Being an important crop world-wide, barley is under intensive studies both genetically, taxonomically and from evolutionary points of view. Genetic diversity is an important feature in barley genetic research and plant breeding. Our knowledge has increased enormous by using many modern techniques of biotechnology by using RFLPs, AFLPs, AFPDs, PCRs (RAPDs, SSRs, S-SAPs) etc. No doubt, the many different marker genes provide us with a detailed understanding of the genetic composition of the barley genome, especially if combined with increased chromosome and genetic analyses of linkage and biochemical studies of DNA constitution and amino acid composition.

During several decades stocks containing many hundred morphological marker characters as well as their information have been brought together all over the world. Genetic studies have been performed to determine the number of gene loci involved in many different morphological characters. They originate in different parts of the world occurring in different genetic backgrounds and under different environmental conditions. They are kept in different local and national collections with a high degree of duplication amongst them. It is therefore important to get them assembled and make the material as well as the information usefully available in all parts of the world not only for plant breeders, but also for research studies for molecular marker mapping. Many efforts have been made during the last decade to make many of the morphological marker genes from Gene Centra world-wide comparable by transferring them into a common genetic background (the two-rowed barley cultivar ‘Bowman'). These backcrossed-derived lines are extremely useful for linkage studies, assessment of specific marker genes, determination of linkage drag, and marker assisted gene transfer.

Many of the Genetic Marker Stocks and also their back-crossed derived lines are to-day kept at the Main Stock Center at the National Small Grains Germplasm Research Facility at Aberdeen, Idaho. Discussions are going on to have duplicates placed in other regions (i.e. Europe, Asia). Many other collections with thousands of accessions are established in different Germplasm Centers and local Gene Banks, i.e. Germplasm Center at Okayama, Japan, Nordic Gene Bank, Sweden, The German Gene Bank at Gatersleben, just to mention some of them. Most of the materials are well documentated by detailed genetic studies. It is the responsibility of these Centers to assemble the stocks and to keep the collection alive. Discussions are on the way to have duplicates of the Marker Stocks in different locations (Europe, Asia). It is the duty of the researchers to transmit the knowledge of the different characters to the younger generation or those who are only dealing with molecular barley genetics.

During the last five years, all available information for about 500 new or revised descriptions of different morphological barley genes have been compiled and collected. These descriptions are published in a special volume of Barley Genetics Newsletter, both electronically and as a hardcopy (BGN 26). They are mainly aimed to serve as basic information for the incorporation and conversion into an Inernational Database, and are going to be transferred into the International Triticeae Genome Database for Barley Genes and Barley Genetics Stocks "GrainGenes" according to a special format. This work is in progress and will hopefully be fulfilled during 1999. Every morphological/physiological character will be illustrated with an image. During the last years about 1100 slides have been included into a dataprogram at the Nordic Gene Bank in Sweden. More work in correcting and modifying these images have to be done, and it will take another couple of years until these photographs are completely ready to be included into GrainGenes and added to the descriptions of the morphological genes. This International Database aims to maintain the knowledge and also the distribution of material with different morphological characters to the barley community all over the world.

The use of the existing morphological gene markers will also form a major input for all future gene mapping. They will always be immensely valuable for molecular genetical analyses of cloned mutant genes. Many different molecular marker maps do exist to-day, it is very importan to integrate these maps with the morphological marker maps. Here the coordinator for ‘Integrating of Barley Molecular and Morphological/Physiological Marker Maps' has a very important task and responsibility to follow all the information given by barley researchers, combine and up-date all the maps. There will always be the demand for Morphological Marker Genes and they will serve as an important basic material. Molecular and classical barley geneticists have to work close together and act as a good complementation team..