The citrus plants comprise the genus Citrus and relatives of it, with emphasis to Poncirus, Fortunella, Microcitrus, Eremocitrus and Clymenia. They are among the oldest plants cultivated, a large portion of them native to the Asian continent. The introduction, conservation, characterization, evaluation and documentation of citrus are activities fundamental in dealing with germplasm of this important plant group, contributing as basis to breeding programs and to the diversification of cultivars
