3.3.5.3. Non-traditional improvement, mutation breeding.
Somaclonal mutants, the so-called Giant Cavendish Tissue Culture
Variants (GCTCV), have been developed for over 3 decades in
Taiwan (Hwang and Ko, 2004). Somaclones with enhanced tolerance to TR4 are recurrently selected in TR4-infestedfields, and
several are now widely tested or used, especially in Southeast Asia.
However, they are not completely resistant and can usually be
grown for only one or two cycles in TR4-infested sites. Conversion
to, and production of, these somaclones by the trades would be
costly and would radically change export production norms given
the need to replant frequently. Poorfinger and hand architecture
for the somaclones further complicates their use by the export
trades. Despite these deficiencies, the GCTCVs are currently the best
TR4-tolerant alternatives for the exported Cavendish clones.