Polymerase chain reaction (PCR) based indexing of black pepper (Piper nigrum L.) plants against Piper yellow mottle virus

Abstract

A polymerase chain reaction (PCR) based method was used for indexing 845 plants representing 14 popular varieties of black pepper (Piper nigrum) showing no visible external symptoms (apparently healthy) for Piper yellow mottle virus (PYMoY), among which 694 plants were positive (82%) for PYMoV. The percentage of infected plants ranged from 59% to 100% in different varieties; 100% of the tested plants of Panniyur-6 were infected with PYMoV and Sreekara had the least number of infected plants (59%). Some of the indexed PCR positive plants exhibited visible symptoms such as mild chlorosis, yellow specks and mottling in 1-3 months after testing. The study showed that indexing by PCR successfully detected PYMo V in infected black pepper plants showing no visible symptoms. The method can be used in certification programmes to identify PYMoY-free plants for further propagation.