VARIABILITY IN STORAGE RESPONSE WITHIN A COFFEE (COFFEA SPP) CORE COLLECTION UNDER SLOW GROWTH-CONDITIONS

An in vitro core collection of African coffee germplasm, structured in 32 diploid diversity groups, was established and conserved under slow growth for 3 years (6 subcultures). The initial objective was to stor e twenty accessions per group, with four replicates per accession. A s tatistical model was developed to analyse observations of survival rat es within each diversity group. The goodness of fit of the model was s hown. Survival analysis indicated a broad variability of the accession s in their response to the storage conditions and confirmed the import ance of structuring the coffee complex down to the intraspecific level . Intra- and inter-group differences had consequences on the genetic r epresentativity of the in vitro core collection. For practical purpose s, conservation was carried on when the intra-group genetic drift was less than 50%.