Development of GSO alsike clover for the South Island high country

Abstract

A breeding programme to improve. the herbage yields and persistence of alsike clover (Trifolium hybniium L.)' for the South Island high country was initiated in 1984. A screening trial with gennplasm from the Baltic region of Russia, local types collected in the Mackenzie Basin, selected plants from high. country trials and overseas cultivars was established under grazing at Mt John, Tekapo. Material was assessed over 3 years for seasonal herbage yields, shoot density, growth habit and plant survival. Principal Component Analysis was used to order the agronomic performance of the.alsike lines. A set of superior alsike lines from the Russian and local New Zealand groups was identified. These lines were not significantly better than commercial alsike but showed a consistent pattern of higher yields in all seasons and years. Overseas cultivars had average to poor yields and many had low shoot densities. Elite plants were selected from the superior lines and combined in a polycross in 1988. A progeny test was sown to determine the lines with high breeding value to make up a cultivar. Similar parameters to the screenings, including seedling establishment, were assessed in the progeny test. Seventeen elite progeny were identified in 1991 and the best four plants removed from each progeny and isolated to form the 'G50' alsike clover selection. The selection is currently in comparative grazing trials in the high country. Keywords: high country, progeny test, screening, selection, Trifolium hybridum