Detecção por PCR em tempo real e identificação molecular do Banana streak virus e Cucumber mosaic virus de Musa spp

Abstract

Cucumber mosaic virus and Banana streak virus cause mosaic and streak diseases in bananas. These two viruses are responsible for severe damages to this crop around the world, limiting the commerce of propagative plant material when they infect banana seedlings. Thus, there is the need to establish plant indexing tools to guarantee the quality of propagative material. The objective of this work was to test Real Time PCR protocols to detect and identify both viruses from banana samples collected in Northern Parana state using TaqMan® probes and SYBR Green®, with primers and probe already described. PCR amplification products were cloned and sequenced, confirming the identity of the viruses as Banana streak OL virus and Cucumber mosaic virus subgroup IA. Real Time PCR analysis resulted in amplification curves, confirming Banana streak OL virus infection in 5 out of 18 analyzed banana samples in TaqMan® Real Time PCR reactions. Cucumber mosaic virus was also detected in both onestep and two-step RT-PCR TaqMan® analysis in naturally infected banana and in inoculated plants of pepper, petunia, squash cv. "Caserta" and tobacco, and the two-step protocol was the most effective one, with better results. Infected banana plants were also tested for Cucumber mosaic virus by SYBR Green®, with two distinct pair of primers, and only one of them resulted in amplifications exclusively in known Cucumber mosaic virus infected plants.