Vasconcellea

Abstract

Vasconcellea, comprising 21 species, is the largest genus of the Caricaceae, best known for the monotypic genus Carica, including papaya (C. papaya), one of the most important tropical fruit crops. It is distributed from Mexico to Chile, with the center of diversity in Ecuador and Colombia. Because of their preference for higher altitudes, most Vasconcellea species are referred to as highland or mountain papayas. Currently, five of them are threatened and red-listed and four are not found in protected areas, while none of them are currently present in seed collections, raising questions on their conservation and urging for rapid action. Some Vasconcellea species have potential as novel tropical fruits, particularly V.?×?heilbornii, V.?cundinamarcensis, and V. goudotiana, which are being used for a growing (niche) market for new exotic products. As a source of papain, several Vasconcellea species show proteolytic activity up to 17 times as high as that of papaya. Others are being used as a source of new genes for papaya breeding, particularly for disease resistance (especially against papaya ringspot virus), cold tolerance, and specific organoleptic traits. Optimal use of Vasconcellea genetic resources requires a better understanding of its genetic potential, as well as the development of technologies to create intergeneric hybrids with papaya, as conventional breeding faces significant barriers. Cytogenetic and molecular studies, based on AFLP, PCR-RFLP, and SRR analysis, have allowed a better understanding of the evolution of the main Vasconcellea species, indicating complex hybridization and introgression processes among multiple species, which contrasts with the straightforward domestication of the common papaya. Genomic research in Vasconcellea has been limited to the sequencing of some gene fragments and the development of BAC libraries for a few species. Recent progress on papaya genomics, the development of a high-density genetic map, and the sequencing of the genome will help in the identification of genes of interest in Vasconcellea, either for papaya breeding or for the development of Vasconcellea species as new crops. (Résumé d'auteur

Reproductive biology of Vasconcellea quercifolia A. St.-Hil. (Caricaceae), a moth-pollinated ‘highland papaya’

“…(Badillo 1971(Badillo , 2000. It is stated that V. cundinamarcensis presents rare cases of andromonoecy, a trait shared only with C. papaya (Scheldeman et al 2011). Flowers of studied species of Caricaceae are sexually dimorphic for their size and number for inflorescence, nectar production, and phenology (Baker 1976;Bawa 1980;Bullock and Bawa 1981;Aguirre et al 2009).…”

Molecular Phylogeny, Biogeography and an e-Monograph of the Papaya Family (Caricaceae) as an Example of Taxonomy in the Electronic Age

“…E. Honorio 1365). Vasconcellea  heilbornii, a sterile hybrid between V. cundinamarcensis, V. stipulata, and V. weberbaueri (maintained in cultivation as a parthenogenetic clone), was excluded from this study Scheldeman et al, 2011). Seven of the 13 species of Moringaceae were chosen as outgroups for rooting purposes (Olson, 2002).…”

“…Annual world production of Carica papaya is now >10 million tons, making papaya an extremely important fruit crop (Scheldeman et al, 2011;FAOStat, 2011). Papaya is a vital source of vitamins for people in the humid tropics, and proteinases obtained from the milky latex extracted from unripe fruits are widely used in the food and pharmaceutical industry (Krishnaiah et al, 2002;.…”

“…The so-called highland papayas from the Andes (Vasconcellea spp.) regarded as underexploited crops, have a number of desirable traits, including disease resistance, cold tolerance, and latex with high proteolytic activity (Scheldeman et al, 2011). Breeders have sought to introduce these features to C. papaya using traditional plant breeding techniques.…”

“…One of the main impediments for C. papaya production is the papaya ring spot virus, although some Vasconcellea are tolerant to the disease Siar et al 2011;. The lack of knowledge of the true closest relatives of papaya resulted in the assumption that the highland papayas (Vasconcellea species) are the best group to use in papaya improvement (Scheldeman et al 2011;. The persistent neglect of all genera except Carica and…”