Distribution and genetic diversity of begomoviruses infecting tomato and pepper plants in the Philippines

Abstract

Begomoviruses were found to be the major viruses infecting tomato plants in the Philippines based on the surveys conducted from 2005 to 2006. Pepper-infecting begomoviruses were also detected. Isolates of four distinct begomovirus species, Ageratum yellow vein virus (AYVV), Tomato leaf curl Cebu virus (ToLCCeV), Tomato leaf curl Mindanao virus (ToLCMiV) and Tomato leaf curl Philippines virus (ToLCPV), were characterised at the DNA sequence level by comparing 20 DNA-As from tomato samples comprising 13 from Luzon, 2 from Cebu and 5 from Mindanao Islands, along with 3 DNA-As from pepper samples, 1 each from Luzon, Cebu and Mindanao Islands. Two of these species (ToLCCeV and ToLCMiV) were distinct novel begomoviruses, while AYVV was detected for the first time in the Philippines. By geographic distribution, two tomato begomoviruses (ToLCPV and ToLCCeV) were detected in Luzon and Cebu Islands. The ToLCMiV was also detected in Luzon Island. The three tomato begomoviruses, AYVV, ToLCCeV and ToLCMiV, were detected in Mindanao Island. A ToLCPV isolate infecting pepper was also detected in Luzon Island, while ToLCCeV was detected in pepper samples from Cebu and Mindanao Islands. The diversity of viruses and their distinct geographic distribution need to be taken into consideration in the development and deployment of resistance against begomoviruses in the Philippines. Strategies for the use of post-transcriptional gene silencing for the control of tomato-infecting begomoviruses in the Philippines are discussed.