II. 23. Primary trisomic analysis of an incomplete dominant zebra mutant, zbc, in barley. (1)
T. Tsuchiya and Ruth Baldivia (2) Colorado State University, Fort Collins, CO 80523 U.S.A.
(1) Supported in part by USDA/SEA Research Grant 12-14-5001-265 and USDA/SEA Minority High School Apprenticeship Grant 31-2006-2165 to T. Tsuchiya.
(2) Ruth Baldivia is a student of Poudre High School, Fort Collins, Colorado.
There are two types of zebra Colorado mutants; one (CSU B8-9) is a Mendelian recessive and considered to be located on chromosome 4 but proved to be on another chromosome than 4 (Seip and Tsuchiya, 1978; Tsuchiya, 1974; Tsuchiya and Haines, 1975); the other type is an incompletely dominant zebra Colorado mutant (Utah T41) which was confused with the one previously mentioned (Woodward, 1957: Robertson et al., 1965).
The incomplete zebra mutant (Utah T41) was crossed with primary trisomics of S.E. 16 (Tsuchiya, 1967). F2 seeds were harvested from F1 trisomic plants. In this article the result of genetic analysis in the cross Triplo 6 x Zebra (Utah T41) is reported. Table 1 shows the F2 segregating ratios.
The result indicates that the segregation ratio is clearly disomic (x2 3:1 = 0.906) in the total F2 population. Also the trisomic portion showed an appreciable number of recessive homozygotes. These results indicate that the zebra gene in Utah T41 is not associated with chromosome 6.
Table 1. F2 segregation ratios of the cross Triplo 6 x Zebra (Utah T41).
References:
Robertson, D. W., G. A. Wiebe, R. G. Shands and A. Hagberg. 1965. A summary of linkage studies in cultivated barley. Hordeum species: Supplement III, 1954-1963. Crop Sci. 5:33-43.
Seip, L. and T. Tsuchiya. 1978. Trisomic analysis of lg 4 and zbc. BGN 8:86-89.
Tsuchiya, T. 1974. Report from Genetic Stock Center at Fort Collins, Colorado. BGN 4:107-110.
Tsuchiya, T. and R. L. Haines. 1975. Trisomic analysis of nine mutant genes in barley. BGN 5:67-69.
Wheatley, G. W. 1955. Linkage relationships in group IV in barley. M.S. Thesis. Utah State Agr. Coll.
Woodward. R. W. 1957. Linkages in barley. Agron. J. 49:28-32.
