Wheat breeding: objectives and comment

Diagram demonstrating the relationships between: present and future concerns; pests and diseases; marketing attributes; stress tolerance (adaptation); and Plant type & agronomy.

Broadly, wheat breeding consists of developing a strategy involving objectives — the actual aims, the problems to be addressed — and it involves technologies, including machinery, selection strategies such as the development of disease epidemics, yield trials, quality assessments, molecular markers, breeding procedures including crossing strategies, organisation of segregating generations and seed increase.

Of these, setting objectives is fundamental to wheat breeding and should be the initial focus. The accompanying diagram aims at illustrating the dynamic nature of these objectives by using colours to indicate the period of development.

The three compartments indicate the status of the objectives within the program. Only a few objectives can be the focus of intense selection at any one time. Other objectives must be maintained — for instance, without stem rust resistance, the wheat industry in northern NSW and Qld would cease.

And a further group of objectives which involve considerable input from other scientific disciplines must be under development and assessment.

In my opinion wheat breeding i n Australia has been very effective with Benefit-Cost Ratios (BCRs) in the south-east ranging from 15:1 to 20:1 (BCR) in the south-east ranging from 15:1 to 20:1, comparable with data published by the GRDC for other investments. This strongly suggests that the GRDC should, at the very least, maintain its expenditure on wheat breeding, currently, some 10% of the total portfolio.