Phylogeny reconstruction and hybrid analysis in Allium subgenus Rhizirideum

Berlin

2000

S. 1000-1009

5 Abb., 3 Tab., 39 Lit. Ang.

Bandaufführung

10001S

136354

Amplified fragment length polymorphisms (AFLPs) for assessing nuclear DNA diversity have been used for the reconstruction of the phylogeny and evolution of several sections of Allium subgenus Rhizirideum. A dataset of 355 characters for 33 accessions belonging to 20 species has been compiled. The band-sharing of five interspecific hybrids and of an F2 population between Allium cepa and Allium roylei with their parents indicated a heterozygosity level between 6 and 14%, which allows the use of dominant markers such as AFLPs for phylogeny reconstruction. A majority rule consensus tree based on 56 most-parsimonius trees (CI = 0.528) revealed a separate clade for each of the sections, Cepa, Rhizirideum and Schoenoprasum, and one clade combining the sections Oreiprason and Petroprason. An unweighted pair group mean average (UPGMA)-based dendrogram showed the same subdivision. The trees and the 'Hybrid Distance' approach both supported the assumption of a hybrid origin for A. roylei with considerable subsequent secondary evolution. The establishment of three alliances in the section Cepa and the close relationship of sections Oreiprason and Petroprason are now confirmed. The predictions of the Soybean domestication scenario, i.e. selection of a crop from one progenitor with subsequent narrowing of the genetic diversity of the crop, which applies to the cultigens A. cepa and Allium fistulosum, is supported by the Hybrid Distance approach.