II.11 Strange behavior of a white stripe mutant in barley.
T. E. Haus, Department of Agronomy, Colorado State University, Fort Collins, Colorado 80523, USA.
A white stripe mutant was obtained from X2 of irradiated seed of the variety Moravian. This mutant has narrow white stripes on the leaves from seedling stage to near maturity. It is similar in appearance to the wst stock, the gene for which is located on chromosome 3. In the homozygous state the stock produces approximately 50% of albino seedlings.
To determine the nature of inheritance of this mutant, designated tentatively Mo wst, a cross was made using msg 12 as a female parent. All F1 plants were normal green in appearance. From 100 F2 seeds germinated, there were 64 green and 24 albino seedlings, but no white stripe plants. The albino seedlings were grown as long as possible in the event that they might eventually develop as white stripe plants, but they died--developing no chlorophyll. The F2 green plants were grown to maturity and genotypes determined in the F3. From 60 F2 plants, 43 F3 lines segregated green to albino, 17 lines were pure green. No white stripe plants were observed in the F3 1ines. This cross was repeated with similar results.
Considering the possibility of genetic background modifying the expression of this gene, several other crosses were made with all data summarized as follows:
Each of the above sets of data fit a 3:1 ratio except the last cross. No logical hypothesis for these results has been proposed. At the present time F1 plants of a cross with one of the wst segregates found in the Mo wst x ert-i and normal Moravian are being grown to see if by chance those plants will produce stripe progeny in the F2 generation.
