Molecular studies of cytoplasmic male sterility in Petunia

Abstract

A large number of different mutations has been shown to give rise to male sterility in over 175 species of plants, and references are fast going out of date as more are being mapped all the time (Regan and Moffatt 1990). In over 140 species of angiosperms, certain male sterility mutations are inherited with the cytoplasmic genomes rather than following the Mendelian inheritance patterns of typical nuclear genes (Laser and Lersten 1972). Cytoplasmic Male Sterility (CMS) is a maternally inherited trait which results in the abortion of pollen development and thereby the loss of male fertility in an otherwise hermaphroditic plant. The trait is economically important because it is used commercially for the production of hybrid seed in some agriculturally significant cultivated species such as maize. Unfortunately the CMS phenotype has been associated with undesirable effects in some plants where it was used extensively in the breeding germplasm, such as susceptibility to southern corn leaf blight in maize associated with type T CMS, which wiped out 15% of the total U.S. maize crop in 1970 (reviewed in Leaver 1992). Thus, due to its economic importance, CMS has been a subject for molecular study in a number of species, such as brassicas, rice, maize, sunflower, and beans (Hanson and Conde 1985). Interestingly, though the chloroplast genome is also maternally inherited, CMS has been found to be associated with the mitochondrial genome in every species in which its coding location has been determined Thus, study of the CMS phenomenon has also led us to some fascinating insights into the structure and function of plant mitochondrial genomes.KeywordsMitochondrial GenomeMale SterilityCytoplasmic Male SterilitySomatic HybridAlternative OxidaseThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.