Abstract Detail

Rupert Barneby and his legume legacy

Kazempour Osaloo, Shahrokh [1].

Molecular systematics of Old World Astragalus L. (Fabaceae) as inferred from nrDNA ITS sequence data.

The nuclear rDNA internal transcribed spacer region was sequenced for 200 accessions of the Old World Astragalus (including monotypic segregate genera Barnebyella, Ophiocarpus and Thlaspidium plus newly established monotypic genus Podlechiella), two species from aneuploid North American Astragalus and for three related genera (two Oxytropis species, Colutea persica and Biserrula pelecinus) plus outgroup taxa consisting of Caragana grandiflora and Chesneya astragalina. A total of 652 nucleotide sites was analyzed using both maximum parsimony and neighbor-joining distance methods as implemented on PAUP* 4.0. The resulting trees revealed that all Astragalus species sampled except three annuals A. epiglottis, A. annularis and Podlechiella vogelii (=A. vogelii), belong to a well-supported monophyletic group, so-called Astragalus s. str. The three segregate genera Barnebyella, (=A. migpo), Ophiocarpus (=A. ophiocarpus) and Thlaspidium (=A. thlaspi) are clearly nested within Astragalus. Our results confirm earlier studies that showed P. vogelii is allied with Colutea, rather than with any Astragalus species, at the base of the trees. Likewise, Astragalus epiglottis and A. annularis are sister taxa and, in turn, form a highly supported clade with Biserrula pelecinus. Within the Astragalus s. str. assemblage, the best supported large clade, is composed of solely perennial sections including sects. Chlorostachys, Cenanthrum, Aegacantha, Caraganella, Nuculiella, Chronopus, Astragalus, Alopecuroidei, Lxiflori, Eremophysa, Pelta, Pendulina and Caprini. While three other large clades, each comprises several perennial and annual sections, for instance, sects. Theiochrus and Oxyglottis, Glycyphyllus and Cyamodes, and Lotidium and Platyglottis, respectively. The monophyly of either the eight traditionally recognized subgenera of Astragalus (Epiglottis, Trimeniaeus, Phaca, Hypoglottis, Calycophysa, Tragacantha, Cercidothrix and Calycocystis) or Podlech’s three new subgenera (Trimeniaeus, Astragalus, and Cercidothrix) is not supported. Among species-rich sections analyzed, only sects. Cenanthrum, Caraganella Eremophysa, Laxiflori, Lotidium, and Incani are monophyletic.

1 - Tarbiat Modarres University, Department of Plant Biology, Tehran, 14115-175, IRAN

Keywords:
Fabaceae
matK
molecular phylogenetics
nrDNA ITS
molecular systematics.

Presentation Type: Symposium
Session: 19-3
Location: Magpie (Cliff Lodge)
Date: Monday, August 2nd, 2004
Time: 2:30 PM
Abstract ID:585