Detection and identification of viruses associated to mealybug wilt pineapple in Blitar, East Java, Indonesia

Abstract

Pineapple is one of the essential export commodities in Indonesia. However, its production is constrained by pathogen infections, including viruses. Recently, a field surveyed at a pineapple production area in Blitar regency found virus-like symptoms such as leaf reddish intermingle with chlorosis and necrotic leaf tips with incidence up to 50% on clone 7350. However, until present, the genetic identity of causal viruses has been limitedly available in Indonesia. The study aimed to detect and identify the virus species associated with mealybug wilt pineapple (MWP) in Blitar regency. Total RNA was extracted and detected by one-step RT-PCR using a universal primer of Ampelovirus, a specific primer of pineapple mealybug wilt-associated virus (PMWaV) 1 and 2, and confirmed by DNA sequencing. The PMWaV-1 and PMWaV-2 were successfully amplified by specific primers, while by Ampelovirus universal primers negatively amplified any DNA. It confirmed that the causal virus is associated with corresponding symptoms only by PMWaV-1 and -2 on clone 7350. Based on partial sequences of the HSP70 gene confirmed the existence of both species. The identity of PMWaV-1 Blitar isolates showed the highest similarity of nucleotide and amino acid to isolates from Taiwan, Mexico, and Ghana. The PMWaV-2 Blitar isolates showed the highest similarity to isolates from Taiwan, Mauritius, Cuba, and Ghana. The highly incidence of MWP suggests that cultivating virus-free vegetative propagation will become the best strategy to manage the viruses in the fields.