The world’s fourth most important crop has many challenges to sustainable production as climatic zones shift and change in agricultural systems accelerates.  Potato already consumes around half of the irrigation water used in the UK and suffers from pests and pathogens which continue to threaten production and continue to change. There are solutions for the problems of potato production and these depend on the amazing range of diversity to be found in potato and its wild relatives, reflecting the wide range of habitats and pest and pathogen pressures experienced by them. Further details can be seen on our dedicated Commonwealth Potato Collection website.

Figure 1: The Commonwealth Potato Collection Glasshouse

The wild species in the Commonwealth Potato Collection (Figure 1, above), members of the tuber-bearing part of the Solanum genus, come from habitats which include the extreme upper limits to vegetation in the high central Andes, coastal and lowland marshes in Chile, relatively low altitude damp tropical forests of the eastern Andes, to the dry deserts of the western Andes and of Mexico and New Mexico and Arizona in the US.  The range of morphological variants associated with adaptation to these environments indicates the adapatability of the genus and the rich store of cross-compatible diversity for breeding (Figure 2, below).

Figure 2: Leaf diversity in wild tuber-bearing Solanum

The diversity in the collection includes a broad range of cultivated diploid and tetraploid landrace potatoes.  These lines have been crucial to past breeding, for example supplying the H1 gene which is in most UK cultivars and confers resistance to the Potato Cyst Nematode species Globodera rostochiensis.  They have also supplied the germplasm for a type of potato new to the UK market, Phureja potatoes (Solanum tuberosum Group Phureja). The promise of truly high throughput molecular methods opens the possibility of sampling these genomes in ways not possible previously.  With this in mind, adapted and unique sets of highly diverse Andean cultivated potato germplasm have been developed for temperate latitudes, including tetraploid (Neotuberosum) and now diploid (Stenotomum) populations (Figure 3, below).  These latter types represent the initial domesticated form of potato and carry much more diversity than the derived Phureja types.

Figure 3: Diverse diploid Andean potatoes undergoing selection for local adaptation

The understanding of the genetics of European potato has always been restricted by the difficulties associated with their polyploid and outbreeding nature. A further population from the CPC under development comes from the discovery of a self-fertile CPC accession of Phureja. This line has been further inbred and multiplied, opening the possibility of recombinant inbred lines and chromosome substitution lines from interspecific crosses, better parents for potato genetic mapping populations and the development of mutagenised diploid potato populations (Figure 4, below).

Figure 4: Mutagenised inbred Phureja potato population undergoing manual self-pollination