II.43 Allelism testing of genes between brachytic and erectoides mutants.
T. Tsuchiya, Department of Agronomy, Colorado State University, Fort Collins, Colorado 80523, U,S.A.
Many genes of newly induced mutations were proved to be allelic to old, established genes in barley (Tsuchiya, 1973, 1974a,b). Several erectoides mutants which had typical brachytic trait characteristic to brachytic mutants were crossed with the two brachytic stocks (br, br 2) and the F1 phenotypes were analyzed. Materials used and the results of F1 analysis are shown in Table 1 and 2, respectively.
Table 1. Brachytic and erectoides mutants used in the experiment.
Table 2. Phenotype of F1 hybrids from various cross combinations.
These results showed that all genes of these erectoides mutants which showed brachytic characteristics were not allelic to br or br 2.
Based on the results obtained from allelism testing between brachytic and short awn (ari-) mutants the author suggested that ari-i should be changed to br (Tsuchiya, 1974; BGN 4: 80-81.). All five ert- mutants used in this experiment showed typical brachytic characteristics similar to brachytic (br in Himalaya and Moravian) and brachytic 2 (br 2 in Svanhals). The author proposes the change of the symbol for these ert-mutants as follows:
It is obvious from these results that so-called erectoides mutants (ert-) are a mixture of brachytic (br) and short rachis internode (l) mutants. And so-called ari- (ari-) mutants are a mixture of brachytic (br) and short awned (lk) mutants.
The author has shown many cases in which newly obtained mutants were treated as non-allelic mutants without allelism testing (Tsuchiya, 1973, 1974 a, 1974 b, 1975; Tsuchiya and Haus, 1973). It is important to make allelism tests not only between new mutants but also between new and old, established mutants before new gene symbols are given. Also the careful observation of diagnostic characteristics is important in proper classification of the mutant types.
References:
Tsuchiya, T. 1973. Allelism testing between established marker stocks and Swedish mutants. BGN, 3: 67-68.
Tsuchiya, T. 1974a. Allelic relationships of genes for short-awned mutants in barley. BGN, 4: 80-81.
Tsuchiya, T. 1974b. Further results of allelism testing in barley. BGN, 4: 82-85.
Tsuchiya, T. 1975. Allelism testing of some morphological and chlorophyll mutants in barley. BGN, 5: 64-67.
Tsuchiya, T. and T.E. Haus. 1973 Allelism testing in barley. I. Analysis of ten mapped genes. J. Hered. 64: 282-284.
