II.33. Allelism testing of various mutations in barley*.
T. Tsuchiya. Department of Agronomy, Colorado State University, Fort Collins, Colorado 80521, U.S.A.
* Reports II.33. (p.80) through II.42. (p.108) by T. Tsuchiya and co-workers are based on the results of researches supported by NSF Research Grants GB4482X and GB30493 and Colorado State University Experiment Station Project (Hatch 8).
Extensive allelism testing was started at the Genetic Stock Center, Agronomy Department, Colorado State University in 1968. An allelism test between gp and gp 2 for grandpa mutants showed that these two genes are allelic (Matchett et al., 1971; Tsuchiya, 1971). At least seven cases of maternal inheritance of chlorina mutants in the variety Trebi and other varieties have been found recently (McMullen and Haus, 1971; McMullen, 1972; Tsuchiya, 1971). The results obtained from other allelism tests with various mutant types is reported in this brief article together with some data from previous experiments with three maternally inherited chlorina mutations (Trebi VIII, Trebi 67-8043A and 68-9002) The mutant types used in the experiments were as follows:
1. Chlorina and light green seedling mutations
2. White streak and similar type mutations including variegated and
ribbongrass
3. Glossy sheath, stem and spike
4. "Bikini"
1. Chlorina mutants
Eleven chlorina mutants and three normal green stocks were used in these experiments. The results are shown in Table 1. These results lead to the following conclusions:
(1) Trebi VIII, Trebi 67-8043A and 68-9002 are all maternally inherited chlorina mutations (For the first two mutations, see T. Tsuchiya and D. W. Robertson, 1971).
(2) The chlorina gene of Coast IV is not allelic to either US 156 (lg 9 = lg 4) or 28-3117-2, and is not maternal inheritance.
(3) The chlorina gene of 28-3117-2 is not allelic to that of US 156 (lg 9 = lg 4).
(4) The results from crosses between Coast V (chlorina, maternal) as the female and Trebi 67-8043A and 28-3117-2 as male are not explained at present. Critical analysis is necessary to solve this problem.
(5) The chlorina gene in Smyrna III is allelic to f 7 of Smyrna II.
(6) The chlorina gene f 3 is not allelic to f 7. In F2, four types segregated; green, f 3 type, f 7 type and double recessive.
Table 1. Allelism test among viable yellow mutants.
2. White streak mutants
Thirteen white streak mutants were used in this experiment. The characteristics and gene symbols are shown in Table 2. Diagnostic characters of 10 white streak mutations (1-10) are more or less similar to each other showing various sizes (length and width) of white streaks distributed evenly over leaf sheaths and blades with some long and wide white stripes. Variegated (va) has finer streaks than the 10 stocks mentioned above. Variegated 3 (va 3) did not express very well in many cases, but late tillers have wide and long white stripes similar to that in Ribbongrass (rb). Ribbongrass (rb) expresses its diagnostic wide and long white stripe after the 3rd or 4th leaf stage. The character expression is conspicuous in late tillers.
Table 2. White streak mutants used in allelism tests.
The mutant for wst (CI 11767) was studied by Robertson (1967). The mutants wst 2, wst 3, wst 4 were studied by Takahashi and Moriya (1969). Two variegated mutants (va and _a 3) were reported by Walker et al. (1963). The white streak mutant in Moravian was produced by T. E. Haus (unpublished). All other mutants have been collected and maintained in the Barley Genetic Stock Center in Fort Collins, Colorado, U.S.A.
Table 3. Phenotype of F1 hybrids in crosses among white streak type mutants.
The results shown in Table 3 lead to the following conclusions:
(1) The genes for white streak mutations in Caldecott's streak (5), Grandpa fine stripe, CI 6856 (6), white streak in CI 11766 (10), wst 3 in Akashinriki (3), streak of CI 6758 (8) are all allelic to wst in CI 11767 (1).
(2) Therefore, the gene symbol wst 3 should be discarded. For detailed discussion refer to Takahashi (1972) and Tsuchiya (1972).
3. Glossy sheath and spike
Seven mutants for glossy sheath and spike were tested in these experiments. All mutations were induced by radiation treatment. The materials used are shown in Table 4 and the results obtained are given in Table 5.
Table 4. Materials and characteristics of mutants with glossy sheath and spike.
Table 5. Allelism test among mutants with glossy sheath, stem and spike.
From the results shown in Table 5 the following conclusions are made:
(1) cer-a1 and K M 1 are allelic to gs 3 on
chrolmosome 1.
(2) KM 53 is not allelic to gs 3 (= KM 1 = cer-a1),
gs 5 or gs 6
(3) cer-m20 is not allelic to gs 6.
4. Bikini mutants.
A radiation-induced mutant type "Bikini" was reported by Nybom (1954) as dwarf with highly deformed and bizarre spikes. A picture of the mutant was shown. Several mutations induced by radiation in some Japanese barley varieties (medium to tall, two-rowed type) were morphologically similar to Nybom's "Bikini" and to each other (Tsuchiya, 1962). The general characteristics are: Extremely dwarf with thick and crooked culm (bent at or near node), ligule- and auricle-less, wide and dark green leaves, very small compact spikes which are six-rowed or multiflorous type with small florets and seeds and short awns.
The following two mutants were used in this study:
Bikini 1: KM (Kmut) 186 b in variety Ko A
Bikini 2: KM (Kmut) 197 a in variety Ko A
Because of abnormal spikes which make it difficult to cross, heterozygotes were used for crossing. The results are shown in Table 6.
Table 6. Segregation of F1 hybrids of crosses between heterozygous plants "Bikini 1" and "Bikini 2".
From this result it is concluded that the genes controlling the two "Bikini" characters are allelic
References:
1. Haus, T. E. Personal correspondence.
2. Lundqvist, U. and D. von Wettstein. 1962. Induction of eceriferum mutants in barley by ionizing radiation and chemical mutagens. Hereditas 48:342-362.
3. Matchett, R. W., H. G. Nass and D. W. Robertson. 1971. Inheritance and linkage studies with the grandpa gene in barley, Hordeum vulgare. Can. J. Genet. Cytol. 13:489-498.
4. McMullen, M. 1972. Allelism testing of seven chlorina mutations in Trebi barley. BGN 2:76-79.
5. McMullen, M. and T. E. Haus. 1971. Allelism testing of chlorina mutants in Trebi barley BGN 1:68-69.
6. McProud, W, L. and R. F. Eslick. 1971. BGN 1:168-174.
7. Nybom, N. 1954. Mutation types in barley. Acta Agr Scand. 4:430-456.
8. Robertson, D. W. 1967. Linkage studies of various barley mutations (Hordeum species). Crop Sci. 7:41-42.
9. Takahashi, R. 1972. Information of linkage and mapping of genes on chromosome 3. BGN 2:127-131.
10. Takahashi, R. and I. Moriya. 1969. Inheritance and linkage studies in barley. IV Ber. Ohara Inst. landw Biol. 15:35-46.
11. Tsuchiya, T. 1962. Radiation breeding in two-rowed barley. Seiken Ziho 14:21-34.
12. Tsuchiya, T. Unpublished.
13. Tsuchiya, To and D. W. Robertson. 1971 Two more cases of maternal inheritance of chlorina mutation in barley. BGN 1:65.
14. Walker, G. W. R., J. Dietrich, R Miller and K. Kasha. 1963 Recent barley mutants and their linkage, II. Genetic data for further mutants. Can. J. Genet. Cytol. 5:200-219.
