Chloroplast capture

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.^[1] For instance:

• 1) species A's (having chloroplast genome a and nuclear genome AA) pollen hybridizes 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 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 backcrosses 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 AA).

Known cases of chloroplast capture

Gymnosperm

• Juniperus (Cupressaceae) ^[2]
• Pinus (Pinaceae) ^[3]

Angiosperm

• Quercus (Fagaceae) ^[4]
• Ruppia (Ruppiaceae) ^[5]
• Heuchera (Saxifragaceae) ^[6]