World collection of barley genetic stocks has been maintained at the Barley Genetic Stock Center, Colorado State University, Ft. Collins, Colorado, U.S.A. since the early 1920s. The curator, Tak Tsuchiya, will retire in four years (1993). The future of this Stock Center is uncertain at present. Whatever would happen to this Barley Genetic Stock Center, it is important to maintain all stocks in good shape and keep their records with as much information as possible.

A program has started in September 1988 to grow the entire collection for increasing fresh seeds and storing in the USDA National Seed Storage Laboratory (NSSL) for a long-term storage. This program became possible with the cooperation and support of the NSSL and the Director, Dr. Steve Eberhart.

Stocks are grown in the USDA-ARS greenhouse in Ft. Collins. Records are taken for key marker genes and major characteristics. However, information on the plant height is not recorded because of variable growing conditions in different times in the greenhouse. Since some 200 stocks are grown at one time and probably three to four times a year, some 600-800 stocks will be grown each year. It will take at least three years to grow entire collections. Also, because of various problems such as poor germination, poor tillering, and others, some stocks have to grow two or three times to harvest enough seeds to deposit in the NSSL. It is anticipated to complete the entire work in four years or maybe five years.

During this growing period, various associated research work will be conducted. Simple genetic studies have been initiated to test genetic nature of many chlorophyll mutants, especially homoviable stocks. For this purpose the following crosses have been made for some mutants:

1. Reciprocal crosses, chlorophyll mutants x green plant (SE16) and SE16 × chlorophyll mutants.

2. Crosses among chlorophyll mutants showing similar or the same characteristics.

3. Crosses between genetically identified and established stocks and the mutants showing similar or the same characteristics as the established stocks.

F₁ and F₂ plants are grown to determine (1) maternal or Mendelian inheritance, (2) monogenic or multigenic inheritance, (3) allelic relations among similar mutants, or (4) dominant or recessive nature.

Some results of these experiments are reported in the Reports section in this issue.

Various multiple genetic stocks have been developed in the past several years. These stocks contain some major genes located in the same individual chromosome arms to provide materials which are more useful for critical linkage analysis than other stocks. Table 1 gives multiple marker stocks for chromosome 7.