GENOTYPIC VARIATION IN PHENOLIC COMPONENTS OF CELL-WALLS IN RELATION TO THE DIGESTIBILITY OF MAIZE STALKS

Stalks of several normal maize hybrids, displaying a broad range in ce ll-wall digestibility, were examined for lignin content and monomeric composition and for ester-linked and ether-linked p-coumaric and ferul ic acids. Genotypic variation was found in all of these components. Ch anges in cell-wall digestibility were associated with several phenolic component characteristics. It was therefore difficult to attribute a clear causal effect on degradability to a single cell-wall component, and to distinguish direct from indirect effects. However, amongst norm al hybrids, it seemed that the lignin content, together with the conte nt of etherified ferulic acid, which probably acts as a bridge between lignins and hemicelluloses, had a strong influence on the inhibition of the cell-wall digestibility.