Genetic variation for seed yield components in the birdsfoot trefoil cultivar, Grasslands Goldie

Abstract

The persistence of hard-seeded perennial legumes can be facilitated by breeding and management programs that enhance seedling recruitment and maintain plant population density. In northern New South Wales, day length limits optimal flowering intensity and seed set of the otherwise promising birdsfoot trefoil cultivar, Grasslands Goldie (Lotus corniculatus L.). We studied the feasibility of improving flowering and seed production traits of this cultivar. To measure the extent of genetic variation for seed yield components, half-sib families derived from 45 parent plants collected from a population of cv. Goldie collected from Inverell, New South Wales were grown in the field at Glen Innes, NSW, and Canberra, ACT. Flowering time, flowering intensity and seed yield components (umbels per stem, pods per umbel, pods per stem, seeds per pod and seed mass) were recorded at both sites, while plant weight, height and width were also measured at the Canberra site. There was significant genetic variation among half-sib families and high narrow-sense heritabilities (on a family mean basis) for flowering time (0.73 ± 0.11), flowering intensity (0.66 ± 0.12) and plant height (0.78 ± 0.10). High estimates of narrow-sense heritability for seed yield components indicated that selection advance would be achieved under both sward and spaced plant conditions. There was evidence that selection for prolific flowering in cv. Grasslands Goldie was associated in the progeny populations with an increase in the number of umbels per stem. This component is a readily measured indicator of flowering intensity and should prove useful in developing more prolific and persistent populations from further selection within cv. Goldie and other birdsfoot trefoil populations.