Serological and molecular diagnosis of Potato leafroll virus (PLRV) in potato tuber-seeds in Antioquia, Colombia

摘要

Viral diseases are one of the most limiting phytosanitary problems in the production of potato with Potato leafroll virus (PLRV), Potato virus Y (PVY), Potato virus S (PVS) and Potato yellow vein virus (PYVV) having the biggest economic impact in crops of the Andean region. These viruses are transmitted by hemipteran insects and tubers. In this work, the presence and distribution of PLRV in Solanum tuberosum v. Diacol-Capiro and S. phureja v. Criolla-Colombia tubers was investigated using serological and molecular tests. 128 samples from three types of tissues (skin, dormant buds and sprouts) were tested using DAS-ELISA while a 12-sample subset from each variety was used for real time RT-PCR (RT-qPCR). With DAS-ELISA, PLRV was detected in 3,1% and 10,1% of Diacol-Capiro and Criolla-Colombia samples, respectively; in the latter, PLRV was detected mostly in the tuber skin. PLRV was detected in 83,3% and 91,6% of Diacol-Capiro and Criolla-Colombia samples, respectively, using RT-qPCR. Threshold cycles (Ct) were in the 17,72 to 30,59 range. Sequencing of RT-qPCR fragments resulted in 99-100% nucleotide identity with respect to the PLRV coat protein. These results highlight the need of using certified tuber-seed in potato crops in Colombia and strengthening the seed certification programs using highly sensitive techniques such as RT-qPCR.