Soursop yellow blotch virus: transmission, hosts, purification and antiserum production.

Abstract

Soursop tree, Annona muricata L., presents an increasing industry demand in several regions of Brazil, particularly in the Northeast and Amazon and Minas Gerais states. The productivity of this fruit crop is highly dependent on the variety, on cultural practices and on the health of the crop. The yellow blotch is the main disease that affects the soursop tree. It's caused by the rhabdovirus Soursop yellow blotch virus (SYBV), which reduces the plant development and yield. The present work had the following objectives: study the transmission of SYBV for soursop and other anonaceae species by sap and graft transfusion; identify alternative hosts of the virus; investigate the transmission of the virus by cutting instruments and insects vectors; purify and raise a polyclonal antiserum specific for the virus. The results showed that SYBV was transmitted by sap and graft only to soursop trees (cvs. 'AB', 'Crioula', 'Lisa' and 'Morada') and to the anonaceae species sweetsop, A. squamosa L., and biriba, Rollinia mucosa (Jacq.) Bail). There was not transmission with cutting instruments and with three different insects under the conditions established in this work. The cleaning of the SYBV permitted to acquire a polyclonal antiserum, which was used to detect the virus in plants under orchards conditions, as well as in asymptomatic leaves of young infected plants. The antiserum contributes to get healthy seedlings for the vegetative propagation of soursop.