GrainGenes
A Database for Triticeae and Avena
Ramage and Scheuring, pp. 59-60
II.30 Shrunken endosperm mutants Seg6 and Seg7.
R. T. Ramage and J.F. Scheuring. Department of Plant Sciences, University of Arizona, Tucson, Arizona 85721, U.S.A. "R"
Two plants with "thin" seed were collected from a field of commercial 'Ingrid' (C.I. 10083) barley near Creston, Montana in 1972. The two plants were designated 71-Cr-18 and 71-Cr-l9. Progenies of the two plants were grown in the greenhouse at Tucson, Arizona. The progenies were examined cytologically and found to have normal pollen mother cell meiosis and normal ovule and pollen fertility. Seed weights of the two mutants were compared with normal 'Ingrid'. 71-Cr-18 produced seed that weighed about 75 percent of normal 'Ingrid' and 71-Cr-19 produced seed weighing about 90 percent of normal 'Ingrid' seed.
The two mutant lines were grown in the field at Bozeman, Montana. Seed weights of the mutants were compared with normal 'Ingrid'. 71-Cr-18 produced seed weighing about 50 percent of normal 'Ingrid' seed and 71-Cr-19 produced seed weighing about 75 percent of normal 'Ingrid'.
The two mutants were grown in the field at Tucson, Arizona and seed weights again compared with normal 'Ingrid'. Under this environment, 71-Cr18 and 71-Cr-19 produced seed weighing about 25 and 40 percent of normal 'Ingrid'.
Progenies of 71-Cr-18 and 71-Cr-19 were crossed with normal 'Ingrid' barley. The F2 of both crosses segregated about 3 normal: 1 shrunken endosperm plants indicating that the mutants were monofactorial recessive.
Another monofactorial recessive shrunken endosperm mutant was obtained from R.F. Eslick. It was of spontaneous origin in material of hybrid origin and came to us under the designation B-71-AJ-72.
The two mutants in 'Ingrid', 71-Cr-18 and 71-Cr-19, and the line B-71-AJ-72 were crossed with each other and with the shrunken endosperm mutants sel, se2, se3, se4 and se5. All F1's had normal endosperm except those from the cross of 71-Cr-18 with B-71-AJ-72. Reciprocal crosses had been made between 71-Cr-18 and B-71-AJ-72 and both F1's had shrunken endosperm. We conclude that mutants B-71-AJ-72 and 71-Cr-18 are allelic to each other and non-allelic to sel, se2, se3, se4 and se5. The mutant 71-Cr-19 is non-allelic to sel, se2, se3, se4,se5, and B-71-AJ-72 and 71-Cr-18.
Following the recommendation of R.F. Eslick, we suggest that the mutant B-71-AJ-72 be designated seg6f, the mutant 71-Cr-18 be designated seg6g and the mutant 71-Cr-19 be designated seg7h.
In the allele tests, all F1's involving seg6f (B-71-AJ-72) were partially sterile. When examined cytologically, the F1's were found to have a ring of four chromosomes plus 5 pairs at metaphase I of pollen mother cell meiosis. This indicates that seg6f is homozygous for a translocation.