Flowering map of papaya germplasm: Support for genetic breeding and conservation programs

Brazil is the world's second leading producer of papaya. However, to sustain future production and growth particularly in the face of climate change, the development of new cultivars adapted to the country's various producing regions is a priority, mainly taking climate change into consideration. Research on the flowering phenology of papaya germplasm can facilitate choice of the most favorable moment to perform hybrid combinations for improvement. In this study, we analyzed the flowering phenology of 119 accessions of the Embrapa Papaya Active Germplasm Bank. The variables temperature, relative humidity and precipitation were collected from a nearby meteorological station and the data on average number of flowers produced per hermaphrodite plant were submitted to multivariate cluster analysis. The flowering of these accessions was influenced by environmental conditions, mainly rainfall patterns, characterizing seasonal behavior. The results showed two flowering peaks, the first coinciding with spring and the second with winter. In addition, we observed the formation of three different groups regarding flower production. The results obtained allow zoning of the flowering throughout the year for the 119 accessions, helping to improve the planning of hybridizations of interest. As far as we know, there are no reports in the literature of this type investigation with such a representative number of Carica papaya varieties.