In vitro digestibility of the testa in tannin-free field beans (Vicia faba L.)

Abstract

The seed-coat of all white-flowered varieties of Vicia faba and segregants tested was free of tannin. In two field trials, the whole grain of white-flowered varieties was significantly higher in in vitro digestibility of the dry matter, on aveiage 4-7 % higher, than coloured-flowered varieties of similar seed size. In subsequent trials where the testa and cotyledon were examined separately, this difference was shown to be largely due to a mean D value (digestibility of the organic matter) of the testa in tannin-free varieties of 56-4% compared with 17-2% in tannin-containing varieties. Seed size was positively correlated with D value but not because of differing proportions of testa.Differences between varieties in acid-pepsin solubility and protein content of the testa were much smaller and not associated with presence of tannin. The testa colour of some tannin-free F% plants was a darker shade of grey than either parental population. An inbred line completely lacking in anthocyanin in flowers and stem but with the normal black wing spot had tannin in its testa.Grains of peas from the coloured-flowered variety, Minerva, reacted to a tannin test wheieas those from white-flowered varieties, Greenshaft and Flavanda, did not.The case for breeding further tannin-free varieties of Vicia faba is discussed.

Inheritance, Characterization and Selection of Tannin-Free Fababeans (Vicia Faba L.)

“…This compound pleiotropic effect on plant, flower and seed has been implicated as a predominant coat color. Bond ( 1976) Marquardt et al (1978a) and is similar to that used to distinguish between red and white wheats (Wrigley and McCausland 1977 x Fidrim (UMFB-9 x Kodrim) x Kodrim (Kodrim x x Kodrim …”

“…occurring, water-soluble compounds of high Fababean cultivars with white flowers and molecular weight (between 500 and 3000), lacking reddish brown pigment in the containing a large number of phenolic nectaries of their stipules were first hydroxyl or other suitable groups which described by Erith (1930). These cultivars enable them to form effective cross-links have been found to contain no condensed between protein, cellulose and other mac-tannin in their seed coats (Bond 1976). romolecules (Swain 1965).…”

FACTORS AFFECTING IN VITRO RUMEN DIGESTION OF FABA BEAN CULTIVARS (Vicia faba L.)

“…L'adjonction de tanins condens6s isol6s du testa de f6verole (cv. Diana) au milieu de fermentation in vitro a abaiss6 la DIVMS et la digestibilit6 des protdines du con-Several studies have demonstrated a relationship between in vitro dry matter disappearance (IVDMD) and the presence of condensed tannins in whole plant sorghum (Cummins 191 l), sorghum grain (Schaffert et al 1914b), Sericea forages (Cope and Burns 1971) and faba bean testae (Bond 1976;Griffiths and Jones 1977). Tannins appear to exert a negative effect on IVDMD by binding soluble protein in the in vitro fermentation media, thereby creating a nitrogen deficiency (Ramachandra et al l9ll;Schaffert et al 1914b), or by direct inhibition of celi wall digesting enzymes (Griffiths and Jones 1977).…”

Comparative Cell Wall Constituent Levels of Tannin-Free and Tannin-Containing Cultivars of Fababeans (Vicia Faba L.)

“…Martin-purified by chromatography in a Sephadex Tanguy et al (1911) have also shown that LH-20 column. Chicks fed a diet containing fababean condensed tannins depressed the 7'76 CANADIAN JOURNAL OF ANIMAI-SCIENCE Bond (1976) and Marquardt et al (1978) have shown that certain cultivars of fababeans are tannin-free. These cultivars Dro- (1963).…”