Last year, we reported the results of TB mapping crosses made to symbolized unplaced mutants in the Coop's collection (MNL72:79). This year, we repeated the arm-locating cross for all of the mutants that gave positive TB tests last year, and made full TB mapping crosses on additional unplaced mutants. The mutants for which we obtained positive results are summarized in Table 1. Additional crosses with linkage markers will be made to confirm chromosome arm placement, and allelism tests will be conducted with mutants with similar phenotype located on the same chromosome arm.
The placement of l4 to 7S, as reported last year, turned out to be incorrect. Out of seven additional crosses of l4 by TB-7Sc made this year, none segregated for luteus seedlings.
Table 1. Results of TB tests of symbolized unplaced mutants.
|Mutant||Arm-locating TB Cross||Number of Positive Tests/Total Number of Crosses with this TB||Mutants on Same Chromosome Arm with Similar Phenotype||Note|
|al*-JRL||TB-9Lc||2/2||ar1, v1, v30|
|l3||TB-6Lc||16/19||l10, l12, l15||1|
|v*-PI267226||TB-5La||2/2||v2, v3, v12, yg1|
1. A repeat and confirmation of tests reported in MNL 72.
2. Found to be allelic to al1, as reported elsewhere in this MNL.
3. Found to be allelic to lw2, as reported elsewhere in this MNL.
4. This mutant was not found to be uncovered by TB-3La.
5. These mutants were not found to be uncovered by TB-1Sb.
Return to the MNL 73 On-Line Index
Return to the Maize Newsletter Index
Return to the MaizeGDB Homepage