II. 1. A mutant of barley: Elongated glume, semifertile.
H. Ahokas, Department of Genetics, University of Helsinki, P. Rautatiekatu 13, 00100 Helsinki 10, Finland. "R"
The mutant appeared in a single plant row of the Kmut 184a stock obtained from Dr. T. Tsuchiya (Tsuchiya, 1969) and grown in Finland in two seasons. The segregation of phenotypes was 27 non-mutants, 9 (mo2), 10 (e), and 3 (mo2,e). This resembles the F2 segregation of dihybrid, the parent plant being heterozygous for two genes.
The glumes of the mutant are lemma-like (wide or elongated), but each glume also bears an opposite palea-like leaf, and often well-formed floret parts, usually three stamens, and one pistil. These dorsal flowers are O – 80% fertile in the original stock, KoA. They are often open pollinated probably due to the wide opening at anthesis. The lemma-like leaf is usually not fused with caryopses, so that the dorsal kernels are semi-nude.
The mutant with an Mo2/Mo2 background was crossed with Svalöfs Guldkorm 91 carrying an e allele, which is allelic to that of Takahashi's linkage tester v-e-sk (BGN 2:170-171). The F1 plants displayed sterile dorsal flowers without stamens or pistils and with smaller lemma and palea-like leaves. The phenotypes in F2 were: 2 non-mutant, 35 with e-glume typical of Guldkorn 91, and 127 with sterile or few fertile dorsal flowers of the F1 type. The numbers 35:127 fit the 1:3 ratio (X2 = 0.996, P > 0.30).
It appears that the present mutant is sensitive to background and at least partially allelic to the normal e allele. The two non-mutant F2 segregants may result either from open pollination or else from intragenic recombination.
By combining the mutant with six-rowed characteristic, phenotypes with many kernel rows could be perhaps obtained, although this might not be practicable.
The stock was sent to the Barley Genetic Stock Center (Fort Collins).
Acknowledgments:
The work was done under the auspices of the Academy of Finland.
Reference:
Tsuchiya, T. 1969. Characteristics and inheritance of radiation-induced
mutations in barley. Some extreme mutations. IAEA, STI/PUB/231: 537-590.