Background: Banana (
Musa
spp.) is an important staple food, economic crop, and nutritional fruit worldwide.
Conventional breeding has been seriously hampered by their long generation time, polyploidy, and sterility of
most cultivated varieties. Establishment of an efficient regeneration and transformation system for banana is
critical to its genetic improvement and functional genomics.
Results: In this study, a vigorous and repeatable transformation systemfor banana using direct organogenesiswas
developed. The greatest number of shoots per explant for all five
Musa varieties was obtained using Murashige
and Skoog medium supplemented with 8.9 μM benzylaminopurine and 9.1 μM thidiazuron. One immature
male flower could regenerate 380–456, 310–372, 200–240, 130–156, and 100–130 well-developed shoots in
only 240–270 d for Gongjiao, Red banana, Rose banana, Baxi, and Xinglongnaijiao, respectively. Longitudinal
sections of buds were transformed through particle bombardment combined with
Agrobacterium
-mediated
transformation using a promoterless β-glucuronidase (GUS) reporter gene; the highest transformation
efficiency was 9.81% in regenerated Gongjiao plantlets in an optimized selection medium. Transgenic plants
were confirmed by a histochemical assay of GUS, polymerase chain reaction, and Southern blot.
Conclusions: Our robust transformation platform successfully generated hundreds of transgenic plants. Such a
platform will facilitate molecular breeding and functional genomics of banana.
