Condensed Tannin Concentrations of Three Lotus Species Grown in Different Environments

Hernán Acuña1*, Alex Concha2 and Marcos Figueroa2

Condensed tannins (CT) present in Lotus spp., depending on their concentration in the plant, can prevent bloating and improve protein absorption in ruminants. With the objective to know the variability of this characteristic, the CT concentration (% dry matter basis) was determined by the butanol-HCl procedure in 13 cultivars of Lotus corniculatus L. (Lc) introduced from North and South America and Oceania, 11 accessions of Lotus tenuis Waldst. & Kit. ex Willd. (Lt), and 22 accessions of Lotus uliginosus Schkuhr (Lu) collected in Chile, from 32° to 38° S and 36° to 46° S, respectively. The field experiments, with two randomized complete blocks, were established in autumn 1998, in five different environments in the central-southern zone of Chile (clay soil, sandy soil, and three volcanic soils with different levels of water availability). The herbage sampling was conducted in spring-summer 1999-2000, when the plants were in full flowering. Significant differences between cultivars or accessions were found within each site, in total CT and/or in extractable or protein or fiber bound fractions of CT concentrations. The Lc and Lu genotypes showed high variability, with a range of 4.7 to 8.7% and 6.3 to 11.0%, and means of 6.1 and 8.2%, respectively, of total CT. The Lt general mean was 4.8%, considerably higher than the figures reported in the literature, and had low variability. This information will contribute to select genotypes for the improvement of this species by selection and breeding.

Keywords: Lotus corniculatus, L. tenuis, L uliginosus, condensed tannins.
1 Instituto de Investigaciones Agropecuarias, Casilla 426, Chillán, Chile. E mail: hacuna@inia.cl*
*Corresponding author.
2 Universidad de Concepción, Facultad de Agronomía, Casilla 537, Chillán, Chile. Partial results of this work have been presented in: 28th Annual Meeting of the Chilean Society for Animal Production, Talca, Chile, 2003; 20th International Grassland Congress, Ireland and the United Kingdom, Dublin, 2005, and Lotus Newsletter 35(1):11-12, 2005.