3. Vivipary designated as vp5, found in Dr. Wiggans' cultures, is closely linked with yellow endosperm, as can be seen from the F2 data presented below. If it is Y, which it probably is, then vp5 is located in chromosome 6. Classification of vp5 is good. In cultures where germination has gone too far resulting in discoloration of kernels, classification of endosperm color is difficult.

Last summer's data in regard to pb-x confirm the previous observation of its close linkage to Y, as shown below. Four pb genes are listed in the Linkage Summary, all of them have been lost. Therefore pb-x will be designated as pb5 although it has not been tested for allelism with the other four.

Backcross data for vp5 and pb5 follow:

Genes Phase XY Xy xY xy Total % Recomb.
Vp5 Y CB 1489 35 33 482 2039 3.3
Pb5 Y CB 231 1 2 250 494 0.6

G. A. Lebedeff