E. H. Coe and S. McCormick (MNL 53:29) have reported that a new locus, whp, acting as a duplicate factor with c2, causes sand-white, plump, non-functional pollen to be shed. TB lines have been or are being converted to either +/+, C2/c2 or +/+, c2/c2 constitution for crossing to a uniform strain that is whp/whp and either C2/c2 or c2/c2.
The first observations of critical crosses were done this past summer. Plants grown from colorless kernels derived from valid TB males were classified for hypoploids by greater than 50% pollen abortion and/or by gross plant phenotype.
Since all hypoploids scored shed yellow pollen, whp does not appear
to be located on any of the following chromosome arm segments:
Arm segment | Total no. plants scored | No. of hypoploid plants |
1La | 109 | 15 |
3Sb | 104 | 26 |
3La | 38 | 11 |
4Sa | 162 | 17 |
5La | 190 | 34 |
6Lc | 163 | 64 |
7Lb | 155 | 37 |
8La | 69 | 10 |
9Sb | 106 | 14 |
9Lc | 28 | 5 |
The tests are continuing.
S. A. Modena and E. H. Coe
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