Inheritance of Three Genes for Plant Color in American Pima Cotton.

Three new plant color mutants were found in American Pima cotton (Gossypium barbadense L.). These monogenic recessive mutants were not alleles of 12 previously identified plant color mutants in Gossypium. In the field, two of these emerged with green cotyledons. The first six to eight true leaves were yellowish-white to white, and subsequent leaves were progressively greener until midseason when the new leaves were practically a normal green. Greenhouse-grown plants of these mutants were a normal green color over their lifespan, suggesting that the expression of the mutant color depended on cool temperatures such as that occurring in the field in April and May. We propose that these two mutants be named albivirescent-1 and albivirescent-2 and be given the gene symbols av1 and av2 The foliage of the third new Pima plant color mutant was light green throughout the life of the plant in the field or greenhouse, indicating that the expression of the gene was not affected by temperature. We propose that this mutant be named light green with the gene symbol ltg.