maize mutant phenotypes

Ds-Cbreaker A1 Sh2; (Ds-3L2-A1 Sh2) elfed ear of the original Ds-3L2 A1 Sh2/a1 sh2, Ac/- mutant plant with 3 Cl Sh:1 cl sh kernels overlaid with Ac pericarp sectors. These purple kernels include those with various levels of mosaics of sectors for simultaneous loss of A1 and Sh2. The largest colorless sh areas have small islands of colored nonshrunken tissue (recovery spots) indicating proximal location of Ds between the centromere and the A1 locus. The purple nonshrunken class includes those with large colorless shrunken sectors, those with many small colorless shrunken sectors, as well as tiny pits, and those with no sectors at all. Many of the large colorless shrunken class have tiny colored nonshrunken islands within their borders.

Ds-Cbreaker A1 Sh2; (Ds-3L2-A1 Sh2) View of the original selfed ear, with mosaic kernels showing consequence of breakage and loss in various genotypic combinations in the 3N endosperm. Whole kernels are described from left to right. (1) An A Sh/A Sh/a sh Ac/-/- kernel with frequent losses of both A Sh chromosomes which appear as colorless spots only when both losses overlap. The rough surface is due to concurrent Sh losses as well. (2) An A Sh/a sh/a sh, Ac/-/- kernel with large colorless areas from early loss with occasional smalls islands of colored Sh tissue. Also chains of such islands suggesting that lost fragments may recover. The bottom half of this kernel has a large purple sector with no colorless spots within its borders, indicating that the loss mechanism has stopped. (3) An A Sh/a sh/a sh, Ac/-/- kernel where a single loss occurred at an early division and the other sector was stable, with the exception that activity occurred once to produce a small colorless shrunken sector. (4) An A Sh/A Sh/a sh, Ac/-/- kernel with erratic loss pattern with small sectors, resulting from sequential early loss covering most of the kernel and a subsequent loss of the second A Sh chromosome.