Assessment of diversity in Harpagophytum with RAPD and ISSR markers provides evidence of introgression. Issue 4 (October 2014)

• Record Type: Journal Article
• Authors: Muzila, Mbaki; Werlemark, Gun; Ortiz, Rodomiro; Sehic, Jasna; Fatih, Moneim; Setshogo, Moffat; Mpoloka, Wata; Nybom, Hilde
• Is Part Of: Hereditas. Volume 151:Issue 4/5(2014)
• Page Start: 91
• Page End: 101
• Publication Date: 2014-10
• Subjects: Heredity -- Periodicals; Genetics -- Periodicals; Cytogénétique; Génétique; Hérédité; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 576.5
• DOI: 10.1111/hrd2.00052
• Languages: English
• ISSNs: 0018-0661

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The genus <italic>Harpagophytum</italic> has two species: <italic>H. procumbens</italic> which is an important medicinal plant in southern Africa, and <italic>H. zeyheri</italic>. Genetic diversity in 96 samples, obtained by germinating seeds collected from Botswana, was assessed using six inter‐simple sequence repeat (ISSR) and 10 random amplified polymorphic DNA (RAPD) primers. These DNA markers yielded a total of 138 polymorphic bands. Polymorphism information content (PIC) ranged from 0.06 to 0.39 for ISSR primers, and from 0.09 to 0.43 for RAPD primers. Jaccard's similarity coefficients were highest when seedlings derived from the same fruit capsule were compared, while seedlings from different fruits on the same plant had intermediate values. The lowest values were recorded among seedlings from different plants. These results were consistent with an outcrossing breeding system in <italic>Harpagophytum</italic>. Analysis of molecular variance revealed significant differentiation (P < 0.01) between taxonomic units within <italic>Harpagophytum</italic>. About 39% of the variability occurred between the two species, <italic>H. procumbens</italic> and <italic>H. zeyheri</italic>. Plants with an intermediate morphology, i.e. putative hybrids (PH), showed 21% differentiation when compared with <italic>H. procumbens</italic> ssp. <italic>procumbens</italic> (PP), and 19% when compared with <italic>H. procumbens</italic> ssp. <italic>transvaalense</italic> (PT) or with <italic>H. zeyheri</italic> (ZZ). In addition, a deviating variant of PT was identified, here termed '<italic>procumbens</italic> new variety' (PN). PN showed only 9% differentiation when compared with PT, 22% when compared with PP or with PH, and 41% when compared with ZZ. Considerable differentiation between the two <italic>Harpagophytum</italic> species was revealed also by a cluster analysis. Introgression was, however, suggested by the intermediate position of the putative hybrid plants in a principal component analysis while inter‐specific gene flow was shown by a Bayesian genetic structure analysis.</p> </abstract>