Mix of male and female chloroplast DNA reveals rapid hybridization, new citrus family tree shows
The mother of all citrus plants lived about 13 million years ago, scientists have learned by tracing the maternal side of the citrus family tree. Yet it is dad’s contribution that has revealed the growing family’s entire portrait.
Starting about 8.08 million years ago, the citrus family tree began branching out. That’s when Australian limes and citrons split from the original Citrus genus, researchers report April 14 in Molecular Biology and Evolution. Several subsequent rounds of speciation led to branches carrying lemons, limes, oranges, tangerines and other citrus fruits. Learning how these species and varieties evolved may help breeders devise new varieties that can withstand drought and disease while still making tasty fruit, scientists say.
Researchers from Valencia, Spain, determined the genetic makeup of chloroplasts — organelles in plant cells that carry