The improvement of Borage as a commercial source of gamma-linolenic acid

Background: Market demand for of the essential human fatty acid supplement, gamma-linolenic acid (GLA) has been consistently increasing and borage is being more widely grown as an alternative plant source to the traditional source of GLA, evening primrose. Commercial yields of borage seed are low (around 300kg/ha) due to the lack of development of improved commercial cultivars. Only limited investigation has been conducted in Australia, with early Canadian phenotypes still being used in New Zealand and Australia today, with erratic and risky production consequences. Our industry partners, Willala Agricultural Pty Ltd, see opportunity for production of this crop in Australia and increased sales of product if commercial yields and their reliability can be lifted through selection of improved plant type and agronomic research and development.

Objectives: TThe project seeks to increase the commercial yield of GLA from borage, through selection and breeding for improvements in plant type, such as determinate growth, harvestability and yield of oil and GLA among introduced lines.

Work undertaken to date: The Tasmanian Institute of Agricultural Research, in conjunction with Willala Agricultural Pty Ltd, have acquired borage seed lines from individuals and companies within Australia, Europe and America with interests in borage production. As opportunities have arisen, further acquisition of genetic material bas continued. These lines have been maintained in isolated plantings. Since 1999-2000 these lines have also been evaluated in replicated trials. The major part of this project's work to date has been further replicated experiments to gain comparative data on promising lines, as they are identified and newly acquired lines. Overall, seed yields and oil content tend to be inversely proportional but show some heritability. GLA percentages of oil have been consistent through experiments and also show heritability. Lines performing best under local conditions have been selected and these have been crossed in an initial program to provide improved lines for the industry stakeholder. While the initial four-year period of work ended in June, continuation of the selection program is under discussion.