Genetics and development of nine male-sterile tomato mutants

A search was conducted in commercial plantings of the San Marzano tomato for male-sterile mutants, potentially useful in producing F 1 hybrid seed and in cross-breeding. Among 150 unfruitful plants, 12 were found to be genetically male-sterile. Breeding results indicate that the male sterility of each mutans, is determined by a single recessive gene. One gene-ms5-was recovered four times. Eight other nonallelic genes-ms 6 to ms 1 3-were demonstrated. No mutants for female sterility or cytoplasmic male sterility were found. [Vol. 18, No. 17 These effects are determined precisely and consistently, each preparation of a given mutant revealing the same pattern of breakdown.