三种甘薯病毒多重RT-PCR检测技术的建立

本文根据GenBank中甘薯G病毒(SPVG)、甘薯卷叶病毒(SPLCV)和甘薯羽状斑驳病毒(SPFMV)外壳蛋白(CP)基因序列设计特异引物,对多重RT-PCR退火温度、延伸温度、模板浓度、引物浓度进行改良优化,建立能同时检测3种甘薯病毒的多重RT-PCR方法。该方法能同时扩增出SPVG、SPLCV和SPFMV特异片段,其大小分别是800、276和570bp。测序结果表明,扩增出的3种病毒序列与相应参考序列相似性达到98%以上。灵敏度分析结果表明,多重RT-PCR方法能够检测cDNA的量为0.1ng。应用建立的多重RT-PCR检测方法对田间样品进行检测,结果显示该方法可以特异、快速、灵敏地同时检测3种甘薯病毒。这些研究结果可为甘薯病毒检测提供参考。

Establishment of multiplex RT-PCR system for detection of three viruses in sweet potato

Antimicrobial constituents of the seeds of Indigofera amblyantha Craib were isolated by using bioactivi-ty-guided fractionation.The antimicrobial activity assays were designed against the fungi Magnaporthe grisea ,Fu-sarium oxysporum ,Sclerotinia sclerotiorum and Venturia pyrina by using the hyphal growth inhibition method and the bacteria Ralstonia solanacearum ,Escherichia coli ,Staphyloccocus aureus ,Pseudomonas aeruginosa and Bacil-lus subtilis by using the disc method.The results showed that A-4 and A-5 fractions had higher bioactivity than others.Their inhibition ratios against V .pyrina were 77.66% and 74.67 %,respectively.The diameters of inhi-bition zone against R .solanacearum were 1.37 cm and 1.66 cm,respectively.Two compounds with antimicrobial activity were isolated and elucidated as Balansenate Ⅰ and Ⅱ mainly by1 H and 13 C NMR spectral data.The re-sults of bioassay showed that the MIC values and the MBC values of the two compounds against S .aureus were 250 and 500 mg/L,respectively.