Highlights of accomplishment from the above research are (1) the development of a new tomato variety with multiple disease resistance, including resistance to Phytophthora infestans, (2) the development of several potato breeding lines with both monogenic and multigenic resistance to late blight which were deposited in the USDA’s National Potato Breeding Program, (3) the discovery and delineation of physiologic race specialization in P. infestans, (4) the discovery of the sexual stage of P. infestans, about 100 years after the species was named, (5) the discovery of compatibility types in P. infestans which we named A¹ and A², (6) the establishment of sexual patterns in the genus Phytophthora including the transfer of the compatibility type designations to the other heterothallic species in the genus, and (7), since retirement, the development of a new dichotomous key for the identification of species of Phytophthora
