Inheritance of Ephemeral Leaf Mutant of Upland Cotton.

Developmental mutants of plants may be useful in studies of physiological development and of gene expression and gene action. The objectives of the study were to determine the inheritance of a newly discovered developmental leaf mutant of upland coton (Gossypium hirsutum L.) and to determine whether it was allelic to, or linked to veins-fused (vf) or to strap leaf (s). This mutant is named ephemeral, because it expresses only for a short time during plant growth. The gene associated with this expression was assigned the symbol ep. It was inherited as a monofactorial recessive in 198S, but in 1984, about half of the (normal x ephemeral)F1 plants were intermediate in expression. In the greenhouse, usually a single leaf is affected at about Node 6, and progressively more leaves are affected until Node IS, but leaves at Node 18 and above appear normal. In the field, expression is much more restricted and may be limited to just a few leaves at Nodes 5 to 10. The mutant phenotype resembles that of veins-fused, but ep is not allelic to, nor closely linked to vf to s.