Plant Cell, Tissue and Organ Culture

, Volume 82, Issue 1, pp 19–44

Intergeneric somatic hybridization and its application to crop genetic improvement

Authors

    • National Key Laboratory of Crop Genetic Improvements, National Center of Crop Molecular BreedingHuazhong Agricultural University
  • Xiaoyong Xu
    • National Key Laboratory of Crop Genetic Improvements, National Center of Crop Molecular BreedingHuazhong Agricultural University
  • Xiuxin Deng
    • National Key Laboratory of Crop Genetic Improvements, National Center of Crop Molecular BreedingHuazhong Agricultural University
Article

DOI: 10.1007/s11240-004-6015-0

Cite this article as:
Liu, J., Xu, X. & Deng, X. Plant Cell Tiss Organ Cult (2005) 82: 19. doi:10.1007/s11240-004-6015-0

Abstract

Related or distant species of cultivated cs are a large pool of many desirable genes. Gene transfer from these species through conventional breeding is difficult owing to post- and pre-zygotic sexual incompatibilities. Somatic hybridization via protoplast fusion is a possible alternative for gene transfer from these species to cultivated crops. Since the early days of somatic hybridization many intergeneric somatic hybrids have been developed through symmetric fusion, asymmetric fusion and microfusion. Somatic hybrids are mainly selected by using markers such as specific media or fusion parents with special features, biochemical mutants, antibiotic resistance and complementation strategy. The hybridity of the regenerants is determined based on morphological, cytological and molecular analysis. The inheritance patterns of nuclear and cytoplasmic genomes in the somatic hybrids are diverse. Nuclear DNA from both fusion parents co-exists congruously in some hybrids with translocation and rearrangement of chromosomes, but spontaneous elimination of chromosomes from either or both fusion parents has been observed very often. In asymmetric fusion, chromosome elimination is an important issue that is a complicated process influenced by many factors, such as irradiation dose, phylogenetic relatedness, ploidy level of fusion parent and regenerants. As for chloroplast genome, uniparental segregation is mainly detected, though co-existence is also reported in some cases. The mitochondrial genome, in contrast to chloroplast, undergoes recombination and very frequent rearrangements. Somatic cell fusion has potential applications for crop genetic improvement by overcoming sexual incompatibility or reproductive barriers, and by realizing novel combinations of nuclear and/or cytoplasmic genomes.

Keywords

asymmetric fusion chloroplast DNA chromosome elimination crop genetic improvements intergeneric somatic hybridization mitochondria DNA somatic hybrids symmetric fusion

Copyright information

© Springer 2005