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A bstract Four new accessions were obtained by crossing some Sicilian high value cultivars (‘Buscionetto’, ‘Nocellara del Belice’, ‘Nocellara Messinese’ and ‘Tonda Dolce’). The olives were harvested at the green stage and characterized through the evaluation of agronomic and morphological parameters. The DNA was extracted from young leaves of the obtained hybrids and genotyped at 9 nuclear microsatellite loci. The olives were directly brined in order to test the quality of the fermented products. The results of genetic variability clustered all the analyzed samples in two main groups. The carpological parameters of the new hybrids revealed that they are very suitable for table olives. The phenological stages of the new hybrids allow a longer period of commercialization compared to the reference varieties because the ‘C’, ‘E’ and ‘B’ hybrids showed a substantial ripening period advance. The sensory profiles of ‘A’ and ‘C’ hybrids were quite similar, while the other two ones showed different sensory results.

Blood oranges have been cultivated in Italy since the early 19th century. Growers and breeders were able to identify and collect many somatic mutants, which differed in their major pomological traits, such as fruit size and firmness, pulp and peel pigmentation, and ripening period. Recently, in the framework of a genetic resource conservation program, most of the accessions collected at CREA in recent decades were planted in a single block to evaluate their characteristics. The presence of many selections in the same block, of the same age and grafted on the same rootstock is extremely important for a reliable characterization of the pomological characters, particularly pigmentation, which is strongly influenced by both the environment and the rootstock. The collection consists of 88 genotypes, including old lines and nucellar selections. Some commercial Tarocco, Moro and Sanguinello varieties were also included in the collection to facilitate comparison among clones. Moreover, the pomological features of 20 elite Tarocco clones cultivated nearby in the same experimental station were used as a further reference. The pomological characterization, based on 13 traits and performed in two consecutive years, revealed significant variability. Some genotypes showed strong year-to-year variability, mainly in fruit pigmentation, probably due to different climatic conditions during winter. Similarly, other traits such as fruit size, total soluble solids and acidity also varied among and within the varietal groups. These findings have a potential utility in identifying promising clones, which might fulfil the growing market needs such as higher anthocyanin content and longer shelf life.

A flesh-specific oligonucleotide custom array was designed to study gene expression during blood orange ripening. The array included 301 probes derived from a subtracted SSH library, a cDNA-AFLP collection, and a set of regulatory genes from the Harvest citrus database. The custom array was hybridized using samples of Moro, a pigmented cultivar, and Cadenera, a common cultivar, at three different ripening stages: the immature phase, the halfway point of maturation (corresponding to the start of Moro pigmentation) and the full ripening. Of the 301 probes, 27 in total, corresponding to 20 different transcripts, indicated differential expression in stage-to-stage and/or cultivar-to-cultivar comparisons. Transcripts encoding for anthocyanin biosynthesis represented most of the total over-expressed probes. The remaining differentially expressed transcripts were functionally associated with primary metabolism as flavor biosynthesis, defense and signal transduction. The expressed products associated with probes indicating differential expression were confirmed by qRT-PCR. The microarray was designed considering a small collection of sequences useful for monitoring specific pathways and regulatory genes related to fruit ripening and anthocyanin pigmentation. The main novelty of this customization is the use of expressed sequences specifically derived from blood orange flesh to study different cultivars and ripening stages, and the provision of further information about processes related to anthocyanin pigmentation in citrus fruit flesh.