Chloroplast capture is an evolutionary process through which inter-species hybridization and subsequent backcrosses yield a plant with new genetic combination of nuclear and chloroplast genomes. For instance, 1) species A's (having chloroplast genome a and nuclear genome AA) pollen hybridizes (backcross) to species B's (b and BB) ovule, yielding the 1st hybrid (F1) with chloroplast genome b and nuclear genome A (50%) and B (50%); 2) species A's pollen again hybridizes (backcross) to F1's ovule, yielding the 2nd hybrid (F2) with chloroplast genome b and nuclear genome A (75%) and B (25%); 3) species A's pollen again hybridizes (backcross) to F2's ovule, yielding the 3rd hybrid (F3) with chloroplast genome b and nuclear genome A (87.5%) and B (12.5%); 4) after further backcross generations, a plant is obtained with the new genetic combination (chloroplast genome b and nuclear genome A).
Known cases of chloroplast capture
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- Terry RG, Nowak RS, Tausch (2000) Genetic variation in chloroplast and nuclear ribosomal DNA in Utah juniper ( Juniperus osteosperma, Cupressaceae): evidence for interspecific gene flow. American Journal of Botany 87: 250-258
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- Whittemore, A. T., Schaal, B. A. (1991) Interspecific gene flow in sympatric oaks. PNAS 88: 2540-2544
- Ito, Y., T. Ohi-Toma, J. Murata, and Nr. Tanaka (2013) Comprehensive phylogenetic analyses of the Ruppia maritima complex focusing on taxa from the Mediterranean. Journal of Plant Research 126(6):753-62.
- Soltis, D. E., P. S. Soltis, T. G. Collier, and M. L. Edgerton. 1991. Chloroplast DNA variation within and among genera of the Heuchera group: evidence for extensive chloroplast capture and the paraphyly of Heuchera and Mitella. American Journal of Botany 78: 1091–1112.