Domestication and Genetics of Papaya: A Review

Abstract

A wealth of plant species used by humans for different purposes, but mainly as food, originated and domesticated in the Mesoamerican region. Papaya (Carica papaya) is the third most cultivated tropical crop worldwide, and it has been hypothesized that Mesoamerica is the most likely center of its origin and domestication. In support of it, many wild populations of papaya occur throughout Mesoamerica and hence represent the gene pool of genetic variability for further evolution and future crop management. Despite its importance, a dearth of information exists regarding the status of wild populations of papaya, as compared to the extent of knowledge, and interest, on domesticated varieties. We review the evidence on the extant wild populations of papaya, as well as its origin and distribution. Also, we synthetize what is known on the domestication history of the species, including the domestication syndrome that distinguishes wild and domesticated papayas. Moreover, we make an account of the use of genetic markers to assess genetic diversity of wild and domesticated papaya, and discuss the importance of papaya as the first species with a transgenic cultivar to be released for human consumption, and one that has its complete genome sequenced. Evidence from different disciplines strongly suggest that papaya originated and was domesticated in Mesoamerica, and that wild populations in the region possess, still, high genetic diversity compared to the domesticated papaya. Finally, we outline papaya as an excellent model species for genomic studies that will help gain insight into the domestication process and improvement of papaya and other tropical crops.

Network Analysis of the Papaya Orchard Virome from Two Agroecological Regions of Chiapas, Mexico

“…Papaya and its virus interactions. Carica papaya is the only species in the family Caricaceae, a cultivated species originating and domesticated in southern Mexico (52). Papaya viruses tend to be specialists, but some also may infect relatives of C. papaya.…”

“…Horovitzia, Jarilla, and Jacaratia are the closest genera to Carica and are native to southern Mexico and Central America. Vasconcellea is the most closely related genus in South America (52). Plant viruses, known or emerging, are often reported in papaya plants, and 22 viral species are known to cause disease in papaya.…”

“…PapMV triggers systemic acquired resistance (SAR) in papaya, increasing the expression of a marker protein related to pathogenesis (PR1), which inhibits subsequent infections by PRSV (20). PapMV-triggered SAR may be a mechanism of plant defense against PRSV that could help in managing the disease, because papayas lack a set of genes conferring resistance to ringspot disease (20,52). Future studies of the virome at the individual host level, compared to those from bulked samples, will help to clarify virus interactions.…”

Mutualistic and antagonistic interactions differ in wild and domesticated papaya (Carica papaya) in its centre of origin

“…The papaya ( Carica papaya ) is the third most cultivated tropical fruit worldwide. It originated and was domesticated in Mesoamerica, where wild populations still grow in tropical and subtropical forests (Chávez‐Pesqueira & Núñez‐Farfán 2016, 2017). Because of its rapid growth, continuous harvest and multiple uses, papaya is a common crop widely present in tropical regions of Mexico as extensive and local plantations.…”

“…Because of its rapid growth, continuous harvest and multiple uses, papaya is a common crop widely present in tropical regions of Mexico as extensive and local plantations. In many parts of Mexico, wild papayas occur within pollen/seed dispersal range of papaya plantations (Chávez‐Pesqueira & Núñez‐Farfán 2017). The two main differences between wild and domesticated papayas relate to flower morphology and fruit size.…”