A simple diagnostic technique to detect potato viruses at post-harvest conditions

摘要

Potato (Solanum tuberosum L.) is one of the major vegetable crops. Viral diseases are the major limiting factor for successful cultivation of potato. In the present study, a reverse transcription polymerase chain reaction (RT-PCR) based protocol for PVX detection was developed and was compared to an enzyme linked immuneosorbent assay (ELISA) based PVX detection methods. Three potato cultivars (Lady Rosetta, Spunta and Hermes) were stored for 1 and 3 months at 4 oC (95% RH) Detection of potato leaf roll virus (PLRV), potato virus Y (PVY) and potato virus X (PVX) were carried out on potato leaves and tubers before and after storage using RT-PCR method with specific primers designed to detect these viruses. Spunta and Lady Rosetta have moderate and high resistances, respectively, while Hermes loses in chemical quality progressively during storage at 9°C, and similar has virtually no resistance to LTS at 4°C. To insure good quality of seed potato, changes in sugars and ascorbate content were investigated in different genotypes and storage periods. The different parameters of LTS resistance or susceptibility in these cultivars were indicated by changes in sugars (total soluble and total reducing) content and ascorbate concentration in relation to tuber respiratory profiles during wound healing (9 °C), LTS (4°C) and reconditioning (16 °C). Tuber ascorbate content began to decrease during storage period and continued to decline progressively through storage stages, consistent with susceptibility of potato genotypes to LTS. RT-PCR might represent fast, practical, and sensitive alternatives for the detection of PLRV, PVY and PVX from green and/or tuber tissues.