Molecular identification of viral pathogens in Crocus sativus / 中草药

ABSTRACT

Objective: To investigate the viral pathogens in cultivated Crocus sativus. Methods: Viral pathogen identification was carried out by the observation of virus particle morphology and cytopathology as well as the detection of DAS-ELISA, RT-PCR, and sequencing. Results: Linear virus particles of 600-900 nm in length were observed in C. sativus by negative staining under transmission electron microscope (TEM). Bundles of linear virus particles, cylindrical inclusion bodies of subdivision II, and amorphous inclusion bodies were observed in the cells of C. sativus under TEM after ultrathin-section. These observations resembled the cytopathology of infectious Bean yellow mosaic virus (BYMV). Positive result of DAS-ELISA was obtained from the leaves of C. sativus by using monoclonal antiserum against BYMV capsid protein. Positive result of RT-PCR induced by the Potyvirus specific primers (Sprimer and M4) was also obtained. Sequencing after RT-PCR revealed that the viral sequence in this diseased C. sativus had a homology of 99% with the BYMV sequence. Conclusion: The pathogenic virus of this C. sativus disease is identified as BYMV.