Transfer Of RDV Gene Into Maize Inbred Lines And The Resistance By Agrobacterium Tumefacines Infection

Maize(Zea mays L.) is one of the most important crops. However, huge yield losses and deteriotation of quality of cultivated plants were caused due to continuous exposure of plant to pathogens. Today MDMV disease remains one of the major factors limiting crop production world wide. The crop breeding of disease resistance is limited by lacking the resistance resource and the hereditary isolation of different plant species. Plant gene transformation can sovle the problems that conventional crop breeding is diffcult to sovle, such as introdu cing crop disease resistance. The plant gene transformation depends on the gene clone and tissue culture technique. The combination of conventional breeding approaches and tissue culture techniques has opened new avenues for crop improvements which were not available previously. The current advancement of biotechnology has ushered agricultural research into a new era of transgenic organisms. Great attention has been paied to maize gene transformation at home and abroad. The transgenic maize lines with insect resistance and herbicide resistance have been released in commercial production. However, there is no report about transgenic maize line with MDMV resistance gene. In'this paper, we use the maize lines,such as: 478, jinhuang93B, C649 and R146 to induce regeneration plants and transfer the RDV genes into them by the transformation techniques, such as, Agrobacterium tumefacines infection. This paper result suggested:Callus of each maize inbred lines can grow normally on N6 medium, The supplement of silver nitrate in media was found to be improving both the quality and quantity of the embryogenic calli. High concentration of MS and cytokinin show to be most favorable for the formation of the embryogenic callus and shoot differentiate;Two inbred lines were transformed with pWM101S6 containing RDV gene expression cassettes by Agrobacterium tumefacines infection.After 3 months of selection on the medium containing 15mg/L hygromy. 269 regenrated plants were obtained. Most of them could grow to maturity and set seed. Molecular biology analysis showed that 46 plants contained the RDV gene. By PCR, PCR-Southern and Southern hybridization foreign gene was integrated into the maize genomy.Seedings from self-fertlized transgenic plants were inoculated with MDMV for virus resistant evaluation of transgenic genetation in field. Among 18 transgenic lines of 478, showed resistance to MDMV and delayed in symptom development. The esterase and peroxidase analysis also suggustes that foreigning gene was integrated into the maize genome . Stable integration and inheritance of RDV gene in the transfermation generation was confirmed.