Genetic Resources of Citrus and Related Genera

Genetic resource is the part of the organisms that can reproduce identical copies of the organism with identical genomic profiles. Generally, seeds, pollen, bud wood are considered as genetic resources of Citrus and its related genera. Citrus have three basic taxa, pummelos (Citrus maxima (L.) Osb.), citrons (C. medica L.) and mandarins (C. reticulata Blanco). Citrus species, cultivar, landraces have evolved by series of interspecific hybridizations, consequently, a huge diversity gained in citrus genus. Recently, Australian limes, Mangshanyegan, Kumquats and Clymenia spp. are included in the citrus genus. Due to high economic value of Citrus, researchers collect citrus germplasm and maintain them in the gene bank at major citrus producing countries worldwide. Significant progress has been made on the citrus germplasm collection, management and conservation. In this chapter we summarize the present status of the citrus germplasm collection and management, as well as discuss the future path to protect the valuable citrus genetic resources for future use.