Indications on sources of oil palm (Elaeis guineensis Jacq.) genetic resistance and susceptibility to Ganoderma sp., the cause of basal stem rot

Oil palm basal stem rot, caused by Ganoderma sp., results in major losses in the oil palm plantations of Southeast Asia. Results and field observations are now becoming available for planting material of strictly known origins. These observations seem to confirm that there are differences in performance from one origin to another. Indeed, among the parental materials, the general susceptibility of Deli material stands out from a degree of resistance in the La Mé or Yangambi origins. The performance of commercial materials varies substantially and is discussed in this paper. For instance, one cross planted in several places, and its reproduction in hybrid form, are relatively little affected by the disease, whereas another cross and three clones derived from it seem to be severely affected by Ganoderma at an early stage. E. oleifera x E. guineensis also express very few symptoms in zones with a high disease incidence. These results, which tally in many ways, could be used initially to discard sources of marked susceptibility and, secondly to draw up a selection strategy for resistance. They could also provide a range of control crosses for elaborating and developing early screening. (Résumé d'auteur