Morphological and molecular characterisation and differentiation of Sargassum baccularia and S. polycystum (Phaeophyta)

Abstract

Two Sargassum species (S. baccularia and S. polycystum) collected from Teluk Kemang and Cape Rachado, Port Dickson, Negeri Sembilan, Malaysia, which are alike in morphology except for the rhizoidal system and vesicles, were characterised using random amplified polymorphism DNA (RAPD). The genomic DNA of both species was isolated from the leaves using a modified CTAB method. Four random primers, that is, OPA2, OPA3, OPA4 and OPA13, successfully amplified the DNA. The polymorphisms generated by these four primers were analysed using the Dice Coefficient of Similarity and cluster analysis was carried out using GelCompar II Version 2.0 (Applied Maths, Kortrijk, Belgium) based on UPGMA. DNA analysis showed that three primers were able to differentiate the two species. Morphological analysis using Principal Components Analysis (PCA) and discriminant function analysis supported the molecular data. Both species are characterised by heavily muricate main branches, oblonglanceolate leaves with dentate margins and discoid holdfasts and spherical vesicles; both are dioecious. The only difference is that S. polycystum has secondary holdfasts transformed into stolons. This last characteristic is therefore a very important criterion and may contribute to the difference shown by DNA analysis.

Identification of random amplified polymorphic DNA (RAPD) marker for differentiating male from female and sporophytic thalli of Gracilaria changii (Rhodophyta)

“…The DNeasy Plant Mini Kit was found to be unsuitable for Gracilaria, as it could not efficiently remove the polysaccharide. This was also observed with Sargassum, which has alginic acid (Ho 1995a;Wong et al 2004). This can be overcome by using only the tips of Gracilaria that are freshly ground using liquid nitrogen.…”

“…The random amplified polymorphic DNA (RAPD) assay was successfully used in the classification of seaweeds at the genus and species levels: Gracilaria (González et al 1996;Lim et al 2001), Gelidium species (Patwary et al 1993;Bouza et al 2006), Porphyra (Dutcher and Kapraun 1994;Huh et al 2006), Sargassum species (Ho et al 1995a, b;Wong et al 2004), Hizikia fusiformis (Park et al 1998), Laminaria (Billot et al 1999) and Furcellaria lumbricalis (Valatka et al 2000). Sex-specific markers using RAPDs have been identified in insects (Holloway et al 2000), fish (Iturra et al 1998;Liu et al 1999) and plants (Deputy et al 2002;Lemos et al 2002;Mandolino et al 2002;Xu et al 2004).…”

ANALYSES OF EXPRESSED SEQUENCE TAGS FROM SARGASSUM BINDERI (PHAEOPHYTA)1

“…Over the last decade, there has been interest in supplementing traditional systematics of this genus with molecular approaches (Ho et al. 1995a, b, Wong et al. 2004).…”

Molecular-Assisted Taxonomic Study on the Sargassum C.Agardh (Fucales, Phaeophyceae) in Northwestern Luzon, Philippines

“…Although it is unclear whether the material used by Kantachumpoo et al (2015) is the same as that described in Noiraksar & Ajisaka (2008), it is likely that the S. baccularia sensu Kantachumpoo et al (2015) has been misidentified. In Malaysia, Wong et al (2004) also noted the confused taxonomies of S. baccularia and S. polycystum and showed that S. polycystum and S. baccularia can be distinguished based on random amplified polymorphism DNA (RAPD) and morphology. For the latter, they suggested that the absence of secondary holdfasts derived from secondary axes distinguishes S. baccularia from S. polycystum .…”