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The national white clover genetic resource centre

M.Z.Z. Jahufer and L.A. Brien

NSW Agriculture, Agricultural Research and Advisory Station, Glen Innes NSW 2370

The broad genetic diversity of white clover, Trifolium repens, is derived from its wide geographic distribution and strong cross-pollinating nature (2). The initial phase of the National White Clover Improvement Programme (NWCIP) established a Genetic Resource Centre and developed a germplasm collection representing this global genetic diversity (1). The objective is to undertake screening, seed multiplication and characterisation of accessions with application to the grazing industries.

Methods

Quarantine screening/seed increase

All accessions are screened by testing foliar samples to prevent introduction of exotic viruses. Only virus-free material is seed increased. Sufficient seed is randomly sampled to minimise the possibility of change in gene frequency and random genetic drift during seed increase. Accessions are isolated from each other with bee cages when the first buds appear. Pollination is carried out using nucleus beehives. Seed is maintained in (i) a working collection (2-5°C), and (ii) long-term storage (-18°C).

Seed multiplication

Isolated seed multiplication in the field provides seed for support research, regional testing, and a back-up germplasm collection held at the National Trifolium Centre, Perth.

Preliminary typing and field characterisation

Preliminary typing based on key morphological attributes provides a systematic basis for selecting accessions for field characterisation and regional testing. Field characterisation on spaced plants provides information on the variation of plant morphological attributes. Characterisation is done using a plant descriptor list based on a format used by the International Board for Plant Genetic Resources. Characterisation data will be used in conjunction with results from the initial phase of regional testing to identify cohorts for subsequent testing.

Results and discussion

A world sourced germplasm collection of over 600 accessions consisting of material from Northern, Central and Eastern Europe, the Mediterranean region, North Africa, North and South America, New Zealand and Australia has been established. To date, 155 accessions have been screened/seed increased and 90 accessions have been characterised. Characterisation of sheep and dairy plant types will be completed by 1994.

Acknowledgements

NWCIP is funded by the Wool Research and Development Corporation and the Dairy Research and Development Corporation.

References

Jahufer, M.Z.Z. 1989. FAO/IBPGR Plant Genetic Resources Newsletter, 80, 26-27.

Williams, W.M. 1987. In: White Clover. (Eds M.J. Baker and W.M. Williams) (CAB International: United Kingdom). pp. 299-322.

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