Editing Blackcurrant (section)

===Research and cultivars===
[[File:Ribes nigrum 'Vertti'.jpg|thumb|Green currant is a variant of blackcurrant cultivated in [[Finland]]; its berries lack the  dark color and strong aroma typical of blackcurrant. This particular cultivar is 'Vertti'.]]

There are many [[cultivar]]s of blackcurrant. 'Baldwin' was the mainstay of the industry for many years but it has now largely been superseded by more productive and disease-resistant varieties.<ref>{{cite book |title=The Royal Horticultural Society Encyclopedia of Gardening |editor-last=Brickell |editor-first=Christopher |year=1992 |publisher=Dorling Kindersley |isbn=9780863189791 |page=415 }}</ref><ref name=varieties>{{cite web |url=http://www.blackcurrantfoundation.co.uk/growing-blackcurrants/growing/varieties |year=2009 |title=The blackcurrant: Varieties| publisher=The Blackcurrant Foundation |access-date=2016-12-12}}</ref> During the 20th century in Europe, much hybridisation work has been carried out in order to reduce the plant's susceptibility to disease and frost and also to increase yields. This effort centered mainly in Scotland, Poland, and New Zealand.<ref name="bfhistory">{{cite web|title=A History of Blackcurrants|url=http://www.blackcurrantfoundation.co.uk/growing-blackcurrants/history/history-blackcurrants|publisher=Blackcurrant Foundation|access-date=10 December 2017|date=2017}}</ref>

In Britain the [[Scottish Crop Research Institute]] was tasked with developing new varieties suitable for growing in the north of the country. They produced new cultivars that had greater cold tolerance, especially in the spring, ripened earlier and more evenly and had greater fungal disease resistance. Frost tolerance was improved by selecting for late flowering and [[Molecular genetics|genetic research]] identified genes involved in resistance to gall mite and the blackcurrant reversion virus. 'Ben Lomond' was the first of the 'Ben' varieties and was released in 1975. This was followed by several other cultivars for the juicing industry such as 'Ben Alder' and 'Ben Tirran'. The cultivar 'Ben Hope' was released in 1998 with increased tolerance to gall mite, and in the same year, 'Ben Gairn' became available. It shows resistance to the reversion virus.<ref name=SCRI/> For gardeners and the pick-your-own market, 'Ben Sarek', 'Ben Connan' and 'Big Ben' were introduced and have large, sweet berries.<ref name=varieties/> The cultivars 'Ben Connan'<ref>{{cite web | url = https://www.rhs.org.uk/Plants/56451/Ribes-nigrum-Ben-Connan-(B)/Details | title = ''Ribes nigrum'' 'Ben Connan' | publisher = RHS | access-date = 17 February 2021}}</ref> and 'Big Ben'<ref>{{cite web | url = https://www.rhs.org.uk/advice/profile?pid=1027 | title = Blackcurrants | publisher = RHS | access-date = 17 February 2021}}</ref> have gained the [[Royal Horticultural Society]]'s [[Award of Garden Merit]].<ref name=RHS/> and new varieties are being developed continually to improve frost tolerance, disease resistance, machine harvesting, fruit quality, nutritional content and fruit flavour.<ref name=varieties/>

Varieties producing green fruit, less strongly flavoured and sweeter than typical blackcurrants, are cultivated in [[Finland]], where they are called "greencurrants" (''viherherukka'').<ref>{{cite journal|last=Junnila|first=S.|display-authors=etal|date=1987|title=A green-fruited blackcurrant variety 'Vertti'|journal=Annales Agriculturae Fenniae|volume=26|pages=278–283}}</ref> In Poland, the Research Institute of Horticulture has done work on improving the blackcurrant with regard to disease and pest resistance, fruit quality, adaptations to local conditions and mechanical harvesting. Researchers have crossed various varieties and introduced inter-specific genetic material from the gooseberry (''[[Ribes grossularia]]''), the [[redcurrant]] (''Ribes rubrum'') and the flowering currant (''[[Ribes sanguineum]]''). The resulting offspring were further back-crossed to ''R. nigrum''. Cultivars produced include 'Tisel' and 'Tiben' in 2000 and 'Ores', 'Ruben' and 'Tines' in 2005. Further cultivars 'Polares' and 'Tihope' are being tested.<ref name=Pluta>{{cite web |url=http://www.inhort.pl/home_en.html |title=The blackcurrant breeding program in Poland, aims and recent improvements |last=Pluta |first=Stan |publisher=Research Institute of Horticulture, Skierniewice, Poland |access-date=2013-09-10 |archive-url=https://web.archive.org/web/20130917110240/http://www.inhort.pl/home_en.html |archive-date=2013-09-17 |url-status=dead }}</ref> Since 1991, New Zealand has become an important centre for research and development, as its temperate climate is particularly suitable for cultivation of the crop. Breeding programmes are concentrating on yield, large fruit size, consistency of cropping and upright habit.<ref>{{cite web |url=http://www.plantandfood.co.nz/page/news/video-index/video/blackcurrant-breeding/ |archive-url=https://web.archive.org/web/20130209071620/http://www.plantandfood.co.nz/page/news/video-index/video/blackcurrant-breeding/ |url-status=dead |archive-date=9 February 2013 |title=Blackcurrant breeding plots at Waipuna farm |author=Langford, Geoff |year=2010 |work=Plant and food research |publisher=The New Zealand Institute for Plant & Food Research |access-date=2013-06-03 }}</ref>

In North America, there is a need for this fruit to have resistance to white pine blister rust. New cultivars such as 'Crusader', 'Coronet' and 'Consort' have been developed there by crossing ''R. nigrum'' with ''[[Ribes ussuriense|R. ussuriense]]'' and these show resistance to the disease. However the quality and yield of these varieties are poor as compared to non-resistant strains and only Consort is reliably self-fertile. Back-crossing these varieties to a parent have produced new strains such as 'Titania' that have a higher yield, better disease resistance, are more tolerant of adverse weather conditions and are suitable for machine harvesting.<ref name=VCE>{{cite web |url=http://pubs.ext.vt.edu/438/438-107/438-107.html#L3 |title=Specialty Crop Profile: Ribes (Currants and Gooseberries) |author1=Bratsch, Anthony |author2=Williams, Jerry |publisher=Virginia Cooperative Extension |access-date=2013-09-08 |archive-date=2013-09-09  |archive-url=https://web.archive.org/web/20130909235035/http://pubs.ext.vt.edu/438/438-107/438-107.html#L3 |url-status=dead }}</ref> Two new releases from a black currant breeding program in British Columbia, Canada, 'Blackcomb' and 'Tahsis', were selected for their immunity to white pine blister rust and their frost tolerance.<ref>{{Cite web|url=http://www.berrycrops.net/|title=McGinnis Berry Crops|website=Berrycrops.net|access-date=2024-03-28}}</ref>