The primary gene pool of cassava (Manihot esculenta Crantz subspecies esculenta, Euphorbiaceae)

The primary gene pool (GP-1) of a crop is composed of gene reservoirs that cross easily with the domesticated, while the crosses regularly produce fer tile offspring. The GP-1 is further subdivided into cultivated and wild gen e pools. The cultivated gene pool encompasses commercial stocks of the crop , as well as landraces. The wild GP-1 of the crop comprises putative ancest ors and closely related species that show a fair degree of fertile relation ships with the domesticate. Two South American wild subspecies of cassava ( M. flabellifolia and M. peruviana) were proposed as natural members of the wild GP-1 of the crop. Another Brazilian species (M. pruinosa) is morpholog ically so close to both wild subspecies that it may turn out as another mem ber of the wild GP-1.