Inheritance of maintenance and restoration of the Diplotaxis muralis (mur) cytoplasmic male sterility system in summer rape

Abstract

The inheritance of Diplotaxis muralis (L) DC. mur cytoplasmic male sterile (CMS) system maintenance and restoration in summer rape (Brassica napus L.) was studied by crossing eight summer rape cultivars of diverse origin to a winter habit mur CMS A-line. The F1 progenies from all eight crosses were male fertile and were selfed to produce the F2 generation. The F2 generation was grown in the field and data on segregation for male fertility and sterility were recorded and analyzed. The F2 segregation data showed that mur CMS restoration in summer rape is controlled by dominant alleles at one to three restorer genes. The number of genes for the restoration of male fertility in mur CMS varied both among and, occasionally, within cultivars. Maintainer lines for mur CMS must carry recessive alleles in homozygous condition at all three restorer genes. The ready availability of summer rape restorers suggests that the mur CMS system has good potential for hybrid cultivar development and hybrid seed production in summer rape; however, maintainers in summer rape must first be discovered or developed. Key words: Cytoplasmic male sterility, canola, Brassica napus, male sterility