In vitro screening of almond (Prunus dulcis (Mill.)) genotypes for drought tolerance

Screening and identifying drought tolerant almond genotypes is required in order to improve and stabilize almond production under semi-arid and arid conditions. In this study, we evaluated responses of five high yield and late blooming almond genotypes to drought stress induced in vitro, and compared their drought tolerance to the drought tolerant peach×almond hybrid ‘GF677’. Explants established on the MS medium and subjected to three polyethylene glycol (PEG) osmotic stress for 40 days. Plant growth indices, leaves relative water content (RWC), membrane stability index (MSI), were significantly reduced under drought stress. On the other hand, proline concentration and number of lateral shoots were significantly increased under drought stress. Drought tolerant genotypes maintained higher levels of RWC, and MSI under drought stress. Growth of drought tolerant cultivars was more stable. Proline accumulation in the explants was found to be a general response of almond to drought stress. The results suggested that drought tolerant almond genotypes may be screened by in vitro experiments