Development of Ogura CMS Fertility-Restored Interspecific Hybrids for Use in Cytoplasm Replacement of Golden-Heart Materials in Brassica rapa

Genes (Basel). 2023 Aug 11;14(8):1613. doi: 10.3390/genes14081613.

Abstract

Ogura cytoplasmic male sterility (CMS) is one of the important methods for hybrid seed production in cruciferous crops. The lack of a restorer of fertility gene (Rfo) in Brassica rapa L. restricts the development and utilization of its germplasm resources. In this research, Brassica napus with the Rfo gene was used to restore the fertility of Ogura CMS B. rapa with the golden heart trait. Through the distant cross of two B. rapa and four B. napus, six interspecific hybrid combinations received F1 seeds. The six combinations were different in seed receiving. By morphological observation and molecular marker-assisted selection (MAS), in F1, individuals containing the Rfo gene all appeared fertile, while those without it remained male-sterile. The pollen viability of the fertile individuals was measured, and the fertile lines of the six interspecific hybrid combinations were different (40.68-80.49%). Three individuals (containing both Rfo and GOLDEN genes) with the highest pollen vitality (≥60%) were backcrossed with fertile cytoplasmic B. rapa, resulting in a total of 800 plants. Based on the MAS, a total of 144 plants with GOLDEN but no Rfo were screened (18%). Moreover, through morphological investigation, one individual with normal cytoplasm, stable fertility but without the restoring gene Rfo, the GOLDEN gene, and morphological characteristics similar to those of B. rapa was obtained. These results increased the diversity of B. rapa germplasm and provided a new method for the utilization of CMS germplasm in Brassica crops.

Keywords: Brassica rapa; GOLDEN gene; Ogura CMS; restorer of fertility gene (Rfo).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brassica rapa* / genetics
  • Crops, Agricultural
  • Cytoplasm / genetics
  • Cytosol
  • Fertility / genetics
  • Gastropoda*
  • Humans
  • Infertility*

Grants and funding

This work was supported by grants from the National Key Research and Development Program of China (2022YFD1200502), the China Agriculture Research System (CARS-23-A-14), the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS-ASTIP-IVFCAAS) and Central Public-interest Scientific Institution Basal Research Fund (No. Y2023LM19). This work was performed at the State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China, and the Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Beijing, China.