Plums

Abstract

Most of the plums grown commercially are either the hexaploid, Prunus domestica (European) or the diploid, P. salicina (Asian or Japanese). Common goals of European plum breeders are cold hardiness, modest tree size, self fertility and productivity. Some of the key abiotic problems confronting Japanese plum production are susceptibility to spring frosts, insufficient winter hardiness and limited soil adaptations. Fruit quality and disease resistance are important goals in all plum breeding projects. The genetics of only a few traits have been investigated in plum; however, significant progress has been made in identifying horticulturally useful germplasm. A Myrobalan plum clone was crossed with an almond-peach hybrid to generate a microsatellite genetic linkage map and a resistance gene to the root knot nematode (Ma) was identified. A transgenic European plum clone was produced that carries the plum pox virus coat protein gene (PPV-CP) and has strong resistance to all four major serotypes of PPV.