Inheritance of condensed tannins in birdsfoot trefoil

Neither the inheritance of condensed tannins (CT) in tannin-positive birdsfoot trefoil (Lotus corniculatus L.), nor the quantitative genetic analysis of CT concentration in a forage legume have been previously reported. The objective of this study was to determine the inheritance of CT concentration in tannin-positive birdsfoot trefoil. High-, medium-, and low-tannin parents were selected from NC-83 birdsfoot trefoil germplasm and intercrossed in two independent six-parent diallel sets to generate progenies for quantitative genetic analyses. Maturity, herbage yield, leaf fraction (LF) and CT concentration were analyzed for 1067 individual F₁ plants from 30 progenies in both diallel sets. Mean CT concentrations of the 30 progenies ranged from 6.1 to 93.4 g catechin equivalent (CE) kg^-1 DM. General combining ability (GCA):specific combining ability (SCA) ratios of 0.93 and 1.0 were observed for CT concentration in both diallel sets, at or near the theoretical maximum of unity, indicating a predominance of additive genetic effects for CT concentration. Specific combining ability effects were detected in one diallel set where 3 of 15 progenies exhibited significant SCA effects. The evidence from this study indicated that CT concentration in birdsfoot trefoil was controlled primarily by additive genetic effects.