THE USE OF NON-TRANSGENIC TECHNOLOGIES FOR THE DEVELOPMENT OF PAPAYA RINGSPOT VIRUS RESISTANCE IN CARICA PAPAYA

R. Drew
Despite availability of transgenic papaya that are resistant to Papaya ringspot virus form P (PRSV-P), the virus continues to spread and be the major disease of Carica papaya (papaya) worldwide. Transgenic papaya containing PRSV-P coat protein constructs, and that are resistant to PRSV-P have become increasingly available over the last 20 years, and have been developed in many countries against many strains of the virus. However, transgenic papayas have not been accepted by governments in most countries and none of the top 20 papaya producing countries grow transgenic papaya for commercial production. An alternative to transgenic technology is intergeneric hybridization of papaya with PRSV-P resistant Vasconcellea species and subsequent backcrossing of the resistance to papaya. Papaya has been hybridised with PRSV-P resistant V. quercifolia and the virus resistance backcrossed into papaya. Backcross 4 and 5 generations have been shown to exhibit resistance to both the Philippine and Australian strains of PRSV-P. However, the resistant plants do produce mild symptoms of the virus at certain stages of growth. A more durable resistance to PRSV-P has been demonstrated by V. pubescens which appears to be immune to PRSV-P. As F1 populations between papaya and V. pubescens are infertile, V. parviflora is being used as a bridging species to transfer PRSV-P resistance from V. pubescens to papaya. Molecular markers have been developed for PRSV-P resistance in V. pubescens and are being developed for V. quercifolia. Putative resistance genes for PRSV-P resistance in V. pubescens are being sequenced and characterised. When transgenic papaya are accepted for production in more countries, it is expected that both transgenic resistance and resistance from Vasconcellea species can be combined to provide durable resistance to PRSV-P and progress towards elimination of this devastating disease.
Drew, R. (2014). THE USE OF NON-TRANSGENIC TECHNOLOGIES FOR THE DEVELOPMENT OF PAPAYA RINGSPOT VIRUS RESISTANCE IN CARICA PAPAYA . Acta Hortic. 1022, 23-29
DOI: 10.17660/ActaHortic.2014.1022.2
https://doi.org/10.17660/ActaHortic.2014.1022.2
PRSV-P coat protein constructs, intergeneric hybridization, Vasconcellea, backcrossing, molecular markers
English

Acta Horticulturae