Reaction to drought stress of citrus progenies with potential use for rootstocks development

The objective of this study was to evaluate citrus progenies reaction to drought stress and shoot emission capacity in order to identify those with potential for generating hybrids that can be used as rootstocks, mainly in the Coastal Tablelands of the Brazilian Northeast, where the rainfall distribution does not meet the water requirements for citrus production throughout the year. The Citrus Breeding Program of Embrapa Cassava and Fruits conducted controlled crossings having as female parents the ‘Rangpur Santa Cruz’ lime (RSCL) and the ‘Sunki of Florida’ mandarin (SFM), and as male parents, besides this mandarin, the ‘Indio’ (IDC) and ‘Riverside’ (RSC) citrandarins, ‘Thomasville’ citrangequat (THOM), ‘Swingle’ citrumelo (SWC), ‘Argentina’ citrange (AGC) and ‘Benecke’ trifoliate orange (BKTO). The hybrids generated were visually evaluated in the period from 2011 to 2014 for drought stress and water use capacity, on the basis, respectively, of leaf curling, evaluated at the end of periods of intense drought stress, and shoot emission, determined immediately after the occurrence of rains following those intense stress periods. The hybrids of RSCL were less sensitive to drought stress, and the SFM mandarin generated hybrids with good water use, due to their good shoot emission capacity in response to water deficit. This is an indication of the capability of this mandarin to produce hybrids with good rehydration ability.