II.47. Cytological identification of a reciprocal translocation found in a genetic stock (Utah 3), for purple lemma and pericarp (Re 2).
T. Tsuchiya and R. J. Singh. Department of Agronomy, Colorado State University, Fort Collins, Colorado 80521, U.S.A.
The genetic stock, Utah 3, for purple lemma and pericarp (Re 2) was found to have a new karyotype. From karyotype analysis it was obvious that one of the translocated chromosomes was chromosome 6. Since the satellite of the new chromosome 6 was much larger than normal chromosome 6 it was concluded that the satellite was the site of translocation in chromosome 6 (Tsuchiya, 1972). Detailed karyotype analysis showed that chromosome pairs of 5 and 7 were normal. Therefore, the other chromosome involved in this translocation was assumed to be one of four non-satellited long chromosomes, 1 to 4.
Re 2 stock was crossed with the primary trisomic for chromosome 1, 3 and 4 and the telotrisomic for 2L and 2S. Meiosis of F1 hybrids was studied in diploid and trisomics with the results shown in Table 1.
Table 1. Chromosome configurations of F1 hybrids between trisomics and Utah 3 (Re 2).
From the results shown in Table 1, it was concluded that the translocation in this genetic stock, Utah 3, is T 1 - 6.
International Coordinator for Translocation Stocks, R. T. Ramage, gave
the following designation (BGN 3:85-86):
Utah 3 T 1-6m
The genetic stock which is free from the translocation and homozygous for Re 2 gene will be isolated within a year or so for distribution.
(Supported partly by NSF Research Grant GB30493 to T. Tsuchiya.)
