Analysis of microRNA Expression Characteristics Related to Low Temperature Stress in Chewing Cane

[Objectives]To explore microRNA expression characteristics related to low temperature stress in chewing cane.[Methods]The research on miRNA under abiotic stress of sugarcane at home and abroad mainly focused on the types and regulation of miRNA under cold,heat,drought,high salt,and mechanical stress.However,there are few studies on miRNA under low temperature stress in chewing cane.The target genes of miR394 and miR825 in chewing cane were predicted and functionally analyzed by bioinformatics technology.[Results]The results showed that the target genes of miR394 and miR825 were mainly members of the WRKY transcription factor family,involved in plant growth,development and stress resistance.Real-time fluorescence quantitative PCR analyzed the expression characteristics of target miRNA in different tissues of chewing cane at different periods of low temperature stress.[Conclusions]The results showed that the expression of chewing cane miR394 and miR408 had temporal and spatial specificity and tissue specificity,both of which could respond to low temperature stress with significant differential expression.

Residue of Organphosphorus Pesticides in Chewing Cane Juices Detected by QuEChERS and GC-NPD Method

[ Objective] The paper was to establish a quick detection method for residue of organphosphoras pesticides in chewing cane juices and provide guarantee for edible safety of chewing juice. [ Method] By using QuEChERS and GC-NPD method, a rapid analysis method for residue of six kinds of organphosphorus pesti- cides （dichlorves, chlorpyrifos-methyl, malathion, fenthion, chlorpyrifos and triazophes） in sugarcane juices was established. [ Resdt] QuEChERS method was significantly superior to traditional extraction method and could extract six kinds of organphesphorus pesticides from chewing cane juices effectively, which gready saved organic reagent and time. Good linearity was found in different standard curves; when the concentration of pesticides was from 0. 020 toO. 100 rag/L, the re- covery rate was from 68.58% to 92.85%, and relative standard deviation （RSD） was ranged from 2.16% to 9.89%. [ Conclusion] The sensitivity, accuracy and precision of QuEChERS method were consistent with the technical requirements of pesticide residue determination. It not only could shorten sample processing cycle effectively, but also ensure that no impurity was in the sample peak and the recovery rate was also consistent with the requirements of residual analysis.

Study on Residues and Digestion of Cyantraniliprole in Chewing Cane

[Objective]The paper was to establish a method for the determination of cyantraniliprole residue in chewing cane,and analyze the residue and digestion dynamics of cyantraniliprole in chewing cane.[Method]The chewing cane samples were extracted by acetonitrile,purified by improved QuEChERS method,and detected by UPLC/MS/MS.[Result]Cyananseramide showed a good linear relationship in the concentration range of 0.005-0.250 mg/L(R2=0.9991).When the added mass concentration ranged from 0.02 to 0.40 mg/kg,the recovery rates of cyantraniliprole were respectively 83.1%-110.1%for chewing cane leaves and 88.2%-109.2%for chewing cane stems;the relative standard deviations were respectively2.38%-7.98%for chewing cane leaves and 2.26%-3.10%for chewing cane stems.The limit of detection(LOD)in chewing cane was 0.05μg/kg and the limit of quantification(LOQ)was 0.02 mg/kg.The trial results of two chewing cane fields in Guangxi showed that the half-lives of cyantraniliprole in chewing cane leaves were 7.76 and 6.12 d,respectively,and the correlation coefficients were 0.9570 and 0.9241,respectively.[Conclusion]The method is sensitive,accurate,simple and rapid,and it can be used to determine the residue and half-life of cyantraniliprole in chewing cane.The results will provide technical support for the safe use of cyantraniliprole in chewing cane.

Agronomic and Economic Evaluation for Intercropping between Chewing Cane and Peanut

[Objectives]To explore the proper intercropping pattern between chewing cane and peanut.[Methods]A field experiment was carried out to investigate the yield and economic benefit of chewing cane and peanut,as well as the changes in soil properties under different chewing cane/peanut intercropping patterns.Three chewing cane/peanut intercropping patterns were designed,in which with every row of chewing cane intercropping one row of peanut(CP_(1)),intercropping two rows of peanut(CP_(2))and chewing cane mono-cropping(MC).[Results]It had no significant effect on the agronomic characters of chewing cane and peanut in CP_(1)and CP_(2),compared with MC.The soil properties before the planting(BP)and after the harvest(AH)indicated that the chewing cane/peanut intercropping patterns significantly increased soil organic matter and soil available nitrogen contents,but decreased soil available potassium contents,and CP_(2)had better effect on soil structure than CP_(1).The total production value and economic benefit were increased significantly on the CP_(1)and CP_(2),comparing the MC,and the benefit of CP_(2)was higher significantly than that of CP_(1).The land equivalent ratios(LER)for CP_(1)and CP_(2)were 1.94 and 1.72,respectively,which was significantly higher than that of MC(0.83).Although planting cost was increased in chewing cane/peanut intercropping patterns partly,the production value and the profits were enhanced significantly.[Conclusions]CP_(2)could be significantly advantageous for the yield and benefits of chewing cane and peanut and soil properties.The favorable intercropping pattern for economic return would be one row of 120 cm width for chewing cane with two rows of peanut.