Conventional linkage analysis with triple marker stock (nld, fs, va) on the long arm of chromosome 7II*

R. Riley and T. Tsuchiya
Department of Agronomy
Colorado State University
Fort Collins, Colorado 80523, U.S.A.
*Supported by USDA-CSU Cooperative Research Project No. 58-82HW-6-8 and CSU Hatch Project.

Acrotrisomic analysis by Riley and Tsuchiya (1988) showed that three genes, nld (narrow leaf dwarf), fs (fragile stem), and va (variegated), are located on the distal 72.4% of the long arm of chromosome 7. A conventional linkage analysis was conducted using triple genetic marker stock, nld-fs-va, located on the long arm of chromosome 7 in barley to determine gene distances and correct order. Table I shows the frequency of the eight expected phenotypic classes resulting in the BC1 generation. Results indicate that fs is located between nld and va with a map distance of 13.5 between nld and fs and 35.5 map units between fs and va. The total distance between nld and va was 49.0 map units and can be considered independent (Fig. 1).

The result for the recombination between nld-fs differ from the result of Hayashi et al. (1983) who report a recombination value of 21.6%.

Table 1.Summary of BC1 data for the conventional linkage analysis of triple
marker stock, nld-fs-va.

Fig. 1.Map construction for three genes on the long arm of chromosome 7, distances are given in percent recombination, C indicates the centromere.

References:

Hayashi, J., I. Moriya, and R. Takahashi. 1983. BGN 13:42-44.

Riley, R., and T. Tsuchiya. 1988. BGN 18:14-15.

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