“…Other species, such as sweet orange (C. sinensis), grapefruit (C. paradisi), and lemon (C. limon), are of hybrid origin (Barkley et al, 2006;Federici et al, 1998;Nicolosi et al, 2000;Pang et al, 2007). In addition, several studies have suggested that genetic variations within the mandarin are larger than those in citron and pummelo (Hirai and Kajiura, 1987;Hirai et al, 1986;Li et al 2006;Yamamoto and Tominaga, 2003).…”