Citrus

Abstract

The general area of origin of citrus is believed to be south-eastern Asia, though its cultivation probably started in China. Commercial citrus species and related genera belong to the order Geraniales, family Rutaceae, subfamily Aurantoidea. All rootstocks and varieties are included in the genus Citrus, except for kumquats (Fortunella spp.), and trifoliate orange (Poncirus trifoliata L. Raf.), which is used exclusively as a rootstock. Commercial citrus fruits fall into several main groups, namely sweet oranges (C. sinensis (L.) Osb.), mandarins (C. reticulata Blanco, C. deliciosa Ten.), satsumas (C. unshiu (Mak.) Marc.), clementines (C. clementina Hort. ex Tan.), grapefruits (C. paradisi Macf.), pummelos (C. grandis (L.) Osb.), lemons (C. limon (L.) Burm. f.) and limes (C. aurantifolia (Christm.) Swing.). There are other species of relative importance in certain areas, such as sour oranges (C. aurantium L.), citrons (C. medica L.) and bergamots (C. bergamia Risso & Poit.). In addition, there are some commercial hybrids which are used as rootstocks including citranges (sweet orange × trifoliate orange) and citrumelos (grapefruit × trifoliate orange), and also important variety hybrids such as tangelos (mandarin × grapefruit or pummelo), tangors (mandarin × sweet orange) and mandarin hybrids.