Improving the genetic merit of temperate forage legumes helps ensure profitability and sustainability of our Australasian pastoral industries. Today’s plant breeders are supported by a range of underpinning research activities including genetic resources exploration and enhancement, plant physiology, plant health, feed quality, agronomy, quantitative genetics and plant biotechnology; and have collaborative interfaces with animal and farm systems science. Lifting the rate of gain by integration of molecular tools, innovative breeding strategies, and new genetic resources is the major objective of our white clover breeding network. This paper, presented at the Australasian Grassland Association’s recent Legume Symposium, focuses on the key research and development achievements in white clover breeding for Australasia, and on the success and future of an Australasian collaboration to breed improved cultivars for the region’s temperate environments. The paper reports on successful developments in the areas of improving white clover root systems for phosphate uptake, pest tolerance, development of novel inter-specific hybrids and marker-aided breeding. The successful trans-Tasman collaboration in white clover breeding and future work is also discussed.

Grasslands Tribute is a medium-large leaved white clover released in 2003. It was initially bred for drought tolerance and winter activity in Victor ia, Australia from crosses among elite New Zealand germplasm. Tr ibute was then screened for agronomic performance in New Zealand and reselected for medium-large leaf size, uniform flowering pattern, absence of foliar disease and high seed yield potential. Almost half of the 11 parental lines of Tribute came from half-sib families based on a Syrian accession with the remaining half-sibs based on Sustain, Southern Europe II and Crau in approximately equal proportions. The decision to release Tribute was based on its consistent performance and persistence under grazing in a series of seven New Zealand trials. Tribute was the best medium-large leaved variety under both sheep and dairy grazing, with only the large-leaved Kopu II having better performance under dairying. It shows strong growth in all seasons but has very good coolseason growth, and good drought tolerance in Canterbury. Keywords: breeding, cultivars, dairy, sheep, Trifolium repens, white clover

A ryegrass breeding programme to improve the cool season activity and summer quality of perennial ryegrass (Lolium perenne L,) in southern regions was initiated in 1986. One of the strategies assessed wild ryegrass populations from 50 dairy and sheep farms in Southland, West Otago and Westland. The plants were collected and evaluated as spaced plants in a high and low fertility site at DSIR Grasslands Gore in comparison with current ryegrass cultivars. Principal Component Analysis was used to order the performance of the ryegrass populations in relation to the observed characters of seasonal growth, tillering, crown rust infection, recurrent ear emergence and endophyte presence. Ihe collection consisted of many short-leaved densely tillered prostrate plants with high levels of crown rust infection and recurrent flowering. In comparison the cultivars had fewer, but larger tillers, rapid leaf extension and good rust tolerance. There were no strong distinguishing features between plants from dairy and sheep farms and 30% of plants had no endophyte. Selected ecotypes hybridised with New Zealand and European cultivars produced plants with better cool season growth and summer quality than standard cultivars. The ecotype germplasm is an important source in the development of new cultivars suited to the southern region. Keywords plant evaluation, Lolium perenne, ryegrass hybrids, southern New Zealand ecotypes

Herbage accumulation and botanical composition of pastures containing 4 morphologically-contrasting white clovers (Kent wild white, Southland uncertified, 'Grasslands Huia', and 'Grasslands Pitau') are described. The clovers were grown in monoculture and in association with either 'Grasslands Ruanui' or 'Nui' perennial ryegrass under grazing frequencies of 4 and 6 weeks. Clover production in monoculture and mixtures was least from the small-leaved Kent, intermediate for medium-leaved clovers, and greatest from the largeleaved Pitau. Kent was inferior in all seasons, whereas the superiority of Pitau reflected good autumn-winter growth. In all mixtures, the ryegrass and clover components showed improved production under infrequent grazing for all seasons. Within a grazing frequency, pastures containing Kent produced the lowest clover yields but had the largest associated grass yields, whereas pastures containing the larger-leaved Pitau showed the converse. This compensatory effect resulted in the pasture mixtures producing similar total herbage. Differences in grass/clover compositions were related to the morphology of clover types. This has implications for competitive effects in grasslclover mixtures and for nutrient cycling in pastures. A desirable clover type would incorporate the potential to produce large quantities of nutritious feed and the ability to support an efficient transfer of nutrients to grasses, thus ensuring a reliable distribution of herbage yield.

Nine subterranean clover cultivars and 10 white clover varieties, differing in characters such as morphology and flowering date (sub clover), or growth habit and seeding ability (white clover), where evaluated for persistence and production at 8 summer-dry hill country sites. Results for the first 3-4 years suggest the sub clovers on the New Zealand Acceptable Herbage Cultivars List (Mt Barker, Tallarook, Woogenellup, Glare) should be revised. Regeneration of Woogenellup and Glare was consistently poor, while Tallarook performed well at most sites. The current unavailability of Tallarook seed means Mt Barker is the only effechve option for grasslands in most of New Zealand. Cultivars of the sub clover subspecies yanmnicum (Larisa, Trikkala) showed promise for winter~wet, summer dry environments, as did Nangeela in winter-cold environments. A late-flowering, prostrate, low oestrogenic sub clover similar to Tallarook would be well suited to large areas of summer-dry hill country. There is a clear need for a white clover cultivar adapted to summer-dry hill country as none of the varieties tested survived severe moisture stress at 2 sites (Hawke's Bay, North Canterbury), and none performed consistently well at the other sites. New Zealand vaneties (Hula, Pitau, G18 and a hill country selection) showed best persistence and production. The overseas cultivars Haifa, Tamar, Louisiana and Clarence Valley, which are all adapted to dry conditions in their country of origin, were consistently poor. Firm selection criteria for dry hill country were not identified, though stolen density and seeding ability should be incorporated and the strong influence of management and soil fertility on genotype performance must be recognised. Keywords: subterranean clover (Trifolium subterraneum L.), white clover (Trifolium repens L.), hill country, dryland, cultivars, persistence, genotype-environmental interaction.