‘Garnem’ and Myrobalan ‘P.2175’: Two Different Drought Responses and Their Implications in Drought Tolerance

Abstract

One of the challenges in rootstock breeding programs is the combination of tolerances to different abiotic stresses in new interspecific hybrids adapted to a wide range of environmental conditions. In this work, two Prunus L. rootstocks: Myrobalan ‘P.2175’ (P. cerasifera Ehrh.) and the almond × peach hybrid ‘Garnem’ (P. amygdalus Batsch × P. persica (L.) Batsch) were subjected to drought during 24 h to understand their drought response mechanisms. The study was conducted monitoring leaf water potential (LWP), stomatal conductance (gs), relative water content (RWC), and electrolyte leakage (EL); as well as the abscisic acid (ABA) content in roots. The relative expression of five drought-relative genes was also studied. The obtained results allowed examining the drought tolerance potential of ‘Garnem’ and Myrobalan ‘P.2175’, demonstrating the great potential of ‘Garnem’ as drought tolerance source in future selections in breeding. Furthermore, based on the obtained data, the transcription factor Myb25-like could be a good biomarker of drought sensitivity for use in Prunus rootstock breeding programs.