PCR Allele Competitive Extension (PACE).

PCR allele competitive extension (PACE™) is a marker system to analyze single nucleotide polymorphisms (SNPs). As strongly related technologies like kompetitive allele-specific PCR (KASP™) or Amplifluor®, PACE is based on a polymerase chain reaction (PCR) with two competing allele-specific primers and an endpoint fluorescent measurement. The system requires sequence information surrounding the SNP of interest and a qPCR machine or a fluorescent plate reader.

On genetic diversity in caraway: Genotyping of a large germplasm collection.

Caraway (Carum carvi) is a widespread and frequently used spice and medicinal plant with a long history of cultivation. However, due to ongoing climatic changes, the cultivation is becoming increasingly risky. To secure caraway cultivation in future, timely breeding efforts to develop adapted material are necessary. Analysis of genetic diversity can accompany this process, for instance, by revealing untapped gene pools. Here, we analyzed 137 accessions using genotyping by sequencing (GBS). Hence, we can report a broad overview of population structure and genetic diversity of caraway. Population structure was determined using a principal coordinate analysis, a Bayesian clustering analysis, phylogenetic trees and a neighbor network based on 13,155 SNPs. Genotypic data indicate a clear separation of accessions into two subpopulations, which correlates with the flowering type (annual vs. biennial). Four winter-annual accessions were closer related to biennial accessions. In an analysis of molecular variance, genetic variation between the two subpopulations was 7.84%. In addition, we estimated the genome size for 35 accessions by flow cytometry. An average genome size of 4.282 pg/2C (± 0.0096 S.E.) was estimated. Therefore, we suggest a significantly smaller genome size than stated in literature.