Genetic diversity in two species of Caricaceae and their genetic relationship to Carica papaya L

ABSTRACT

The species Vasconcellea monoecious and Jacaratia spinosa are wild germplasm belonging to the Caricaceaefamily, and are useful in breeding programs of the cultivated species, Carica papaya. The aim of this work was to study the genetic relationships between the three species, and understand the genetic diversity within wild species, using RAPD markers. Accesses belonging to the Caricaceae Germplasm Collection of the Plant Breeding Laboratory of the North Fluminense Federal University (UENF) were collected in two different states of Brazil, Rio de Janeiro and Espirito Santo, and genotyped using molecular markers. The results indicated that the wild species were genetically relatively distant from the cultivated species, and also very distant from each other. This suggests that there may be great difficulty in obtaining interspecific hybrids between these species. The estimates of diversity obtained here demonstrated that the species J. spinosa was superior to V. monoecious. The results showed low genetic variability among the accessions for each species analysed, indicating that insertion of new genetic material into the Caricaceae Germplasm Collection of UENF is essential.

Key words:
Vasconcellea monoica ; Jacaratia spinosa ; RAPD markers; Germplasm; Genetic improvement