In vitro collections such as the ITC are susceptible to somalclonal variation. This, coupled with the misclassification and mislabelling of accessions, can degrade the integrity of a germplasm collection. The Field Verification project aims to ensure the genetic integrity of the ITC accessions by systematically evaluating their trueness-to-type, while also adding value to the collection by generating morphological and molecular characterization data that are available for users via the MGIS database. Accessions that have been field verified are therefore evaluated as true-to-type and are available for distribution.
The diagram below illustrates the process. After each decade in in vitro storage at the ITC, accessions are sent to field collections of participating partners to be planted and described in their fields and to MGC and DART for molecular assays. Characterization data is then compiled and evaluated by a team of Musa taxonomists (TAG), from which a decision is taken to keep or remove the accession from distribution.
Ploidy Level: The ploidy refers to a multiple of the basic number of chromosomes in a cell. Musa accessions can be diploids (denoted as 2x), triploids (3x) or tetraploids (4x). Some cases of mixoploidy or mixte ploidy were also reported. The cytological characterization to determine the ploidy of ITC accessions is carried out at the Institute of Experimental Botany (IEB) in Olomouc, Czech Republic.