Blackcurrants (Ribes nigrum) as a domesticated crop is comparatively recent, occurring within the last 400-500 years (Keep, 1995). The modern-day commercial cultivars of blackcurrant are significantly advanced from their wild progenitors, with a range of desirable attributes selected within the available germplasm by breeders in Europe and beyond.
In the UK cultivars of blackcurrant have been bred for their deep purple colour, which indicates a high level of anthocyanins; and for their attributes which benefit the environment such as pest and disease resistance.
Initial records in the UK date back to the seventeenth century, in herbals referring to the medicinal properties of the fruits (Roach, 1985), and by 1826 five cultivars were listed by the Royal Horticultural Society. Much of the subsequent cultivar development during the 19th century was based on the introduction of plants raised by private individuals or by nurserymen from open-pollinated seed of the existing cultivars. In 1920, Hatton identified 26 cultivars classified into four main groups of similar or synonymous cultivars.
The centre of diversity for the currant section of the Ribes genus extends from northern Scandinavia across Russia. As a result, there have been significant breeding efforts in these regions, with Russia in particular having many programmes in the 20th century producing a wide range of locally-adapted cultivars. In Scandinavia, initial breeding involved the selection of superior local ecotypes from the available wild germplasm, leading to the development of cultivars such as `Brödtorp’ and `Øjebyn’, both of which are still grown today in parts of Europe.
Elsewhere in Europe, by the late 19th century the cultivar `Baldwin’ was the most important in the UK, and it is still grown on a reduced scale today in some regions. However, the development of state-funded breeding programmes within the UK and elsewhere led to the production of a series of cultivars as hybrids between existing cultivars within Hatton’s classification, and it became apparent that expansion of the genetic base available to breeders was important for the crop’s future development.
One of the main problems initially encountered in commercial blackcurrant growing was inconsistency of cropping of the available cultivars, mainly due to spring frost damage at flowering time. Crops of `Baldwin’ and most other early UK and European cultivars are particularly prone to damage, with yields decimated. The use of frost-hardy germplasm from Scandinavia in blackcurrant breeding, allied to high-yielding types with increased fruit quality, was successfully employed in the breeding programme based at the Scottish Crop Research Institute, leading to the `Ben’ series of cultivars. These cultivars, starting with `Ben Lomond’ in the 1970s up to the recently released `Ben Hope’ and `Ben Gairn’, are now the pre-eminent cultivars in the UK and worldwide.
Since the 1990s, `Ben’ cultivars have also been developed for the New Zealand industry, through selection of germplasm adapted to the local environmental conditions. The most active breeding programmes for blackcurrant at the present time are based in Scotland (SCRI), Poland, Lithuania, Norway and New Zealand.