RESULTS IN DEVELOPMENT OF WEEVIL RESISTANT SWEET POTATO LINES BY GENE T

Abstract

This paper presents the results in developtment of transgenic sweet potato (Ipomoea batatas L.) cv. KB1 resistant to sweet potato weevil (Cylas formicarius). The two vector constructions were transferred successfully into Vietnam’s sweet potato KB1 mediated by A. tumefaciens via multiple shoot inducting callus. Totally, the authors selected and regenerated 401 lines, including 246 putative transgenic lines carrying cry3Ca1 gene and 155 lines with vip2-1 gene in selection medium. The putative transgenic lines were proved positive by PCR and finalized by Southern hybridization: (1) Twenty seven transgenic lines of cry3Ca1 and 19 transgenic lines of vip2-1 gene were proved positive by PCR reaction; (2) Seven putative transgenic lines of cry3Ca1 and 10 putative transgenic lines of vip2-1 were proved successfully by Southern hybridization, confirming that the transgenic lines of KB1 cultivars contained a single or two copy of the transgene. Besides, the resistance to sweet potato weevil (C. formicarius) of transgenic sweet potato clones was also tested under controlled conditions. The transgenic lines of cry3Ca1 and vip2-1 were damaged by C. formicarius much lower than wild type. The results are expected to bring a prospect to improve the weevil resistance of sweet potatoes in Vietnam.