Development and application of RAPD-SCAR markers to identify intra-species hybrids of industrial Saccharomyces cerevisiae

Development of species-specific ISSR-derived SCAR marker for early discrimination between Cinnamomum verum and Cinnamomum cassia

BACKGROUND

Cinnamomum verum (true cinnamon) and Cinnamomum cassia (cassia cinnamon) are two important species belonging to family Lauraceae. These species are recognized by morphological, chemical composition and essential oil contents. The appropriate identification of species would be considerably improved by a genetic method. The main objective of the present study was to develop molecular markers distinguishing between C. verum and C. cassia.

METHODS AND RESULTS

A total 71 ISSR (Inter simple sequence repeat) and four universal barcoding (ITS, rbcL, matK, and psbA-trnH) genes were used to distinguish both the species. No sequence variation was observed between the two species for any DNA barcode gene. However, one ISSR i.e. ISSR-37 showed a clear distinction between the species and produced 570 bp and 746 bp amplicons in C. verum and C. cassia, respectively. The polymorphic bands were converted into species-specific SCAR markers. The SCAR-CV was specific to C. verum and amplified 190 bp band, however there was no amplification seen in the C. cassia samples.

CONCLUSION

The SCAR marker generated in this study can be employed as efficient, economical, and reliable molecular tool for the identification of C. verum.

Development of a novel SRAP-SCAR marker for rapid identification of lager and ale types in brewer's yeast

BACKGROUND

Beer is a globally consumed and universally popular beverage. According to the fermentation conditions of brewer's yeast, ale yeast and lager yeast are the two major varieties. Normal phenotypic and genotypic approaches are insufficient and time-consuming for identifying these two forms of yeast. Therefore, a method for the rapid and cost-effective identification of lager and ale-type brewer's yeasts is necessary.

METHODS AND RESULTS

In this study, we analysed the genetic diversity of 23 industrial brewer's yeasts from around the world using sequence-related amplified polymorphism (SRAP) markers and produced stable sequence characteristic amplification region (SCAR) markers. The specific DNA fragments identified by the SRAP marker were sequenced and primers were constructed; the resultant SCAR marker (757 bp) was then confirmed against the indicated brewer's yeast type.

CONCLUSION

The development of SRAP-SCAR marker is more economical, simple, and fast compared to morphological markers.

The utility of iPBS retrotransposons markers to analyze genetic variation in yeast

Yeasts are one of the main organisms in the food industry and effective components of many ecosystems. The method for identifying and detecting certain yeast species or strains is a crucial step for the food industry and should be simple, reliable, fast, and inexpensive. In our study, inter-priming binding sites (iPBS) retrotransposon marker system was employed to elucidate the genetic variability at intraspecies and interspecies levels among 112 yeast strains belonging to eight species previously obtained from fermented foods. The molecular identification of yeast strains was firstly confirmed by sequencing the D1/D2 domain of the 26S rRNA. The eight selected retrotransposon-based primers produced 278 bands, all of which were polymorphic with an average of 34.75 polymorphic fragments per primer. The averages of polymorphism information contents and the resolving power values for the iPBS marker system were 0.23 and 10.11, respectively. The genetic parameters within each yeast species obtained from iPBS markers were observed as; the percentage of polymorphic loci for each species ranging from 19.23% to 71.21%, Nei's gene diversity from 0.085 to 0.228, while Shannon's information index values ranging from 0.125 to 0.349. The value of gene flow (0.09) and genetic variation among the populations (0.85) showed higher genetic variation among the species. UPGMA analyses demonstrated considerable genetic variability in the yeast strains, clustered them according to their species, and revealed the intraspecific variation. Each of the selected iPBS primer provided enough species-discrimination. Present evaluations suggest the utility of iPBS marker system to estimate the genetic variation of yeast strains. This study is a preliminary point for further studies on the identification methodology, and population genetics of yeast species having importance in the food industry with iPBS markers.