Differentiation of homokaryons and heterokaryons of Agaricus bisporus with inter-simple sequence repeat markers

Abstract

Morphologically different fifteen slow growing single spore isolates (SSIs) were screened from germinated basidiospores of Agaricus bisporus; assumed to be homokaryons, and subjected to growth rate, spawn run, fruiting and inter-simple sequence repeat (ISSR) analysis for confirmation of true homokaryons. The present studies are the first report of fingerprinting on differentiating homo- and hetero-karyotic SSIs using ISSR markers. The patterns were highly polymorphic and very reproducible. Among 40 primers tested, 7 ISSR primers were selected for the analysis of genomic DNA and generated a total of 54 ISSR fragments, sufficient to differentiate the 15 isolates from each other. ISSR fingerprinting detected 46.30% polymorphic loci. All appressed homokaryons carried a subset of ISSR markers found in the heterokaryons, and these were not able to produce a fruiting body. A test of cross-fertility and the following fruiting trial proved that 3 of the 15 SSIs with different ISSR fingerprints were homokaryons. None of the discarded SSIs have any missing bands present in the parental heterokaryotic control; these are heterokaryons derived from non-sister nuclear pairs. It is revealed that homokaryons are probably restricted to the assumed morphological classes of SSIs. These results demonstrate that ISSR markers provide an efficient alternate for identification of homokaryons and suggest these markers be considered as new tools for the survey of Agaricus species.

Genetic Diversity Analysis Reveals that Geographical Environment Plays a More Important Role than Rice Cultivar in Villosiclava virens Population Selection

“…Molecular markers have been widely used for the identification, taxonomy, evolution, as well as genetic diversity of bacteria, protozoa, fungi, plants, and animals (17)(18)(19)(20)(21)(22)(23)(24), such as restriction fragment length polymorphism (RFLP) (25), random amplified polymorphic DNA (RAPD) (26), amplified fragment length polymorphism (AFLP) assays (27), simple sequence repeats (SSR) (28), inter-simple sequence repeats (ISSR) (29,30), and single-nucleotide polymorphisms (SNP) (31). Several reports on genetic diversity of V. virens have been published in recent years.…”

Local epidemiology of the wood decay agent Laetiporus sulphureus in carob stands in Sicily

“…The HRM genotyping of the ten SSR markers allowed to distinguish all isolates from one another. In addition, this analysis allowed detection of heterozygous allelic conditions, often observed in heterokaryotic basidiomycetes (Nazrul & YinBing, ), yet uncommon in the L. sulphureus isolates analysed in this study. The relatively high number of observed alleles per locus and the high gene diversity (0.581) are not in disagreement with the hypothesis that L. sulphureus retains high allelic recombination due to sexual reproduction (Milgroom, ), although the fungus is also known to develop an asexual stage (Bernicchia, ; Stalpers, ).…”

Drought-Induced Stress Priming in Two Distinct Filamentous Saprotrophic Fungi

“…The artificial soil was inoculated by placing a 1-cm 2 agar plate (malt extract peptone agar) with fungal hyphae on top of the soil. As the soil was nearly nutrient free, all samples were adjusted one-time to a water content equivalent to 50% of the maximum water holding capacity (WHC) with a liquid growth medium (2% glucose, 0.2% peptone, 0.2% yeast extract, 0.1% K 2 HPO 4 , 0.46% KH 2 PO 4 , and 0.05% MgSO 4 ; [28]). Subsequently, samples were pre-incubated for approximately 3 weeks in a climate chamber at 20°C until fungal growth was observable all over the soil surface.…”