Assessment of allozyme variation among New Zealand populations of Gracilaria chilensis (Gracialiares, Rhodophyta) using starch-gel electrophoresis

Abstract

New Zealand populations of Gracilaria chilensis are uniform in anatomical reproductive characteristics but vary morphologically and have been found to separate into two distinct groups with respect to agar methylation level, namely low (24-30 %) and high (43-47 %). To investigate the genetic variation within New Zealand populations of this species, 14 isozyme loci detected by starch-gel electrophoresis were examined in 17 wild populations from a wide range of localities, and in cultures derived from these populations. Five of these loci were polymorphic, but the genetic variation within populations was low: of the 17 populations examined, 15 were fixed at all loci (heterozygosity 0.000) and in the remaining two populations the observed heterozygosity was still low (0.004 and 0.011). The genetic distances between the populations ranged from 0.00 to 0.43. UPGMA cluster analysis separated the populations into two groups, a northern group and a group found throughout the country. Although these two groups do not correlate with the two groups based on agar methylation level at every locality, the correlation is sufficiently striking to merit further investigation.

Biogeography of a southern hemisphere freshwater fish: how important is marine dispersal?

“…Conversely, significant structure has been observed among New Zealand populations of marine fish (Smith et al . 1978), bivalves (Smith 1989) and algae (Intasuwan et al . 1993).…”

Phylogeography of a high‐dispersal New Zealand sea‐star: does upwelling block gene‐flow?

“…Indeed, most genetic studies to date have presented isozyme analyses of commercially important marine taxa sourced from just a few sites in the New Zealand region (Smith et al . 1978, 1981; Smith 1986, 1989; Smith & Johnston 1986; Intasuwan et al . 1993).…”

MOLECULAR IDENTIFICATION OF TWO SIBLING SPECIES UNDER THE NAME GRACILARIA CHILENSIS (RHODOPHYTA, GRACILARIALES)1,3

“…A significant amount of morphological, biological, and molecular data indicate that Chilean populations attributed to G. chilensis do indeed belong to only one species, such as morphological and interbreeding studies (Bird et al 1986), RFLPs of plastid DNA (Bird et al 1990, González et al 1996), RAPD (González et al 1996, Meneses 2001), and nuclear internal transcribed spacer (ITS)–RFLP analyses and crossability trials (Candia et al 1999). In contrast, RFLP analyses (Candia et al 1999), allozyme data (Intasuwan et al 1993), and chemotype analyses (Wilcox et al 2001) indicate the occurrence of two distinct species in New Zealand. However, none of the studies of G. chilensis to date has obtained sequences from both WPO accessions and Chilean samples.…”