Cytoplasmic male sterility in rapeseed (Brassica napus L.): female fertility of restored rapeseed with "Ogura" and cybrids cytoplasms

Publisher Website
Google Scholar
Abstract
The study of Brassica napus L. plants carrying restorer genes introgressed from radish (Raphanus sativus L.) showed that these genes ensured restoration of male fertility in rapeseed for all the male sterility-inducing cytoplasm studied, i.e., "Ogura"-type cytoplasm and that of four cybrids obtained by protoplast fusion. Plants with high levels of restored male fertility were obtained. However, the introduction of restorer genes was accompanied by a large decrease in seed set. Observations of embryo sacs inside the ovules and correlation between number of seeds per pod and percentage of octonucleate embryo sacs indicated that low seed set could be attributed to a high rate of embryo sac abortion, mainly at the uninucleate stage. Introduction of too much radish genetic information was assumed to be the cause of this low female fertility. Female fertility must be improved before the restored material can be used for F1 hybrid rapeseed production.Key words: Brassica napus, Raphanus sativus, cytoplasmic male sterility, restorer, cybrid, female fertility, embryo sac.