The genetics of withering or deciduous bracteoles in cotton

The character Withering Bracteole inGossypium hirsutum is shown to be controlled by a single recessive genebw. This gene has a pleiotropic action causing leaf crumpling and also sterility to a greater or less extent. Pollen grains carryingbw appear to have an advantage in fertilization. At a low modifier levelF 2 ratios of 2·1 Normal: 1 Withering Bract were obtained, andbwbw plants were more or less sterile and had severely crumpled foliage. At a higher modifier levelF 2 ratios rose to 7·2∶1, presumably because many of thebwbw plants were indistinguishable from normal. In such families the deleterious effects ofbw were largely masked, but as a result the bracteoles also failed to wither effectively. This gene is therefore considered to be useless as a means of removing the bracteoles to facilitate mechanical picking.