Table 2: Transgenic papaya developed by various research groups through gene technology.
Gonsalves et al. used gene gun technology when transferring an untranslatable CP gene for the development of a PRSV-resistant papaya variety. This showed resistance to homologous PRSV isolates from Hawaii, Australia, Taiwan, Mexico, Jamaica, the Bahamas, and Brazil. The PRSV-resistant (Hawaiian) transgenic papaya variety SunUp was developed through transformation of somatic embryos with the CP gene of the Hawaiian PRSV strain . Tennant et al. [34developed transgenic papaya expressing the CP gene of the mild PRSV strain from Hawaii (PRV HA 5-1). This transgenic papaya showed a high level of resistance against a severe strain of PRSV (PRV-HA). Bau et al. developed transgenic papaya lines expressing a CP gene with broad-spectrum resistance PRSV of different strains in different geographical areas in Taiwan. Magdalita et al.developed genetically engineered papaya using the CP gene of Philippine PRSV and regenerated putative transgenic R0 plantlets, which were moderately susceptible whilst R1 plantlets were completely resistant.