Barley research accelerated

Press, 5 March 1982, Page 20

Barley research accelerated

Enthusiasm is running high among barley researchers at Crop Research Division. D.5.1.R., Lincoln. and the reason for this is the rapid progress being made with double haploid barleys. The term double haploid is applied to barley in which a single set of chromosomes from the egg cell have been doubled to give a true breeding barley. The principal reason for the research into, double haploids is that they speed up the long drawn out process of breeding new, barley varieties. With traditional methods two barley parents are crossed, then the offspring are selected for about seven generations until they become stable and uniform genetically and. this process, takes seven or eight years. The double haploid method involves taking the first generations then crossing this with a closely related weedy barley grass species (Hordeum bulbosum).

One set of chromosomes from the weed rapidly dies. leaving just one set of chromosomes from the female barley parent in. the resulting plant. With a little chemical trickery this plant can be induced to duplicate its single set of chromosomes ■— thus a normal plant with an identical pair of chromosomes results.

The technique was discovered by Dr Ken Kasha in Canada and has since been used by British. Danish. Canadian and New Zealand researchers.

The first cultivar bred by the double haploid metnod. "Mingo” was . released to Canada in 1980 and the second cultivar “Gwylan” was released by D.S.I.R. and grown commercially in Canterbury for the first time this year.

Gwylan (meaning seagull in Welsh) was bred by Mr Richard Pickering of the Welsh Plant Breeding Station. Gwylan is the first cultivar to be released from the collaborative Welsh-New Zealand research programme and it has been the highest yielding barley in recent National List Trials in Canterbury. Mr Pickering made the original cross in 1975 and the barley was released four years later.

This is the sort of rapid progress which encourages plant breeders to expand their research programmes. The Canterbury Malting Company and Crop Research Division are jointly sponsoring the research programme. Mr Pickering was invited io New Zealand for six months to assist in sorting out teething problems? Since he arrived. Mr Pickering who is how regarded as an international leader in the field, has been able to give the programme considerable impetus.

Although the principle of the technique is straight-for-ward. it is technically difficult to achieve a good success rate in producing the haploids. It is essential, in what is basically a numbers game, that many thousands of these plants are produced each year.

Mr Pickering has been assisting researcher Mr Pablo Guerrero with some of the secrets of the trade to improve the number of hybrid seeds produced, the quality of these seeds and the rate of plantlet regeneration and chromosome doubling. Mr Pickering is delighted with the facilities here in New Zealand and this has enabled rapid progress to be made. “We are now in the .position to produce 7000 to 8000 double haploid plants annually,” said Mr Pickering, although he added rather wistfully, “it’s a seven day a week job.” During his stay Mr Pickering has been able to pinpoint some of the small differences in techniques which have

contributed to the success of the programme. Problems of embryo formation influenced by the pollen source have largely been solved and the battle against Canterbury’s hot dry days has been solved by improving humidity control in the glasshouse. Seed quality of the hybrids has been improved by changing the type of bag which is put over the.artificially pollinated seed heads. With such a delicate techr nique many small changes in materials and conditions will have a major effect upon the end result. The researcher must exercise extreme accuracy under precise conditions. This makes the job very difficult and few people have the patience or inclination for such work.

In a six week period, over 1000 double haploids have

been produced. These will be handed on to the plant breeder for evaluation and seed increase.

Each of the haploids will be evaluated against material which has come up through "the old system” but the big advantage will be that the cultivar will be uniform and stable and will not require any further selection.

Each of the double haploids will stand (or fall) on its own merits as it conies out of the laboratory. Mr H. Kearney, general manager of the Malting Company described the progress made during the last six months as the most exciting in the company's 20 years involvement ” with D.S.I.R.

Mr Kearney said that progress in barley breeding has been rapid over recent years

and cultivars quickly become outclassed.

"In order to improve on the material currently available in New Zealand, he said, we will have tb use European and New Zealand material with known high yields and malting quality and use the latest available techniques to bring this material into commerce." "In the long run.” said Mr Kearney, "it is just part of a continuing struggle to improve the quality of our product and to do what we can to help our growers and suppliers.” Both D.S.I.R. and the Canterbury Malting Company are devoting more resources to the programme. Mr Pickering returns to his research at . Aberystwyth shortly and a new appointment will be made to take charge of this challenging project.