Ribes x nidigrolaria

Abstract

Ribes x nidigrolaria, best known as Jostaberry, is an artificial, fertile F-2 amphidiploid hybrid of complex parentage from crossbreeding of the F1-hybrid (Ribes nigrum ‘Langtraubige Schwarze’ x R. divaricatum) resistant to mildew and the F-1 hybrid (R. nigrum ‘Silvergieters Schwarze’ x R. grossularia ‘Grune Hansa’) resistant to white pine blister rust by Dr. Rudolf Bauer in Germany (Bauer 1973, 1986; Bauer and Weber 1989). The first cultivar of R. x nidigrolaria was introduced by Dr Baeur in 1977 under the name josta. The resulting double hybrids carries the characteristics of their four genetical grand parents with combined mildew and rust resistance, resistance to other leaf-fall diseases and to gall mite and have sufficient self-fertility (Baeur 1973). This hybrid is sometimes erroneously referred to as Ribes x culverwellii MacFarlane. The latter is a nearly sterile hybrid of R. nigrum and R. uva-crispa. Despite its complex parentage Ribes x nidigrolaria is a fully fertile taxon and relatively easily escapes (Mang 1992; Weber 1995). R. x nidigrolaria has been recorded as an escape on riverbanks (between granite blocks) in Flanders, Belgium, probably bird-dispersed or from washed-up rhizomes (Verloove 2011). It was first seen along river Leie near Wervik, subsequently also along river Schelde (at its junction with Ringvaart). Further, in 2010 it was discovered in grassland (former dump) along motorway near Drongen.