II.9 Gene ordering near the centromere of chromosome 1.
R. F. Eslick, M. M. Rahman and C. W. Crowell. Agronomy Department, Montana State University, Bozeman, Montana 59715, U.S.A.
Male sterile 10, ms1O would appear to be near the centromere of chromosome 1, having provided no recombinations with the breakpoints of translocations T1-3c, T1-5a, T1-5b, T1-6a, T1-6d and T1-7a (Eslick, in press). From F3 progeny rows, the F2 genotypes of the hybrid [Ms10nlk2/ms10NLk2] were established and are recorded in Table 1. Assuming a low number of double crossover gametes as compared to single cross over gametes and comparing the observed numbers to the type of crossing over required to obtain the gametes with the three possible gene orders (Table 1), then the gene order is clearly ms1O-n-lk2.
Table 1. Data for gene ordering male sterile 10, naked and short awn 2 on chromosome l.
From F3 progeny hills, the F2 genotypes of the hybrid [n ms10 Ac2/N Ms10 ac2] were determined and the observed numbers recorded in Table 2. Again comparing observed numbers with expected single and double crossovers the gene order must be n-ms1O-ac2.
Table 2. Data for gene ordering naked, male sterile 10 and the albino ac2 on chromosome 1.
The data confirms the usual gene ordering from reported recombination values.
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Eslick, R. F., (1971) Balanced male steriles and dominant preflowering
selective genes for use in hybrid seed production. Barley Genetics II (Proceedings
of Second Barley Genetics Symposium):292-297.
