--Michael G. Muszynski and Peter A. Peterson
In a row planted with sectored kernels (C2-b857246/c2) from the previously reported C2 breaker (MNL 64:9), a variegated plant appeared among 14 normal green plants. The youngest leaves inside the whorl are a pale yellow-green with dark green clonal sectors. This variegation was lost as the leaves matured and turned a normal dark green. The variegation in the leaves of the tiller was more extreme.
This exceptional plant was selfed and outcrossed onto c2/c2. Progeny plants from the selfed and outcrossed ears also showed this same variegation. Since the original kernel came from an outcross and the mutant phenotype is heritable by outcrossing, this mutant has been designated V*-m for a dominant, virescent mutable.
The progeny plants from the original outcross and self are segregating
for a stable dominant virescent phenotype as well as the green and V*-m
phenotypes.
Cross | green | virescent | virescent mutable |
C2-b/c2 V*-m/+ self | 9 | 1 | 9 |
C2-b/c2 V*-m/+ x c2/c2 | 13 | 4 | 4 |
Because of the limited sample size no definite conclusions can be made,
but the presence of the three phenotypes indicates two-factor control of
mutability. There was no correlation between kernel phenotype (Cl, sect
or cl) and plant phenotype. It would therefore appear that the factor controlling
C2 breakage is unrelated to the virescent mutability. Studies on
the heritability of plant phenotypes and system tests are in progress.
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