A High‐Density, Sequence‐Enriched Genetic Map of Hordeum bulbosum and Its Collinearity to H. vulgare

Abstract

Hordeum bulbosum L., a wild grass and close relative of cultivated barley (Hordeum vulgare L.), gained importance in plant breeding as inducer of haploid plants in crosses with barley and also as a genetic resource for introgression of disease resistance/ tolerance genes into cultivated barley. Genetic mapping of genes introgressed from H. bulbosum is a prerequisite for their efficient utilization in barley breeding, but often hindered due to repressed recombination. The mechanism underlying the reduced frequency or lack of meiotic recombination between H. bulbosum and H. vulgare chromatin in introgressed segments is not understood. It may be explained by lack of genome collinearity or other structural differences between both genomes. In the present study, two F 1 mapping populations of H. bulbosum were analyzed by genotyping-by-sequencing (GBS) and four dense H. bulbosum genetic maps containing 1449, 996, 720, and 943 SNP markers, respectively, revealed overall a high degree of collinearity for all seven homeologous linkage groups of H. vulgare and H. bulbosum. The patterns of distribution of recombination along chromosomes differed between barley and H. bulbosum, indicating organizational differences between both genomes.

High-resolution mapping of Rym14Hb, a wild relative resistance gene to barley yellow mosaic disease

“…In the absence of a genomic sequence for a Rym14 Hb plant, we cannot precisely define the genes present in the Rym14 Hb interval. However, as synteny between the two Hordeum species is high (Wendler et al 2017 ), it is still relevant to assess the genes annotated in the orthologous interval of the H. vulgare reference genome as a proxy for suggesting Rym14 Hb candidate genes. In the respective interval of the ‘Morex’ V2 reference sequence, 30 high-confidence (HC) (Table 3 ) and 17 low-confidence genes (Monat et al 2019 ) are annotated.…”

High-resolution mapping ofRym14Hb, a wild relative resistance gene to barley yellow mosaic disease

“…In the absence of a genomic sequence for a Rym14 Hb plant, we cannot precisely define the genes present in the Rym14 Hb interval. However, as synteny between the two Hordeum species is high (Wendler et al 2017), it is still relevant to assess the genes annotated in the homolog interval of the H. vulgare reference genome as a proxy for suggesting Rym14 Hb candidate genes. In the respective interval of the Morex V2 reference sequence 30 high-confidence (HC) ( Table 1) and 17 low-confidence genes (Monat et al 2019) are annotated.…”

Construction of a high-density genetic map and fine mapping of a candidate gene locus for a novel branched-spike mutant in barley

“…Based on 14,348 SLAF markers, a high-density genetic map of barley was constructed with a total length of 1,347.44 cM. Many high-density genetic maps have been constructed using SSR, DarT and SNP markers for different barley populations [21][22][29][30][31]. Of them, the high-density genetic map constructed by Wang et al [21] had relatively high quality, with 1,375.8 cM length and a 0.7 cM mean adjacent marker distance.…”