Fusarium wilt caused by the soil inhibating fungus, Fusarium f.sp. cubense is a major factor limiting commercial banana production in Malaysia. Control measures involving field sanitation, soil fumigation, organic amendments and crop rotation are generally non-effective. The only effective method of controlling fusarium wilt is the planting of new resistant varieties.
The development of a genetic engineering system for the plant regeneration of transformed tissues into whole plants is essential in producing commercialisable transgenic banana of disease resistance. Agrobacterium-mediated gene transfer and microprojectile bombardment are used to introduce genes that encode proteins with antifungal properties such as Chitinase, Î²-1,3- Glucanase and Thaumatin-Like Proteins (TLPs) into banana tissues. However, combinations of the defense gene products have shown considerably more promise in reducing disease than single transgene introductions.
Multiple bud clumps (Mbcs) and corm slices of banana were used as target tissue to receive these genes. Screening in antibiotic selection media (Kanamycin, hygromycin, basta and geneticin) and the presence of reporter genes (GFP and GUS), used to detect the inserted antifungal genes in targeted tissues. Polymerase Chain Reactions (PCR) analyses of the leaves, pseudostem and roots of regenerated plantlets showed the presence of the transgene. The antifungal ability of these bananas against fusarium was assayed in vitro and the tolerant plantlets will be maintained in the glass house for further evaluation.
A new tool is therefore available to contribute to the genetic improvement of banana in Malaysia.