Study of Molecular Markers for Xanthohumol and DMX Contents in Hop (Humulus lupulus L.) by QTLs Mapping Analysis

Abstract

Recently, a medicinal usage of hop metabolic compounds is of increasing interest, mainly prenylflavonoids: xanthohumol (X) and desmethylxanthohumol (DMX). Quantitative trait loci (QTL) mapping is a good tool for finding reliable molecular markers for prospective breeding. We used STS, SSR, EST-SSR and AFLP molecular markers for analysing 116 individual female F1 hop genotypes. A total of 106 markers were used to construct the genetic linkage maps for female parent Taurus and male parent H06/14. In QTL analysis, 14 putative QTL molecular markers for xanthohumol content, 8 putative QTL molecular markers for DMX content and 8 putative QTL molecular for bitter acid content were detected. A QTL marker for an allele of the O-methyltransferase (omt1) gene confirmed the negative correlation between xanthohumol and DMX contents caused by final methylation. The other QTL molecular markers for alleles of chalcone synthase-like genes (vps, chs3, and chs4), 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase (ispF), geranylpyrophosphate synthase (gpps) and leucoanthocyanidin reductase 1 (lar1) genes showed the interconnection of bitter acids, terpenes and other polyphenols biosynthetic pathways. The reliability of QTL markers was proven by correlation analyses in 68 world hop cultivars.