Photosynthetic Performance of Oil Palm Genotypes under Drought Stress

Water deficiency and potential drought periods could be important ecological factors influencing cultivation areas and productivity once different crops are established. The principal supply of vegetable oil for oil crops is oil palm, and new challenges are emerging in the face of climatic changes. This study investigated the photosynthetic performance of 12 genotypes of <i>Elaeis</i> exposed to drought stress under controlled conditions. The assay included genotypes of <i>Elaeis guineensis, Elaeis oleifera,</i> and the interspecific O×G hybrid (<i>E. oleifera</i> × <i>E. guineensis</i>). The principal results showed that the <i>E. guineensis</i> genotype was the most efficient at achieving photosynthesis under drought stress conditions, followed by the hybrid and <i>E. oleifera</i> genotypes. The physiological parameters showed good prospects for vegetal breeding with different O×G hybrids, mainly because of their ability to maintain the equilibrium between CO₂ assimilation and stomatal aperture. We validated 11 genes associated with drought tolerance, but no differences were detected. These results indicate that no allelic variants were represented in the RNA during sampling for the validated genotypes. In conclusion, this study helps to define genotypes that can be used as parental lines for oil palm improvement. The gas exchange data showed that drought stress tolerance could define guidelines to incorporate the available genetic resources in breeding programs across the early selection in nursery stages.