Vol. 18 Five alleles which have previously been associated with the long arm of chromosome 7 were analyzed to determine their physical location on that arm using acrotrisomic 7S^7L and multiple genetic marker stocks.

Acrotrisomic 7S^7L used in the present study was obtained in an F₂ population derived from a cross between Triplo 7 and Utah T41 (Furst and Tsuchiya, 1983). Acrotrisomic 7S^7L is deficient for 72.4% of the long arm of chromosome 7 with complete short arm.

Multiple marker stocks (nldnld vava fsfs) and (rr ss) were crossed as the male parents to Acrotrisomic 7S^7L The five marker genes and their respective phenotypic expressions are listed below.

F₂ segregation ratios for the two crosses are shown in Tables 1 and 2. Four of the five alleles tested (nld, va, fs, and r) showed disomic type segregation, indicating that these four genes are located on the deficient distal 72.4% segment of the long arm. The results for the allele s is inconclusive because only one plant of 20 in the trisomic portion of the population was recessive in phenotype. It is possible that the gene is located on the proximal 27.6% segment of the long arm of chromosome 7. A larger population should be studied to localize this gene using acrotrisomic analysis

References:

Furst, E. and T. Tsuchiya. 1983.BGN 13:47-48.

Shahla, A. and T. Tsuchiya. 1984.BGN 14:52-53.

Tsuchiya, T. , A. Shahla, and A. Hang. 1987. Barley Genetics V (Proc. 5th Intern. Barley Genet. Symp.) (In press).