The Establishment Of RT-PCR System And Varieties And Distribution Of Potato Viruses In Sichuan

Potato is a kind of Solanaceae plant which is easily infected by viruses. At present,there are more than 35 different viruses has been reported to affect potatoes in the worldand about 6-7 kinds included and the potato spindle tuber viroid (PSTVd) can affect thecrop and cause severe damage. The virus infection not only causes potato viral diseasedirectly, but also causes important cultivars degeneration and decreases the output ofpotato. Now, virus infection is a primary factor which restricts potato production inSichuan Province. There are 5 of the most important potato viruses in China when theirdistribution and effect on yield is combined and also listed as target of disease control.They are Potato Virus X (PVX), Potato Virus Y (PVY), Potato Virus S (PVS), Potato VirusA (PVA) and Potato Leaf Roll Virus (PLRV).Now, enzyme-linked immuno-sorbent assay(ELISA) is a usually method used todetect potato viruses, it can detect viruses in a few minutes by extracting and testing leavesjuice from infected potato plant. Therefore it is suitable to detect viruses for a large scale ofpotato sample. But this method has some defects like that spending too much time inimmuno-serum preparation, high cost and low sensitivity. Reversetranscription-polymerase chain reaction (RT-PCR) is a viral detection method at molecularlevel which emerges in resent years, it has many advantages of fast detection, highsensitivity and strong specificity. So it has prospect in the potato virus detection.Nowadays, most laboratories in China have not establish RT-PCR method in potato virusesdetection, hence, establishment of RT-PCR method detecting potato viruses has practicalsignificance in Sichuan Province for virus-free seed tuber production. Five pairs of DNAprimers of potato viruses were synthesized in the research based on the literature reportedboth in China and abroad, the total RNA was directly extracted from virus-infectedpotato leaves, after the reverse transcription-polymerase chain reaction, a specific DNAfragment with expected length was obtained and the virus is detected. A new method of thedetection for potato virus by RT-PCR was established and applied to the Sichuan potatovirus detection at molecular level. Sichuan has not taken the general investigation of viral disease distribution andharmfulness in main potato production area for more than 20 years. In order to understandthe main potato virus distribution and the harmful situation in Sichuan recent years, 981specimen of disease-infected potato plant, symptom leaves, free-virus tissue culture andseed tubers were collected from 21 counties of Sichuan province and detected byDAS-ELISA. with 8 antiserums of potato viruses. The resultgive us many new information of the potato virus distribution and incidence in the crop inSichuan.