Advanced Resistance to Sweetpotato Feathery Mottle Virus (SPFMV) in Transgenic Sweetpotato

摘要

Viral diseases of the sweetpotato (Ipomoea batatas L. (Lam)) are highly prevalent and often cause serious damage to the plants, particularly the severe strain sweetpotato feathery mottle virus (SPFMV-S) that causes "obizyo-sohi" disease in Japan. In addition, reported strains in Japan include the ordinary (0) strain and Tokushima (T) strain. Some varieties have been found to be genetic resources of SPFMV resistance. However, the degree of the resistance is inadequate, and much time is required to introgress the resistant gene(s) into the hexaploid genome of the sweetpotato by conventional breeding. On the other hands, a transgenic sweetpotato has been developed to confer viral resistance to SPFMV using current biotechnology by introducing SPFMV-S coat protein (CP) genes, which have a significant resistance to purification virus of SPFMV-S. In this report, virus resistance was evaluated under conditions nearer to those of the field environment to confirm the advanced resistance in the transgenic sweetpotato.