Inheritance of male sterility in Lesquerella fendleri

Lesquerella fendleri (Gray) Wats. (lesquerella, Brassicaceae), native to th e southwestern United States, is a potentially useful industrial oilseed cr op. The seed oil contains hydroxy fatty acids, similar to castor (Ricinus c ommunis L.) seed oil. The unique properties of the oil, along with coproduc ts, allow additional applications that would not compete with castor oil. P lants with vestigial anthers (male-sterile) were discovered in a greenhouse -grown, nonselected population in 1993. The inheritance of the trait was in vestigated through four crop seasons. Crosses were made among male-sterile and male-fertile plants from an open pollinated population, thus, they were heterozygous for many traits. Statistical analysis indicated that male ste rility is expressed as a result of two nonlinked nuclear genes with epistat ic relations and different cytoplasms, which cause partial or total fertili ty restoration. These ratios fit a 13:3 epistatic ratio, indicating that ma le sterility is controlled by homozygous recessive alleles at one locus in combination with at least one dominant allele at the second locus, i.e., ms 1ms1 Ms2_. Some cross results were skewed in favor of fertile phenotypes pr esumably due to cytoplasmic effects causing partial fertility restoration. Male-sterile lines could be used for hybrid development and this informatio n will be helpful in implementing a strategy for hybrid development. Hybrid plants and higher yields will enhance the potential for commercialization of this new alternative crop.