General combining ability （GCA） is an important index to evaluate the utilization value of parental inbred lines. In order to analyze the genetic mechanism of combining ability of maize， 537 hybrid combinations obtained from NCII genetic mating design were used as materials， seven multi-locus genome-wide association study （MGWAS） methods were used to identify significant loci for GCA of kernel row number， kernel length， and kernel width in Xinxiang， Zhoukou， and combined environment， combining with 11 734 high-quality single nucleotide polymorphism （SNP） markers obtained from the maize 5.5K liquid breeding chip. Based on MGWAS， five genomic selection methods were used to predicting the GCA effects. The results showed that 46 SNPs were detected and significantly associated with GCA of kernel row number and two kernel traits （P<8.52×10^-7）. Among them， ten loci were detected using two-to-five MGWAS methods simultaneously， and eight SNPs were co-located in at least two environments. Six SNPs （1_43440622， 2_69742504， 2_71037706， 2_197716855， 5_219239213， and 8_134634317） were both environment-stable and MGWAS method-stable loci， which were important loci controlling the GCA effects of kernel row number and kernel traits. The prediction accuracy of GCA for kernel row number and kernel width was high when using five random effect models， with a value of 0.62~0.74， and the prediction accuracy of GCA for kernel length was low， with a value of 0.28~0.45. In most cases， adding significant SNPs identified from different MGWAS as fixed effects into genomic best linear unbiased prediction(GBLUP) and reproducing kernel Hilbert space(RKHS) improved the prediction accuracy of GCA for kernel row number and two kernel traits in the three environments， with the percentage increase of 0.66%~15.96% for kernel row number and kernel width and 9.26%~83.05% for kernel length. The results of this study provide important gene information and technical guidance for subsequent gene function verification and genomic selection-assisted breeding of key loci.

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.

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.

Tomato brown rugose fruit virus （ToBRFV） belongs to the genus Tobamovirus in the Virgaviridae family and is classified as a quarantine virus in China， posing a serious threat to the safety of tomato production. Signal transduction system plays an important role in plant disease resistance， and phospholipid signaling is crucial in the process of extracellular resistance signal transduction. Phospholipase C （PLC） is critical in the transmembrane signaling of the phospholipid signaling system. In this study， we first identified 10 tomato PLC genes based on bioinformatics， including seven phosphati-dylinositol-specific phospholipase C （PI-PLC） and three non-specific phospholipase C （Non-specifc -PLC， NPC）， the seven PI-PLC PLC proteins have three core structural domains （PLC_X c， PLC_Y c， C2） and an EF_hand-like structural domain， and the three NPC proteins only have a phosphoesterase structural domain. 10 tomato PLC proteins can be divided into seven branches according to their structural similarity， namely NPC1， NPC2， NPC6， PI-PLC2， PI-PLC3， PI-PLC4 and PI-PLC6. In addition， the 10 tomato PLC secondary structures were similar in proportion， but there were significant differences in tertiary structures. Co-linearity analysis showed that there were 3， 12 and 16 pairs of co-linear relationships between the distribution of tomato PLC genes and rice， Arabidopsis and Raymond-type cotton PLC genes. Finally， to clarify which tomato PLCs are involved in the plant defense response against ToBRFV， this study examined the relative expression levels of the PLC gene family after ToBRFV inoculation by transcriptome sequencing， and the results showed that SlNPC1， SlNPC6 and SlPLC4 were expressed at higher levels in the ToBRFV-inoculated samples， while the expression levels of other PLC genes were reduced after ToBRFV inoculation. This study lays the technical and theoretical foundation for tomato ToBRFV resistance research and breeding.

Phytoene Synthase 1 （SlPSY1）， a key rate-limiting enzyme of carotenoid synthesis， directly affects the accumulation of carotenoids in tomato fruit. We constructed and transformed the bait vector pSlPSY1pro-AbAi into the yeast cell to explore the transcriptional regulation of SlPSY1. Then， the AP2/ERF family transcription factor SlJERF1 and 10 other proteins were screened by yeast-one-hybrid experiment using the yeast hybrid cDNA library built by mixed tissue of tomato. Subsequently， the sequence of SlJERF1 gene was cloned and the recombinant vector pGADT7-SlJERF1 wasconstructed. The molecular interaction between SlJERF1 and SlPSY1 promoterwas varified through yeast-one-hybrid point-to-point test. The results showed that the yeast in the control group could not grow normally under 150 ng·mL^-1 Aureobasidin A （AbA）， while the yeast transformed with SlJERF1 could grow normally， indicating the interaction between SlJERF1 and the promoter of SlPSY1 gene. This result provides an important theoretical basis for the regulatory network of carotenoid synthesis， and confers new ideas for further study in the future.

NAC transcription factors are involved in plant growth and development， fruit pigment accumulation， cell wall morphogenesis， and plant senescence. To systematically study the precise function of SNAC4 （SlNAC48， Gene ID： 101247735） and SNAC9 （SlNAC19， Gene ID： 101248665） in the tomato ripening and aging， we designed SNAC4/9 knockout targets and constructed a single guide RNA （sgRNA） expression cassette through Overlapping Polymerase Chain Reaction （Overlapping PCR） method. Single or multiple sgRNA expression cassettes were assembled into pYLCRISPR/Cas9 vector by the Golden Gate cloning method. PCR and sequencing results showed that the SNAC4/9 knockout vector was successfully constructed. The genes encoding Cas9 protein and sgRNA were introduced into Micro-Tom tomato cells by the Agrobacterium transformation method， and the target and off-target of positive seedlings were detected. The results showed that tomatoes were mutated successfully without off-target. The identification of T₁ mutants further demonstrated that CRISPR/Cas9 gene editing targets in tomato could be inherited stably between generations. Compared with wild type， SNAC4/9 knockout fruits had less pigment accumulation and delayed ripening， suggesting that SNAC4/9 played an essential role in tomato fruit ripening. This study provided genetic material and an experimental basis for further exploring the mechanism of SNAC4/9 regulating pigment metabolism and cell wall metabolism in tomatoes.

In order to reduce the usage of herbicides in corn fields and improve the control effect of herbicides， formulation optimization and field efficacy of coconut oil tank mix adjuvant， which has been reported to be synergistic on herbicides in our previous study， were studied. Results showed that the optimum formula of the additives was obtained with n-hexanol as the solvent and 1.40∶3.60 as the compound emulsifier Span-80 versus Tween-80. In the greenhouse test， the synergistic ratios of coconut oil tank adjuvant to nicosulfuron and mesotrione could be increased by 11.24-49.35 percentage points， and those to mixture of nicosulfuron?and atrazine and mixture of mesotrione and atrazine could be increased by 14.71-31.25 percentage points， and the weeds control effect of adding adjuvant after the reduction of herbicide is equivalent to that of the constant amount without adjuvant. In the mixed treatment of oxaflutole and atrazine， the synergistic effect of the coconut oil tank mix adjuvant was 2.33-6.99 percentage points higher than that of the ethyl and methyl ester vegetable oil adjuvants. The field test results showed that the synergistic ratio of coconut oil tank mix adjuvants to post-emergence herbicides such as mixture of nicosulfuron?and?atrazine， mixture of mesotrione and atrazine， was 8.46%-13.57%. It was indicated that the control effect of herbicides at a reduction dosage after adding tank adjuvant was better than of herbicides at the recommended dose without adjuvant. In conclusion， the coconut oil tank mix adjuvant could reduce the herbicide dosage and herbicide cost， and provide a theoretical basis for the development of new pesticide additive products.

In order to explore the changes of root morphological distribution， nutrient accumulation and yield under different root configuration maize varieties intercropping， monoculture and intercropping treatments were conducted both in the field and pot-cultivation to study the variation characteristics of intercropping of maize （Zea mays L.） on root traits， spatial distribution， nutrient accumulation and grain yield， two maize varieties JS501 （small root angle type） and LY16 （large root angle type） with different root system architecture were used as experimental materials. The results showed that the total root length， total root surface area， total root volume and root diameter of maize population under intercropping treatments increased by 10.19%， 19.55% and 15.95% on average compared with monoculture treatments， respectively. But there was no significant change in root diameter between intercropping and monoculture treatment. In 0~20 cm soil layer， the total root length， total surface area and total volume of maize in intercropping were 15.27%， 21.82% and 9.44% higher than those in monoculture， and 12.95%， 9.18% and 20.31% higher than monoculture at 20~40 cm， respectively. Intercropping enlarged the horizontal distribution of JS501 root and extends outward by 5 cm， deepened root vertical distribution by 10 cm in intercropping treatments and increased root length density by 26.03% on average in 40~60 cm soil layer. Intercropping also significantly improved root activities by 27.83% compared with monoculture. The accumulation of nitrogen， phosphorus and potassium in intercropping population increased by 18.27%， 14.79% and 15.75% on average compared with monoculture， respectively. Land equivalent ratio was more than 1 under intercropping and dry matter weight and grain yield were increased significantly by 11.03% and 15.36% on average compared with monoculture， respectively. Path analysis showed that total root surface areas significantly affected the accumulation of N and K， which indirectly affected dry matter accumulation and 100-grain weight， and significantly increased grain yield under intercropping conditions. However， the correlation coefficient between factors in monoculture was lower than that in intercropping. In summary， intercropping changed the spatial distribution of maize roots with different root architecture and increased the proportion of roots in deep soil. It reshaped root architecture in 40~60 cm soil layer， improved root activities and make use of the root spatial complementary. These characteristics promoted the nutrient accumulation and increased grain yield. This study provided a theoretical and practical strategy for high efficiency of nutrient resources and sustainable agriculture.

In order to explore the biological function of the FaGI gene in tall fescue. In this study， yeast two-hybrid， bimolecular fluorescence complementation and co-immunoprecipitation were used to explore the proteins interacting with FaGI， and the overexpression vector p1300-FaGI was transformed into Arabidopsis thaliana by an Agrobacterium-mediated method， and the FaGI transgenic Arabidopsis lines were obtained. The wild type Col-0， overexpression FaGI gene lines and gi mutant of Arabidopsis thaliana were used for transcriptome sequencing and observing flowering performance. The results showed that the FaCO protein interacting with FaGI was screened by yeast two-hybrid method， and the interaction between FaGI and FaCO in vivo and in vitro was proved by bimolecular fluorescence complementation and co-immunoprecipitation. The flowering time of Arabidopsis plants overexpressing the FaGI gene was about 1.24 days earlier than that of wild-type Col-0. Differentially expressed genes （DEGs） of 1 963 and 92 were screened by comparing FaGI-OE and gi with WT， respectively. Compared with wild-type plants， the differentially expressed genes of overexpression FaGI lines were enriched in biological processes and metabolic pathways related to growth and development， photoperiod pathway， hormone synthesis and signal transduction， and carbon metabolism. In conclusion， FaGI affects the expression of photoperiod pathway-related genes， and overexpression of FaGI promotes flowering in Arabidopsis under long-day light conditions. At the same time， the function of FaGI are diverse and complex， which can be used as target genes for molecular breeding of tall fescue. The results of this study laid the foundation for revealing the function of FaGI gene and its regulatory network.

Jasmonic acid （JA） is involved in regulating various important biological processes such as plant growth， development and defense， in which JAZ proteins play an important role as the repressor in jasmonic acid-mediated biotic and abiotic stress response processes. To investigate the function of SlJAZ11， this study analyzed the expression pattern of SlJAZ11 after treatment with hormones such as salicylic acid （SA） and jasmonic acid （JA） as well as pathogenic bacteria infection， and the results showed that SlJAZ11 was able to respond to the induction of salicylic acid， jasmonic acid and Pseudomonas syringae pv. tomato （Pst DC3000）. A tomato cDNA library was screened by yeast two-hybrid assay， and 14 potential interacting proteins of SlJAZ11 were obtained. The interactions between the candidate SlENT， SlOOLG and SlJAZ11 were further verified by yeast two-hybrid point-to-point assay and bimolecular fluorescence complementation technique （BiFC）， and the interactions between SlENT and SlJAZ11 were confirmed. Analysis of the expression pattern of SlENT revealed that its expression was significantly inhibited by SA and Pst DC3000， while MeJA significantly induced its expression， indicating that SlJAZ11 may regulate JA-mediated disease resistance in tomato by interacting with SlENT. This study may lay a good molecular foundation for elucidating the function and mechanism of SlJAZ11.

In order to scrutinize the state of stress during compression bulk milk powder， commercially available infant formula was used as a simulation object. Based on the resting angle， regression model between the powder particle and the simulated resting angle was studied to assess the optimal contact parameter by designing diverse parameters with different combination by using the Plackett-Burman test， the steepest climbing test and the Box-Behnken test. Furthermore， the change trend of compression volume of bulk milk powder， contact force chain distribution between surface particles and upper impact dye， and contact force chain distribution between section particles were assessed. The results demonstrated that static friction coefficient between the milk powder particles was 0.359， the rolling friction coefficient was 0.099， and the milk powder particle-stainless steel static friction coefficient was 0.125. The simulated compression trend of bulk milk powder was basically consistent with the real compression trend of change， indicating that the Edinburgh Elasto-Plastic Adhesion （EEPA） contact model could well simulate the compression process of milk powder. When the pressure reaches 2 500 N， the surface particles of bulk milk powder were highly likely to break due to the undivided load pressure and had a crushing trend from the surface to the inside. It was constant with the analysis results of the compressive strength of bulk milk powder. The compression model could well represent the stress in the compression process of milk powder. The results of this study provides a theoretical basis for selecting process parameters for bulk milk powder.

To analyze gene distribution in wheat lines involved in 2019—2020 Shandong regional trial， one hundred and twenty-six wheat lines were tested with 64 Kompetitive Allele Specific polymerase chain reaction （KASP） markers which were specific to 55 genetic loci. The markers are related to yield， quality， resistance， flower time and etc. Over 90% KASP markers give acceptable genotyping， which provides an efficient technology for gene identification. Favorable allele frequencies of 20 genes are above 80%， including Vrn-A1， Vrn-B1， Vrn-D1， Ppd-A1， Ppd-B1， Ppd-D1， Psy-D1， Glu-A3g， Rht-D1， Pinb-D1， TaCwi-A1-1， TaGW2-6B， TaSus1-7B， TaGASR7-A1， 1-feh-w3， TaDreb-B1， PRR-A1， PRR-B1， TaFT3-B1 and TaMOT1-D1. Favorable allele frequencies of 26 genes are below 30%， including Vp1-B1， Ppo-D1， TaPds-B1， Zds-A1， TEF-7A， Lr46， Glu-B3g， TaGS5-A1， TaCwi-4A， 1B/1R， Rht-B1， Lr68， TaELF3-B1， Pina-D1， Sbwm1， TaPHS1， Pm21， COMT-3B， TaCKX-D1， TaSdr-B1， Pch1， Lr34， Yr15， Fhb1， TaMoc-7A and TaGS-D1， notably，favorable alleles of TaMoc-7A， Lr34， Fhb1， Pch1， Yr15， and TaSdr-B1 are not detected. Favorable allele frequencies of 9 genes are between 30% and 80%， including Pinb2-V， TaPod-A1， Lox-B1， Glu-A1， Glu-D1， TaGS2-B1， TaGW2-6A， TaSus1-7A， and Lr14a. Favorable allele frequencies of 55 genes show polarization trend. Among all tested lines， JinongCH03， CG086， and JinongCH01 are the only one possessing favorable alleles of TaCKX-D1， Pm21， and COMT-3B， which could be used as gene donors for kernel weight， powdery mildew resistance， and stem lignin content improvement and breeding. In this study， genotypes of 55 genes in 126 wheat lines are clarified， allelic distribution of important agronomic genes in wheat lines attending the Shandong regional trial was basically clarified， which will serve as the foundation for marker assistant selection breeding.

Thousand grain weight (TGW) is one of the three important components of crop yield. Increasing grain weight is an effective way in the improvement of crop yield. In this study, to elucidate the genetic machanism of 1000-grain weigth an association mapping panel consisting of 242 sorghum landraces/cultivars collected mainly from 16 sorghum planting provinces across China was genotyped using whole-genome re-sequencing method. TGW of each accession was phenotyped across seven environments over three years from 2018 to 2020. Multi-locus association analyses based on 2 015 850 SNPs were carried out using mrMLM 4.0 R package which comprises the mrMLM, FASTmrMLM, FASTmrEMMA, ISIS EM-BLASSO, pLARmEB, and pKWmEB models. Results showed that TGW displayed a continuous and normal distribution as a typical quantitative trait. The variations of TGW were ranged from 10~50 g under seven environments. A total of 323 quantitative trait nucleotides (QTNs) for TGW were detected using six models. The phenotypic variation explained by individual QTN varied from 0.4% to 26.6%. Six multi-locus models revealed differential QTN numbers associated with TGW. The maximum number of associated QTNs was observed in FASTmrMLM model followed by pKWmEB model, pLARmEB model, mrMLM model, ISIS EM-BLASSO model, and FASTmrEMMA model. After merging the same QTNs, 96 consistently reliable QTNs were detected using multi-locus GWAS methods and/or at least two seasons, which were distributed unevenly on 10 chromosomes. Among them, 4 QTNs overlapped with previously reported QTLs. Besides, 5 candidate orthologous to documented rice grain weight genes, like GW7/GL7, BG2, OsARF4, RSR1, TGW6, were found to be located within four QTNs. These results help us to understand the genetic architecture of grain size and pave the way for exploration of underlying molecular mechanisms and molecular design breeding of this trait in sorghum breeding practices.

To explore the characteristics of the root systems of wheat （Triticum aestivum L.） varieties with different nitrogen （N） efficiencies and their responses to rhizosphere soil enzyme activities， a field experiment was conducted based on 30-year long-term trial site during 2018—2020， in which the wheat varieties included in N efficient varieties of Zhengmai 113 （ZM 113） and Yangao 21 （YG 21）， and N inefficiency varieties of Fengdecun 5 （FDC 5） and Zhengmai 27 （ZM 27）. The root characteristics， N absorption and utilization， and differences in root soil enzyme activities were studied under conditions of no N fertilizer （N0） and conventional N fertilizer （N1）. The results indicated root vigor reached the maximum at the booting stage for all varieties. At the N0 level， the average root vigor of ZM 113 and YG 21 was 16.13%~24.22% higher than that of ZM 27 and FDC 5. Meanwhile， it was 10.22%~62.49% at the N1 level. The root length， root surface area， and root volume were significantly higher under N1 treatment compared with those under N0 treatment. The N uptake efficiency of ZM 113， YG 21， and ZM 27 was significantly higher than that of FDC 5， while N use efficiency of ZM 27 was relatively low. Under the fertilization treatments， rhizosphere soil β-glucosidase （BG）， eucine amiopeptidase （LAP）， and polyphenol oxidase （POX） activities of ZM 113 and YG 21 were significantly higher than FDC 5 and ZM 27 （P<0.05）. Besides， there was a positive correlation between rhizosphere soil enzyme activity and root morphological indexes. This indicated that the higher root activity， root length， root surface area， and root volume of ZM 113 and YG 21 promoted the uptake of nitrogen， which was the fundament for high nitrogen efficiency， and higher rhizosphere soil enzyme activity promoted the efficient use of nitrogen. This study provided a theoretical basis for the breeding and cultivation of nitrogen-efficient wheat varieties.

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.

With global warming， drought stress has become one of the important factors restricting the safe production of tomato and other vegetable crops. The use of rootstocks from wild resources is a low-cost and efficient way to improve plant disease resistance and stress resistance. Previous studies have found that grafting GZ-01 rootstock， a native semi-wild tomato in Guizhou， can improve the drought tolerance of plants. In order to explore the molecular mechanism of GZ-01 on enhancing drought tolerance of wild tomato plants， the response of grafted tomato and self-grafted tomato plants to drought stress was compared by using semi-wild tomato rootstock GZ-01 and red fruit tomato as experimental materials， combined with morphophysiology and molecular biology. The results showed that under drought stress， when compared with the R/R of self-grafted plants， the damage of cell membranes of GZ-01/R grafted plants was significantly reduced， the antioxidant capacity， dry matter accumulation， CO₂ assimilation rate and water utilization efficiency of plants were significantly improved， the water loss rate of ex vivo leaves was significantly reduced， the lower stomatal closure ratio was significantly increased， and the expression of ABA synthesis-related genes and ABA content were significantly increased. Grafted plant GZ-01/R may affect the opening and closing of stomata， regulate leaf water loss， and improve plant water utilization by regulating the synthesis of ABA， thereby affect the response of plants to drought stress. This study lays a foundation for the development and utilization of native semi-wild tomato resources in Guizhou， and provides theoretical support for enhancing drought stress and studying molecular regulatory network pathways of stress resistance.

Hemerocallis is a traditional garden plant in China， which has high economic value because it can be used as both food and medicine. Although the natural distribution of Hemerocallis is the largest in china， the related research lags behind foreign countries. At present， the horticultural varieties used in China mainly rely on foreign imports， and hortiaultural varieties with our own intellectual property rights are relatively few.In this paper， the germplasm resources of domestic Hemerocallis were introduced in detail， and the breeding achievements of new Hemerocallis varieties at home and abroad were summarized from the perspectives of different breeding objectives， such as flower shape， flower aroma， flower color， flowering period， cold resistance， disease resistance， etc. The breeding achievements of new Hemerocallis varieties at flowering time and cold resistance at home were highlighted. At the same time， the new breeding technology was summarized， and the problems and prospects in the domestic Hemerocallis breeding were discussed， which aimed to provide reference for the breeding new varieties of Hemerocallis.

To explore the effect of salinity on the growth, fatty acid composition and bacteria community associated with Isochrysis zhanjiangensis, the algal cells were semi-continuously cultured with four salinities (12, 18, 24 and 30). After reaching the stable growth state, the cell density (OD₇₅₀), chlorophyll fluorescence parameters, fatty acid composition, and bacteria community were analyzed. The results indicated that the higher cell density, F_v/F_m, and F'_v/F'_m were obtained at salinity 18~24. There were no significant differences among the fatty acid compositions under salinity 12, 18 and 24. The saturated fatty acids under salinity 30 were significantly higher, while unsaturated fatty acids were significantly lower than that in other three groups. Overall, the salinity at 18~24 was more beneficial to its growth and UFA accumulation in I. zhanjiangensis. The bacteria community was analyzed by 16S rDNA amplification sequencing. It was speculated that the diversity of bacteria community at salinity 12 was significantly higher than others according to Chao1, ACE, and Shannon indexes. PCoA analysis indicated that the compositions of bacteria community were similar among groups with salinity 18, 24 and 30, significantly different from that with salinity 12. Further analysis showed that Proteobacteria (92.70%) was the dominant phylum at salinity 12, with the largest proportion of genus Brevundimonas. The dominant phylum at salinity 18, 24 and 30 were phylum Cyanobacteria, accounting for 97.63%, 97.41% and 93.51%, respectively, demonstrating that “salinity 12” and “salinity greater than or equal to 18” were two distinct environments for I. zhanjiangensis, which would drastically affect the composition of bacteria community. This study will provide data for optimizing the cultivation scheme of I. zhanjiangensis and lay the foundation for in-depth studies of the effect of salinity on the bacteria community.

To explore the relationship between the major metabolic components and the compression wood formation of Cunninghamia lanceolata, three-year-old erect seedlings of C. lanceolata were selected as materials for the research, observe its growth characteristics after being placed at an inclination of 45° to the vertical for 30, 60 and 90 days, and determine the lignocellulose content, gas chromatography-mass spectrometry(GC-MS)was used to identify and analyze the metabolic components of the xylem. Tracheid anatomy revealed that the cell walls of the compression wood were deformed. Chemical composition analysis showed that the content of total lignin and hemicellulose increased, and the content of cellulose decreased. The GC-MS results identified 20 components in compression wood(CW), opposite wood(OW)and control/straight wood(CK). These include seven organic acids, three monosaccharides, two disaccharides, three types of alcohol, two types of amino acids, one phenol and one glycoside. Principal component analysis and significance test identified 11 common metabolites between different treatments and time intervals. Among them, the content of glycolic acid, glycine, ribonic acid and palmitic acid in CW was significantly lower than that in OW and CK. In addition, galactose and sucrose content in CW was much higher than that in OW and CK. The experimental results give a new insight to reveal compression wood formation of C. lanceolata at a metabolic level. Understanding the molecular mechanism in compression wood formation benefits the directed breeding of high-quality wood species. This study provides theoretical basis for functional improvement of wood.

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.