Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/9/2006
Publication Date: 7/1/2006
Citation: Riday, H. 2006. Breeding for improved frost-seeded red clover seedling establishment. In: Mercer, C.F., editor. Proceedings of Advances in pasture plant breeding, April 18-21, 2006, Christchurch, New Zealand. p. 141-144.
Interpretive Summary: Red clover is often established by frost-seeding into existing pastures. The failure rate for this method of establishment is 30-40%. No cultivar improvement for increased frost-seedability has been attempted by plant breeders. This was a pilot study to measure the genetic control of frost-seedability, as well as to test out an experimental frost-seedability selection protocol. It was found that different genetic controls were operating for seedling performance in frost seeded conditions compared to regular seeding conditions. The genetic control of seedling germination under frost seeded conditions was very low. Genetic control was much more evident in frost seeded conditions for seedling height. Based on this research a selection program will be implemented to develop improved frost-seeded red clover cultivars.
Technical Abstract: In the colder parts of the United States, in late winter after disappearance of snow cover, red clover (Trifolium pratense L.) is often broadcast seeded into forage legume-depleted grass pastures to increase pasture forage quality. This method of establishment is referred to as frost seeding. Frost seeding has an estimated 30-40% establishment failure rate in Wisconsin, USA. In this study 40 red clover halfsib families from one breeding population and six check populations were evaluated for spring 2005 establishment by 1) broadcast seeding into existing pasture under frost-seeded conditions and 2) standard drill seeding into 15 cm-spaced rows. In June 2005 seedling counts and heights were measured on halfsib family plots. Narrow sense heritability estimates on a halfsib family basis for seedling stand counts under frost- and drill-seeded establishment were h2 = 0.02 and 0.21 respectively. Heritabilities for seedling height under frost- and drill-seeded establishment were h2 = 0.50 and 0.26. Genetic correlations between seedling counts and heights under frost- and drill-seeded establishment were rA = 0.42 and 0.19 respectively. No significant genetic correlations between frost- and drill-seeded heights (rA = -0.09) or seedling counts (rA = 0.20) were detected. These results suggest that seedling performance in frost-seeded conditions is a distinct trait from seedling performance in standard drill-seeded conditions and that each needs a separate selection program.