The Blackberries of South America — An Unexplored Reservoir of Germplasm

Abstract

The genus Rubushas been divided into 12 sub-genera, of which only five contain fruits of pomological interest. Two of these, the Eubatusand the Orobatus, contain all the blackberries. The Eubatushas been further sub-divided into six sections and four of these ( Xerocarpi, Dissitiflori, Floribundiand Duri) are restricted to South America (4). The Moriferisub-section of the Eubatus, which contains all the European and eastern American blackberries. In this sub-section the peculiarities of the breeding system have produced many thousands of microspecies—a term used for a population wihch differs morphologically, however slightly, from other uniform populations. Thus, if the taxonomists are correct, it would be true to say that diversity in the blackberries is most developed in South America, because it is based upon differences of higher taxonomic rank there than elsewhere. By contrast, the blackberries of Europe and eastern America can be regarded merely as a network formed originally from a few, but an unknown number of, diploids and now represented by a great diversity of their polyploid, sub-sexual hybrid derivatives.