A Study Of Clover Virus Species And Molecular Detection In Lanzhou City

Clover as an important plant grass and green plant is widely used in theproduction. Alfalfa mosaic virus (AMV) and white clover mosaic virus (WCMV)were a major pathogen infecting clover virus diseases. In this study, mainviralpathogens naturally occurred on ciovers in Lanzhou city, the main types ofviruses and forms of viruses particles and inclusions,symptom types and host tissuephysiological and pathological changes of clover virus diseased plants weresystemically investigated by biological, DSA-ELISA,electron microscopetechniques,TR-PCR and survey in fields.So laid the foundation for the clover virusdisease in field detection. The results were summarized as follows:1.In2010and2012, clover virus disease symptoms and morbidity wrer surveyedin different green belts and test-growing areas of Lanzhou City. A field surveyshowed that, clover virus disease generally occurs, the incidence rate and diseaseindex are28.14%and17.45, the main symptoms was macular mosaic, mottle mosaic,variegation mosaic, rosette stunt, shrinkage chlorotic, ring plaque and ring stria. Thepeak incidence and performance symptoms of white clover were different from redclover, the main symptom of white clover were macular mosaic and reached peakincidence in late April to early May; red clover reached peak incidence in June andthe main symptoms were striation mosaic and rosette stunt. Environment infect onoccurring of clover virus disease significantly，when temperature is25℃and relativehumidity at45%respectively， the disease index reached71.67and72.08respectively.2.Two of the main viruses causing white clover and red clover virus diseasewere identified as alfalfa mosaic virus (AMV) and white clover mosaic virus(WCMV) through the DAS-ELISA test， and detection rate were100%、83.3%,composite infection rate of83.3%. The biological measurement resultsshowed that the AMV could infect6families,16species and WCMV could infectpeas, beans, chenopodium quinoa and so on.3.In the electron microscope to see the AMV virions generally bacilliform or quasi-equiaxed long shape, size18～20nm×58～18nm; WCMV virion lanes arecurved linear,size480nm×13nm. Observed disease leaf microstructure ultra-thintissue, the starch granules in chloroplasts of the infected leaves were more, lamellarstructure loose; confusion or even disintegration; vacuolar twisted atrophy.There areaggregates concurrent arranged by bacilliform virions and bundle arranged by linearvirion in cytoplasm.4. For the field acquisition of clover disease leaf with the typical symptoms ofvirus disease, according to the reported nucleotide sequence of coat protein (AMV)and white clover mosaic virus (WCMV) genome sequence design PCR primers,amplified by RT-PCR was consistent with the expected size878bp and841fragmentsof bp, the application of the method respectively. Collected from the field in4samples of AMV、WCMV virus detection, results showed the detection rate were100%、75%.