Spontaneous Frequencies of Genetic and Other Sterilities in Barley, Hordeum vulgare L 1

Collections of highly sterile barley plants, Hordeum vulgare L., from farm fields and experimental plots were made during the period 1960‐1966. Progeny tests showed about 10% of these sterile plants were monogenic recessive male sterile types. A higher frequency of male sterility was found in the two‐rowed than in the six‐rowed varieties. A detailed census in a single farm field of ‘Betzes’ barley showed that 1 out of 709 plants were partially sterile and 1 out of 3,995 plants were highly sterile. When collected under Montana conditions the highly sterile plants are the class of sterility most likely to produce genetic male steriles. We estimate that one genetic male sterile plant should be found by examining approximately 40,000 plants.