Research aflvanee in the molecular biology of cytoplasmic male sterility in plants Populus nigra×Populus deltoids “108” Transformed the Chimeric Genes of Spider Insecticidal and Bt Sequence and functional analyses of the tapetum-specific promoter Osg6B from rice (Oryza sativa L.) CO-CULTURE TRANSFORMATION OF TOBACCO LEAF DISC BY RECOMBINANT AGROBACTERIUM TUMAFAClENS STRAIN pACK 403