growth and development of citrus

Fruit set is characterized by the shedding of a variable number of flower and growing ovaries. This physiological process is called abscission. In citrus, flower and ovary abscission has an special relevance due to its economic and commercial implications. Crop will be scarce if a massive abscission of reproductive structures takes place. However, final fruit size will not reach a commercial diameter if high setting is produced. On the other hand, fruit detachment force decreases during ripening and an important fruit loosening can occur if harvesting is postponed by commercial reasons. Environmental conditions such as drought and salinity are frequent in the Mediterranean basin leading to leaf and fruit damage and abscission as well.

In this context our objectives are:

1) The understanding of the physiological and molecular basis of citrus abscission caused by adverse environmental conditions.

2) Global expression analysis of activation of abscission zones during fruit set and ripening.

3) Transcriptome analysis at the ovary wall during fruit set in different Clementine and sweet orange cultivars.

4) Molecular characterization of abscission zone development.

5) Hormonal control of citrus root growth: anatomical and molecular analysis of the interaction between gibberellin, auxin and ethylene.