The CEREALAB database is a web-based tool realized to help cereal breeders in choosing molecular markers associated to economically important phenotypic traits; it contains phenotypic and genotypic data obtained from the integration of available open source databases with the data obtained by the CEREALAB project. Information integration in the CEREALAB database is obtained by using the MOMIS (Mediator Environment for Multiple Information Sources) system. As a result of the wide use of the CEREALAB database, several extensions and Improvements were introduced and a new data entry module was implemented. Moreover, data provenance was introduced and partially implemented in the CEREALAB database. Data Provenance is particularly required in data integration systems, where information coming from different sources, potentially uncertain or even inconsistent with each other, is integrated. In this context, having the possibility to trace the lineage of specific data can help identify possible unexpected or questionable results.