PLASMON MUTATIONS IN CYTOPLASMIC MALE-STERILE PEARL MILLET, PENNISETUM TYPHOIDES

William M. Clement Jr. ¹

¹ Department of Biology, Vanderbilt University, Nashville, Tennessee 37235

Spontaneous mutations from sterile to fertile were demonstrated in four different cytoplasmic male-sterile stocks of pearl millet. One stock, ASM-3, was of African origin, and the other three, LMS-1A, ASM-5, and ASM-7, all had the same cyptoplasm of Indian origin, but differed in nuclear make-up. These reversions were shown to be plasmon mutations, rather than genic in nature. ASM-3 mutated at the lowest rate, about 0.03/100 heads. LSM-1A, ASM-5, and ASM-7 all had the same cytoplasm but mutated at the respective rates of 0.15, 0.26, and 1.02/100 heads, indicating that plasmon mutation rate is strongly influenced by the nuclear environment.