Glandless Boll in Upland Cotton and Its Use in the Study of Natural Crossing

GLANDLESS BOLL IN UPLAND COTTON AND ITS USE IN THE STUDY OF NATURAL CROSSING GLANDLESS boll is described as the complete absence of oil glands in the bolls of upland cotton Gossypium hirsutum L. The stem, hypocotyl, and petiole were later found to be without oil glands. The glandless condition of the hypocotyl was pointed out to the writer by Stephens. The leaves and bractioles of the glandless mutation, however, have as many oil glands per unit area as is found in the corresponding parts of normal plants. The appearance of glandless boll plants is otherwise similar to normal plants. Also, the lint and seed characteristics of glandless boll are comparable to that of normal boll cotton. Oil glands are an important taxonomic character useful in the classification of cotton and cotton relatives. The in-