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.

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.

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.

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.

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.

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.

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.

Light is an important factor affecting the physiological metabolism of fruits. In order to study the effects of light-emitting diode （LED） treatment on carotenoids and soluble sugar metabolism in postharvest nectarines， ‘Zijinhong 3’ nectarine was used as the material in the experiment and treated with blue， red and white LED lights for 8 days taking the darkness storage as the control. The correlations of carotenoids with the pulp color and soluble sugars in nectarine fruits were analyzed. The results showed that all LED treatments promoted the accumulation of carotenoids in nectarine fruits， among which the effects of white light and blue light were significant. A total of 9 kinds of carotenoids were detected， in which β?-carotene and violaxanthin were the main. Different carotenoids had different responses to different LED lights. The accumulation of violaxanthin， luteoxanthin， zeaxanthin， β?-cryptoxanthin， β?-carotene and cis-?β?-carotene were significantly promoted by the blue light at the end of storage， while 9-cis-violaxanthin， antheraxanthin and lutein content were higher under white light. The color of the flesh showed different correlation coefficients with different kinds of carotenoids. L^* value showed an extremely significant negative correlation with total carotenoids， while a^* and CIRG value showed extremely significant positive correlation with the total carotenoids. 3 kinds of soluble sugars （fructose， glucose and sucrose） were detected. Blue light promoted the accumulation of fructose and glucose in fruits， while white light promoted the catabolism of sucrose. The correlations between the compositions and content of carotenoids and soluble sugars were different under different LED treatments. However， the total carotenoids in all treatments showed a significant positive correlation with fructose and glucose. These findings can provide reference data for postharvest quality control of nectarine fruits.

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.

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.

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.

Over past two decades， the application of nuclear techniques has been integrated into many aspects of scientific research and production practice in food and agriculture， and nuclear techniques are unique and irreplaceable in some areas. This review provides a comprehensive overview of the latest developments and major achievements from the nuclear application in major fields of food and agriculture around the world. The application status and innovative development of nuclear techniques in the fields of animal production and health， food safety and control， plant mutation breeding and genetics， water and soil management and agricultural environment， and insect pest control were reviewed emphatically. Considering many severe global challenges faced by the food and agriculture around the world， the authors discussed and showed the prospects and strategic priorities of nuclear application in food and agriculture.

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.

In order to investigate the causes of the continuous crop disorder， this study took the one-year planting and its rhizosphere soil as the control， and the 3-year， 6-year and 9-year continuous cropping and its rhizosphere soil as research objects. The physicochemical properties， enzyme activity and microbial community changes， as well as the agronomic traits and quality of flowering cabbage were measured. The results showed that continuous cropping induced soil bulk density， conductivity， total nitrogen and fast-acting potassium content increased significantly. After 9-year continuous cropping， soil bulk density was increased by 1.33 g·cm^-3； compared with control， conductivity and total nitrogen content increased by 34.21% and 54.29%， respectively； rapidly available potassium content increased by 2.41 times. However， continuous cropping caused pH， total organic carbon， total phosphorus， alkali-hydrolyzed nitrogen and fast-acting phosphorus content decreased significantly. After 9 years’ continuous cropping， the total phosphorus and effective phosphorus decreased by 26.55% and 26.07%， respectively. The activities of sucrase， alkaline phosphatase， catalase and cellulase in the rhizosphere soil under continuous cropping were significantly decreased compared with controls After 9 years’ continuous cropping， the lowest activities were 55.43%， 59.28%， 33.73%， and 52.37%， respectively， while urease activity was the highest at 6 years of continuous crop. Long-term continuous crop altered the abundance and diversity of microbial communities in the rhizosphere soil， with bacterial community abundance decreasing and diversity increasing， while fungal community abundance and diversity decreased. With the increase of continuous cropping years， the length of carex， stem thickness， aboveground dry and fresh weight， root dry and fresh weight， and yield all decreased by 39%， 18%， 26%， 22%， 28%， 41% and 22.97% compared with controls， respectively， after 9 years of continuous cropping. With the increase of continuous cropping years， the soluble sugar， soluble protein， and vitamin C content of carex decreased. The soluble sugar content， soluble protein content and vitamin C content of flowering cabbage decreased by 20%， 22% and 27%， respectively after 9 years of continuous cropping. In conclusion， the long-term continuous crop led to the deterioration of soil environment of flowering cabbage， which resulted in the decrease of yield and quality of flowering cabbage. In this study， we initially investigated the growth conditions and soil environment of flowering cabbage in Ningxia after long-term continuous crop and provided a reference for the subsequent work that reduce continuous crop disorder of flowering cabbage.

In order to understand the mutagenic effect of heavy ion radiation on peony， the seeds of Fengdan peony were irradiated by ¹²C⁶⁺ heavy ion beams under doses of 0， 10， 20， 40， 60， 80， 100， 120， 150， 200， 300 Gy， respectively， the phenotype of peony after irradiation were analyzed， and the changes of chemical compounds， structures and contents in the leaves of peony seedlings under different radiation doses were studied by Fourier transformation infrared spectroscopy （FTIR）. The results showed that heavy ion radiation could significantly inhibit the emergence rate， and the half-lethal dose was between 10 and 20 Gy. 80-120 Gy can significantly inhibit plant height， reduce leaf length and width， and induce leaf deformation. 10-20 Gy can promote the formation of cellulose， hemicellulose and lignin， and promote the formation of protein secondary structure α-helix and β-sheet. 20-150 Gy can inhibit the synthesis of esters， lignin， amino II and amino A， promote protein methylation， glycoprotein mutation， lipid oxidation and degradation， inhibit the formation of β-sheets linked to pectin， and promote the formation of protein secondary structures such as β-sheet， random coils， α-helices， loops and turns. Through principal component， loading diagram and cluster analysis， it was found that the radiation doses of 10， 20， 40 and 60 Gy could significantly change the chemical compositions in leaves of Fengdan peony， which were clustered into one category； when the radiation dose was 200 Gy， the chemical substances in the leaves of peony showed great differences， which could be clustered into one group； there was no significant difference between the other dose groups and the control group， which were clustered into one category. The results of this study will provide an appropriate mutagenic dose range （10-20 Gy） and theoretical basis for ¹²C⁶⁺ heavy ion radiation breeding of peony seeds.

To study the heterosis and genetic models of the main quality traits of tea plants under different genetic backgrounds， three crossbreeding F1 populations were constructed with Baojing Huangjincha 1 as the male parent and Fuding Dabaicha， Anhui 1 and Bixiangzao as the female parent， and the genetic analysis of four main quality traits， including water extract， tea polyphenols， amino acids and caffeine， was carried out by using a mixed genetic model of major genes plus polygene. The results showed that， except for water extract， the genetic variations of the other components were quite extensive. Four traits in the three crossbreeding F1 populations had varying degrees of mid-parent heterosis， and over-parent heterosis was widespread. The water extract and tea polyphenols in three combinations showed positive mid-parent heterosis， caffeine showed different positive and negative mid-parent heterosis， while amino acids showed negative mid-parent heterosis and biased maternal inheritance. Trait inheritance in the three crossbreeding F1 populations fit a total of three models， but all were controlled by two pairs of major genes plus polygenic. Water extract， amino acid and caffeine were detected in two pairs of additive-dominant major genes in the F1 population derived from Fuding Dabaicha and Bixiangzao， and tea polyphenols were inconsistently expressed in two pairs of additive-dominant major genes and two pairs of equi-additive major genes in the two combinations； water extract， tea polyphenols and amino acid were detected in two pairs of equi-additive major genes in the F1 population of the cross with Anhui 1 as the maternal parent， and caffeine showed the inheritance of two pairs of additive major genes. The heritability of water extract and caffeine genes was higher than 50%， and the heritability of tea polyphenol and amino acid genes ranged from 1.083% to 99.246% in the three crossbreeding F1 populations. This study provides a preliminary analysis of the inheritance pattern of major quality components of tea tree and the interaction effect among the major genes， providing a theoretical basis for QTL localization analysis and molecular marker-assisted breeding of major quality component traits for tea.

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.

In order to create flax germplasm， the flax variety Longya 10 was used as the test material， and ethyl methane sulfonic acid （EMS） was used as the mutagen in the study. The results showed that the best EMS concentration and time for mutating oil flax seeds were 0.20% and 24 h； With observations of the phenotypes in fields generation by generation， in the M₈ generation， 22 flax mutants with obvious differences in plant height， growth period， powdery mildew resistance and other characters from the wild-type control were screened， including 4 early-maturity mutants trait， 1 large-grain mutant， 3 dwarf or semi-drawf mutants， 2 higher plant mutants， 17 powdery mildew resistant mutants， 2 white pedal mutants and 2 stay-green mutants. These materials can be used not only as germplasm resources for genetic improvement of oil flax， but also as basic materials for gene mining for important traits. Meanwhile， some materials with elite comprehensive traits and high yield can be bred into new cultivars and applied in flax production. This study provides a reference for flax germplasm innovation and EMS mutagenesis breeding， and lays a material foundation for new variety breeding and discovery of genes for important traits.

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.