Transgenic resistance is an attractive strategy for controlling disease in banana. Unfortunately, there are no ‘off the shelf’ resistance genes available for the major banana diseases. We have therefore been developing and testing a range of potential resistance genes for four pathogens causing the major diseases: banana bunchy top babuvirus (BBTV; bunchy top disease), Fusarium oxysporum fsp. cubense (FOC; fusarium wilt), Mycosphaerella fijiensis (BS; black sigatoka), and Mycosphaerella musicola (YS; yellow sigatoka). For BBTV, we are testing two resistance strategies—a mutated-Rep strategy and a Rep-activated suicide-gene strategy. Transgenic bananas expressing BBTV Rep in which either one of two essential motifs was mutated were unfortunately susceptible to BBTV when exposed, indicating this strategy was ineffective. The Rep-activated suicide-gene strategy looks to be significantly more promising based on results with the geminivirus tobacco yellow dwarf virus. Transgenic lines expressing the split suicide gene have been generated and multiplied and will be challenged early in 2005. For fungal resistance, we have developed or are developing three different strategies: expression of an antimicrobial peptide, amplification of banana R genes, and inhibition of the apoptotic response. We have generated transgenic lines expressing the synthetic antimicrobial peptide D4E1. Extracts from these plants inhibited the germination and growth of FOC in vitro. However, these plants were susceptible to FOC when exposed in the glasshouse. An alternative strategy involved amplifying potential R genes from a population of Musa acuminata ssp. malaccensis, a wild diploid banana segregating for resistance to FOC Race 4. One R gene candidate (RGC-2) was expressed in plants resistant to FOC but not in plants that were susceptible. Further, this RGC was similar in significant sequence to two R genes that confer resistance to other Fusarium species. We have isolated the complete gene sequence of RGC-2 including the promoter and terminator and transformed this into susceptible bananas. Resultant plantlets are currently being multiplied and will be screened in the first half of 2005 for resistance to FOC. Finally, we are investigating the potential for inhibitors of apoptosis to confer resistance to necrotrophic fungi, which include BS and probably YS and FOC. The first transgenic bananas expressing apoptosis inhibitors are currently being regenerated.