Two new alleles to male-sterile mutants ms2 and ms8
--M. R. Trimnell and M. C. Albertsen
Two new male-sterile mutant alleles were identified in elite proprietary
breeding material. MCA observed a selfed progeny row segregating for male-sterile
plants at our research station at Garden City, KS, in 1987. We grew remnant
seed in Johnston, IA, in 1988 and observed a segregation of 11 male fertiles
to 6 male steriles. Two male-sterile plants were sibbed with two male-fertile
plants in the row, resulting in the following:
Ear #1 7 male fertiles 7 male steriles
Ear #2 12 male fertiles 1 mostly fertile (shedder)
The 7 male-sterile plants were testcrossed with known heterozygotes
of the male-sterile mutants listed in Table 1. Progenies were grown in
Johnston in 1989. At least 15 plants were observed per row. As shown in
the table, there was a segregation of 10 male fertiles to 10 male steriles
among the ms2 testcross progeny. Our designation for this new allele
is ms2-GC87A.
The other allele was observed in our Hawaii winter nursery in 1987 by
Mr. George Peverly, G. He observed a selfed progeny row segregating for
male sterility from our research station at York, NE. The male-sterile
plants were crossed with A632, and progenies were grown in Johnston in
1988. All plants were male fertile, so self pollinations were made. The
next summer, progeny from two ears were grown with the following results:
Ear #1 13 male fertiles 2 male steriles
Ear #2 17 male fertiles 1 male sterile
We decided to conduct the allelism tests even though the p2 value was
marginal (4.45; .05> P >.025). Only three male-sterile plants could be
used in testcrosses, so fertile plants were selfed to determine heterozygosity
and testcrossed with male steriles from known male-sterile plants. These
progenies were grown in Johnston in 1989, and results are given in Table
1. At least 15 plants were observed per row. Allelism was observed when
ms8
was used as a heterozygous male. Segregation was 9 male fertiles to 8 male
steriles. Our designation for this new allele is ms8-YK87A.
Table 1. Testcrosses made to two spontaneous male-sterile mutations
occurring in elite proprietary breeding material.
|
|
ms2-GC87A | ms8-YK87A |
| ms1 | All Fertile | All Fertile |
| ms2 | 10 fert : 10 ster | All Fertile |
| ms5 | All Fertile | -- |
| ms7 | All Fertile | -- |
| ms8 | All Fertile | 9 fert : 8 ster |
| ms9 | -- | All Fertile |
| ms10 | -- | All Fertile |
| ms11 | -- | All Fertile |
| ms12 | All Fertile | -- |
| ms13 | -- | All Fertile |
| ms14 | All Fertile | -- |
| ms17 | -- | All Fertile |
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