Bioversity’s collection of bananas and plantains and their wild relatives (Musa species) is kept at the International Transit Centre (ITC) at Katholieke Universiteit Leuven, Belgium. The banana collection – with more than 1500 accessions – is the largest in the world. About 75% are traditional varieties or landraces and 15% are wild relatives. The remaining 10% is largely breeding and research material.
In the 30 years since it was established, the ITC has distributed more than 17,000 samples to 109 countries.
Accessions are kept in-vitro, as 20 shoot cultures in continuous light at 16°C. They are subcultured each year, and after several years of maintenance the tissue cultures are replaced with new material grown in the greenhouse and checked for genetic integrity. This prevents the accumulation of changes that can occur in plants kept in tissue culture for long periods of time.
Accessions are also cryopreserved in liquid nitrogen at -196°C. This stops both the growth of plant cells and all biological deterioration, so accessions can be preserved indefinitely and resuscitated into fully viable banana plants. As further insurance, a safety duplicate set of cryopreserved material is being deposited for safe-keeping at the French research institute for development (IRD) in Montpellier, France.
The ITC is also a global hub for the safe movement of Musa germplasm around the world. It has a system for indexing accessions for the presence of viruses and has researched protocols for cleaning up infected accessions. Only accessions that are tested virus free – currently 65% of the collection – are distributed, and work continues to ensure the entire collection is available for distribution.
Bioversity also maintains the Musa Germplasm Information System (MGIS) with access to information from 24 national banana collections and morphological and molecular data on many of its accessions.