Genetics of Virescent-4 Mutant in Cotton.

We observed a yellow seedling (at the third true leaf stage) in a border row of our cotton genetics nursery. The yellow leaves became normal green at the mature plant stage. Inheritance studies showed that the virescent mutant is monogenic and recessive to normal green. Tests for allelism with other virescents and pigment mutants showed that it is controlled at a new locus. It is not linked with any of the 12 marker loci with which it was tested. The new virescent mutant is named virescent-4 and assigned the gene symbol v4v4.