Development of polymorphic microsatellite markers in a tropical tree species, Melaleuca cajuputi (Myrtaceae)

How much effort is required to isolate nuclear microsatellites from plants?

The attributes of codominance, reproducibility and high resolution have all contributed towards the current popularity of nuclear microsatellites as genetic markers in molecular ecological studies. One of their major drawbacks, however, is the development phase required to obtain working primers for a given study species. To facilitate project planning, we have reviewed the literature to quantify the workload involved in isolating nuclear microsatellites from plants. We highlight the attrition of loci at each stage in the process, and the average effort required to obtain 10 working microsatellite primer pairs.

Polymorphism of simple sequence repeats reveals gene flow within and between ectomycorrhizal Suillus grevillei populations

•  Gene flow within and between two populations of the ectomycorrhizal fungus Suillus grevillei is shown here using co-dominant simple sequence repeat (SSR) markers. •  Co-dominant SSR markers were developed for S. grevillei. Distribution and frequency of alleles at the three codominant SSR markers were analysed within two S. grevillei populations in two Larix Kaempteri stands located 700 m apart. •  Among eight SSR loci isolated from S. grevillei, five loci (designated SG1-5) were polymorphic and SG1-3 were co-dominant. Genets (73) previously identified by inter-simple sequence repeat markers at the Larix stands were divided by the combination of SG1-3 into 22 genotypes. Most of the SSR genotypes were spatially clustered, indicating that the dispersal distance of S. grevillei spores was relatively short. •  There was no conspicuous genetic differentiation within or between the two S. grevillei populations, indicating extensive gene flow. The spread of alleles within or between populations might be by repeats of short-distance spore dispersal rather than long-distance spore dispersal.