GENETIC DIVERSITY AND PLASTICITY IN SELECTED PROGENY OF PLUM CULTIVAR 'JUBILEUM'

A joint domestic plum breeding program between the Latvia State Institute of Fruit-Growing (LSIFG) and Department of Horticultural Plant Breeding of the Swedish University of Agriculture was performed in 1996-1999. Cultivar ‘Jubileum’ was widely used in crosses as a parent due to its possible genetic plasticity. As a result diverse plum hybrid material was obtained. From more than 1000 hybrids 22 elite plants were selected for further evaluation to detect their suitability for Latvia climate conditions. Progeny of cultivar ‘Jubileum’ obtained in breeding showed great diversity of fruit shape – from round to elongated elliptic, fruit colour – from yellow to violet-blue and fruit size – from 30 to 70 g. High variability had also stone adherence to flesh, as well as diversity in canopy height and shape. The phenotypical and molecular marker (microsatellite, SSR) characterization has been applied to evaluate genetic diversity. The characterization results discovered that crosses of cultivar ‘Jubileum’ used in the Latvian-Swedish plum breeding program had wide diversity among the features of parent cultivars and obtained hybrid material. Progeny of cultivar ‘Jubileum’ had wide genetic diversity and inheritance plasticity, confirming its featured application in further plum breeding. Inheritance of plum features was dependent on the gender of parent cultivar – features of female parent had higher heritability in the progeny. Analysis of twelve microsatellite (SSR) markers set for plum molecular characterization showed good applicability for the molecular analysis of genetically related germplasm and could be applied for further characterization and plum cultivar identification.