Biotechnology

High-Tech Tools for Food Security: Biotechnology at ICARDA
Three major avenues in biotechnology are now followed by ICARDA: tissue culture applications, molecular marker applications and transformation technologies.

Tissue Culture
Development of doubled-haploid breeding systems in cereals
Plant breeding using the doubled-haploid system is a key technology to speed up the breeding process. The center previously used the anther culture technique but now isolated microspores are being used. The microspores, obtained after grinding, spinning and filtering eight plant spikes, are placed in petri dishes for regeneration in an induction medium.
When these regenerate to the green plantlet stage they are only haploids with half the required chromosomes, and require further chemically-assisted doubling using colchicine. Speed is the prime advantage of the technique. In traditional plant breeding after crossing, it might take at least five generations before the breeder has a plant with the sufficiently homozygous characters. A doubled haploid developed from a cross will produce a completely homozygous plant in one generation.
Bread wheat, barley and durum wheat are the main target plants for the development of doubled haploids. In the case of durum wheat, the research is being carried out in cooperation with the University of Paris and the French Government. There is ongoing research to produce bread wheat lines with multiple resistance to diseases, including yellow rust (Puccinia striiformis). Another major activity in tissue culture is the use of somoclonal variation to develop safer varieties of the legume-Lathyrus sativus (grass pea). This highly drought-tolerant legume is found in Bangladesh, Nepal and Ethiopia where it may be the only food source available for the poorest people in times of drought-inspired famine. In a mixed diet, it causes no difficulty but eaten in large quantities it leads to a build-up of neurotoxins causing a spastic paralysis of the legs, called lathyrism.
These neurotoxins are caused by the presence of beta-odap, an essential zinc carrier for the plant. ICARDA is developing stable lines of plants with reduced ß-ODAP.

Molecular Markers
In molecular biology, DNA molecular-marking techniques have been used for some time. Genetic fingerprinting is used to identify particular desirable genes required for specific breeding projects.
The DNA of the offspring from an F1 , a segregating population, is examined using different marker technology (AFLPs, microsatellite-based markers, RFLPs, RAPDs). Since the gene markers also segregate in these segregating populations, researchers try to find out which gene marker correlates best to disease resistance, allowing the location of resistance genes on a genetic map of the plant. Further germplasm lines can be evaluated for resistance by using the marker and without putting the plants into a field trial.
This is particularly useful where national agricultural programs are seeking germplasm with traits conferring resistance to diseases or pests not found in Syria. Existing successes include identifying markers for powdery mildew (Erisyphe graminis) and Rhynchosporium secalis (or scald) in barley, fusarium wilt and cold tolerance in lentil, and Ascochyta blight in chickpea. Many of the marker activities are supported through collaborations with advanced research institutes, such as the University of Frankfurt, Germany, for markers in chickpea; the Risoe National Laboratory, Denmark, in barley; and Washington State University for lentil.

Genetic Transformation
Transgenic chickpea plants have been produced, thanks to collaboration between ICARDA and the University of Hanover in Germany, and University of Naples in Italy. With assistance from the German government's BMZ fund, it has been possible to develop a transformation procedure for chickpea into which the stilbene-synthase gene from vines and antifungal proteins can be introduced with the intention of giving chickpea stable resistance to Ascochyta.
A further collaboration with CLIMA (Center for Legumes in Mediterranean Agriculture) in Australia may produce varieties of lentil with resistance to herbicides. One of the biggest problems of the lentil crop is the parasitic weed Orobanche which could be controlled effectively by spraying without harming the otherwise sensitive lentil plants. Another target for this program is the introduction of the Bt (Bacillus thuringiensis) gene which could give lentil resistance to a major insect pest, Sitona.

Biosafety Policymaking
When available, these genetically-transformed plants will be tested in Egypt, which is the only country in the West Asia and North Africa region at present with a working biosafety regulatory system.
ICARDA is, however, working closely with a number of countries in the region, including Algeria, Lebanon, Morocco, Palestine, Syria and Tunisia, to establish suitable biosafety regulations to allow the introduction of genetically-engineered plants in the future. This is being done in collaboration with Egypt's Agricultural Genetic Engineering Research Institute (AGERI) and the FAO. Support for this activity from other agencies will be welcomed.
For more information on ICARDA's biotechnology work, please contact:
Dr Michael Baum,
ICARDA, PO Box 5466, Aleppo, Syria.
Tel: (+963-21) 2213433. Fax: 2213490
E-mail: M.BAUM@CGIAR.ORG

Pre-pollen microspores are placed in petri dishes filled with a specific regeneration medium. Eight flower spikes, comprising about 400 anthers, are used in isolating the microspores to give high regeneration efficiency for each petri dish.

When pre-pollen microspores regenerate to the green plantlet stage they are only haploids with half the required chromosomes, and require further chemically-assisted doubling. A doubled haploid developed from a cross will produce a completely homozygous plant in one generation.

Before scientists can map genes of desirable characters, they must evaluate crops in the field to find those characteristics. Here, ICARDA staff carry out evaluation at ICARDA's satellite research station at Breda, Stria.