To clarify the molecular mechanism of spike of mutant sui1， the phenotype identification and the transcriptome analyses of rachis and peduncle in different growth stages （tooting stage as T1 and filling stage as T2） were performed. The results showed that the spike mutant had shorter length of rachis and peduncle， lower plant height and aggravated incidence of FHB. Results of transcriptome analyses showed that at the same period， the differentially expressed genes between mutant and parent in peduncle was more than that in rachis， and there were more differentially expressed genes at tooting stage than at filling stage in rachis. A total of 2 526 differentially expressed genes was screened， among which 890 were up-regulated， 1 636 were down-regulated. The study of gene ontology classification found that genes annotated with molecular functions in different tissues were equally enriched and most of them were focused on ATP binding. KEGG enrichment analysis showed that plant-pathogen interaction pathway had the most enriched genes. The highest enrichment factors of rachis in different stages were carbon fixation in photosynthetic organisms. The highest enrichment factor of peduncle in different tissues was photosynthesis-antenna proteins pathway. From plant-pathogen interaction pathway， 160 related genes were selected. There were 63 genes related to the defense response （39%）， 21 genes related to protein kinase activity （13%） and 18 genes related to ADP binding（11%）. It is speculated that these genes may be important for the rachis and spike type of wheat mutant sui1. This study provides data support for further exploring the molecular mechanism and gene regulation network of wheat spike type variation in the future， and also provides important information for the wheat yield and disease resistance.
UEVs protein is a variant of ubiquitin binding enzyme E2， which can catalyze substrate ubiquitination by forming a complex with E2. In order to explore the role of UEVs protein in nitrogen absorption and utilization， the gene of ubiquitin binding enzyme variant like protein named CaUev1D-L，
Anthocyanin synthase （ANS） is the key enzyme in the phycocyanin synthesis pathway. To investigate the function and expression characteristics of ANS gene in Rhododendron hybridum Hort. In this study， Rhododendron hybridum Hort. petals at different developmental stages and roots， stems and leaves were used as experimental materials， the RhANS cDNA sequences were cloned using reverse transcription （RT-PCR） and RACE techniques； Anthocyanin content in petals of Rhododendron hybridum Hort. at different developmental stages were determined using ultra-performance liquid chromatography mass spectrometry （Waters UPLC-Qtof）. And the relative ANS gene expression in petals and different organs of Rhododendron hybridum Hort. at different developmental stages were detected using quantitative real-time PCR （qRT-PCR）； The RhANS gene was recombined into a prokaryotic expression vector （pET-28a） and the target protein was purified by expression in E.?coli （BL21）. The enzymatic activity of the target protein RhANS was also detected using HPLC. The results showed that the RhANS cDNA cloned from Rhododendron hybridum Hort was 1 350 bp in length and open reading frame （ORF） sequence was 1 074 bp， encoding 357 amino acids. and contained the structural domain 2OG-FeII-Oxy of the 2-ketoglutarate dioxygenase family gene； Anthocyanin content of Rhododendron hybridum Hort. showed a gradual increase with flower opening； RhANS gene was expressed in all four floral stages and different organs （roots， stems and leaves） of Rhododendron hybridum Hort. petals. RhANS expression and anthocyanin content showed an increasing trend at different flower developmental periods. The expressed protein induced by the E.coli prokaryotic expression vector was about 40 kDa in size， which was similar to the theoretical value. The high performance liquid chromatography （HPLC） assay showed that the target protein had ANS enzyme activity. This study provides a theoretical basis for the molecular regulatory mechanism of anthocyanin biosynthesis in Rhododendron.
In order to explore the biological function of ROP gene in cotton resistance to stress， homologous approach was used to obtain the GhROP6， and its physicochemical properties， structure and evolutionary relationship were analyzed by bioinformatic methods. Real-time quantitative polymerase chain reaction （qRT-PCR） technology was used to detect the tissue expression specificity of GhROP6 gene and the expression pattern under different stress and exogenous hormone treatments. The VIGS vector of GhROP6 gene was constructed and transformed into cotton， and its silencing efficiency was detected by qRT-PCR. The results showed that the open reading frame （ORF） of GhROP6 gene was 597 bp in length， encoding a class I ROP protein containing 198 amino acid. Multiple sequence alignment showed that GhROP6 was consistent with ROP protein structure and highly homologous to ROP proteins of other species； Phylogenetic tree analysis showed that GhROP6 protein had the highest homology with Arabidopsis AtROP6 protein； GhROP6 gene was expressed in roots， stems， true leaves and cotyledons of cotton， and the expression level was the highest in true leaves； GhROP6 gene has different responses to drought， high salt， low temperature， high temperature stress and exogenous abscisic acid （ABA）， auxin （IAA） treatments， and may play an important role in cotton stress response. GhROP6 was effectively silenced in leaves and roots of cotton， indicating that GhROP6 gene silencing plants were obtained. The present study provides a foundation and deepens our understanding about molecular and biological functions of GhROP6 genes.
In order to identify the genetic diversity and population structure of foxtail millet cultivars from different ecological regions， 29 phenotypic traits and 36 pairs of SSR markers were texted with 175 foxtail millet cultivars. The results showed that the genetic diversity index of quantitative traits was the highest， and the qualitative traits was the lowest. The phenotypic traits with the highest genetic diversity indexes were spike number （2.082 8）， days from flowering to maturity （2.012 5） and grain color （1.078 7）. Alleles of 401 were detected by 36 pairs of SSR primers， with an average of 11.4 per alleles. The average Shannon index was 2.017 2， and polymorphic information contents （PIC） was 0.810 6. Markers B142 and B225 were found to be more suitable to evaluate the genetic similarity of foxtail millet. Phenotypic and SSR marker diversity comparison results showed that middle and late-maturing spring-sowing region （ML） had the highest diversity level， followed by early-maturing spring-sowing region （EM）， and summer-sowing region （SS） is the lowest. The 10 trait indexes of millet varieties in ML were the highest， and the whole growth period was the longest. In the ML， Fenyang had the highest phenotype and SSR marker diversity level， Changzhi had the highest genetic diversity index of quantitative traits， TaiyuanⅡ had the highest genetic diversity index of growth period. In different types of ML， the differences of 7 quantitative traits were not significant. Fenyang had the highest plant height and the lowest milled millet percentage， while Taiyuan had the longest panicle neck， but significantly lower panicle diameter. Clustering analysis based on both phenotypes and SSR markers was correlated with the origin of varieties. Cultivars derived from Jingu 21 or Yugu 18 were clustered when clustering with phenotypic traits， but became discretely when clustering by molecule marker. The study will provide scientific basis for genetic study and selection of new varieties of foxtail millet resources.
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.
Phytophthora capsici is an important plant pathogenic oomycetes， and lacks the necessary genes for sterol synthesis. Exogenous sterols play an important role in the life history of Phytophthora and Pythium. In order to clarify the effects of β-sitosterol on Phytophthora capsici at different growth and development stages， gradient concentrations （0.2， 1.0， 5.0， 25.0 and 125.0 μg·mL-1） were set to determine its effects on the mycelial growth， morphological structure， formation of sporangium and oospores of P. capsici LT263. The changes of mycelial membrane permeability of LT263 were observed after treatment with different concentrations of β-sitosterol. The results showed that β-sitosterol could promote the growth and development of P. capsici at low concentration of 0.2 μg·mL-1 and inhibit the growth and development when concentration was higher than 5.0 μg·mL-1. The results showed that the β-sitosterol had teratogenic effects on mycelial growth of P. capsici and increased the permeability of cell membrane at EC50 （10.0 μg·mL-1）. Meanwhile， the inhibitory rates of β-sitosterol on mycelial growth， formation of sporangium and oospores of P. capsici were 6.2%， 70.0% and 55.3%， respectively. The results demonstrated that the β-sitosterol was important to the growth and development of P. capsici， and the effect depends closely on the concentration of β-sitosterol. High concentration of β-sitosterol could effectively inhibit the growth and development of P. capsici and has potential application value in the prevention and control of Phytophthora diseases caused by P. capsici.
Downy mildew（DM）is an extremely damaging disease for quinoa worldwide. In order to clarify the disease occurrence and damage， pathogenicity differentiation and pathogen species of quinoa DM， the disease was systematically investigated， the pathogen species were identified based on morphological and molecular biological methods， and the pathogenicity was determined by artificial inoculation in the laboratory using leaf disc method. The results of disease investigation showed that the quinoa DM in different ecological regions of Gansu was generally serious， and even in outbreak trends in some areas. The incidence and index of DM disease in Linxai Eryin climate region were 83.70% and 80.44， respectively， and the lowest were 19.26% and 16.67 in Baiyin semi-arid region， respectively. The pathogens of quinoa DM in Gansu province were identified as peronospora variabilis with morphological and molecular biological methods， and there were significant differences in the size of sporangia and oospores among different strains（P<0.05）. Pathogenicity analysis showed that there were significant differences among different strains（P<0.05）. The most virulent strain was GSKL from Linxai Eryin climate region， and the weakest strain was GSTZ from Tianzhu high-elevation cold region with disease index of 90.00 and 44.67， respectively. Phylogeny analysis showed that DM strains among different ecological regions of Gansu existed genetic differentiation of geographic populations. This study provides a theoretical foundation for the prevention and control of quinoa DM in Gansu province.
In order to obtain standardized irradiation sterilization processes for dried sweet potato， the effects of different irradiation sources of γ ray and electronic beam， irradiation doses and dose rates on the main components， appearance quality and storage characteristics of dried sweet potato were investigated. The results showed that no microorganisms were detected in the dried sweet potato after irradiated with γ-ray dose≥4 kGy and subsequently incubated at 36 °C for 10 d or stored at room temperature for 90 d. The same result was observed in the dried sweet potato irradiated with γ-ray dose≥6 kGy and incubated at 36 ℃ for 30 d at constant temperature or stored at room temperature for 360 d. No significant changes in soluble solids， carotenoid contents， and sensory indexes were observed in dried sweet potato after treatments with γ-ray irradiation. The higher the dose rate at the same dose， the greater the influence on the appearance of dried sweet potato. Due to the high dose rate of electron beam， the appearance of dried sweet potato changed significantly after irradiation. Thus， the minimum effective dose was recommended to be 4 kGy for irradiating dried sweet potato with a shelf life of 90 d. The results would provide basis for the establishment of irradiation sterilization process for dried sweet potato.
In order to clarify the effect of acetylated distarch phosphate （ADSP） on the quality properties of reheated surimi gel during frozen storage， frozen Alaskan pollock surimi was used as raw material， subjected to setting-freezing-reheating which changed the gelation of the two-step heating process， and the microstructure， drip loss， water distribution state， texture characteristics and dynamic viscoelasticity of reheated surimi gel during frozen storage were analyzed. The results indicated that as the storage time extended， the voids of the surimi gel became larger， the drip loss increased， the non-flowing water decreased， the free water increased， the hardness and gumminess first decreased and then increased， the adhesiveness increased， the cohesiveness remained unchanged， and the dynamic viscoelasticity decreased. Under the same freezing storage period， with the increase of ADSP content， the voids of the surimi gel became smaller， the drip loss decreased， and the water distribution state were relatively stable， among which the addition of 5% and 7% showed the best effect. The results of texture characteristics showed that the increase of ADSP addition was conductive to improving the quality of reheated surimi gel. Although the hardness， cohesiveness and gumminess of surimi gel with the addition of 5% and 7% were basically the same， the adhesiveness of 5% ADSP-surimi gel started to increase late and changed slightly during frozen storage. The dynamic viscoelasticity results showed that the storage modulus of 5% ADSP-surimi gel in the later stage of high-temperature heating was the highest， followed by 7%. In the result of loss modulus， 7% ADSP-surimi gel had the highest viscosity， followed by 5%. Comprehensive analysis showed that adding 5% ADSP could effectively reduce the quality change of reheated surimi gel during frozen storage. These results may provide a theoretical reference for scientific regulation of frozen surimi-based products and the application of modified starch in surimi-based products.
To improve the production of natural melanin， this study explored the effects of carbon and nitrogen sources， rotational speed， pH value and temperature on melanin production from Inonotus hispidus （Bull.） P. Karst.， and used orthogonal tests to select the most suitable fermentation medium formulation and fermentation conditions for extracellular melanin production. The results showed that the optimal fermentation medium formula after optimization was： mannitol 20 g·L-1， beef extract 5 g·L-1， carbon to nitrogen ratio（C/N）4∶1， vitamin B1 10 mg·L-1. The optimal fermentation conditions were： temperature 25 ℃， initial fermentation pH 6， rotation speed 180 r·min-1， and fermentation 10 days. Under these culture conditions， the content of extracellular melanin of Inonotus hispidus （IHEM） was as high as 3.29 g·L-1， which was 17.32 times higher than that before optimization. The results of in vitro chemical antioxidant activity of IHEM showed that IHEM had good antioxidant activity， and the effect on ABTS radical scavenging was better， and the concentration for 50% of maximal effect （EC50） was 0.019 mg·mL-1. In conclusion， we explored the fermentation conditions for high production of extracellular melanin by Inonotus hispidus， which provided theoretical support for high melanin production by deep fermentation.
In order to investigate the sterilization effects and mechanism of contact glow discharge plasma （CGDP） on Fusarium solani， the influences of voltage， processing time， ascorbic acid concentration and initial concentration of spores on the sterilization effects during CGDP treatment was studied， in which Fusarium solani was used as the test material. The growth of Fusarium solani， spore morphology， cell membrane integrity and the active particles produced during the process were also analyzed. In addition， the sterilization kinetic characteristics of CGDP at different voltages were analyzed by three mathematical models， Linear， Weibull and Log-Logistic， and their fitting effects were evaluated by four parameters： correlation coefficient （R2）， exact factor （Af）， deviation factor （Bf） and root mean square variance （RMSE）. The results showed that CGDP had a significant sterilization effect on Fusarium solani spores. Increasing the voltage， extended processing time， decreasing the ascorbic acid concentration and the initial concentration of spores could effectively inhibit spore growth and increase the sterilization efficiency （P<0.05）. The concentration of active substances ·OH， H2O2 and NO3- increased to 1.57 mg·L-1， 73.89 mmol·L-1 and 12.72 mg·L-1 after glow discharge for 30 min， respectively， and the pH value reduced from 7.07 to 4.66. The amount of nucleic acid and protein leakage within the spores， as well as PI staining and SEM results indicated that the fungicidal effects of CGDP on Fusarium solani may be induced by attack from active substances affer disrupting spore morphology and cell membrane integrity. The results of the fit showed that that the Weibull model had the best fit （R2 = 0.924 2） and the minimum value of RMSE （0.636 7） when describe and predict the sterilization kinetics of CGDP on Fusarium solani. The results of this study should provide theoretical guidance for the study of low temperature plasma sterilisation technology and mechanisms.
In order to reveal the relationship between the degradation of cell wall polysaccharides or tissue structure changes and storage ability of kiwifruits， the degradation of characteristics of polysaccharides in the cell wall of Hongyang and White kiwifruit fruits were studied during storage at 25 ℃ and 4 ℃， and the differences of cell microstructure and calcium content between the two fruits during storage at 25 ℃ were compared. The results showed that the contents of hemicellulose （HCL）， cellulose （CL） and covalent soluble pectin （CSP） of Hongyang and White kiwifruits decreased continuously， while the contents of water soluble pectin （WSP） increased continuously， and the contents of ironic soluble pectin （ISP） remained relatively stable under 25 ℃ and 4 ℃ storage. The content of polysaccharide in cell wall of Hongyang kiwifruit changed faster. There was a significant negative correlation between fruit hardness and WSP content， and a significant positive correlation between fruit firmness and CSP content. In the early stage of 25 ℃ storage， the activities of pectate lyase （PL） and β-galactosidase （β-Gal） of Hongyang kiwifruit were significantly higher than that of White. The activity of pectin methylesterase （PME） in Hongyang was significantly higher than that in White during the middle and late storage. When stored at 4 ℃， the PME activity of Hongyang was significantly higher than that of White. In the early stage of storage at 4 ℃， there was no significant difference between β-Gal activity， while Hongyang PL activity was lower than White. Correlation analysis showed that pectin degrading enzymes significantly correlated with fruit softening of Hongyang and White at 25 ℃ were PME and PL， respectively. At 4 ℃， the pectin degrading enzyme significantly related to White fruit softening was PME. During storage at 25 ℃， the number of epidermal cell layers of White fruit was more， and the arrangement of flesh cells was closer. The pulp cells of White contains more calcium oxalate crystals. In addition， the contents of water-soluble calcium， pectin calcium， calcium phosphate and calcium oxalate in White were significantly higher than those in Hongyang under 25 ℃ storage. This study provided theoretical basis for revealing the degradation of cell wall polysaccharides and the changes of tissue structure of kiwifruit fruit after harvest.
In order to improve the functional properties of rice bran glutenin， rice bran glutenin and β-Cyclodextrin were heated to combined at 60， 70， 80， 90， 99 ℃ for 40， 80， 120， 160， 200 min. The turbidity， grafting degree， emulsifying properties and structural properties of the composite aggregate were analyzed to explore the thermal aggregation behavior of rice bran glutenin and β-cyclodextrin. The results showed that when the complex reaction of rice bran gluten and β-cyclodextrin was heated at 80 ℃ for 160 min， the emulsification of the complex aggregates reached the maximum， which was 2.39 times higher than that of natural rice bran gluten. When heated at 80 ℃ for 200 min， the emulsion stability of the composite aggregates reached the maximum， which was 2.39 times higher than that of natural rice bran gluten. The rice bran glutenin combined with β-cyclodextrin formed large particles aggregates under this temperature. In the complex， the structure of the rice bran gluten peptide chain was opened， the content of free sulfhydryl groups increased， the disulfide bonds were broken， and the hydrophobic groups exposed. β-sheets of rice bran glutenin transformed into α-helices and β-turns to form intermolecular hydrogen bonds in the form of covalent bonds. This would make the complex aggregate molecules easier adsorpted to the oil-water interface， and the emulsifying activity and emulsifying stability of the complex aggregate were significantly improved（P<0.05）. These results provided theoretical basis for the subsequent improvement of the functional properties of rice bran protein and the deep processing of rice bran protein.
To clarify the current situation of heavy metal content in the muscles of commercially available freshwater fish in Hubei， Guangdong， Henan and Heilongjiang provinces， 133 samples of 11 species of freshwater fish were collected from September to October 2021 in 11 cities and districts the above four provinces， Concentrations of chromium （Cr）， copper （Cu）， total arsenic （As）， cadmium （Cd）， mercury （Hg） and lead （Pb） in muscle were determined by inductively coupled plasma-mass spectrometry （ICP-MS）. The results of the pollution evaluation according to the National Standard for Food Safety Limits for Contaminants in Food （GB 2762-2017） showed that the five heavy metals Cr， Cu， Cd， Hg and Pb did not exceed the limits in the tested samples， while the content of As in freshwater Lateolabrax japonicus and Channa argus exceeded the limit （0.1 mg·kg-1）， with levels of 0.182～0.738 mg·kg-1 and 0.180～0.628 mg·kg-1， respectively.
Wolfberry production has become a major agro-industry on the Qinghai-Tibetan Plateau， but there are some problems such as low nitrogen utilization rate and environmental pollution. Appropriate N inputs with nitrification inhibitor are beneficial for reducing N loss， improving N use efficiency and mitigating GHG emissions. In order to explore the suitable fertilization method of wolfberry cultivation， the experiment in Qinghai Nuomuhong Farm was conducted in Qaidam in 2020， using 11-year-Ningqi 1 as the experimental material， setting four treatments （N267 267 kg N·hm-2； N133 133 kg N·hm-2； N267I1.33 267 kg N·hm-2 combined with 1.33 kg nitrapyrin·hm-2； N133I0.67 133 kg N·hm-2 combined with 0.67 kg nitrapyrin·hm-2）， which aimed to estimate the effect of N application rate and nitrapyrin on the fate of 15N-urea in wolfberry-soil system. Our results indicated that N267I1.33 maximized dry matter accumulation， N uptake and plant 15N accumulation （Ndfa）， which was 25.04%， 30.17% and 1.96% higher than N267， respectively. Compared with other treatments， the soil 15N residues in 0-200 cm soil layer of N267I1.33 increased by 73.89%~122.47% in autumn fruiting period， and 80.33%~165.86% in dormancy period. N267 treatment resulted in the highest 15N loss rate， which was 4.25 percentage points higher than that of N267I1.33， while the 15N loss rate of N133I0.67 was the lowest， 2.08~10.29 percentage points lower than that of other treatments. The fruit yield of N267I1.33 was the highest， which was 5.00%~9.48% higher than other treatments. In conclusion， the addition of nitrapyrin is beneficial for improving the 15N-urea residue and reducing soil N loss in later stage of wolfberry growth. The combination of 267 kg N·hm-2 with 1.33 kg nitrapyrin·hm-2 could obtain the highest fruit yield of wolfberry， plant N uptake and soil N residue， which was the recommendation of N application in high-fertility wolfberry orchard in Qaidam. The results of this study provide a scientific basis for rational fertilization wolfberry production in Qaidam.
13C tracing is an effective way to accurately quantify the contribution of plant carbon sources to soil carbon. In order to establish an economical and applicable 13C pulse labeling method for sugarcane and obtain 13C enriched sugarcane leaves， a self-made fully closed labeling room was used for labeling experiments in this study. The sugarcane variety was GT58. Four Na213CO3 levels （0， 0.32， 0.64 and 1.28 g·m-3） were conductedand recorded as CK， T1， T2 and T3. 13CO2 pulse labeling was performed every 7 d for 6 h， a total of 6 times. At the beginning and end of the sixth pulse labeling， the gas in the labeling room was collected， and the CO2 concentration and δ13C-CO2 were measured. Plants were destructively collected in 7 d after the 2nd， 4th and 6th labeling， and the δ13C value， total carbon and contents of N， P and K in sugarcane leaves and roots were measured. The 13C labeling efficiency of sugarcane leaves and roots was further calculated. The results showed that more than 95% of the 13CO2 released by the exogenous source was utilized by sugarcane photosynthesis during the sealed marking time.The δ13C value and F value of cane leaves increased with the increase of labeling times and Na213CO3 labeling concentration. After 4 and 6 times of labeling， the average labeling efficiency of 13C in sugarcane leaves was 25.2% and 36.6%， respectively. In general， 13C enriched sugarcane leaves can be obtain by labeling once every 7 days with 0.32 g·m-3 Na213CO3 for 6 h， and labeling 4 times. The results of nutrient contents showed that the contents of N， P and K in sugarcane leaves marked by T1 and T2 concentrations were significantly higher than or equivalent to those in unlabeled sugarcane leaves. After labeling for 4 times， N， P and K contents in labeled roots decreased by 7.9%~32.9%， 0.9%~20.7% and 21.9%~47.9% compared with unlabeled roots except for P content in roots labeled with T2 concentration. The contents of N and K in sugarcane leaves were significantly or extremely significantly negative correlated with that in roots. It can be seen that 13C pulse labeling affects the absorption and distribution of N， P and K in sugarcane， and promotes the migration of N and K from roots to sugarcane leaves. This study provides a reference for efficient labeling of sugarcane isotopes and nutrient management of sugarcane during labeling， and provides scientific materials for further research on the turnover of sugarcane straw carbon in the system of atmosphere-plant-soil.
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.
To explore effects of nitrogen application rate on the activities of enzymes related to grain nitrogen metabolism and grain protein synthesis of weak gluten wheat after rice stubble， five nitrogen application levels were set to study the effects of different nitrogen application treatments on the activities of key enzymes of grain nitrogen metabolism， the contents of grain soluble protein， free amino acids and irrigation under the field conditions. The results showed that in the range of 0～300 kg·hm-2 nitrogen application， with the increase of nitrogen application， the activities of nitrate reductase （NR）， glutamine synthetase （GS）， glutamic pyruvic transaminase （GPT） and glutamic oxaloacetic transaminase （GOT） during grain filling appeared an upward trend. Compared with the treatment without nitrogen application， the NR activities of wheat grains at test point 1 and test point 2 under nitrogen application treatment increased by 0.48%～28.26% and 9.49%～23.02%， GS activities increased by 7.65%～46.46% and 15.97%～57.32%， GPT activities increased by 18.79%～74.20% and 10.31%～65.13%， GOT activities increased by -5.58%～55.23% and 29.76%～66.59%， respectively. Free amino acid， soluble protein， protein content and protein components of wheat grain at grain filling stage increased with nitrogen application， but when the nitrogen application rate was higher than 225 kg·hm-2， the protein content of wheat grain exceeded the national protein content standard of weak gluten wheat. Correlation analysis showed that the correlation between nitrogen metabolism related the activities of enzymes and free amino acids， soluble protein， grain protein content， gliadin and albumin content at grain filling stage reached a significant level. Wheat grain yield increased first and then decreased with the increase of nitrogen application rate， reaching the maximum value at the nitrogen application rate of 225 kg·hm-2. Compared with the treatment without nitrogen application， the wheat grain yield at test point 1 and test point 2 under nitrogen application treatment increased by 129.63%～230.54% and 72.22%～131.98%， respectively. In conclusion， combined with the selection conditions to ensure the yield and quality of weak gluten wheat and the less impact of nitrogen application on the environment， the nitrogen application rate of 225 kg·hm-2 in Anhui Province is more appropriate. The results of this study provide a theoretical basis for high-efficiency and high-quality production of wheat in weak gluten wheat areas of rice stubble along the Huaihe River in Anhui Province.
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.
The current study aims to clarify the spatiotemporal distribution of wheat root and its relationship with soil available nutrients content. The research was carried out to provide a technical support for effective absorption and utilization of nutrients and ensuring the high and stable yield of wheat. During the wheat growing seasons from 2020 to 2021， a split block design was employed with two wheat cultivars， Zhoumai 30 of large-spike cultivar and Zhoumai 32 of multi-cultivar， and three planting density， which were 1.2×106， 2.4×106 and 3.6×106 plants·hm-2. In 0~20 cm and 20~40 cm soil layer the cubic iron box （20×5×20 cm） was used to get the samples from just above the wheat row， be situated in 1/4 row space， and be situated in 1/2 row space. Root morphological quantitative characteristics （root length density， average root diameter， root volume and total root surface area） and soil available nitrogen， soil available phosphorus and soil available potassium content were determined. The results showed that， in 0~20 cm and 20~40 cm soil layers， total root surface area， root length density and root volume were first increased and then decreased with the development of growing period. In 0~20 cm soil layers， the curve of average root diameter was shaped as a W with the development of growing period. In 20~40 cm soil layers， the curve of average root diameter was shaped as an N with the development of growing period. In the vertical distribution of wheat root， total root surface area， root length density and root volume in 0~20 cm soil layer were significantly higher than those in 20~40 cm soil layer. Average root diameter in 20~40 cm soil layer was higher than that in 0~20 cm soil layer. In the whole growing period， the horizontal distribution of total root surface area， root length density， root volume， in 0~20 cm soil layer was showed as the just above the row > be situated in 1/4 row space > be situated in 1/2 row space. In 0~20 cm soil layer， average root diameter was the highest on just above the row. In soil layer of 20~40 cm， root distribution was relatively uniform， total root surface area， root length density and root volume were the highest on where be situated in 1/4 row space. In 0~20 cm soil layers， root length density， root volume and total root surface area of Zhoumai 32 were the highest at planting density 2.4×106 plants·hm-2. In 0~20 cm soil layers， average root diameter of Zhoumai 30 was the highest at planting density 1.2×106 plants·hm-2. The proportion of root length density， root volume and total root surface area in be situated in 1/4 row space and be situated in 1/2 row space increased with increasing planting density， and Zhoumai 32 is even more obvious. In 0~20 cm and 20~40 cm soil layers， root length density and total root surface area were significantly negatively correlated with contents of soil available nitrogen， soil available phosphorus and soil available potassium during the whole growing period. In 0~20 cm and 20~40 cm soil layers， average root diameter was significantly positively correlated with contents of soil available nitrogen， soil available phosphorus and soil available potassium during the whole growing period. In 0~20 cm soil layer， root volume was negatively correlated with contents of soil available nitrogen， soil available phosphorus and soil available potassium during the whole growing period. In 20~40 cm soil layer， root volume was significantly negatively correlated with content of soil available phosphorus during the whole growing period.These results suggested that the horizontal distribution of root biomass， the further away from the wheat row the less the root biomass， in 0~20 cm soil layer. The horizontal distribution of soil available nutrients content， the further away from the wheat row the more the soil available nutrients content. The root biomass of Zhoumai 32 was the highest at planting density 2.4×106 plants·hm-2. The proportion of root biomass of the further away from the wheat row the increased with increasing planting density， and Zhoumai 32 is even more obvious.The results of the current study provide guidelines for the coordinated spatiotemporal differences between soil nutrient supply and wheat nutrient demand and improving the efficiency of soil nutrient absorption and utilization.
This study was aimed to study the yield and quality of silage maize to meteorological factors， and discuss the relationship between climate and silage maize yield and quality in the mid-late maturing region of eastern inner Mongolia. Silage maize varieties of Beinong silage 368， Dongke 301， Jingke silage 516 and Jingke 968 were used as tested materials for the sowing experiment in Tong Liao in 2018 and 2019. We set four sowing dates which were D1（24th April）， D2 （1st May）， D3 （8th May）， and D4 （15th May）， respectively， to determine the changes of yield and quality of silage maize under different sowing dates， and analyze the response of yield and quality formation of silage maize to meteorological factors. The results showed that with the delay of the sowing date， the growth process of silage maize shortened， and the plant height and stem diameter of all varieties showed an increasing trend， while the number of green leaves had little changes， and the ear height of D2 sowing date was higher. The maximum biomass yield of different varieties was at D2 sowing date. With the delay of sowing date， the neutral detergent fiber and acid detergent fiber content were increased， while the starch content was higher at D2， however the crude protein content of different varieties changed little. A linear function was found between yields and sunshine duration （R2=0.381，P=0.031）， effective precipitation （R2=0.591， P<0.001）， sunshine duration after silking （R2=0.507， P=0.003）， and precipitation after silking （R2=0.367， P=0.039）. A significant difference was found in neutral detergent fiber and acid detergent fiber due to different effective temperature after silking， sunshine duration after silking， and precipitation after silking， Sunshine duration （R2=0.475， P=0.006）， effective precipitation （R2=0.556， P<0.001）， sunshine duration after silking （R2=0.432， P=0.014） and precipitation after silking （R2=0.665， P<0.001） had significant effects on starch content. In conclusion， sunshine duration and rainfall played an important role in silage maize production and development， yield and quality in middle and late maturing region of eastern Inner Mongolia， and the best sowing date was nearly 1st May. The results provide a theoretical basis for high quality and high yield cultivation of silage maize under climate change.
This paper aimed to clarify the changes of fruit quality and green nut cracking rate of six walnut varieties in Yecheng County， J.regia Wen185， J.regia Xinxin2， J.regia Xinfeng， J.regia Zha343， J.regia Xinguang and J.regia Wen179 at different harvesting times， and determine the suitable harvest times of 6 kinds of walnut in Yecheng County. In this experiment， the appearance quality of 6 walnut samples （three diameters， single nut weight， shell thickness， kernel yield， rate of re-nurture kernel， moisture content） and internal qualities （fat， protein， soluble sugar， vitamin E and mineral element content） of six walnut samples were determined. The results showed with the delay of harvesting time， the three diameters of nuts， single fruit weights， kernel yields and rates of re-nurture kernel of the six walnuts varieties showed an increasing trend， the shell thicknesses and water contents showed a decreasing trend， while the intrinsic qualities showed an overall increasing trend. J.regia Wen185 harvested on September 4 with J.regia Xinxin2 on September 24， J.regia Xinfeng on September 14， J.regia Zha343 on September 14， J.regia Xinguang and J.regia Wen179 on September 19， which have basically set the qualities of walnut nuts， fats and protein contents， etc. Too early and too late harvesting will have impact on nuts’ commercial value. Correlation analysis showed that the greater the green nut dehiscence rate， the larger the fruit and the higher the content of intrinsic nutrients. The green fruit dehiscence rate can be used as an important basis for judging that six kinds of walnuts in Yecheng County have entered the suitable harvesting period. According to comeprehensive assessment， the green nut rate of J.regia Wen185， J.regia Xinxin2， J.regia Xinfeng， J.regia Xinguang and J.regia Wen179 reached 75%， while green nut rate of J.regia Zha343 reached 55%. The results of this study provided a theoretical basis for further processing， storage and classification of 6 kinds of walnut after harvesting in Yecheng County.