II. 34. Chromosome location of shrunken endosperm mutants seg6g and seg8k.
R. T. Ramage. USDA-ARS. Department of Plant Sciences, University of Arizona, Tucson, Arizona, U.S.A. "R"
The shrunken endosperm mutants seg6g and seg8k are inherited as maternal plant monofactorial recessives (BGN 6:59-60 and BGN 11:34). Descriptions of genetic stocks of these two mutants have been published (BGN 10: 130 and BGN 11:103). F2 data from crosses of seg6g and seg8k with translocations were obtained in 1979 and in 1982. These data are presented in Table 1.
Table 1. F2 data from crosses of seg6g and seg8k with translocations.
In 1979, seg6g was inherited independently of the break-points of Tl-2d and was very tightly linked with the break-points of T3-4d. In 1982, seg6g was inherited independently of the break-points of Tl-2g and was very tightly linked with the break-points of Tl-3g. The seg6 locus should be located on chromosome 3.
In 1979, seg8k was inherited independently of the break-points of 5 translocations that involved all of the chromosomes except chromosome 1. In 1982, seg8k was very tightly linked with the break-points of Tl-2c, Tl-3g and Tl-5e. The seg8 locus should be located on chromosome 1.
Jarvi and Eslick (Crop Science 15:363-366. 1975) reported that the segl, seg2, seg4 and seg5 loci were located on chromosome 1 and that the seg3 locus was on chromosome 3. It is interesting to note that, of the 7 mutants for this type of shrunken endosperm that have been assigned to chromosomes, 5 are on chromosome 1 and 2 are on chromosome 3. We are making crosses to determine linkage relations between the seg loci.
