In vitro elimination of Piper yellow mottle virus from infected black pepper through somatic embryogenesis and meristem-tip culture.

Abstract

Piper yellow mottle virus (PYMoV) is known to infect black pepper (Piper nigrum) in India and other parts of the world. In the present study, somatic embryogenesis and meristem-tip culture alone and in combination with the antiviral agent ribavirin was attempted for the elimination of PYMoV from infected black pepper explants. Cyclic somatic embryo obtained from the micropylar region of mature seeds from PYMoV-infected black pepper plants of six varieties were regenerated and hardened in the green house. Testing of somatic embryo-derived plants by PCR showed virus elimination in 55−100% of the plants in different varieties of black pepper. Increased PYMoV elimination was obtained when cyclic somatic embryos were pre-treated with ribavirin before regeneration. A protocol for meristem-tip culture of black pepper plants was developed that consisted of excising the meristem from PYMoV-infected black pepper plant and inoculating in the regeneration medium containing antibiotics (to remove endophytic bacterial contamination), followed by rooting and hardening of the plants. Testing of meristem-derived plants showed PYMoV elimination in 84% of the plants. Further elimination of the virus was obtained when meristem-tip culture was combined with ribavirin treatment.