Abstract:

Papaya, Carica papaya L., is an almost herbaceous (succulently soft-wooded), typically unbranched
small tree in the family Caricaceae. Europeans first encountered papaya in the Western Hemisphere tropics
by at least the early 1500s (Sauer, 1966), and various interests were soon disseminating it widely (Ferrão,
1992). Papaya is now cultivated worldwide in tropical and subtropical climates mainly for its melon-like
fruit.
The Caricaceae is classified in the order Brassicales (sometimes called Capparales), which
characteristically express mustard-oil glucosides (glucosinolates) (Jørgensen, 1995; Rodman et al., 1998;
Olson, 2002). Recently, consensus has been developing that the genus Carica L. has only the one species
C. papaya, and that the Caricaceae may comprise six genera (Aradhya et al., 1999; Badillo, 2000; Van
Droogenbroeck et al., 2002, 2004; Kubitzki, 2003; Manshardt, 2002, Havaii University, pers. com.). Most
of the genera are neotropical forest plants, occurring in South America and Mesoamerica or only in
Mesoamerica. Vasconcellea, the largest genus with 21 species, had usually been considered as a section
within Carica. The other neotropical genera are Jacaratia (7 spp.), Jarilla (3 spp.) and Horovitzia (1 sp.)
(Badillo, 1993). The sixth genus, Cylicomorpha (2 spp.), occurs in montane forests in equatorial Africa
(Badillo, 1971)