Molecular Characterization of the Interspecific Origin of Viviparous Onion
1991; Oxford University Press; Volume: 82; Issue: 6 Linguagem: Inglês
10.1093/oxfordjournals.jhered.a111137
ISSN1465-7333
Autores Tópico(s)Banana Cultivation and Research
ResumoRestriction enzyme (RE) analysis of both chloroplast (cpDNA) and nuclear ribosomal DNA (rDNA) was used to establish the phylogeny of the diploid viviparous onion [Allium × proliferum (Moench) Schrad. syn. Allium cepa L. var. viviparum (Metzger) Alefeld]. Six mutations at RE sites in the cpDNA demonstrated that the seed parent of two accessions of diploid viviparous onions (TS6007 and JS01) was identical to A. fistulosum. Variability at RE sites in the nuclear rDNA demonstrated that TS6007 and JS01 always possessed fragments of both A. cepa and A. fistulosum. In contrast, mutations in the cpDNA of Pran, a triploid viviparous onion, were different from A. fistulosum. Equally sized rDNA fragments were always shared by Pran and A. cepa. Only two rDNA fragments were shared by Pran and A. fistulosum, contradicting previous reports that Pran is an interspecific hybrid between A. cepa and A. fistulosum. Therefore, Pran arose from hybridization of A. cepa with an unresolved seed parent. This study confirms that more than one interspecific hybridization occurred in the evolution of the viviparous onion.
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