A genetic polymorphism for tannin production in Lotus corniculatus and its relationship to cyanide polymorphism.

A study of 172 unnamed populations and 22 cultivars of Lotus corniculatus showed: (1) that all plants of most strains of both categories contained leaf tannins (total 172 strains); (2) that 6 strains were tannin-negative; and (3) that 16 strains were polymorphic. Because of the small number of tested plants per strain, the above frequency of polymorphism is probably underestimated. Tannin-negative or polymorphic strains are frequent in Iran and Turkey. Leaftannin production is inherited as a monogenic dominant with tetrasomic inheritance. Repeated scores suggest that some individuals always, others sometimes and yet others never produce leaf tannins. Mean tannin content of 6 cultivars was strongly negatively associated with mean cyanide content.