Inbreeding, Coancestry, and Founding Clones of Japanese-type Plums of California and the Southeastern United States

Abstract

The mean inbreeding and coancestry coefficients of Japanese-type plums grown in California and the southeastern United States were one-half or less of those calculated for peach. The three most important founding clones for the major California cultivars were ‘Santa Rosa’, ‘Eldorado’, and ‘Gaviota’; for the plums of the southeastern United States they were ‘Methley’, ‘Santa Rosa’, and ‘Mariposa’. The species background of both groups of plums was ≈50% P. salicina , although the sources of P. salicina differed between groups. For the California cultivars, the other half was composed of P. simonii and P. americana , whereas, for the southeastern group, the major contributing species was P. cerasifera , with lesser contributions from P. simonii, P. americana, P. angustifolia , and P. munsoniana.