Blackberry Breeding

Abstract

Blackberries are classified taxonomically in the genus Rubus , subgenus Eubatus , and consist of a highly variable and complex group of plants. Bailey (1) recognized over 350 species of blackberries, but the taxonomy of the subgenus is still in much confusion. Blackberries range from evergreen, subtropical types to deciduous clones that survive beyond the Arctic Circle. Most are indigenous to the northern hemisphere but some occur in the tropical mountain regions of the southern hemisphere. A naturally occurring ploidy range from diploid (2 x = 2 n = 14) to dodecaploid (12 x = 2 n = 84) exists (5). Homoploid blackberry species are mostly interfertile and biological systems encouraging outcrossing are common, thus native populations of blackberries in much of the world are highly hybrid (7). Consequently, it is difficult to assign cultivars to specific species, since progenitors of modern cultivars were selected from the wild.