INHERITANCE OF MALE STERILITY IN LESQUERELLA FENDLERI (GRAY) WATS.

Authors: Dierig, David; RAY, D - UNIV OF ARIZONA

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2001
Publication Date: 12/31/2001
Citation: Dierig, D.A., Ray, D.T. 2001. Inheritance of male sterility in lesquerella fendleri (gray) wats. Journal of the American Society for Horticultural Science 126:737-743.

Interpretive Summary: Seed yield improvements are necessary for commercialization of lesquerella, a potential new oilseed crop. Hybrids are more productive in seed yields in many other crops compared to open-pollinated plants. However, it can be time-consuming and laborious to produce hybrids unless a male sterile strategy can be implemented where removal of plants' pollen-bearing structures is not necessary. In this study we found that male sterility in lesquerella is a recessive trait and controlled by two different genes. These two genes interact to alter the expected number of plants expressing male fertility (having pollen) to male sterility. Another finding was that a factor inherited only from some of the female parents caused, in some degree, the expected number of sterile offspring to revert to fertile plants. This information is necessary in devising a field plan to cross male sterile plants with desired pollen plants and to predict if the trait will be present in the offspring. This information benefits plant breeders who wish to improve lesquerella seed yields. Producers and processors also benefit from more economically produced seed and seed oil.

Technical Abstract: Lesquerella fendleri (Gray) Wats., Brassicaceae, native to the southwestern United States, is a potential oilseed crop. The seed oil contains hydroxy fatty acids similar to castor. Unique properties of the oil, along with co-products, allow additional applications that would not compete with castor. In 1993, plants with vestigial anthers (male sterile) were discovered in a greenhouse-grown, unselected population. The inheritance of the trait was investigated 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. Chi square results indicate that male sterility is expressed as a result of two nonlinked nuclear genes with epistatic relations and different cytoplasms, causing partial or total fertility restoration. Ratios fit a 13:3 epistatic ratio, although some cross results were skewed in favor of fertile phenotypes presumably due to cytoplasmic effects causing partial fertility restoration. Male sterile lines could be utilized for hybrid development, and this information 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.