the effect of selenium enrichment. The potassium silicate type outperformed the maifanstone type， with T3 （potassium silicate type of 3.6 kg·hm^-2） producing the most substantial effects. Compared with the control group， T3 increased the selenium content of ginger shoots and ginger blocks by 254.87% and 366.03%， respectively. Both selenium-containing conditioners boosted ginger yield and the contents of N， P and K from 22.25% to 66.59%， 7.71% to 29.08%， 15.83% to 43.32% and 18.29% to 41.92%， respectively. The study showed that the utilization of selenium-containing conditioners resulted in an increase of 0.33-1.86 percentage points in the soluble sugar content of ginger， while the soluble protein and curcumin content increased from 56.56% to 115.47% and 15.86% to 68.07%， respectively. The activities of superoxide dismutase（SOD）and peroxidase（POD）in ginger leaves augmented from 38.07% to 78.82% and 26.80% to 40.38%， respectively. Additionally， the application of selenium-containing conditioners lowered the content of malondialdehyde（MDA） from 10.76% to 50.51%. The conditioners also led to an observable increase of 0.35-0.67 in soil pH compared with control. Soluble selenium（SOL-Se）， exchangeable selenium and carbonate bound selenium（EXC-Se）content in soil also increased by 1.58-4.57 and 4.09-8.23 percentage points， respectively， while residual selenium（RES-Se）was reduced by 1.22-2.84 percentage points. The T3 treatment， with a potassium silicate type of 3.6 kg·hm^-2， produced the best effect on soil active selenium. Consequently， the application of selenium-containing conditioners significantly improved the nutritional quality of ginger， promoting its growth， quality and yield， while enriching the selenium accumulation. These findings provide theoretical support and technical insights for the high-quality production of selenium-enriched ginger.

To determine influence of nitrogen， phosphorus and potassium fertilizers and fertilization indexes in the main potato producing areas under dry weather， 3-year fertilizer experiment was conducted to clarify soil basic nutrient status， correction coefficient， nutrient utilization rate and other parameters， and to explore the abundance and deficiency indexes of soil nitrogen （N）， phosphorus （P） and potassium （K） nutrients， relative yield and recommended fertilizer application amount. The correction coefficient of soil alkali-hydrolyzed nitrogen， available phosphorus， available potassium and soil available nutrient， the function equation of recommended fertilizer amount and the effect model of N， P and K fertilizer were established to study the effect of fertilizer combined application on potato yield. Results showed that the soil nutrients were low nitrogen， medium phosphorus， high potassium， low organic matter and slightly alkaline. There was a significant power exponential negative correlation between the correction coefficient of soil available nutrient and the contents of alkali-hydrolyzed nitrogen， available phosphorus and available potassium. The average contribution rate of soil fertility in the experimental area was 54.39%； the relative yields by N， P and K were 77.64%， 87.57% and 84.22%， and the yield increased by N， P and K were 30.74%， 16.68% and 23.08%， respectively. The nutrient absorption and utilization rates of nitrogen， phosphorus and potassium were 32.58%， 16.32% and 45.40%， respectively. The correction coefficients of available nutrients in soil were nitrogen 0.56， phosphorus 0.48 and potassium 0.35. The amount of nutrients absorbed by100 kg tuber was N 0.4 kg， P₂O 0.15 kg and K₂O 0.9 kg， respectively. Under the experimental conditions， the single factor and interaction effect of increased application of N， P and K on potato yield were firstly increased and then decreased. The highest yield combination of combined application of N， P and K was N₂P₂K_2。The maximum yield was 24 860.32 kg·hm^-2， the fertilizer amount N∶P₂O₅∶K₂O=1∶0.97∶0.92 （N： 165 kg·hm^-2）， and fertilization profit of 34 472 yuan·hm^-2； The optimal economic yield was 24 774 kg·hm^-2， the fertilizer amount N∶P₂O₅∶K₂O=1∶1.04∶0.79 （N： 154 kg·hm^-2）， and the fertilizer profit was 34 603 yuan·hm^-2. The findings provided scientific basis and technical reference for balanced fertilization in potato production in the dry area.