Abstract
Elimination of chromosomes or chromosome fragments during somatic cell division in sticky chromosome plants is shown by genetic tests to occur for those segments of chromosomes carrying the plant color genes a, B, and Pl. The relative frequencies with which fragment or whole chromosomes carrying these genes are eliminated are probably in the Order B>Pl>a.
Elimination of the chromosome carrying the aleurone color gene C (number 9), or fragments including this gene, is shown to be relatively frequent in endorsperm tissue homozygous for the st gene. Chromosome unbalance resulting from elimination is apparently reIated to the “scarring” characteristic of endosperm tissue homozygous for the st gene.
The frequency of chromosome rearrangements (for the most part, reciprocal translocations) was 1 in 64 in the progeny of st plants as compared wich a frequency of 1 in 594 for comparable normal controls.
The frequency of mutations in the progeny of sticky chromosome plants was 1 in 49 as compared with 1 in 379 for the normal controls.
In no case was a detected mutation inseparably associated wich a detected chromosome rearrangement.
In the F1 of the Cross st×bm1 there appeared a group of plants showing longitudinal white stripes. This striping was not carried by the parents and was not transmitted to progeny resulting from self-pollination. Presumably some cytoplasmic abnormality was produced in the st parent, transmitted to the F1 plants, but not carried to the next generation.
