Abstract:Objective To screen strains for producing α-ketoglutaric acid by solid fermentation, and study the effects of fermentation products on animal growth, intestinal structure and immune function.Method Nine strains (including lactic acid bacteria, yeast and Aspergillus) were fermented and α-ketoglutaric acid content in the fermentation products was detected. Succinic acid was added during the fermentation to study its effect on the production rate of α-ketoglutaric acid. Subsequently, sixteen 4-week-old C57/BL mice were randomly divided into two groups, 5% normal fermented material or 5% α-ketoglutarate-rich fermented material was added to the common diet for four weeks. Animal feeding and growth, intestinal structure, and phagocytosis and blood picture of monocyte-macrophages were analyzed.Result The solid fermentation of yeast produced a trace amount of α-ketoglutaric acid, Bacillus subtilis produced about 60 μg/g α-ketoglutaric acid, and α-ketoglutaric acid was not detected using other strains. The addition of succinic acid to the solid fermentation of Bacillus subtilis promoted the accumulation of α-ketoglutaric acid with the maximum production rate of 0.3%. Dietary supplementation of 5% targeted α-ketoglutarate fermentation product slightly reduced body weight and body weight gain of mice(P>0.05), significantly increased the soleus muscle weight of mice (P<0.05), and significantly reduced brown fat weight in mice (P<0.05). The fermentation product had no significant effect on the villus length and crypt depth of mouse ileum and jejunum. Blood and immunological indicators revealed that α-ketoglutarate-rich fermentation product significantly reduced the percentage of neutrophils, increased the percentage of lymphocyte, and increased the content of red blood cell hemoglobin. Moreover, the fermentation product also significantly increased the phagocytic function of mouse monocyte-macrophages (P<0.05).Conclusion The addition of succinic acid can promote accumulation of α-ketoglutaric acid in the solid fermentation process of Bacillus subtilis. Adding α-ketoglutarate-rich fermentation in the diet can significantly increase the muscle weight, decrease the fat weight of mice, and significantly improve the immune function of mice.

Abstract:Objective To analyze the current situation and existing problems of cross-breeding utilization of Leiqiong yellow cattle in Zhanjiang,promote the application of the hybrid improvement technology of Leiqiong yellow cattle, and improve the production efficiency and economic benefits of beef cattle.Method We selected Simmental×Leiqiong F1 generation, Limousin×Leiqiong F1 generation, Angus×Leiqiong F1 generation and Leiqiong yellow cattle as the research object. Under the same feeding conditions, 390 hybrids of F1 generation and Leiqiong yellow cattle including newborn, 3-month-old, 6-month-old and 24-month-old cattles were selected, and their body weight and body size indicators were measured. Three 24-month-old F1 hybrid cattles and three Leiqiong yellow cattles were slaughtered, and the longest back muscles were selected for meat quality analysis.Result Limousin cattle had obvious effects on variety improvement through hybridizing with Leiqiong yellow cattle, especially in improving the birth weight, 24-month-old weight and body size development. The meat tenderness of Limousin×Leiqiong F1 generation was better compared with other three groups, while Simmental×Leiqiong F1 generation had the worst meat tenderness. The eye muscle area of Simmental×Leiqiong F1 generation was larger than that of Leiqiong yellow cattle. The eye muscle area of Angus×Leiqiong F1 generation was larger compared with other three groups. The shortcoming of white beef in Leiqiong yellow cattle was improved in the F1 generation of three hybrid groups. The essential amino acid contents of Limousin×Leiqiong F1 generation, Angus×Leiqiong F1 generation and Leiqiong yellow cattle were not significantly different, while the essential amino acid content of Simmental×Leiqiong F1 generation was significantly lower than that of Leiqiong yellow cattle.Conclusion Limousin cattle has a better overall performance in improving the body shape, growth rate and meat quality of Leiqiong yellow cattle.

Abstract:Objective To analyze the factors affecting weaning-to-service interval(WSI) of sows, estimate genetic parameters of WSI in sows, and provide theoretical references for pig breeding program.Method The research data are the reproductive records of Yorkshire and Landrace in two farms (A and B) of South China collected from 2011 to 2016. Duncan's method was used to analyze the factors affecting WSI of sows. The genetic parameters were estimated using AI-REML of DMU software combined with EM algorithm.Result Parity and weaning years had highly significant effects on WSI of sows (P<0.01). Weaning season had highly significant effect on WSI of Landrace sows in both A and B farms and Yorkshire sows in B farm (P<0.01), while it had no significant effect on WSI of Yorkshire sows in A farm (P>0.05). The number of suckling piglets had no significant effect on WSI of sows in both farms (P>0.05). The heritabilities of WSI in Yorkshire and Landrace sows in A farm were 0.02 and 0.04 respectively, and the heritabilities of WSI in both Yorkshire and Landrace sows in B farm were 0.06.Conclusion The WSI of sows in South China is a low heritability trait, which is significantly affected by parity and weaning season. In practical production, the WSI of sows after first delivery should be shortened,and the sows should be weaned in cold season.

Abstract:Objective To compare the expression profiles of mRNA among ovarian stroma, large follicles and small follicles of goat (Capra hircus), and lay a foundation for exploring the mechanism of follicular development.Method High-throughput sequencing technology was used to sequence the transcriptome of ovarian stroma, large follicles and small follicles in Chuanzhong black goats during estrus. The expression profiles of mRNA were detected by bioinformatics, and the differentially expressed genes were screened out. The GO and KEGG pathways of differentially expressed genes were analyzed. Finally, five differentially expressed genes were randomly selected and were verified by fluorescence quantitative PCR.Result The differentially expressed genes of ovarian stroma vs large follicles, ovarian stroma vs small follicles and small follicles vs large follicles were 524, 180 and 403, respectively. Fifteen genes related to follicular development, such as INHA and TNFRSF19, were screened. They were mainly involved in endoplasmic reticulum protein processing, steroid biosynthesis, oocyte meiosis signaling pathway and so on. Quantitative results were basically consistent with sequencing results verified by qRT-PCR.Conclusion The gene expression profiles of ovarian stroma, large follicles and small follicles in Chuanzhong black goats are different, and the gene expression patterns of small follicles and ovarian stroma are relative more similar.

Abstract:Objective To explore the effects of M gene rearrangement of rabies virus HEP-Flury on gene transcription and protein expression, reveal the correlation between phenotypic consequences of virus in mouse neuroblastoma (NA) cells and M gene rearrangement.Method The gene transcription, expression, growth and spread of parent strain rHEP-Flury and M gene rearranged virus stains (M2 and M4) in infected NA cells were compared by fluorescence quantitative PCR, Western blot, growth and spread experiments of virus in NA cells.Result The transcription and expression of rabies virus structural gene were mainly affected by RNA synthesis of virus genome. The gene position mainly affected the ratio of transcription in a complete transcription process. The transcription ratios of leader RNA (LeRNA) and L mRNA of M gene rearranged viruses were significanthy higher than those of rHEP-Flury. The growth and spread of M gene rearranged viruses in NA cells were inferiorer than rHEP-Flury.Conclusion rHEP-Flury has wild-type gene order of rabies virus. Its growth and spread in NA cells are superiorer to M gene rearranged viruses. The position of structural gene in genome determines its transcription ratio in a complete transcription process and affects the growth and spread of virus in NA cells.

Abstract:Objective To understand the parameters of nutrient requirement for fruit-bearing plants of the main cultivars of litchi (Litchi chinensis Sonn.) and the relation between litchi plant nutrient and soil fertility, and supply the basic data for nutrient management of litchi.Method Ten plants from ten litchi main cultivars including ‘Feizixiao’, etc, with medium to high fruit yield and approximately 15 years of age, were excavated at fruit harvest in the main production areas of South China. The biological characteristics of these plants were examined. Moreover, leaf, fruit, trunk and root samples of ten cultivars were collected to investigate the nutrient accumulation and distribution in various parts of litchi plants. The relations between tissue nutrient contents in litchi plants and soil nutrients were calculated.Result The aboveground biomass of these trees ranged from 158.2 to 344.9 kg. Fruit yield per tree varied from 38.4 to 101.8 kg and accounted for 18.0%-38.1% of total biomass of the aboveground part. Litchi leaf contained the highest nitrogen (N) content, while trunk had the maximum calcium (Ca) or N content. N or potassium (K) was detected with the upmost content in epicarp, endocarp, pulp and seed, whereas Ca commonly dominated in root. Molybdenum (Mo) was undetectable in various parts in some cultivars. Based on the yield of 50 kg fruit, N, P, K, Ca and magnesium (Mg) accumulation of litchi aboveground part was 811.9, 86.4, 586.0, 792.5 and 112.8 g respectively. And 114.5 g N, 14.4 g P, 105.1 g K, 21.6 g Ca and 12.5 g Mg were taken away with 50 kg fruit harvest, which amounted for 15.8%, 18.9%, 20.2%, 3.4% and 12.6% of total N, P, K, Ca and Mg nutrients accumulated in the aboveground part of litchi, respectively. Foliar K, Ca and Mg contents had a significantly positive correlation with soil available K, Ca and Mg contents respectively (P<0.05), whereas the other forliar nutrients were not closely related to soil nutrients.Conclusion The nutrient removal by fruit harvest and pruning is the lowest nutrient addition amount to maintain soil fertility and healthy plant growth for the next year. Soil available K, Ca and Mg contents can be used to predict K, Ca and Mg contents in litchi leaves. Application of Ca, Si and Mo in litchi is recommended to be further investigated.

Abstract:Objective To investigate the impacts of earthworms on soil acidification characteristics and aluminum (Al) fractions of latosolic red soil in South China, and provide a theoretical basis for acidification improvement of latosolic red soil in South China.Method The earthworms (Eisenia fetida) were incubated with latosolic red soil under laboratory conditions. After 40 days of incubation, Al fractions in earthworm cast and soil,namely exchangeable (Al_Ex), weakly organically bound (Al_Orw), organically bound (Al_Or), amorphous (Al_Amo), Al occluded in crystalline iron oxides (Al_Oxi), and amorphous aluminosilicate and gibbsite (Al_Aag) fractions, were determined using sequential extraction methods. Earthworm cast and soil pH, organic carbon, total nitrogen, and cation exchange capacity (CEC) were determined. The principal component analyses were applied to study the distribution of different Al fractions in different treated soils. And the soil without earthworm was set as a control.Result Compared to the control soil, pH of earthworm casts increased by 1.27, the total nitrogen, CEC, Al_Or and exchangeable K, Na, and Ca contents increased by 62.16%, 38.22%, 355.70%, 151.38%, 65.38% and 51.90%, respectively, and Al_Ex contents in earthworm casts and soil decreased by 50.95% and 53.14% respectively. The pH, CEC, Al_Or and exchangeable K, Na, Ca contents in casts were significantly higher than those in non-ingested soil.Conclusion Earthworms can significantly increase soil pH and Al_Or, promote the release of exchangeable Ca²⁺ and Mg²⁺, and reduce soil Al_Ex content.

Abstract:目的 从细菌多样性和组成结构角度评估化学肥料与硅酸钠或蚯蚓结合施用对废弃矿区大豆根际细菌群落的影响，为日后矿区复垦和生态恢复提供理论依据。方法 在广东省梅州市黄畲村废弃矿区种植大豆‘华春9号’，试验设置4个施肥处理：氮磷钾肥结合硅酸钠（3NPK+S和5NPK+S），氮磷钾肥结合蚯蚓20条·m^-2（3NPK+E和5NPK+E），以不施肥为对照（3CK和5CK）。在施肥后3和5个月时对大豆根际土壤进行采样。通过提取土壤细菌总DNA、16S rRNA测序和测定土壤基本化学性质，探究该矿区大豆根际细菌群落多样性和结构对不同施肥处理的动态响应过程。结果 与3CK相比，3NPK+E处理显著增加了Chao1和Shannon指数；与5NPK+E处理相比，5NPK+S处理显著增加了Shannon指数。主坐标分析（PCoA）表明，不同处理下的根际细菌群落组成在操作分类单元（OTU）水平上出现显著分离。从属的相对丰度来看，Uncultured_f_Anaerolineaceae是3NPK+S、3NPK+E、5NPK+S、5NPK+E处理土壤中的优势菌属。基于Mantel检验和典型关联分析（CCA）显示，土壤有机质、有效磷和全碳含量对5NPK+E处理的根际细菌群落有显著影响。结论 施加NPK+S和NPK+E肥料均能有效提高矿区土壤细菌多样性，从而间接对土壤修复起促进作用。施肥方式和处理时间均会显著影响细菌群落组成，并且施肥处理时间越长对细菌群落组成的影响越明显。Uncultured_f_Anaerolineaceae富集在施肥处理下的土壤中，这类细菌可能在促使碳转化的过程中起重要作用，同时还具有修复土壤污染的潜力。NPK+E施用增加了有机质含量，对细菌群落的生长有促进作用。

Abstract:Objective To explore the intraspecific genetic structure and genetic diversity of "Candidatus Liberibacter asiaticus" (CLas) in different regions of Guangdong Province, and evaluate the feasibility of using multiple loci in studying genetic diversity of CLas.Method Six polymorphic gene loci, including three phage regions (SC1, SC2 and PJXGC), transposon region (CLIBASIA_05620 -CLIBASIA_05625) and short tandem repeat (STR) genes, STR1 (CLIBASIA_03080) and STR12 (CLIBASIA_01215), were used to evaluate genetic diversity of 176 CLas samples from 10 cities in Guangdong Province.Result Based on the prophage types, the CLas isolates were classified into six groups, among which the strains with Type II prophage were predominate, accounting for 85.23% of the population. Four types of isolates were identified based on transposon sites, and the Clas strains containing the B350 fragment (non-MCLas-A type) were the dominant group, accounting for 76.70% of the population. Based on the two STR loci, nine and ten band types were identified respectively, and the isolates with three CAGT tandem repeats at the STR1 locus were predominate accounting for 56.82% of the population. The distribution of polymorphic bands at the STR12 locus was scattered, and no predominate band type was identified. Cluster analysis showed that CLas populations from Zhanjiang, Maoming and Shenzhen were different from populations of other regions, while the CLas populations collected from Qingyuan and Meizhou were similar.Conclusion Cluster results based on individual locus and based on all six loci are different, indicating the limitation of using single gene locus to analyze the genetic structure of CLas population.

Abstract:Objective To study the metabolites of a symbiotic fungus Aspergillus clavatus XCE02 from Plutella xylostella and their antifungal activities against plant pathogens.Method The metabolites were isolated and purified by column chromatography. Their structures were elucidated by spectral analysis. The antifungal activities of the metabolites against Colletotrichum musae and Fusarium graminearum were investigated using paper disc-agar diffusion method.Result Ten compounds were isolated and identified as gliomasolide A, Sch725674, gliomasolide C, clavatustide A, clavatustide B, 20-hydroxyergosta-4, 6, 8(14), 22-tetraen-3-one, xanthine, ergosterol, ergosterol peroxide and butanedioic acid. At the concentration of 250 μg/mL, gliomasolide A, Sch725674 and gliomasolide C exhibited high inhibitory activities against C. musae and F. graminearum, clavatustide A and clavatustide B showed moderate inhibitory activities against C.musae and F.graminearum and 20-hydroxyergosta-4, 6, 8(14), 22-tetraen-3-one showed moderate inhibitory activity against F.graminearum.Conclusion Gliomasolide A,gliomasolide C and 20-hydroxyergosta-4, 6, 8(14), 22-tetraen-3-one have been obtained from the genus Aspergillus in this study. Gliomasolide A,Sch725674 and gliomasolide C can be used as leading compounds for developing antifungal pesticide.

Abstract:Objective To investigate the lysis abilities of different phages mixtures against Ralstonia solanacearum, study their effects on the generation of phage-resistant strains, and clarify the receptors of four types of phages.Method Four types of phages, including P1556-1, P1556-2, P7-1 and P1521, were mixed in pairs. The sizes of plaques on R. solanacearum plates were determined. The resistance of R. solanacearum to phages was measured by co-culture of R. solanacearum and phages. Adsorption tests using phages, lipopolysaccharide (LPS) and membrane protein were conducted to determine the receptors of phages.Result Phage P1556-1 produced the largest plaque, indicating a strong lytic ability against R. solanacearum. The plaque sizes from the mixtures of two types of phages did not significantly differ from those of individual phages, while mixing two types of phages could slow down the generation of phage-resistant strains. Phage P1556-2 could be adsorbed by LPS of R. solanacearum, phage P1521 could be adsorbed by both LPS and membrane protein, while phage P1556-1 and P7-1 could be adsorbed by neither LPS nor membrane protein.Conclusion Mixing different phages can not improve the lysis ability against R. solanacearum, but can delay the generation of resistant host strain. The receptors of different phages are different.

Abstract:Objective To study the germination and infecting dynamics of sporangia of Peronophythora litchi under different temperature(θ) and wetness duration(t), construct mathematical models based on θ and t,and provide references for precision prediction, prevention and control of litchi downy blight.Method Under controlled temperature and wetness, the effects of temperature (15 to 30℃) and wetness duration (3 to 24 h) on sporangia germination of P. litchii and its infection on litchi were studied. Using the modified Weibull model, the sporangia germination model and disease severity model with good accuracies were fitted in SAS software. The corresponding contour risk prediction maps were drawn.Result Sporangia germination and disease severity were significantly affected by temperature, wetness duration and their interactions. The sporangia germination rate and disease severity increased along with the prolongation of wetness duration. At the temperature of 25℃, the sporangia germination rate reached the highest for all wetness duration treatments. In the same wetness duration, the disease severity of litchi fruit was the highest at 25℃. When the temperature was 15-30℃ and the wetness duration was 2-3 h, the disease severity of litchi leaf was above 0.2. The sporangia infected fruits seriously and quickly, and the disease severity of fruit was above 0.6 under the temperature of 22-30℃ and the wetness duration of 3-24 h. The disease severity models of leaf and fruit due to infection by P. litchii were f(t, θ)={1-exp[-(0.194 3×t)²]}/cosh[(θ-27.769 6)×0.927 7/2] and f(t, θ)={1-exp[-(0.469 3×t)²]}/cosh[(θ-24.556)×0.170 9/2], respectively.Conclusion The occurrence of litchi downy blight depends on temperature and wetness duration. Our models can be used to guide the time and frequency of fungicide application for disease prevention and control.

Abstract:Objective To investigate the responses of arbuscular mycorrhizal fungi (AMF) community to nitrogen and phosphorus additions and the driven factors in the Qinghai-Tibetan alpine meadow, and have a better knowledge of the effects of fertilization on alpine meadow AMF community.Method Through regular analyses and high-throughput sequencing (Illumina Miseq), we studied the effects of nitrogen addition (0, 7.5, 15.0 g·m^-2) and phosphorus addition (0, 7.5, 15.0 and 30.0 g·m^-2 P₂O₅) for three year on soil chemical property, AMF colonization rate, OTU richness, Shannon diversity index and AMF community composition in Qinghai-Tibetan alpine meadow.Result The 36 AMF OTUs from seven families were detected. The addition of nitrogen, phosphorus and their interaction had no influence on AMF colonization rate, OTU richness and Shannon diversity index. Compared with low nitrogen addition treatment, high nitrogen input treatment significantly decreased the relative abundance of Glomeraceae. Soil organic carbon, nitrate nitrogen, available phosphorus and total phosphorus contents were the factors which impacted AMF community.Conclusion Root AMF community in Qinghai-Tibetan alpine Kobresia meadow wasn't affected by nitrogen or phosphorus addition. However, the distribution of community was significantly correlated with edaphic factors.

Abstract:Objective To determine the classification status of endophytic fungus Eef-10. To isolate and identify secondary metabolites of Eef-10 and evaluate their antibacterial and antitumor activities in order to obtain natural active compounds.Method The endophytic fungus was identified by combining morphology and molecular biology methods. The secondary metabolites were mainly separated and purified by vacuum silica gel column chromatography, sephadex LH-20 column chromatography and semi-preparative HPLC. The compounds were identified mainly based on ¹H NMR and ¹³C NMR spectral data as well as related references. The antibacterial activities against five different test bacteria were determined by the MTT method and the antitumor activities against two cancer cells were determined by the CCK8 method.Result Three compounds were isolated from the endophytic fungus Eef-10, namely atraric acid (Compound Ⅰ), ethyl 2, 4-dihydroxy-3, 6-dimethylbenzoate (Compound Ⅱ) and 4-methyl-5, 6-dihydro-2 H-pyran-2-one (Compound Ⅲ). Compound Ⅱ displayed strong inhibitory activities against five test gram-negative bacteria, and the IC₅₀ values were 35.87-55.50 μg/mL. The IC₅₀ values of compound Ⅰ were 67.25-130.55 μg/mL, while compound Ⅲ had IC₅₀ values of more than 200 μg/mL for all five bacteria. The IC₅₀ value of compound Ⅱ for Hep-G2 was 1.50 μg/mL, which was stronger than the positive control camptothecin of 3.6 μg/mL.Conclusion Compounds Ⅰ-Ⅲ were isolated from the endophytic fungus Chaetomium sp. Eef-10 and compound Ⅱ showed great antibacterial and antitumor activities on R. solanacearum and Hep-G2 tumor cells.

Abstract:Objective To reveal the effects of nitrogen and phosphorus additions on growth and leaf nutrient content of Betula alnoides clone seedlings, and select the optimal fertilization formula.Method Four B. alnoides clones (A5, FB4, FB4⁺, BY-1) were chosen as the materials and a completely randomized experimental design with nine treatments including three N levels (0, 200 and 400 mg per seedling) and three P levels (0, 70 and 140 mg per seedling) was conducted to compare the differences in seedling height, root collar diameter, biomass, ratio of root to shoot, branch number, leaf area and leaf nutrient content of B. alnoides clones in different fertilization treatments.Result Seedling height, root collar diameter, biomass, branch number, ratio of root to shoot and leaf area were significantly affected by fertilization treatment, and the effects of clone-fertilization treatment interaction were significantly different in seedling height, root collar diameter, ratio of root to shoot and branch number. Regardless of the clone, the treatment five had superior seedling height, root collar diameter, biomass, branch number and leaf area, being 2.10%-74.13%, 6.67%-91.45%, 12.24%-358.33%, 2.76%-712.64%, 2.46%-456.31% higher than those of other fertilization treatments, respectively. Leaf N and P contents of different fertilization treatments were significantly different, however there was no significant difference in clones and the interaction between clone and fertilization treatments. The contents of N and P in leaves increased with the additions of nitrogen and phosphorus fertilizers, and additions of nitrogen and phosphorus fertilizers could significantly increase the accumulation of these nutrients in leaves. Seedling biomass, leaf N content, leaf P content and N/P mass ratio were in a parabolic relationship, and they showed a significant positive correlation (P<0.000 1). N/P mass ratio of 15 might be the limiting ratio affecting the growth of B. alnoides.Conclusion Fertilization significantly promotes the growth and improves leaf nutrient contents of B. alnoides seedlings, but there is no significant difference among clones. Based on the seedling growth and leaf nutrient content indexes, treatment five (200 mg N and 70 mg P per seedling) exhibits the optimal growth performance for B. alnoides clones.

Abstract:Objective To realize static obstacle avoidance of autonomous navigation agricultural machinery when it operates in the field.Method Two path planning algorithms of obstacle avoidance were proposed under known working environment. The single obstacle avoidance algorithm was proposed based on the movement rule of agricultural machinery and according to the position and the size of the obstacle. On the basis of the single obstacle avoidance algorithm, according to the size of safe driving area, the double/multiple obstacles avoidance algorithm was proposed according to left and right obstacle avoiding strategies.Result When the single obstacle was located in different locations and the speed of agricultural machinery was 0.3 m·s^-1, compared with L algorithm, driving path reduced by 35%, 26%; Accumulative error of driving path reduced by 53%, 82%; Variance reduced by 64%, 66%. When the driving speed was 0.5 m·s^-1, driving path reduced by 38%, 22%; Accumulative error reduced by 66%, 26%; Variance reduced by 41%, 71%. When the speed of agricultural machinery was 0.3 and 0.5 m·s^-1 under the condition of multiple obstacles, accumulative tracking errors of driving path was 9.99, 4.13 m, and variances were 0.022 1, 0.027 0 m², respectively.Conclusion The proposed algorithm has some advantages in driving path, accumulative error of driving path, stability of theoretical path tracking and adaptability to road condition.

Abstract:Objective To study properties of surface material of wheat grinder roller after laser quenching, and solve the problems of grinding roller such as serious wear and short service life.Method Using the principle of rotating combination design of response surface, a mathematical model of laser power, spot diameter and scanning speed with surface hardness of grinding roller material was established according to three-factor and five-level test method. The effects of laser power, scanning speed, spot diameter and reciprocal action among three factors on grinding roller surface hardness were analyzed. The optimal parameter combination was obtained. The wear mechanism of surface material of the grinding roller after quenching was investigated.Result Laser power, spot diameter and scanning speed significantly affected surface hardness of grinding roller material. The effects of laser power, spot diameter and scanning speed on surface hardness of grinding roller material weakened successively. The optimal technological parameter combination was laser power 190 W, spot diameter 0.70 mm and scanning speed 220 mm/s and the sample surface hardness obtained was 688.67 HV, which was 35% higher than original hardness. The mass loss of sample treated by optimal laser quenching parameter combination in wear process was about 7% of the untreated sample. The friction between grinding roller surface material and wheat powder material after laser quenching weakened. The scratches of wheat powder material on sample surface were lighter and shorter. The grooves were shallower and narrower. Conclusion The wear resistance against wheat powder material of grinding roller surface material is obviously enhanced after laser quenching treatment.