The Utilization of Related Prunus Species for Almond Variety Improvement

Abstract

Germplasm from a range of Prunus species in the subgenus Amygdalus, sections Euamygdalus, Spartoides, and Lyciodes has been evaluated for potential value to almond ( P. dulcis) breeding through an international, U. S.-Spain cooperative project. Species evaluated include Prunus argentia, P. bucharica, P. fenzliana, P. mira, P. persica, P scopariaand P. webbii.The absence of severe crossing barriers in the initial hybridization and in subsequent backcrosses demonstrates a direct accessibility of this rich germplasm to almond breeding. The performance of interspecific hybrids, as well as their subsequent backcrosses to cultivated almond, further demonstrate valuable opportunities for transferring useful traits including self-compatibility, resistance to important pests and diseases, the improvement of seed oil quality, tree growth architecture and bearing habit, and tolerance to aberrant environments. The international collaboration has allowed a more thorough evaluation of related germplasm and avoids quarantine restrictions on the U. S. importation of new Prunus accessions.