Effects of R1, a Gene for Red Plant Color, on American Pima Cotton1

A dominant gene conditioning red plant color, R1 was transferred to Gossypium barbadense L. from G. hirsutum L. The R1 gene had no significant effects on seed index, or fiber length, strength and elongation after eight backcrosses to G. barbadense. Homozygous red, R1R1, and heterozygous red, R1rl, significantly reduced lint yield, boll size, lint percentage, and Micronaire. Dosage effects were noted for yield, boll size, and Micronaire. Green BC8F3 plants were not significantly different from the recurrent parent, ‘Pima S‐4,’ for any of the 10 properties measured.