Disruption of genetic identity for genebank maize accessions during conservation

Abstract

Maintenance of the original accessions identity and integrity is one of the priorities among genebank activities. Different factors related to conservation may result in accessions disruption. Regeneration is the most frequent critical point in this process, due to bottlenecks, inbreeding, random genetic drift and unintentional mixing or contamination. On the other hand, genetic drift may occur due to seed viability loss. Therefore, it is very important to establish the balance between the frequency of regeneration and the duration of accession conservation. The aim of the present study was to estimate whether the identity of accessions regenerated after 27 years of medium-term conservation was disrupted. Phenotypic markers were applied on three Maize Research Institute "Zemun Polje" (MRIZP) genebank maize landraces (K2026, K768 and K86), differing in seed viability, kernel type and effective population size. It was estimated that, after the regeneration, there had been no significant changes in the landrace K2026. There were some parameters indicating that genetic drift had occurred in the landrace K768, and that there had been even a certain degree of inbreeding in the landrace K86. According to the results, accession K2026 could still be kept under the same ID number. Due to the genuine identity disruption, assignment of new ID numbers for K768 and K86 should be suggested.