Pest Risk Analysis For The Importation Of Potato Seed From Canada And Research On The Detection Of Potato Virus With RT-PCR

As a big country, potato planting area in China today is among the first in the world output.However, due to the serious diseases and no official managements, there is a huge difference of potato quality comparing with the developed countries in potato producing. Therefore, the introduction and cultivation of high-quality potato varieties is becoming an important part of potato production. The relative pest risk analysis should be done before seed introduced from out country to protect the security of agriculture and zoology. The decline, deteriorating quality, cut and so caused by the spread of potato virus diseases is the main factor of the restricting of the potato production. So, the rapid,accurate and sensitive detection of potato virus will make sure the potato quality. Through the research of the pest risk analysis for the importation of potato seed from Canada,the risk was forecasted and the relative measures to reduce the risk was establish-ed.Besides, the technique of detection on one virus or viruses was established by using reverse transcription polymerase chain-reaction (RT-PCR).Also,the sensitivity was determined.According to the guideline for pest risk analysis constituted by FAO, our PRA initiates by spreading pathway of pests, which relate to potato from Canada. The number of pests on potato is 172. In the light of the geographical distribution, regulatory criteria, economic importance, the possibility for pests spreaded by potato seed, we made a primary assessment and compartmentalize the pests into potential regulated pest (PRP) and non-regulated pest (NRP). The further assessment made for PRP.Basing on the aspects of introduction potential, establishment potential, spread potential after establishment, potential economic importance,and so on.Research defined 24 kinds of quarantine pest (QP) and 22 kinds of regulated non-quarantine pest (RNQP) form Canada potato seed.Potato virus M, Potato virus Y, Potato virus A, Potato virus S and Potato Leaf Roll Virus(PLRV) were selected to detect by RT-PCR. Two methods which included RNAprep Plant Kit and RNAiso Plus were used to extract potato virus RNA.Both of them could extract pure and intact RNA,and qualified for RT-PCR.The primers was designed based on the conservative area of complete genome. To detect PLRV by simplex reverse transcription polymerase chain reaction (RT-PCR) and the amplification fragment was 850bp. The amplified cDNA of PLRV was extracted from the gel,and sequenced.Compared in NCBI BLAST,and the result showed that the sequences of amplification products was correct. By diluting the concentration of cDNA, the minimum detectable concentration of 5 virus han been determined in the simplex,duplex RT-PCR system.By Changing the ratio of primer concentration in the case of stable buffer system to optimize the multiplex RT-PCR system.