Chromosome numbers and karyotype evolution in holoparasitic Orobanche (Orobanchaceae) and related genera

American Journal of Botany
By: , and 



Chromosome numbers and karyotypes of species of OrobancheCistanche, and Diphelypaea (Orobanchaceae) were investigated, and 108 chromosome counts of 53 taxa, 19 counted for the first time, are presented with a thorough compilation of previously published data. Additionally, karyotypes of representatives of these genera, including Orobanche sects. Orobanche and Trionychon, are reported. Cistanche (x = 20) has large meta- to submetacentric chromosomes, while those of Diphelypaea (x = 19) are medium-sized submeta- to acrocentrics. Within three analyzed sections of Orobanche, sects. Myzorrhiza (x = 24) and Trionychon (x = 12) possess medium-sized submeta- to acrocentrics, while sect. Orobanche (x = 19) has small, mostly meta- to submetacentric, chromosomes. Polyploidy is unevenly distributed in Orobanche and restricted to a few lineages, e.g., O. sect. Myzorrhiza or Orobanche gracilis and its relatives (sect. Orobanche). The distribution of basic chromosome numbers supports the groups found by molecular phylogenetic analyses: Cistanche has x = 20, the Orobanche-group (Orobanche sect. OrobancheDiphelypaea) has x = 19, and the Phelipanche-group (Orobanche sects. GymnocaulisMyzorrhizaTrionychon) has x = 12, 24. A model of chromosome number evolution in Orobanche and related genera is presented: from two ancestral base numbers, xh = 5 and xh = 6, independent polyploidizations led to x = 20 (Cistanche) and (after dysploidization) x = 19 (Orobanche-group) and to x = 12 and x = 24 (Phelipanche-group), respectively.

Publication type Article
Publication Subtype Journal Article
Title Chromosome numbers and karyotype evolution in holoparasitic Orobanche (Orobanchaceae) and related genera
Series title American Journal of Botany
DOI 10.3732/ajb.91.3.439
Volume 91
Issue 3
Year Published 2004
Language English
Publisher Wiley
Contributing office(s) Western Fisheries Research Center
Description 10 p.
First page 439
Last page 448
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