Systematics of disjunct northeastern Asian and northern north American Allium (Amaryllidaceae)

CHOI H. J., L. M. GIUSSANI, CHANG GEE JANG, BYOUNG UN OH, AND

BOTANY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2012 vol. 90 p. 491 - 508

1916-2790

This study was undertaken to better understand Allium infrageneric taxonomy, character evolution, species diversification,and patterns of radiation in disjunct species between the New and Old World using morphological and moleculardata. Taxonomic sampling focused on northeastern Asian (mainly Korean and northeastern Chinese) and representative disjunctnorthern North American (Canadian) species. Pistil and seed testa morphology was investigated using light and scanningelectron microscopy, respectively. These characters were useful to assess degree of relationship at different taxonomiclevels in Allium. Phylogenetic studies included nrDNA ITS and cpDNA trnL?trnF sequence data analyzed using maximumparsimony approaches. Our molecular phylogeny recovers a similar topology to that published in recent studies and confirmsthree major evolutionary lines and patterns of radiation regarding the ancestors of subgenera Amerallium and Anguinumin the genus. The northeastern Asian and northern North American disjunction in this genus is inferred to be the resultof multiple intercontinental migrations. Seed testa sculpture attributes in combination with seed shape provide key charactersto distinguish Allium?s major clades in the molecular phylogeny. The two types of ovarian processes, basal hood-like and apicalcrest-like in disjunct Old and New World species, respectively, are newly derived characters in each continent. Most infragenericAllium groups are monophyletic, while subgenus Cepa is polyphyletic.