Effects of Abscisic Acid on Cold Resistance in Digitaria sanguinalis(L.)Scop.

[Objectives]This study was conducted to detect the protective effect of abscisic acid on chilling injury of Digitaria sanguinalis(L.)Scop,and whether this effect is related to antioxidant enzymes and osmotic adjustment.[Methods]D.sanguinalis plants were sprayed with abscisic acid solution,and exposed to cold stress at 15℃for 3 d after one day and then at 5℃for 25 to 30 d in a growth chamber.The changes of plant osmotic potential under this treatment were detected.[Results]Under low temperature stress,the osmotic potential of plants in the abscisic acid treatment and the control increased,but the osmotic potential level of the abscisic acid treatment plants was lower.The SOD activity of plants in the ABA treatment and the control decreased under low temperature stress.Under low temperature stress,the activity of catalase and peroxidase in ABA-treated plants was higher than that in control plants.[Conclusions]This study provides a theoretical basis for the impact of abscisic acid on the physiological response of D.sanguinalis to cold injury.

Study on Antioxidant Enzyme Activity and Physiology and Biochemistry of Solanum nigrum L. under Glyphosate Stress

[Objectives] This study was conducted to investigate the scientific prevention and control of Solanum nigrum L. [Methods] Through experiments on S. nigrum from different sources, it was found that glyphosate stress had significant effects on antioxidant enzyme activity and oxidative damage of sensitive S. nigrum plants. [Results] Sensitive S. nigrum showed oxidative damage under glyphosate stress, while resistant S. nigrum responded to adversity damage by improving its antioxidant enzyme activity. The experimental results showed that the antioxidant enzymes and reduced glutathione of S. nigrum had certain metabolic detoxification effects under glyphosate stress. [Conclusions] This study provides a theoretical basis for scientific prevention and control of S. nigrum , and has a certain reference value for revealing the glyphosate resistance mechanism of S. nigrum .

Polysaccharide extract from Rosa laevigata fruit attenuates inflammatory obesity by targeting redox balance and gut interface in high-fat diet-fed rats

Low-molecular-weight polysaccharides(RLPs)extracted from Rosa laevigata fruits showed multiple biofunctions in Asia.This study aimed to investigate its anti-inflammatory obesity effect in high-fat dietfed rats and further elucidated the underlying molecular mechanism by multi-omics methods.The results showed that RLPs administration had significantly restored immune organ indexes and reduced body weight gain.RNA-seq revealed that the effect of RLPs was partially attributed to its regulation on PPARs signaling by increasing the expressions of Scd,Acox3 and Hmgcs2,and on other redox-related pathways by decreasing the expressions of Cyp2 e1,Il1-r1 and Lbp.Moreover,16 S rRNA sequencing coupled with metagenome sequencing showed that RLPs had significantly reduced the ratio of Firmicutes/Bacteroidetes from 8.01 to2.37,and significantly increased the relative abundances of Alistipes,Prevotella,and Akkermansia from 0.36%,1.10%and 2.61%to 0.65%,2.37%and 4.42%,respectively.Spearman correlation analysis result indicated that the abundances of Lachnospiraceae,Prevotella and Bacteroidales were significantly negatively correlated with obesity phenotype,liver function and inflammatory factors.These results revealed that RLPs exerted significant anti-inflammatory obesity property partially via regulation on gut microbiota interface and the redox balance.Therefore,RLPs could be a promising functional food resource with the potential for redox imb alance-related diseases chemoprevention.

Effects of Different Seed Coating Agents on the Quality of"Grey-matter"Hybrid Rice Seeds

[Objectives]This study was conducted to select suitable mixed seed coating agents for improving the quality of"grey-matter"hybrid rice seeds.[Methods]Three different mixed seed coating agents(A,B,C)were used to coat the seeds of two varieties(Taiyou 390 and Zhenliangyou 8612)of hybrid rice with different"grey-matter"content(5%,15%,25%),and the results were investigated and compared.[Results]The combinations of treatment B(seed coating agent A+Linong)and treatment C(Manshijin+seed coating agent A)could significantly improve indexes including seed germination potential,germination rate,seed vigor,seedling height,fibrous roots and fresh weight of the two varieties with a"grey-matter"content greater than 15%,but had no significant effects on main root length,dry weight,leaf number and tiller number,and the effects of treatment B was better than those of treatment C.That is to say,mixed seed coating agent B(seed coating agent A+Linong)was suitable for use as a seed coating agent to improve the quality of"grey-matter"seeds.[Conclusions]This study provides a reference plan for the safe use of mixed seed batches with"grey-matter"deterioration.

Effects of Polygonatum odoratum Polysaccharide on Reproductive Hormones in Male Rats Fed a High-fat Diet

[Objectives]This study was conducted to investigate the effects of Polygonatum odoratum polysaccharide(POP)on organ relative weights and reproductive hormone levels in male rats fed a high-fat diet.[Methods]Thirty healthy male Sprague-Dawley(SD)rats were randomly divided into two groups according to their body weight:10 in normal control group(Group NC,n=10)and 20 in experimental group(n=20).The rats in experimental group were fed a high-fat diet for eight weeks before they were further randomly divided into two groups:high fat group(Group HF)and high fat+400 mg/(kg·d)POP group(Group HF+POP).In Group HF+POP,the rats were administered with POP for another six weeks,before their blood plasma was collected,and the relative weights of their testis and epididymis were calculated.The plasma levels of testosterone(T),estrogen(E2),follicle-stimulating hormone(FSH),cortisol(C)and luteinizing hormone(LH)were measured by radioimmunoassay,and the plasma levels of sex hormone-binding globulin(SHBG)and insulin-like growth factor-1(IGF-1)were determined by enzyme-linked immunosorbent assay.[Results]Compared with Group HF,POP could effectively inhibit rat obesity caused by high-fat diets,increase the relative weights of their testis and epididymis,plasma levels of LH,E2,FSH,T,SHBG and IGF-1,and reduce the plasma level of E2.[Conclusions]Polygonatum odoratum polysaccharide(POP)is able to effectively regulate the level of reproductive hormones in high-fat diet fed rats,and helps to protect their reproductive function.

Effects of Ethanol Condensation Reflux Extraction and Ultrasound-assisted Extraction on the Content of Total Flavonoids of Pueraria edulis

With Pueraria edulis from different habitats in Yunnan Province,Guangdong Province and Guangxi Zhuang autonomous region as materials,the medicinal materials of P.edulis were extracted by ethanol condensation reflux extraction and ultrasound-assisted extraction,and the effects of different extraction methods the contents of total flavonoids in P.edulis from different areas were compared.The results showed that the best extraction time for P.edulis in Yunnan Province was 20 min,and that for Guangdong and Guangxi Zhuang Autonomous Region was 30 min.The yield of total flavonoids from P.edulis extracted by the condensation reflux extraction method was relatively better.The content of total flavonoids in P.edulis in Yunnan was the highest with an average content of 0.2557%,while the average content of total flavonoids in P.edulis in Guangdong was the lowest with an average content of 0.2108%.

Common Species Distribution Models in Biodiversity Analysis and Their Challenges and Prospects in Application

Species distribution models have been widely used to explore suitable habitats of species,the impact of climate change on the distribution of suitable habitats of species,and the construction of ecological reserves.This paper introduced species distribution models commonly used in biodiversity analysis,as well as model performance evaluation indexes,challenges in the application of species distribution models,and finally prospected the development trend of research on species distribution models.

Effects of Polygonatum sibiricum Polysaccharide (PSP) on Inflammatory Factors in Rats Fed on High-fat Diet

[Objectives]This study was conducted to explore the effects of Polygonatum sibiricum polysaccharide(PSP)on chronic intestinal inflammation caused by high-fat diet.[Methods]Thirty five male healthy SD rats were randomly divided into a normal control group(NC,normal diet,n=10)and a high-fat diet group(HF,high-fat diet,n=25).After 8 weeks,an obesity model was established.The HF group was randomly divided into an HF group and a PSP treatment group[PSP,300 mg/(kg·d)].After 6 weeks of intervention with PSP,rat serum was collected,and the spleen and thymus were stripped,and weighed.Serum IgG,IgM,LPS and IL-1βand IL-6 contents were detected by ELISA,and HE staining was adopted to observe the pathological changes of the colon tissue.[Results]PSP reduced the level of LPS caused by high-fat diet and the levels of inflammatory factors IL-6 and TNF-α,increased the indexes of the thymus and spleen serving as immune organs,increased IgG and IgM contents,and alleviated pathological damage to the colon tissue caused by high-fat diet.[Conclusions]This study provides a theoretical basis and experimental basis for the development of drugs for treating metabolic diseases such as obesity and inflammation.

Effects of Polygonatum sibiricum Polysaccharide on Antioxidant Capacity of the Liver in High-fat Diet Rats

[Objectives]This study was conducted to investigate the effects of Polygonatum sibiricum polysaccharide(PSP)on antioxidant function in high-fat diet obese rats.[Methods]Thirty five healthy male SD rats were selected to establish an obesity model after feeding a high-fat for 8 weeks.They were then randomly divided into a normal group(NC),a high-fat diet group(HF),and an HF+P.sibiricum polysaccharide group[HF+PSP,300 mg/(kg·d)].After 6 weeks of PSP intervention,the serum and liver of rats were collected,and the activity of aspartate transaminase(AST)and alanine aminotransferase(ALT)in serum,the enzyme activity of superoxide dismutase(SOD),catalase(CAT)and glutathione peroxidase(GSH-Px)and malondialdehyde(MDA)in liver tissue were measured.The pathological changes of liver tissue were observed by HE staining.[Results]Compared with the HF group,PSP could effectively inhibit obesity caused by high-fat diet.It reduced body weight and serum AST and ALT levels,increased the contents of T-SOD,CAT and GSH-Px in the liver,and inhibited the accumulation of MDA content,thereby reducing damage to liver cells caused by a high-fat diet.It indicated that PSP could effectively inhibit obesity in high-fat diet rats and enhance their antioxidant capacity.[Conclusions]This study provides a reference for the study of the antioxidant capacity of PSP.

Effects of Polygonatum odoratum Polysaccharides on the Quality of White Chili Peppers in Jars

[Objectives]This study was conducted to investigate the effects of Polygonatum odoratum polysaccharides on the quality of white chili peppers in jars.[Methods]White chili peppers were pickled by adding different concentrations of P.odoratum polysaccharides with traditional pickling technology,and its nitrite content,pH and sensory quality were analyzed and detected.[Results]The results showed that,compared with the control group without adding P.odoratum polysaccharides,the nitrite content in white chili peppers in jars decreased after adding P.odoratum polysaccharides.When the addition amount of P.odoratum polysaccharides was 0.002%,the inhibition rate of nitrite reached the maximum.Under the same fermentation time,P.odoratum polysaccharides could significantly reduce the pH value of pickles.When the addition amount of P.odoratum polysaccharide was 0.002%and the pickling time was 3 months,the sensory quality of white chili peppers in jars was the best.At this point,white chili peppers in jars had rich aroma and tasted soft and sour,and the sour and salinity were suitable.As the fermentation time continued to increase,the chili aroma of white chili peppers in jars gradually decreased,and the sour taste became more pronounced.[Conclusions]This study can provide reference for the safety and quality control of white chili peppers in jars.

Effects of Different Proportions of Spent Pleurotus ostreatus Substrate on Seed Germination and Seedling Growth of Mung Beans

[Objectives] This study was conducted to investigate the effects of different proportions of spent Pleurotus ostreatus substrate on the germination and seedling growth of mung beans. [Methods] The cellulose-degrading bacteria HB8 and HF1 were mixed with a commercially available microbial composting agent, respectively, for the composting of spent P. ostreatus substrate. Mung beans were cultivated with different proportions of spent mushroom substrate compost and soil. The seed germination rate, plant height, fresh weight and chlorophyll content of mung bean were used as indicators to investigate the effects of the organic fertilizer from spent P. ostreatus substrate on the growth of mung bean seedlings. [Results] The addition of cellulose-degrading bacteria can significantly improve the composting effect of the spent mushroom substrate. After 8 d of cultivation of mung beans with different ratios of the mushroom substrate organic fertilizer, 50% of the organic fertilizer can make the plant height, fresh weight and leaf chlorophyll content of mung bean seedlings reach the highest value and was suitable for mung bean breeding and cultivation. [Conclusions] This study provides scientific basis and technical indicators for the rapid and harmless treatment of spent mushroom substrate and its application in crop cultivation and nursery.

Research Progress on the Invasion Mechanism of Erigeron annuus

Erigeron annuus(L.)Pers.,an alien species,is widely distributed in most areas of China.It was included in the third batch of invasive alien species list by the Ministry of Ecology and Environment of China,and it is a first-level malignant invasive plant.Due to its great reproducibility with a mass of seeds,power adaptability to the external environment and strong allelopathy,it has highly invasive and adaptability,and has affected the development of the agriculture and forestry,the diversity of local species and the ecosystem.In this paper,we summarized the current invasion situation,invasion and adaptation mechanism of E.annuus,and prospected further research on E.annuus invasion mechanism,hoping to provide a reference for realizing its effective management.

Optimization of Extraction of Saponins from Tribulus terrestris L.

To promote the recovery of saponins from Tribulus terrestris L.,the water dissolution and ethanol precipitation method was adopted to extract saponins from the powder prepared from T.terrestris fruit.The optimal process was to extract with 9 fold of the extracting water at the ethanol concentration of 85 for 3 times,each time 3.5 h.The effects of the factors ranked as the extracting water quantity > treatment time > treatment times > ethanol concentration.Under these optimal conditions,the recovery of saponins was 2.81%.After these crude saponins were purified by D101 macroporous adsorptive resin,the purity was found to be promoted through the UV scanning method,and the recovery of the refined saponins was up to 1.53%.Both of the recovery values were higher than that of the existing process.

Optimization of Enzymatic Extraction of Sodium Chondroitin Sulfate From Bovine Nasal Bone

Taking bovine nasal bone as a raw material,the sodium chondroitin sulfate was extracted by enzymolysis-ion adsorption-alcohol precipitation method,and the enzymolysis process was optimized.After single factor experiments,the response surface analysis was performed by software Design-Expert 8.0,and the optimal enzymolysis conditions were as follows:the trypsin concentration of 0.8%,the pH value of 9.0,the enzymolysis temperature at 52℃,and the enzymolysis time of 2.0 h.With this combination of conditions,the concentration of sodium chondroitin sulfate extract reached 11.3 g/L,the bovine nasal bone yield was 35%,and the finished product content was 92.5%,which provided guidance for industrial production.

Determination of Fosthiazate Residue in Ginger by Gas Chromatography

[Objectives] An analytical method was established for determining fosthiazate residue in ginger by gas chromatography with flame photometric detector(GC-NPD) to evaluate the safety of fosthiazate in ginger. [Methods] The fosthiazate residue in ginger was extracted with dichloromethane, and subjected to sodium chloride salt-out and liquid-liquid extraction with hexane and dichloromethane(the plant and soil samples had no need for the later two steps). The analysis was performed on gas chromatograph equipped with a flame photometric detector(GC-FPD), and the fosthiazate residue was quantitatively determined by calculating the peak area. [Results] The results of degradation dynamics showed that the half-life of fosthiazate was 7.2-8.7 d in ginger plants, and was 9.9-19.8 d in the soil. The results of the final residue test showed that after applying the fosthiazate granules according to the recommended high dose(active component 58.2 g a.i/m^2,WK) and low dose(38.8 g a.i/m^2,WK) once, the final residual amounts of fosthiazate in the ginger and soil were estimated to be <0.02 mg/kg and <0.02-0.103 mg/kg, respectively, while no fosthiazate residue was detected in all control samples(<0.02 mg/kg). The maximum residue limit(MRL) of fosthiazate in ginger was not established in China, and was 0.2 mg/kg in Japan. [Conclusions] The method was proved to meet the basic requirements of pesticide residue analysis on sensitivity, accuracy and precision and have good linearity. It is recommended that when using fosthiazate granules to control root-knot nematode and root rot in ginger, it is applied at the highest dose of 38.8 g ai/m^2,WK once 30 d before ginger cultivation to treat the soil, and ginger is harvested in the ginger harvest period.

Joint Toxicity Determination of Clopyralid,Picloram and Benazolin Mixtures on Broad-leaved Weed Lapsana apogonoides Maxim.in Rape Fields

[Objectives]This study was conducted to investigate the compounding of three herbicides:clopyralid,picloram and benazolin,so as to improve the effectiveness of herbicides.[Methods]With Lapsana apogonoides Maxim.as the target and clopyralid,picloram and benazolin as the test agents,seven gradient concentrations were set up to determine the joint toxicity of the three agents.[Results]When the compounding ratio of picloram,clopyralid and benazolin was 2∶1∶6,the maximum co-toxicity coefficient was 290.0.[Conclusions]The compounding of picloram,clopyralid and benazolin has a significant synergistic effect on L.apogonoides,which reduces production costs and environmental pressure,providing technical support for the effective control of broad-leaved weeds such as L.apogonoides.

Allelopathic Effects of Extracts from Three Asteraceae Plants on Seed Germination and Seedling Growth of Four Plants

[Objectives]This study was conducted to investigate the allelopathic effects of the extracts of Asteraceae plants on plant seeds and seedlings.[Methods]The effects of the extracts of three Asteraceae plants(Erigeron annuus,Bidens pilosa and Inula japonica)on the seed germination and seedling growth of four plants(Setaria viridis,Erigeron canadensis,Chenopodium album and Lactuca sativa)were studied by the Petri dish filter paper method and bioassay method.[Results]Different concentrations(10,20,40,100,200 mg/ml)of the extracts of E.annuus,B.pilosa and I.japonica had different allelopathic effects on the seed germination of the same recipient plant,and with the increase of the concentrations of the extracts,the inhibitory effects were more significant.The extract of B.pilosa had the strongest inhibitory effect.The extracts at the low concentration(10 mg/ml)had no significant effects on the germination rates and germination energy of the four kinds of plant seeds.In terms of root growth and biomass,the extracts of E.annuus and I.japonica showed the effect of low promotion and high inhibition.Under the treatment with high concentrations(100,200 mg/ml)of the extracts from the three Asteraceae plants,the germination of plant seeds,plant root length,stem height and biomass were inhibited.With the concentrations of the extracts of the three Compositae plants increasing,the chlorophyll contents of the four plants showed a downward trend,and the activity of SOD,POD,CAT and other antioxidant protective enzymes showed a trend of first increasing and then decreasing.[Conclusions]These three species of Asteraceae plants had certain allelopathic inhibitory effects on the germination and growth of the four kinds of plant seeds,including S.viridis,E.canadensis,C.album and L.sativa,and they have potential in the development of botanical herbicides or plant protection.

Study on the Resistance Levels of Different Echinochloa crusgalli Populations to Penoxsulam and Bispyribac-sodium

[Objectives]This study was conducted to screen the resistance of Echinochloa crusgalli in some paddy fields in Changde City,Yiyang City and Yueyang City in Hunan Province to penoxsulam and bispyribac-sodium.[Methods]The resistance to penoxsulam and bispyribac-sodium was screened in 11 E.crusgalli populations collected from rice production areas in Changde,Yiyang and Yueyang Cities,Hunan Province,and the resistance level of population HU-2 to penoxsulam was determined.[Results]HU-1 to HU-6 and HU-8 A,a total of seven populations showed high levels of resistance to penoxsulam and bispyribac-sodium.The resistance level of population HU-2 to penoxsulam was extremely high;population HU-7 showed low-level resistance to both drugs;HU-11 population showed low-level resistance to penoxsulam and was susceptible to bispyribac-sodium;and populations HU-8 and HU-9 were susceptible to penoxsulam and bispyribac-sodium.[Conclusions]This study provides a technical basis for the rational use of penoxsulam and bispyribac-sodium and the selection of control chemicals for E.crusgalli in paddy fields.

Harm,Reproduction,Invasion and Control of Spodoptera frugiperda

Spodoptera frugiperda is becoming more and more widely distributed in various regions of the world,and it does more and more harm to agriculture,which seriously affects the growth and development of crops.In this paper,focuses were laid on the harm,reproduction,invasion and control of Spodoptera frugiperda,with the aim to provide more scientific bases for agricultural departments to guide agricultural production and pest control.

Target Resistance of Eleusine indica to Glyphosate

[Objectives]This study was conducted to detect the evolution of resistance to glyphosate in Eleusine indica.[Methods]In the previous study,glyphosate-resistant population T2-4 was screened out from E.indica populations in sugarcane fields in Guangxi.In this study,we determined the resistance index of T2-4 by whole plant bioactivity assay and further explored the molecular biological mechanism of resistance.[Results]The resistance index of T2-4 was 112,and it is thus a highly resistant population.Amino acid mutations were found at positions 102,106 and 381 in the EPSPS sequence of T2-4,containing at least a triple mutation allele in Thr-102-Ile,Pro-106-Ser and Pro-381-Leu and a double mutation allele in Pro-106-Ser and Pro-381-Leu.qPCR was used to determine the EPSPS gene copy number and expression in resistant plants of T2-4.EPSPS gene copy number and expression both increased,with 8.3-fold higher copy number and 2.7-fold higher expression than the sensitive population.Therefore,the resistance of T2-4 to glyphosate was mainly caused by multiple target mechanisms including mutation of EPSPS gene,copy number increase and expression increase,and the resistance of E.indica to glyphosate needs our high attention.[Conclusions]At present,the level of resistance to glyphosate is very high in the sugarcane fields of Guangxi,and it is necessary to take a variety of weed control measures to solve the problem of glyphosate resistance.