21 September 1992 Scholarship Boost for Genetic Work on Asparagus

Prospects for improving the disease resistance of asparagus through genetic engineering have received encouragement with the award of a $1000 scholarship to Lincoln University doctoral student Chen Guangyu from China.

A Turners and Growers Postgraduate Research Scholarship has been won by Chen on the basis of the promising asparagus work he has been involved with since arriving in New Zealand last year on an exchange programme with the Chinese Government.

In a project with Dr Tony Conner of the Crop and Food Research Institute and Lincoln University's Professor Roger Field and Dr Aldo Fautrier, Chen has been researching techniques for the genetic manipulation of plant cells. In particular he has been working on the development of a test tube culture technique that will allow individual genetically modified plant cells to regenerate into whole plants. These techniques will allow DNA material to be introduced, thus facilitating genetic manipulation of asparagus.

Working initially in Dr Conner's laboratory at the Crop and Food Research Institute, Chen now divides his time with Lincoln University's Plant Science Department, where he has taken up doctoral studies.

Continuing to work with Dr Conner, Professor Field and Dr Fautrier, Chen has focused his research on ways of improving the regeneration efficiency of cells. In a Lincoln "first", protoplasts (cells without cell walls) isolated by the improved procedures have been induced to divide and form cell colonies in the presence of actively growing asparagus feeder cells.

The first cell divisions were observed within about a week of isolation. The resulting cell colonies became visible to the naked eye within about a fortnight and developed into callus cultures within three to four months of protoplast isolation. Whole and complete plants have regenerated from the callus (mass of undifferentiated cells) culture.

Plant scientists are interested in the genetic manipulation of asparagus using single cell and molecular techniques in order to produce disease resistant strains and strains carrying other beneficial characteristics.

Efficient procedures for the isolation, culture and regeneration of protoplasts are an essential first step for this work.

Asparagus is a crop of economic importance in many countries including New Zealand.

Many asparagus cultivars have been developed for different regions of the world but all are susceptible to fungal and viral diseases. Other worldwide problems in asparagus production include insect pests such as thrips.

Genetic manipulation at the cellular and molecular level offers potential solutions to these problems. An earlier agrobacterium-mediated method of gene transfer proved inefficient and the approach involving plant regeneration from protoplasts is now the one showing most promise.

The aim of Chen's project is to establish a reliable regeneration system from asparagus protoplasts and then to develop a system for the selection and regeneration of transformed cells.

It is hoped eventually to produce new asparagus cultivars for use in New Zealand horticulture and agriculture. The project is a joint one between Lincoln University's Plant Science Department and the NZ Institute of Crop and Food Research.

Chen, aged 38, came to New Zealand from the Rice Research Institute, Jiangxi Academy of Agricultural Sciences, in Nanchang, Jiangxi Province, China. In 1980 he received a special science prize from the Chinese Government for his work on hybrid rice breeding and from 1986-88 he was a Visiting Scholar at Kansas State University, USA, studying plant molecular genetics.

The Turners and Growers Postgraduate Research Scholarships exist to encourage work that will contribute to improving the production methods, quality and commercial value of fruit, vegetables or flowers for the domestic and export markets. Chen is one of two recipients of the awards in 1992, the other is Dean Stewart of Lincoln University's Soil Science Department who is researching the use of spent mushroom compost as a soil amendment.

Ian Collins, Journalist, Lincoln University, Canterbury, New Zealand