Agronomic and molecular characterization of blood orange varieties and hybrids

Abstract

The citrus industry is a major agribusiness activity in Brazil and is based on the cultivation of sweet oranges varieties with yellow pulp. The production of blood oranges, which have the differential characteristic of fruits with red/purple color of the pulp and the juice due to anthocyanins production, can be considered as a new market opportunity for the Brazilian citrus industry. The anthocyanins accumulation in the fruits of blood orange is obtained when the cultivation occurs in region with low temperatures or with high daily temperature range. However, the anthocyanins can also be accumulated in fruits harvested in warm climate region, if they are put in cold storage on postharvest. The biosynthetic pathway of anthocyanins production in blood oranges had already been partially elucidated with the identification and sequencing of some structural and other regulator genes. This project aims to: a) evaluate the agronomic characteristics of six blood oranges varieties, cultivated in two locations that have different soil and climatic conditions in order to select new cultivars for commercial cultivation and also to assess the effects of climate and varieties in accumulation of anthocyanins in the pulp of the fruits; b) perform the molecular characterization and expression of seven genes involved in the anthocyanins biosynthesis route, and quantify anthocyanins present in the pulp of the fruits in order to elucidate the control of gene expression route of anthocyanins in blood oranges; c) confirm the existence of polymorphisms in the DNA of some blood orange varieties and verify if they are responsible for the accumulation of anthocyanins in the flesh of the fruits; d) characterize agronomically intraspecific hybrids of Pêra de Abril x Sanguinelli sweet oranges.