hybridization
Ridley CE, Kim S-C & Ellstrand NC 2008 Bidirectional history of hybridization in California wild radish, Raphanus sativus (Brassicaceae), as revealed by chloroplast DNA. Am J Bot 95:1437-1442.
- cultivated radish and R. raphanistrum shared no cpDNA haplotypes
- they both shared haplotypes with California wild radish
- evidence for bidirectional hybridization between the progenitor species in the creation of the California lineage
- multiple cultivars and multiple European source populations contributed to the diversity of cpDNA haplotypes within California
- interspecific hybridization between two Raphanus species has stimulated the evolution of a successful lineage
- which has apparently resulted in the extinction of all pure parental populations in the state
- we were surprised by the significant crop contribution to the cpDNA haplotypes of the hybrid lineage
- when grown as a vegetable crop, cultivated radish is unlikely to hybridize at all
- because it is harvested long before the onset of reproduction
- R. raphanistrum is a much more prolific maternal parent than R. sativus under unmanaged conditions
- lower fecundity in R. sativus is likely due to delayed flowering and a shorter reproductive window for both flower and seed production in the crop
- R. sativus takes an average of twice as long to flower as R. raphanistrum across various environments
- all considered, R. raphanistrum should be the overwhelmingly dominant contributor of cpDNA to the hybrid-derived lineage
- we did not observe this
